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Roark CL, Thakkar V, Chandrasekaran B, Centanni TM. Auditory Category Learning in Children With Dyslexia. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2024; 67:974-988. [PMID: 38354099 PMCID: PMC11001431 DOI: 10.1044/2023_jslhr-23-00361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/15/2023] [Accepted: 11/14/2023] [Indexed: 02/16/2024]
Abstract
PURPOSE Developmental dyslexia is proposed to involve selective procedural memory deficits with intact declarative memory. Recent research in the domain of category learning has demonstrated that adults with dyslexia have selective deficits in Information-Integration (II) category learning that is proposed to rely on procedural learning mechanisms and unaffected Rule-Based (RB) category learning that is proposed to rely on declarative, hypothesis testing mechanisms. Importantly, learning mechanisms also change across development, with distinct developmental trajectories in both procedural and declarative learning mechanisms. It is unclear how dyslexia in childhood should influence auditory category learning, a critical skill for speech perception and reading development. METHOD We examined auditory category learning performance and strategies in 7- to 12-year-old children with dyslexia (n = 25; nine females, 16 males) and typically developing controls (n = 25; 13 females, 12 males). Participants learned nonspeech auditory categories of spectrotemporal ripples that could be optimally learned with either RB selective attention to the temporal modulation dimension or procedural integration of information across spectral and temporal dimensions. We statistically compared performance using mixed-model analyses of variance and identified strategies using decision-bound computational models. RESULTS We found that children with dyslexia have an apparent selective RB category learning deficit, rather than a selective II learning deficit observed in prior work in adults with dyslexia. CONCLUSION These results suggest that the important skill of auditory category learning is impacted in children with dyslexia and throughout development, individuals with dyslexia may develop compensatory strategies that preserve declarative learning while developing difficulties in procedural learning. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.25148519.
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Affiliation(s)
- Casey L. Roark
- Department of Communication Science and Disorders, University of Pittsburgh, PA
- Center for the Neural Basis of Cognition, University of Pittsburgh, Carnegie Mellon University, PA
| | - Vishal Thakkar
- Department of Psychology, Texas Christian University, Fort Worth
| | - Bharath Chandrasekaran
- Department of Communication Science and Disorders, University of Pittsburgh, PA
- Center for the Neural Basis of Cognition, University of Pittsburgh, Carnegie Mellon University, PA
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Kristjánsson Á, Sigurdardottir HM. The Role of Visual Factors in Dyslexia. J Cogn 2023; 6:31. [PMID: 37397349 PMCID: PMC10312247 DOI: 10.5334/joc.287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 06/13/2023] [Indexed: 07/04/2023] Open
Abstract
What are the causes of dyslexia? Decades of research reflect a determined search for a single cause where a common assumption is that dyslexia is a consequence of problems with converting phonological information into lexical codes. But reading is a highly complex activity requiring many well-functioning mechanisms, and several different visual problems have been documented in dyslexic readers. We critically review evidence from various sources for the role of visual factors in dyslexia, from magnocellular dysfunction through accounts based on abnormal eye movements and attentional processing, to recent proposals that problems with high-level vision contribute to dyslexia. We believe that the role of visual problems in dyslexia has been underestimated in the literature, to the detriment of the understanding and treatment of the disorder. We propose that rather than focusing on a single core cause, the role of visual factors in dyslexia fits well with risk and resilience models that assume that several variables interact throughout prenatal and postnatal development to either promote or hinder efficient reading.
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Affiliation(s)
- Árni Kristjánsson
- Icelandic Vision Lab, Department of Psychology, University of Iceland, IS
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3
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Saban W, Gabay S. Contributions of Lower Structures to Higher Cognition: Towards a Dynamic Network Model. J Intell 2023; 11:121. [PMID: 37367523 DOI: 10.3390/jintelligence11060121] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/08/2023] [Accepted: 06/11/2023] [Indexed: 06/28/2023] Open
Abstract
Researchers often attribute higher cognition to the enlargement of cortical regions throughout evolution, reflecting the belief that humans sit at the top of the cognitive pyramid. Implicitly, this approach assumes that the subcortex is of secondary importance for higher-order cognition. While it is now recognized that subcortical regions can be involved in various cognitive domains, it remains unclear how they contribute to computations essential for higher-level cognitive processes such as endogenous attention and numerical cognition. Herein, we identify three models of subcortical-cortical relations in these cognitive processes: (i) subcortical regions are not involved in higher cognition; (ii) subcortical computations support elemental forms of higher cognition mainly in species without a developed cortex; and (iii) higher cognition depends on a whole-brain dynamic network, requiring integrated cortical and subcortical computations. Based on evolutionary theories and recent data, we propose the SEED hypothesis: the Subcortex is Essential for the Early Development of higher cognition. According to the five principles of the SEED hypothesis, subcortical computations are essential for the emergence of cognitive abilities that enable organisms to adapt to an ever-changing environment. We examine the implications of the SEED hypothesis from a multidisciplinary perspective to understand how the subcortex contributes to various forms of higher cognition.
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Affiliation(s)
- William Saban
- Center for Accessible Neuropsychology, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
- Department of Occupational Therapy, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shai Gabay
- Department of Psychology, the Institute of Information Processing and Decision Making, University of Haifa, Haifa 3498838, Israel
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Failure to consolidate statistical learning in developmental dyslexia. Psychon Bull Rev 2023; 30:160-173. [PMID: 36221045 DOI: 10.3758/s13423-022-02169-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2022] [Indexed: 11/08/2022]
Abstract
Statistical learning (SL), the ability to pick up patterns in sensory input, serves as one of the building blocks of language acquisition. Although SL has been studied extensively in developmental dyslexia (DD), much less is known about the way SL evolves over time. The handful of studies examining this question were all limited to the acquisition of motor sequential knowledge or highly learned segmented linguistic units. Here we examined memory consolidation of statistical regularities in adults with DD and typically developed (TD) readers by using auditory SL requiring the segmentation of units from continuous input, which represents one of the earliest learning challenges in language acquisition. DD and TD groups were exposed to tones in a probabilistically determined sequential structure varying in difficulty and subsequently tested for recognition of novel short sequences that adhered to this statistical pattern in immediate and delayed-recall sessions separated by a night of sleep. SL performance of the DD group at the easy and hard difficulty levels was poorer than that of the TD group in the immediate-recall session. Importantly, DD participants showed a significant overnight deterioration in SL performance at the medium difficulty level compared to TD, who instead showed overnight stabilization of the learned information. These findings imply that SL difficulties in DD may arise not only from impaired initial learning but also due to a failure to consolidate statistically structured information into long-term memory. We hypothesize that these deficits disrupt the typical course of language acquisition in those with DD.
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Repeated series learning revisited with a novel prediction on the reduced effect of item frequency in dyslexia. Sci Rep 2022; 12:13521. [PMID: 35941176 PMCID: PMC9359986 DOI: 10.1038/s41598-022-16805-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 07/15/2022] [Indexed: 11/09/2022] Open
Abstract
Developmental dyslexia, a difficulty with acquiring fluent reading, has also been characterized by reduced short-term memory (STM) capacity, which is often operationalized with span tasks. The low performance of individuals with dyslexia (IDDs) in such tasks is commonly attributed to poor phonological memory. However, we suggest an alternative explanation based on the observation that many times the items that are used in spans tasks are high-frequency items (e.g., digit words). We suggest that IDDs do not enjoy the benefit of item frequency to the same extent as controls, and thus their performance in span tasks is especially hampered. On the contrary, learning of repeated sequences was shown to be largely independent of item frequency, and therefore this type of learning may be unimpaired in dyslexia. To test both predictions, we used the Hebb-learning paradigm. We found that IDDs’ performance is especially poor compared to controls’ when high-frequency items are used, and that their repeated series learning does not differ from that of controls. Taken together with existing literature, our findings suggest that impaired learning of repeated series is not a core characteristic of dyslexia, and that the reports on reduced STM in dyslexia may to a large extent be explained by reduced benefit of item frequency.
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Blais M, Jucla M, Maziero S, Albaret JM, Chaix Y, Tallet J. Specific Cues Can Improve Procedural Learning and Retention in Developmental Coordination Disorder and/or Developmental Dyslexia. Front Hum Neurosci 2021; 15:744562. [PMID: 34975432 PMCID: PMC8714931 DOI: 10.3389/fnhum.2021.744562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/23/2021] [Indexed: 11/25/2022] Open
Abstract
The present study investigates procedural learning of motor sequences in children with developmental coordination disorder (DCD) and/or developmental dyslexia (DD), typically-developing children (TD) and healthy adults with a special emphasis on (1) the role of the nature of stimuli and (2) the neuropsychological functions associated to final performance of the sequence. Seventy children and ten adults participated in this study and were separated in five experimental groups: TD, DCD, DD, and DCD + DD children and adults. Procedural learning was assessed with a serial reaction time task (SRTT) that required to tap on a specific key as accurately and quickly as possible when stimuli appeared on the screen. Three types of stimuli were proposed as cues: the classical version of the SRTT with 4 squares aligned horizontally on the screen, giving visuospatial cues (VS cues), and two modified versions, with 4 letters aligned horizontally on the screen (VS + L cues) and letters at the center of the screen (L cues). Reaction times (RT) during the repeated and random blocks allowed assessing three phases of learning: global learning, specific learning and retention of the sequence. Learning was considered as completed when RT evolved significantly in the three phases. Neuropsychological assessment involved, among other functions, memory and attentional functions. Our main result was that learning and retention were not influenced by the available cues in adults whereas learning improved with specific cues in children with or without neurodevelopmental disorders. More precisely, learning was not completed with L cues in children with neurodevelopmental disorders. For children with DD, learning was completed with the VS and VS + L cues whereas for children with DCD (with or without DD), learning was completed with combined VS + L cues. Comorbidity between DD and DCD had no more impact on procedural learning than DCD alone. These results suggest that learning depends on the nature of cues available during practice and that cues allowing learning and retention depend on the type of disorder. Moreover, selective attention was correlated with RT during retention, suggesting that this neuropsychological function is important for procedural learning whatever the available cues.
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Affiliation(s)
- M. Blais
- Toulouse NeuroImaging Center, Toulouse University, Inserm, UPS, Toulouse, France
- EuroMov Digital Health in Motion, Univ Montpellier, IMT Mines Alés, Montpellier, France
| | - M. Jucla
- Laboratory of Neuro Psycho Linguistics, University of Toulouse, Toulouse, France
| | - S. Maziero
- Toulouse NeuroImaging Center, Toulouse University, Inserm, UPS, Toulouse, France
- Laboratory of Neuro Psycho Linguistics, University of Toulouse, Toulouse, France
| | - J. -M. Albaret
- Toulouse NeuroImaging Center, Toulouse University, Inserm, UPS, Toulouse, France
| | - Y. Chaix
- Toulouse NeuroImaging Center, Toulouse University, Inserm, UPS, Toulouse, France
- Children’s Hospital, CHU Purpan, Toulouse, France
| | - J. Tallet
- Toulouse NeuroImaging Center, Toulouse University, Inserm, UPS, Toulouse, France
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Reading intervention and neuroplasticity: A systematic review and meta-analysis of brain changes associated with reading intervention. Neurosci Biobehav Rev 2021; 132:465-494. [PMID: 34856223 DOI: 10.1016/j.neubiorev.2021.11.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 11/22/2022]
Abstract
Behavioral research supports the efficacy of intervention for reading disability, but the brain mechanisms underlying improvement in reading are not well understood. Here, we review 39 neuroimaging studies of reading intervention to characterize links between reading improvement and changes in the brain. We report evidence of changes in activation, connectivity, and structure within the reading network, and right hemisphere, frontal and sub-cortical regions. Our meta-analysis of changes in brain activation from pre- to post- reading intervention in eight studies did not yield any significant effects. Methodological heterogeneity among studies may contribute to the lack of significant meta-analytic findings. Based on our qualitative synthesis, we propose that brain changes in response to intervention should be considered in terms of interactions among distributed cognitive, linguistic and sensory systems, rather than via a "normalized" vs. "compensatory" dichotomy. Further empirical research is needed to identify effects of moderating factors such as features of intervention programs, neuroimaging tasks, and individual differences among participants.
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Lagarrigue Y, Cappe C, Tallet J. Regular rhythmic and audio-visual stimulations enhance procedural learning of a perceptual-motor sequence in healthy adults: A pilot study. PLoS One 2021; 16:e0259081. [PMID: 34780497 PMCID: PMC8592429 DOI: 10.1371/journal.pone.0259081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 10/12/2021] [Indexed: 12/02/2022] Open
Abstract
Procedural learning is essential for the effortless execution of many everyday life activities. However, little is known about the conditions influencing the acquisition of procedural skills. The literature suggests that sensory environment may influence the acquisition of perceptual-motor sequences, as tested by a Serial Reaction Time Task. In the current study, we investigated the effects of auditory stimulations on procedural learning of a visuo-motor sequence. Given that the literature shows that regular rhythmic auditory rhythm and multisensory stimulations improve motor speed, we expected to improve procedural learning (reaction times and errors) with repeated practice with auditory stimulations presented either simultaneously with visual stimulations or with a regular tempo, compared to control conditions (e.g., with irregular tempo). Our results suggest that both congruent audio-visual stimulations and regular rhythmic auditory stimulations promote procedural perceptual-motor learning. On the contrary, auditory stimulations with irregular or very quick tempo alter learning. We discuss how regular rhythmic multisensory stimulations may improve procedural learning with respect of a multisensory rhythmic integration process.
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Affiliation(s)
- Yannick Lagarrigue
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, Toulouse, France
- * E-mail:
| | - Céline Cappe
- Cerco, Centre de Recherche Cerveau et Cognition, Université de Toulouse, CNRS, UMR 5549, Toulouse, France
| | - Jessica Tallet
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, Toulouse, France
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9
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Nicolson RI, Fawcett AJ. Mathematics Disability vs. Learning Disability: A 360 Degree Analysis. Front Psychol 2021; 12:725694. [PMID: 34630237 PMCID: PMC8498324 DOI: 10.3389/fpsyg.2021.725694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/31/2021] [Indexed: 11/13/2022] Open
Abstract
A fundamental issue for research in mathematics disability (MD) and reading disability (RD) is: If these disabilities are clearly distinct, why is there so high a level of comorbidity, together with the converse; if these disabilities are so similar, why are there clear differences in underlying causes and aetiology? In order to address this puzzle, we introduce the “360 degree analysis” (360DA) framework and apply it to the overlap between RD and MD. The 360DA process starts by analyzing the issue from four perspectives: theoretical, developmental, affective, and pedagogical. Under 360DA, these analyses are then integrated to provide insights for theory, and for individual assessment and support, together with directions for future progress. The analyses confirm extensive similarities between arithmetic and reading development in terms of rote learning, executive function (EF), and affective trauma, but also major differences in terms of the conceptual needs, the motor coordination needs, and the methods of scaffolding. In terms of theory, commonalities are interpreted naturally in terms of initial general developmental delay followed by domain-independent affective trauma following school failure. Dissociations are interpreted in terms of cerebellar vs. hippocampal learning networks, sequential vs. spatial processing, and language vs. spatial scaffolding, with a further dimension of the need for accurate fixation for reading. The framework has significant theoretical and applied implications.
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Ramezani M, Behzadipour S, Pourghayoomi E, Joghataei MT, Shirazi E, Fawcett AJ. Evaluating a new verbal working memory-balance program: a double-blind, randomized controlled trial study on Iranian children with dyslexia. BMC Neurosci 2021; 22:55. [PMID: 34525977 PMCID: PMC8442443 DOI: 10.1186/s12868-021-00660-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 09/07/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND It is important to improve verbal Working Memory (WM) in reading disability, as it is a key factor in learning. There are commercial verbal WM training programs, which have some short-term effects only on the verbal WM capacity, not reading. However, because of some weaknesses in current verbal WM training programs, researchers suggested designing and developing newly structured programs that particularly target educational functions such as reading skills. In the current double-blind randomized clinical trial study, we designed a new Verbal Working Memory-Balance (VWM-B) program which was carried out using a portable robotic device. The short-term effects of the VWM-B program, on verbal WM capacity, reading skills, and postural control were investigated in Iranian children with developmental dyslexia. RESULTS The effectiveness of the VWM-B program was compared with the VWM-program as a traditional verbal WM training. In comparison with VWM-program, the participants who received training by the VWM-B program showed superior performance on verbal WM capacity, reading skills, and postural control after a short-term intervention. CONCLUSIONS We proposed that the automatized postural control resulting from VWM-B training had a positive impact on improving verbal WM capacity and reading ability. Based on the critical role of the cerebellum in automatizing skills, our findings support the cerebellar deficit theory in dyslexia. TRIAL REGISTRATION This trial was (retrospectively) registered on 8 February 2018 with the Iranian Registry of Clinical Trials (IRCT20171219037953N1).
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Affiliation(s)
- Mehdi Ramezani
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Saeed Behzadipour
- Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran.,Djawad Movafaghian Research Center in Neuro-Rehabilitation Technologies, Sharif University of Technology, Tehran, Iran
| | - Ehsan Pourghayoomi
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.,Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Elham Shirazi
- Mental Health Research Center, Tehran Institute of Psychiatry, Iran University of Medical Sciences, Tehran, Iran.
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Developmental Dyslexia, Reading Acquisition, and Statistical Learning: A Sceptic's Guide. Brain Sci 2021; 11:brainsci11091143. [PMID: 34573165 PMCID: PMC8472276 DOI: 10.3390/brainsci11091143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 10/26/2022] Open
Abstract
Many theories have been put forward that propose that developmental dyslexia is caused by low-level neural, cognitive, or perceptual deficits. For example, statistical learning is a cognitive mechanism that allows the learner to detect a probabilistic pattern in a stream of stimuli and to generalise the knowledge of this pattern to similar stimuli. The link between statistical learning and reading ability is indirect, with intermediate skills, such as knowledge of frequently co-occurring letters, likely being causally dependent on statistical learning skills and, in turn, causing individual variation in reading ability. We discuss theoretical issues regarding what a link between statistical learning and reading ability actually means and review the evidence for such a deficit. We then describe and simulate the "noisy chain hypothesis", where each intermediary link between a proposed cause and the end-state of reading ability reduces the correlation coefficient between the low-level deficit and the end-state outcome of reading. We draw the following conclusions: (1) Empirically, there is evidence for a correlation between statistical learning ability and reading ability, but there is no evidence to suggest that this relationship is causal, (2) theoretically, focussing on a complete causal chain between a distal cause and developmental dyslexia, rather than the two endpoints of the distal cause and reading ability only, is necessary for understanding the underlying processes, (3) statistically, the indirect nature of the link between statistical learning and reading ability means that the magnitude of the correlation is diluted by other influencing variables, yielding most studies to date underpowered, and (4) practically, it is unclear what can be gained from invoking the concept of statistical learning in teaching children to read.
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Luongo A, Lukowski A, Protho T, Van Vorce H, Pisani L, Edgin J. Sleep's role in memory consolidation: What can we learn from atypical development? ADVANCES IN CHILD DEVELOPMENT AND BEHAVIOR 2021; 60:229-260. [PMID: 33641795 DOI: 10.1016/bs.acdb.2020.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Research conducted over the last century has suggested a role for sleep in the processes guiding healthy cognition and development, including memory consolidation. Children with intellectual and developmental disabilities (IDDs) tend to have higher rates of sleep disturbances, which could relate to behavior issues, developmental delays, and learning difficulties. While several studies examine whether sleep exacerbates daytime difficulties and attention deficits in children with IDDs, this chapter focuses on the current state of knowledge regarding sleep and memory consolidation in typically developing (TD) groups and those at risk for learning difficulties. In particular, this chapter summarizes the current literature on sleep-dependent learning across developmental disabilities, including Down syndrome, Williams syndrome, Autism Spectrum Disorder, and Learning Disabilities (Attention-Deficit/Hyperactivity Disorder and Dyslexia). We also highlight the gaps in the current literature and identify challenges in studying sleep-dependent memory in children with different IDDs. This burgeoning new field highlights the importance of considering the role of sleep in memory retention across long delays when evaluating children's memory processes. Further, an understanding of typical and atypical development can mutually inform recent theories of sleep's role in memory.
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Affiliation(s)
- A Luongo
- Department of Psychology, University of Arizona, Tucson, AZ, Unites States
| | - A Lukowski
- Department of Psychological Sciences, University of California Irvine, Irvine, CA, United States
| | - T Protho
- Department of Psychology, University of Arizona, Tucson, AZ, Unites States
| | - H Van Vorce
- Department of Psychology, University of Arizona, Tucson, AZ, Unites States
| | - L Pisani
- Department of Psychology, University of Arizona, Tucson, AZ, Unites States
| | - J Edgin
- Department of Psychology, University of Arizona, Tucson, AZ, Unites States; University of Arizona Sonoran UCEDD, Tucson, AZ, United States.
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Peters L, Op de Beeck H, De Smedt B. Cognitive correlates of dyslexia, dyscalculia and comorbid dyslexia/dyscalculia: Effects of numerical magnitude processing and phonological processing. RESEARCH IN DEVELOPMENTAL DISABILITIES 2020; 107:103806. [PMID: 33152663 DOI: 10.1016/j.ridd.2020.103806] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 10/08/2020] [Accepted: 10/20/2020] [Indexed: 05/19/2023]
Abstract
Specific learning disorders (i.e., dyscalculia and dyslexia) are common, as is their comorbidity. It has been suggested that the core cognitive deficit in dyscalculia is an impairment in numerical magnitude processing; similarly, in dyslexia, phonological processing deficits are considered to be the main cognitive deficit. Cognitive theories on comorbid dyslexia/dyscalculia have suggested a number of hypotheses about which cognitive deficits underlie the comorbidity. However, few studies have thus far directly compared the abovementioned cognitive correlates of dyscalculia and dyslexia. In this study, we assessed symbolic and non-symbolic numerical magnitude and three subcomponents of phonological processing (phonological awareness, lexical access and verbal short-term memory). In addition, we investigated children's domain-general spatial and verbal skills. The effect of these cognitive correlates on dyscalculia, dyslexia and their comorbidity was explored. We did not find differences between children with and without dyscalculia on numerical magnitude processing. On the other hand, children with dyscalculia had significantly lower spatial skills compared to children without dyscalculia. Children with dyslexia performed significantly lower on all subcomponents of phonological processing. Finally, we found an additive effect for comorbid dyslexia/dyscalculia: impairments in children with co-occurring dyslexia and dyscalculia were similar to the sum of the impairments in the isolated dyslexia and isolated dyscalculia groups. The strongest unique predictor of isolated dyscalculia and comorbid dyslexia/dyscalculia was spatial skills, the strongest unique predictor of isolated dyslexia was phonological awareness. As only a limited number of cognitive variables were assessed in this study and the sample sizes were very small, we should be cautious when interpreting these results.
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Affiliation(s)
- Lien Peters
- Numerical Cognition Laboratory, Department of Psychology, Brain and Mind Institute, University of Western Ontario, Canada; Brain and Cognition Research Unit, University of Leuven, Belgium; Parenting and Special Education Research Unit, University of Leuven, Belgium.
| | - Hans Op de Beeck
- Brain and Cognition Research Unit, University of Leuven, Belgium
| | - Bert De Smedt
- Parenting and Special Education Research Unit, University of Leuven, Belgium
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Llompart M, Dąbrowska E. Explicit but Not Implicit Memory Predicts Ultimate Attainment in the Native Language. Front Psychol 2020; 11:569586. [PMID: 33101138 PMCID: PMC7546274 DOI: 10.3389/fpsyg.2020.569586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/04/2020] [Indexed: 11/13/2022] Open
Abstract
The present paper examines the relationship between explicit and implicit memory and ultimate attainment in the native language. Two groups of native speakers of English with different levels of academic attainment (i.e., high vs. low) took part in three language tasks which assessed grammar, vocabulary and collocational knowledge, as well as phonological short-term memory (assessed using a forward digit-span task), explicit associative memory (assessed using a paired-associates task) and implicit memory (assessed using a deterministic serial reaction time task). Results revealed strong relationships between phonological short-term memory and explicit associative memory on the one hand and the three language tasks on the other hand, and no relation between linguistic performance and implicit memory. Taken together, these results cast doubts on the common assumption that L1 grammar learning depends almost entirely on implicit memory and align with the claims of usage-based models of language acquisition that grammatical and lexical knowledge depend on the same cognitive mechanisms.
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Affiliation(s)
- Miquel Llompart
- Chair of Language and Cognition, Department of English and American Studies, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Ewa Dąbrowska
- Chair of Language and Cognition, Department of English and American Studies, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany.,Department of English Language and Linguistics, University of Birmingham, Birmingham, United Kingdom
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Dellatolas G, Câmara-Costa H. The role of cerebellum in the child neuropsychological functioning. HANDBOOK OF CLINICAL NEUROLOGY 2020; 173:265-304. [PMID: 32958180 DOI: 10.1016/b978-0-444-64150-2.00023-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This chapter proposes a review of neuropsychologic and behavior findings in pediatric pathologies of the cerebellum, including cerebellar malformations, pediatric ataxias, cerebellar tumors, and other acquired cerebellar injuries during childhood. The chapter also contains reviews of the cerebellar mutism/posterior fossa syndrome, reported cognitive associations with the development of the cerebellum in typically developing children and subjects born preterm, and the role of the cerebellum in neurodevelopmental disorders such as autism spectrum disorders and developmental dyslexia. Cognitive findings in pediatric cerebellar disorders are considered in the context of known cerebellocerebral connections, internal cellular organization of the cerebellum, the idea of a universal cerebellar transform and computational internal models, and the role of the cerebellum in specific cognitive and motor functions, such as working memory, language, timing, or control of eye movements. The chapter closes with a discussion of the strengths and weaknesses of the cognitive affective syndrome as it has been described in children and some conclusions and perspectives.
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Affiliation(s)
- Georges Dellatolas
- GRC 24, Handicap Moteur et Cognitif et Réadaptation, Sorbonne Université, Paris, France.
| | - Hugo Câmara-Costa
- GRC 24, Handicap Moteur et Cognitif et Réadaptation, Sorbonne Université, Paris, France; Centre d'Etudes en Santé des Populations, INSERM U1018, Paris, France
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16
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Armstrong-Gallegos S. Problems in Audiovisual Filtering for Children with Special Educational Needs. Iperception 2020; 11:2041669520951816. [PMID: 32922716 PMCID: PMC7457682 DOI: 10.1177/2041669520951816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 06/19/2020] [Indexed: 11/17/2022] Open
Abstract
There is pervasive evidence that problems in sensory processing occur across a range of developmental disorders, but their aetiology and clinical significance remain unclear. The present study investigated the relation between sensory processing and literacy skills in children with and without a background of special educational needs (SEN). Twenty-six children aged between 7 and 12 years old, from both regular classes and SEN programmes, participated. Following baseline tests of literacy, fine motor skills and naming speed, two sets of instruments were administered: the carer-assessed Child Sensory Profile-2 and a novel Audiovisual Animal Stroop (AVAS) test. The SEN group showed significantly higher ratings on three Child Sensory Profile-2 quadrants, together with body position ratings. The SEN participants also showed a specific deficit when required to ignore an accompanying incongruent auditory stimulus on the AVAS. Interestingly, AVAS performance correlated significantly with literacy scores and with the sensory profile scores. It is proposed that the children with SEN showed a specific deficit in "filtering out" irrelevant auditory input. The results highlight the importance of including analysis of sensory processes within theoretical and applied approaches to developmental differences and suggest promising new approaches to the understanding, assessment, and support of children with SEN.
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17
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Łockiewicz M, Jaskulska M, Fawcett A. Decoding and word recognition in English as a native and a foreign language in students with and without dyslexia (English vs. Polish students). DYSLEXIA (CHICHESTER, ENGLAND) 2020; 26:18-35. [PMID: 32043745 DOI: 10.1002/dys.1648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 05/29/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
We aimed to investigate the relationship between reading difficulties in native language (NL: Polish) and English as a foreign language in dyslexia in English and Polish students, respectively, and to develop a model of relations between NL phonological awareness, rapid automatized naming, verbal short-term memory, and reading in English. Thirteen English students with dyslexia (ED), 15 without (END) and 16 Polish students with dyslexia (PD) and 16 without (PND) participated. We found that dyslexic deficits and different phoneme-to-grapheme correspondence rules between Polish and English interfered with the accuracy and fluency of word and nonword decoding and word recognition. Whereas END scored higher than PD and PND in all reading measures, ED did not, despite a NL advantage. When compared with PND, ED performed equal in nonword decoding, which depends to a higher degree on phoneme-to-grapheme conversion rather than lexical access. When compared with PD, ED performed equally in nonword fluency, which is most likely a nonscript-dependant skill. More variance in reading was explained by NL than FL factors, even if analogical NL/FL skills predicted a given variable. While in ED and END, these relationships agreed with the literature; in PD and PND, NL phonological awareness was not beneficial for English as a foreign language reading.
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Affiliation(s)
- Marta Łockiewicz
- Social Sciences Faculty, Institute of Psychology, University of Gdańsk, Gdańsk, Poland
| | - Martyna Jaskulska
- Social Sciences Faculty, Institute of Psychology, University of Gdańsk, Gdańsk, Poland
| | - Angela Fawcett
- Department of Psychology, Swansea University, Swansea, UK
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Lipowska M, Łada AB, Pawlicka P, Jurek P. The use of the Warnke Method in dyslexia therapy for children. JOURNAL OF APPLIED DEVELOPMENTAL PSYCHOLOGY 2019. [DOI: 10.1016/j.appdev.2019.101060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Nicolson RI, Fawcett AJ. Development of Dyslexia: The Delayed Neural Commitment Framework. Front Behav Neurosci 2019; 13:112. [PMID: 31178705 PMCID: PMC6536918 DOI: 10.3389/fnbeh.2019.00112] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/03/2019] [Indexed: 01/08/2023] Open
Abstract
It is now evident that explanations of many developmental disorders need to include a network perspective. In earlier work, we proposed that developmental dyslexia (DD) is well-characterized in terms of impaired procedural learning within the language networks, with the cerebellum being the key structure involved. Here, we deepen the analysis to include the child's developmental process of constructing these networks. The "Delayed Neural Commitment (DNC)" framework proposes that, in addition to slower skill acquisition, dyslexic children take longer to build (and to rebuild) the neural networks that underpin the acquisition of reading. The framework provides an important link backwards in time to the development of executive function networks and the earlier development of networks for language and speech. It is consistent with many theories of dyslexia while providing fruitful suggestions for further research at the genetic, brain, cognitive and behavioral levels of explanation. It also has significant implications for assessment and teaching.
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Affiliation(s)
| | - Angela J. Fawcett
- Department of Psychology, College of Human and Health Sciences, Swansea University, Swansea, United Kingdom
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20
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Modulation of striatum based non-declarative and medial temporal lobe based declarative memory predicts academic achievement at university level. Trends Neurosci Educ 2019; 14:1-10. [PMID: 30929854 DOI: 10.1016/j.tine.2018.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 11/04/2018] [Accepted: 11/16/2018] [Indexed: 11/23/2022]
Abstract
BACKGROUND There is a dearth of research on the roles of non-declarative (implicit) learning linked to the striatum and declarative (explicit) learning associated with the medial temporal lobes as predictors of academic attainment. METHODS Participants were 120 undergraduate students, studying Psychology or Engineering, who completed several long-term memory tests. RESULTS There was a significant interaction between the groups (Psychology or Engineering) and task type (declarative or non-declarative): Engineers performed better at declarative and psychologists at non-declarative learning. Furthermore, non-declarative but not declarative learning scores were significant correlates of academic achievement (r = 0.326, p < .05). Moreover, competitive modulation (activation of non-declarative learning in conjunction with deactivation of declarative learning) was a significant predictor of future academic achievement in both psychology (r = 0.264, p < .05) and Engineering (r = 0.300, p < .05) groups. CONCLUSIONS The results confirm that these declarative and non-declarative systems interact competitively and that the extent of this competition may have implications for understanding educational attainment.
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Perceptions of the possible impact of dyslexia on nursing and midwifery students and of the coping strategies they develop and/or use to help them cope in clinical practice. Nurse Educ Pract 2019; 35:90-97. [PMID: 30771752 DOI: 10.1016/j.nepr.2018.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 12/01/2018] [Accepted: 12/29/2018] [Indexed: 11/22/2022]
Abstract
This qualitative grounded theory case study aimed to explore the perceptions of the impact of dyslexia on nursing and midwifery students and of the coping strategies they develop and/or use to help them cope in practice. The questions addressed were: 1. What is the perceived impact of dyslexia on the nursing and midwifery student in clinical practice? 2. How are any difficulties associated with dyslexia managed by the nursing or midwifery student? 3i. What strategies can help and support nursing and midwifery students with dyslexia? 3ii. What are students' and mentors' perceptions of the poster guidelines used by mentors to support nursing and midwifery students with dyslexia in the clinical practice? Having obtained ethical approval for the research and participants informed written consent, a purposive sample of 12 nursing and midwifery students and 22 mentors participated in the study. Data were collected by digitally recorded semi-structured interviews, content analysis of students' practice portfolios and files from students. Evaluative comments from mentors were also collected. Data were analysed using Glasarian grounded theory method. Dyslexia impacted on the students practice negatively and positively. They developed and used simple and other strategies, including those on the poster guidelines, which were evaluated positively.
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22
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Arciuli J. Reading as Statistical Learning. Lang Speech Hear Serv Sch 2018; 49:634-643. [DOI: 10.1044/2018_lshss-stlt1-17-0135] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/08/2018] [Indexed: 11/09/2022] Open
Abstract
Purpose
The purpose of this tutorial is to explain how learning to read can be thought of as learning statistical regularities and to demonstrate why this is relevant for theory, modeling, and practice. This tutorial also shows how triangulation of methods and cross-linguistic research can be used to gain insight.
Method
The impossibility of conveying explicitly all of the regularities that children need to acquire in a deep orthography, such as English, can be demonstrated by examining lesser-known probabilistic orthographic cues to lexical stress. Detection of these kinds of cues likely occurs via a type of implicit learning known as statistical learning (SL). The first part of the tutorial focuses on these points. Next, studies exploring how individual differences in the capacity for SL relate to variability in word reading accuracy in the general population are discussed. A brief overview of research linking impaired SL and dyslexia is also provided. The final part of the tutorial focuses on how we might supplement explicit literacy instruction with implicit learning methods and emphasizes the value of testing the efficacy of new techniques in the classroom. The basic and applied research reviewed here includes corpus analyses, behavioral testing, computational modeling, and classroom-based research. Although some of these methods are not commonly used in clinical research, the depth and breadth of this body of work provide a compelling case for why reading can be thought of as SL and how this view can inform practice.
Conclusion
Implicit methods that draw on the principles of SL can supplement the much-needed explicit instruction that helps children learn to read. This synergy of methods has the potential to spark innovative practices in literacy instruction and remediation provided by educators and clinicians to support typical learners and those with developmental disabilities.
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Affiliation(s)
- Joanne Arciuli
- Faculty of Health Sciences, University of Sydney, Australia
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23
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Nicolson RI, Fawcett AJ. Procedural Learning, Dyslexia and Delayed Neural Commitment. LITERACY STUDIES 2018. [DOI: 10.1007/978-3-319-90805-2_12] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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24
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Tamboer P, Vorst HCM, de Jong PF. Six factors of adult dyslexia assessed by cognitive tests and self-report questions: Very high predictive validity. RESEARCH IN DEVELOPMENTAL DISABILITIES 2017; 71:143-168. [PMID: 29040923 DOI: 10.1016/j.ridd.2017.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 09/05/2017] [Accepted: 09/16/2017] [Indexed: 06/07/2023]
Abstract
The Multiple Diagnostic Digital Dyslexia Test for Adults (MDDDT-A) consists of 12 newly developed tests and self-report questions in the Dutch language. Predictive validity and construct validity were investigated and compared with validity of a standard test battery of dyslexia (STB) in a sample of 154 students. There are three main results. First, various analyses of principal components showed that six or more factors of dyslexia can be distinguished (rapid naming, spelling, reading, short-term memory, confusion, phonology, attention, complexity). All factors are represented by the MDDDT-A. Second, various discriminant analyses showed good predictive validity for both the tests of the MDDDT-A (90%) and the STB (90%). However, predictive validity of the questionnaire was highest (97%). Third, we analysed the best predictors of dyslexia and found that predictive validity is higher when construct validity is high, that is when a set of predictors represents many characteristics of dyslexia. The main conclusion is that a digital test battery can be a reliable screening instrument for dyslexia in students, especially when it is accompanied by self-report questions. A theoretical conclusion is that dyslexia is characterized by at least six cognitive impairments in a complex way. In students, this structure may be modulated by high intelligence and good schooling through various compensation strategies. It is therefore recommended to include assessments of all characteristics of dyslexia to achieve the most reliable diagnoses in different samples and in different countries.
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Affiliation(s)
- Peter Tamboer
- University of Amsterdam, Faculty of Social and Behavioural Sciences, Nieuwe Achtergracht 127, 1018WS, Amsterdam, The Netherlands.
| | - Harrie C M Vorst
- University of Amsterdam, Faculty of Social and Behavioural Sciences, Nieuwe Achtergracht 127, 1018WS, Amsterdam, The Netherlands.
| | - Peter F de Jong
- University of Amsterdam, Faculty of Social and Behavioural Sciences, Nieuwe Achtergracht 127, 1018WS, Amsterdam, The Netherlands.
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Jaffe-Dax S, Frenkel O, Ahissar M. Dyslexics' faster decay of implicit memory for sounds and words is manifested in their shorter neural adaptation. eLife 2017; 6. [PMID: 28115055 PMCID: PMC5279949 DOI: 10.7554/elife.20557] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 01/09/2017] [Indexed: 11/13/2022] Open
Abstract
Dyslexia is a prevalent reading disability whose underlying mechanisms are still disputed. We studied the neural mechanisms underlying dyslexia using a simple frequency-discrimination task. Though participants were asked to compare the two tones in each trial, implicit memory of previous trials affected their responses. We hypothesized that implicit memory decays faster among dyslexics. We tested this by increasing the temporal intervals between consecutive trials, and by measuring the behavioral impact and ERP responses from the auditory cortex. Dyslexics showed a faster decay of implicit memory effects on both measures, with similar time constants. Finally, faster decay of implicit memory also characterized the impact of sound regularities in benefitting dyslexics' oral reading rate. Their benefit decreased faster as a function of the time interval from the previous reading of the same non-word. We propose that dyslexics’ shorter neural adaptation paradoxically accounts for their longer reading times, since it reduces their temporal window of integration of past stimuli, resulting in noisier and less reliable predictions for both simple and complex stimuli. Less reliable predictions limit their acquisition of reading expertise. DOI:http://dx.doi.org/10.7554/eLife.20557.001 The term “dyslexia” comes from the Greek for “difficulty with words”. People with dyslexia struggle with reading and spelling: they may mix up letters within words and tend to read and write more slowly than others. However, not every symptom of dyslexia is related to literacy. Affected individuals also differ from good readers on simple perceptual tasks, such as distinguishing between tones of different frequencies. In a series of trials involving discrimination between pairs of tones, a person’s performance on each trial will be influenced by the tones presented on previous trials. Both good readers and individuals with dyslexia automatically form a subconscious memory of the tones they hear, and use this memory to guide their performance on subsequent trials. However, people with dyslexia benefit less from this effect than good readers. Jaffe-Dax et al. have now identified the mechanism that underlies this phenomenon, revealing new insights into how dyslexia influences brain activity. By varying the interval between successive pairs of tones, the experiments showed that the memory of previous tones decays faster in people with dyslexia than in good readers. A similar effect occurs when the stimuli are nonsense words. Both good and poor readers manage to read nonsense words more quickly on their second attempt. However, people with dyslexia benefit less from the previous exposure when the gap between repetitions is longer than a couple of seconds. Further studies are needed to determine whether and how the faster decay of memory traces for words is related to impaired reading ability in people with dyslexia. One possibility is that the faster decay of memory traces makes it more difficult to predict future stimuli, which may impair reading. An imaging study is underway to investigate where in the brain this rapid decay of memory traces occurs. DOI:http://dx.doi.org/10.7554/eLife.20557.002
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Affiliation(s)
- Sagi Jaffe-Dax
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Psychology, Princeton University, Princeton, United States
| | - Or Frenkel
- Psychology Department, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Merav Ahissar
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Psychology Department, The Hebrew University of Jerusalem, Jerusalem, Israel
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Henderson LM, Warmington M. A sequence learning impairment in dyslexia? It depends on the task. RESEARCH IN DEVELOPMENTAL DISABILITIES 2017; 60:198-210. [PMID: 27856107 DOI: 10.1016/j.ridd.2016.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 11/01/2016] [Accepted: 11/08/2016] [Indexed: 05/12/2023]
Abstract
Language acquisition is argued to be dependent upon an individuals' sensitivity to serial-order regularities in the environment (sequential learning), and impairments in reading and spelling in dyslexia have recently been attributed to a deficit in sequential learning. The present study examined the learning and consolidation of sequential knowledge in 30 adults with dyslexia and 29 typical adults matched on age and nonverbal ability using two tasks previously reported to be sensitive to a sequence learning deficit. Both groups showed evidence of sequential learning and consolidation on a serial response time (SRT) task (i.e., faster and more accurate responses to sequenced spatial locations than randomly ordered spatial locations during training that persisted one week later). Whilst typical adults showed evidence of sequential learning on a Hebb repetition task (i.e., more accurate serial recall of repetitive sequences of nonwords versus randomly ordered sequences), adults with dyslexia showed initial advantages for repetitive versus randomly ordered sequences in the first half of training trials, but this effect disappeared in the second half of trials. This Hebb repetition effect was positively correlated with spelling in the dyslexic group; however, there was no correlation between sequential learning on the two tasks, placing doubt over whether sequential learning in different modalities represents a single capacity. These data suggest that sequential learning difficulties in adults with dyslexia are not ubiquitous, and when present may be a consequence of task demands rather than sequence learning per se.
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Hancock R, Richlan F, Hoeft F. Possible roles for fronto-striatal circuits in reading disorder. Neurosci Biobehav Rev 2017; 72:243-260. [PMID: 27826071 PMCID: PMC5189679 DOI: 10.1016/j.neubiorev.2016.10.025] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/13/2016] [Accepted: 10/27/2016] [Indexed: 01/18/2023]
Abstract
Several studies have reported hyperactivation in frontal and striatal regions in individuals with reading disorder (RD) during reading-related tasks. Hyperactivation in these regions is typically interpreted as a form of neural compensation related to articulatory processing. Fronto-striatal hyperactivation in RD could however, also arise from fundamental impairment in reading related processes, such as phonological processing and implicit sequence learning relevant to early language acquisition. We review current evidence for the compensation hypothesis in RD and apply large-scale reverse inference to investigate anatomical overlap between hyperactivation regions and neural systems for articulation, phonological processing, implicit sequence learning. We found anatomical convergence between hyperactivation regions and regions supporting articulation, consistent with the proposed compensatory role of these regions, and low convergence with phonological and implicit sequence learning regions. Although the application of large-scale reverse inference to decode function in a clinical population should be interpreted cautiously, our findings suggest future lines of research that may clarify the functional significance of hyperactivation in RD.
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Affiliation(s)
- Roeland Hancock
- Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, Box 0984, San Francisco, CA 94143, United States.
| | - Fabio Richlan
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Fumiko Hoeft
- Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, Box 0984, San Francisco, CA 94143, United States; Haskins Laboratories, 300 George St #900, New Haven, CT 06511, United States; Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi Shinjuku, Tokyo, 160-8582 Japan
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28
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Hancock R, Richlan F, Hoeft F. Possible roles for fronto-striatal circuits in reading disorder. Neurosci Biobehav Rev 2016. [PMID: 27826071 DOI: 10.1016/j.neubiorev.2016.10.025"] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Several studies have reported hyperactivation in frontal and striatal regions in individuals with reading disorder (RD) during reading-related tasks. Hyperactivation in these regions is typically interpreted as a form of neural compensation related to articulatory processing. Fronto-striatal hyperactivation in RD could however, also arise from fundamental impairment in reading related processes, such as phonological processing and implicit sequence learning relevant to early language acquisition. We review current evidence for the compensation hypothesis in RD and apply large-scale reverse inference to investigate anatomical overlap between hyperactivation regions and neural systems for articulation, phonological processing, implicit sequence learning. We found anatomical convergence between hyperactivation regions and regions supporting articulation, consistent with the proposed compensatory role of these regions, and low convergence with phonological and implicit sequence learning regions. Although the application of large-scale reverse inference to decode function in a clinical population should be interpreted cautiously, our findings suggest future lines of research that may clarify the functional significance of hyperactivation in RD.
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Affiliation(s)
- Roeland Hancock
- Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, Box 0984, San Francisco, CA 94143, United States.
| | - Fabio Richlan
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Fumiko Hoeft
- Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, Box 0984, San Francisco, CA 94143, United States; Haskins Laboratories, 300 George St #900, New Haven, CT 06511, United States; Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi Shinjuku, Tokyo, 160-8582 Japan
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29
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Tamboer P, Vorst HCM, Oort FJ. Five Describing Factors of Dyslexia. JOURNAL OF LEARNING DISABILITIES 2016; 49:466-483. [PMID: 25398549 DOI: 10.1177/0022219414558123] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two subtypes of dyslexia (phonological, visual) have been under debate in various studies. However, the number of symptoms of dyslexia described in the literature exceeds the number of subtypes, and underlying relations remain unclear. We investigated underlying cognitive features of dyslexia with exploratory and confirmatory factor analyses. A sample of 446 students (63 with dyslexia) completed a large test battery and a large questionnaire. Five factors were found in both the test battery and the questionnaire. These 10 factors loaded on 5 latent factors (spelling, phonology, short-term memory, rhyme/confusion, and whole-word processing/complexity), which explained 60% of total variance. Three analyses supported the validity of these factors. A confirmatory factor analysis fit with a solution of five factors (RMSEA = .03). Those with dyslexia differed from those without dyslexia on all factors. A combination of five factors provided reliable predictions of dyslexia and nondyslexia (accuracy >90%). We also looked for factorial deficits on an individual level to construct subtypes of dyslexia, but found varying profiles. We concluded that a multiple cognitive deficit model of dyslexia is supported, whereas the existence of subtypes remains unclear. We discussed the results in relation to advanced compensation strategies of students, measures of intelligence, and various correlations within groups of those with and without dyslexia.
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Affiliation(s)
| | | | - Frans J Oort
- University of Amsterdam, Netherlands Research Institute of Child Development and Education, Amsterdam, Netherlands
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30
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Carroll JM, Solity J, Shapiro LR. Predicting dyslexia using prereading skills: the role of sensorimotor and cognitive abilities. J Child Psychol Psychiatry 2016; 57:750-8. [PMID: 26662375 PMCID: PMC4991277 DOI: 10.1111/jcpp.12488] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/16/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND It is well established that phonological awareness, print knowledge and rapid naming predict later reading difficulties. However, additional auditory, visual and motor difficulties have also been observed in dyslexic children. It is examined to what extent these difficulties can be used to predict later literacy difficulties. METHOD An unselected sample of 267 children at school entry completed a wide battery of tasks associated with dyslexia. Their reading was tested 2, 3 and 4 years later and poor readers were identified (n = 42). Logistic regression and multiple case study approaches were used to examine the predictive validity of different tasks. RESULTS As expected, print knowledge, verbal short-term memory, phonological awareness and rapid naming were good predictors of later poor reading. Deficits in visual search and in auditory processing were also present in a large minority of the poor readers. Almost all poor readers showed deficits in at least one area at school entry, but there was no single deficit that characterised the majority of poor readers. CONCLUSIONS Results are in line with Pennington's () multiple deficits view of dyslexia. They indicate that the causes of poor reading outcome are multiple, interacting and probabilistic, rather than deterministic.
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Affiliation(s)
- Julia M. Carroll
- Centre for Research in PsychologyBehaviour and AchievementCoventry UniversityCoventryUK
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31
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Le développement typique et atypique des actions: théories, recherches et pratiques. ENFANCE 2016. [DOI: 10.4074/s0013754516001038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
In the first part of this article I present a background in scientific studies on dyslexia, from cognitive science to the neuropedagogical perspective. In this investigation the analysis of mental processes is the most important thanks to comparison with genetic research. In the second part, the dyslexic condition is seen from the perspective of the neuro-motor approach, named the Praxic Motor Theory, which improves neural circuits and inter-hemispherical exchange, electrical transmission and evoked potentials.<br />
In this perspective, the dyslexia condition is a disorder related to lack of coordination, including disorganization in space-time and lateral dominance. The phonological hypothesis referring to a lack of sign-sound association in dyslexia is inappropriate, as the term phonology has been intended in English literature as a more complex process and not simply an association between phoneme and grapheme. It is related to access to the word, groups of sounds, rather than single sounds. In this sense the dyslexic reader does not make a phonological mistake in terms of association, but a kinetic-motor one, in space-time from left to right.
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Achal S, Hoeft F, Bray S. Individual Differences in Adult Reading Are Associated with Left Temporo-parietal to Dorsal Striatal Functional Connectivity. Cereb Cortex 2015; 26:4069-4081. [PMID: 26400921 DOI: 10.1093/cercor/bhv214] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Reading skills vary widely in both children and adults, with a number of factors contributing to this variability. The most prominent factor may be related to efficiency of storage, representation, or retrieval of speech sounds. This phonological hypothesis is supported by findings of reduced activation in poor readers in left hemisphere ventro-lateral prefrontal and temporo-parietal phonological processing regions. Less well explained by phonological theories are reported hyperactivation in prefrontal, striatal, and insular regions. This study investigated functional connectivity of a core phonological processing region, the temporo-parietal junction (TPJ), in relation to reading skill in an adult community sample. We hypothesized that connectivity between TPJ and regions implicated in meta-analyses of reading disorder would correlate with individual differences in reading. Forty-four adults aged 30-54, ranging in reading ability, underwent resting fMRI scans. Data-driven connectivity clustering was used to identify TPJ subregions for seed-based connectivity analyses. Correlations were assessed between TPJ connectivity and timed-pseudoword reading (decoding) ability. We found a significant correlation wherein greater left supramarginal gyrus to anterior caudate connectivity was associated with weaker decoding. This suggests that hyperactivation of the dorsal striatum, reported in poor readers during reading tasks, may reflect compensatory or inefficient overintegration into attention networks.
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Affiliation(s)
- Sanjay Achal
- Department of Neuroscience.,Hotchkiss Brain Institute
| | - Fumiko Hoeft
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco, CA 94143, USA.,Haskins Laboratories, Yale University, New Haven, CT 06511, USA.,Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Signe Bray
- Department of Radiology, University of Calgary, Calgary, AB, Canada T2N 4N1.,Department of Paediatrics.,Alberta Children's Hospital Research Institute.,Child and Adolescent Imaging Research Program, Alberta Children's Hospital, Calgary, AB, Canada T3B 6A8
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Graphomotor skills in children with developmental coordination disorder (DCD): Handwriting and learning a new letter. Hum Mov Sci 2015; 42:318-32. [DOI: 10.1016/j.humov.2015.03.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 02/25/2015] [Accepted: 03/12/2015] [Indexed: 11/16/2022]
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Hayek M, Dorfberger S, Karni A. Effective learning and retention of braille letter tactile discrimination skills in children with developmental dyslexia. Dev Sci 2015; 19:32-40. [PMID: 25754250 DOI: 10.1111/desc.12285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 11/30/2014] [Indexed: 11/30/2022]
Abstract
Children with developmental dyslexia (DD) may differ from typical readers in aspects other than reading. The notion of a general deficit in the ability to acquire and retain procedural ('how to') knowledge as long-term procedural memory has been proposed. Here, we compared the ability of elementary school children, with and without reading difficulties (DD, typical readers), to improve their tactile discrimination with practice and tested the children's ability to retain the gains. Forty 10-11-year-olds practiced the tactile discrimination of four braille letters, presented as pairs, while blindfolded. In a trial, participants were asked to report whether the target stimuli were identical or different from each other. The structured training session consisted of six blocks of 16 trials each. Performance was re-tested at 24 hours and two weeks post-training. Both groups improved in speed and in accuracy. In session 1, children with DD started as significantly less accurate and were slower than the typical readers but showed rapid learning and successfully closed the gap. Only two children with DD failed to benefit from training and were not included in subsequent data analyses. At 24 hours post-training both groups showed effective retention of the gains in speed and accuracy. Importantly, children with DD were able to retain the gains in speed and accuracy, over a two-week interval as effectively as typical readers. Thus, children with DD were as effective in the acquisition and retention of tactile discrimination of braille letters as typical readers of the same age. The results do not support the notion of a general procedural learning disability in DD.
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Affiliation(s)
- Maisam Hayek
- E.J. Safra Brain Research Centre for the Study of Learning Disabilities, University of Haifa, Haifa, Israel.,Special Education Department, Sakhnin Colege, Sakhnin, Israel
| | - Shoshi Dorfberger
- E.J. Safra Brain Research Centre for the Study of Learning Disabilities, University of Haifa, Haifa, Israel.,Gordon College of Education, Haifa, Israel
| | - Avi Karni
- E.J. Safra Brain Research Centre for the Study of Learning Disabilities, University of Haifa, Haifa, Israel.,The Department of Human Biology & the Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
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36
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González-Castro P, Rodríguez C, Núñez JC, Vallejo G, González-Pienda JA. Altered visual sensory fusion in children with reading difficulties. Percept Mot Skills 2014; 119:925-48. [PMID: 25375826 DOI: 10.2466/15.10.pms.119c27z6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Reading is a multi-sensory and multi-cognitive task, and its difficulties (e.g., dyslexia) are not a unitary disorder. There are probably a variety of manifestations that relate to the actual site of impairment. A randomized, pre-test/post-test nonequivalent-groups design was conducted over 4 months with three groups aged between 6 and 8 years. One group comprised 76 participants (34 boys, 42 girls) with reading difficulties and altered sensory fusion (RD+ASF), a second group was made up of 123 students (59 boys, 64 girls) with reading difficulties but without altered sensory fusion (RD), and a third group comprised 81 participants (39 boys, 42 girls) who were young readers (RL) without reading delay, paired with the RD group on reading level. The experimental groups received intervention in the skills of control, stimulus recognition, and phonological awareness during a 4-month period. Both pre-test and post-test measures of errors in reading mechanics and reading routes (word and pseudo-word) were obtained. Poorer results in mechanics and reading routes of the RD+ASF group suggest that the effectiveness of the intervention depended on the characteristics of the groups and on the presence of sensory fusion deficits in the RD students.
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Poon K, Ho CSH. Contrasting deficits on executive functions in Chinese delinquent adolescents with attention deficit and hyperactivity disorder symptoms and/or reading disability. RESEARCH IN DEVELOPMENTAL DISABILITIES 2014; 35:3046-3056. [PMID: 25128789 DOI: 10.1016/j.ridd.2014.07.046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 07/22/2014] [Indexed: 06/03/2023]
Abstract
Many studies reported high prevalence of reading disability (RD) and attention deficit hyperactivity disorder (ADHD) among delinquent adolescents. Very few have examined their cognitive profile. The present study compared the executive functions (EFs) and severity of delinquency in delinquent adolescents with RD and/or ADHD symptoms (AS). Delinquents with AS (n=29), RD (n=24), comorbidity AS+RD (n=35) were recruited from juvenile institutions along with typically developing controls (n=29) from local schools; all completed EF assessments and self-report questionnaires on delinquency. Results showed that pure AS group exhibited impaired inhibition while the pure RD group was weak in processing speed and visual memory. The comorbidity group showed unique impairments in interference control and significantly higher delinquency severity. The present findings suggest that comorbidity AS+RD may influence delinquency severity. It also provides a more comprehensive picture of the unique EF deficits associated with different groups, allowing for better matching for future identification and intervention programme.
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Affiliation(s)
- Kean Poon
- Department of Special Education and Counselling, The Hong Kong Institute of Education, Hong Kong; Department of Psychology, The University of Hong Kong, Hong Kong.
| | - Connie S-H Ho
- Department of Psychology, The University of Hong Kong, Hong Kong
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Lachmann T, van Leeuwen C. Reading as functional coordination: not recycling but a novel synthesis. Front Psychol 2014; 5:1046. [PMID: 25309489 PMCID: PMC4176034 DOI: 10.3389/fpsyg.2014.01046] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 09/02/2014] [Indexed: 11/13/2022] Open
Abstract
The Functional Coordination approach describes the processes involved in learning to read as a form of procedural learning in which pre-existing skills, mainly from the visual, and auditory domain, are (1) recruited, (2) modified, and (3) coordinated to create the procedures for reading text, which form the basis of subsequent (4) automatization. In this context, we discuss evidence relating to the emerging prevalence of analytic processing in letter perception. We argue that the process of learning to read does not have to lead to a loss of perceptual skill as consequence of a "cultural recycling"; learning to read just leads to a novel synthesis of functions, which are coordinated for reading and then automatized as a package over several years. Developmental dyslexia is explained within this framework as a Functional Coordination Deficit (Lachmann, 2002), since the coordination level is assumed to be most liable to manifest deficiencies. This is because, at this level, the greatest degree of fine tuning of complex functions is required. Thus, developmental dyslexia is not seen as a consequence of a deficient automatization per se, but of automatization of abnormally developed functional coordination.
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Affiliation(s)
- Thomas Lachmann
- Cognitive and Developmental Psychology Unit, Center for Cognitive Science, University of Kaiserslautern Kaiserslautern, Germany
| | - Cees van Leeuwen
- Cognitive and Developmental Psychology Unit, Center for Cognitive Science, University of Kaiserslautern Kaiserslautern, Germany ; Experimental Psychology Unit and Laboratory for Perceptual Dynamics - University of Leuven Leuven, Belgium
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Wang Z, Cheng-Lai A, Song Y, Cutting L, Jiang Y, Lin O, Meng X, Zhou X. A perceptual learning deficit in Chinese developmental dyslexia as revealed by visual texture discrimination training. DYSLEXIA (CHICHESTER, ENGLAND) 2014; 20:280-96. [PMID: 24643918 DOI: 10.1002/dys.1475] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 08/13/2013] [Accepted: 02/03/2014] [Indexed: 05/06/2023]
Abstract
Learning to read involves discriminating between different written forms and establishing connections with phonology and semantics. This process may be partially built upon visual perceptual learning, during which the ability to process the attributes of visual stimuli progressively improves with practice. The present study investigated to what extent Chinese children with developmental dyslexia have deficits in perceptual learning by using a texture discrimination task, in which participants were asked to discriminate the orientation of target bars. Experiment l demonstrated that, when all of the participants started with the same initial stimulus-to-mask onset asynchrony (SOA) at 300 ms, the threshold SOA, adjusted according to response accuracy for reaching 80% accuracy, did not show a decrement over 5 days of training for children with dyslexia, whereas this threshold SOA steadily decreased over the training for the control group. Experiment 2 used an adaptive procedure to determine the threshold SOA for each participant during training. Results showed that both the group of dyslexia and the control group attained perceptual learning over the sessions in 5 days, although the threshold SOAs were significantly higher for the group of dyslexia than for the control group; moreover, over individual participants, the threshold SOA negatively correlated with their performance in Chinese character recognition. These findings suggest that deficits in visual perceptual processing and learning might, in part, underpin difficulty in reading Chinese.
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Affiliation(s)
- Zhengke Wang
- Department of Psychology, Peking University, Beijing, China; Department of Basic Education II, Ministry of Education, Beijing, China
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40
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Lachmann T, Schmitt A, Braet W, van Leeuwen C. Letters in the forest: global precedence effect disappears for letters but not for non-letters under reading-like conditions. Front Psychol 2014; 5:705. [PMID: 25101012 PMCID: PMC4102249 DOI: 10.3389/fpsyg.2014.00705] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 06/19/2014] [Indexed: 11/13/2022] Open
Abstract
Normally skilled reading involves special processing strategies for letters, which are habitually funneled into an abstract letter code. On the basis of previous studies we argue that this habit leads to the preferred usage of an analytic strategy for the processing of letters, while non-letters are preferably processed via a holistic strategy. The well-known global precedence effect (GPE) seems to contradict to this assumption, since, with compound, hierarchical figures, including letter items, faster responses are observed to the global than to the local level of the figure, as well as an asymmetric interference effect from global to local level. We argue that with letters these effects depend on presentation conditions; only when they elicit the processing strategies automatized for reading, an analytic strategy for letters in contrast to non-letters is to be expected. We compared the GPE for letters and non-letters in central viewing, with the global stimulus size close to the functional visual field in whole word reading (6.5° of visual angle) and local stimuli close to the critical size for fluent reading of individual letters (0.5° of visual angle). Under these conditions, the GPE remained robust for non-letters. For letters, however, it disappeared: letters showed no overall response time advantage for the global level and symmetric congruence effects (local-to-global as well as global-to-local interference). We interpret these results as according to the view that reading is based on resident analytic visual processing strategies for letters.
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Affiliation(s)
- Thomas Lachmann
- Center for Cognitive Science, Cognitive and Developmental Psychology Unit, University of Kaiserslautern Kaiserslautern, Germany
| | - Andreas Schmitt
- Center for Cognitive Science, Cognitive and Developmental Psychology Unit, University of Kaiserslautern Kaiserslautern, Germany
| | - Wouter Braet
- Center for Cognitive Science, Cognitive and Developmental Psychology Unit, University of Kaiserslautern Kaiserslautern, Germany
| | - Cees van Leeuwen
- Center for Cognitive Science, Cognitive and Developmental Psychology Unit, University of Kaiserslautern Kaiserslautern, Germany ; Experimental Psychology Unit, University of Leuven Leuven, Belgium
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41
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Ferrucci R, Brunoni AR, Parazzini M, Vergari M, Rossi E, Fumagalli M, Mameli F, Rosa M, Giannicola G, Zago S, Priori A. Modulating human procedural learning by cerebellar transcranial direct current stimulation. THE CEREBELLUM 2014; 12:485-92. [PMID: 23328908 DOI: 10.1007/s12311-012-0436-9] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Neuroimaging studies suggest that the cerebellum contributes to human cognitive processing, particularly procedural learning. This type of learning is often described as implicit learning and involves automatic, associative, and unintentional learning processes. Our aim was to investigate whether cerebellar transcranial direct current stimulation (tDCS) influences procedural learning as measured by the serial reaction time task (SRTT), in which subjects make speeded key press responses to visual cues. A preliminary modeling study demonstrated that our electrode montage (active electrode over the cerebellum with an extra-cephalic reference) generated the maximum electric field amplitude in the cerebellum. We enrolled 21 healthy subjects (aged 20-49 years). Participants did the SRTT, a visual analogue scale and a visual attention task, before and 35 min after receiving 20-min anodal and sham cerebellar tDCS in a randomized order. To avoid carry-over effects, experimental sessions were held at least 1 week apart. For our primary outcome measure (difference in RTs for random and repeated blocks) anodal versus sham tDCS, RTs were significantly slower for sham tDCS than for anodal cerebellar tDCS (p = 0.04), demonstrating that anodal tDCS influenced implicit learning processes. When we assessed RTs for procedural learning across the one to eight blocks, we found that RTs changed significantly after anodal stimulation (interaction "time" × "blocks 1/8": anodal, p = 0.006), but after sham tDCS, they remained unchanged (p = 0.094). No significant changes were found in the other variables assessed. Our finding that anodal cerebellar tDCS improves an implicit learning type essential to the development of several motor skills or cognitive activity suggests that the cerebellum has a critical role in procedural learning. tDCS could be a new tool for improving procedural learning in daily life in healthy subjects and for correcting abnormal learning in neuropsychiatric disorders.
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Affiliation(s)
- Roberta Ferrucci
- Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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Mansour A, Bowyer SM, Richard AE, Moran JE, Erdodi LA, Olszewski A, Pawluk L, Jacobson D, Vogt K, Moore AM, Lajiness-O’Neill R. Magnetoencephalography Coherence Source Imaging in Dyslexia: Activation of Working Memory Pathways. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/psych.2014.516193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Hedenius M, Persson J, Alm PA, Ullman MT, Howard JH, Howard DV, Jennische M. Impaired implicit sequence learning in children with developmental dyslexia. RESEARCH IN DEVELOPMENTAL DISABILITIES 2013; 34:3924-3935. [PMID: 24021394 DOI: 10.1016/j.ridd.2013.08.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/15/2013] [Accepted: 08/15/2013] [Indexed: 06/02/2023]
Abstract
It has been proposed that an impairment of procedural memory underlies a range of linguistic, cognitive and motor impairments observed in developmental dyslexia (DD). However, studies designed to test this hypothesis using the implicit sequence learning paradigm have yielded inconsistent results. A fundamental aspect of procedural learning is that it takes place over an extended time-period that may be divided into distinct stages based on both behavioural characteristics and neural correlates of performance. Yet, no study of implicit sequence learning in children with DD has included learning stages beyond a single practice session. The present study was designed to fill this important gap by extending the investigation to include the effects of overnight consolidation as well as those of further practice on a subsequent day. The results suggest that the most pronounced procedural learning impairment in DD may emerge only after extended practice, in learning stages beyond a single practice session.
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Affiliation(s)
- Martina Hedenius
- Unit for Speech and Language Pathology, Department of Neuroscience, University of Uppsala, P.O. Box 256, SE-751 05 Uppsala, Sweden.
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Lum JAG, Ullman MT, Conti-Ramsden G. Procedural learning is impaired in dyslexia: evidence from a meta-analysis of serial reaction time studies. RESEARCH IN DEVELOPMENTAL DISABILITIES 2013; 34:3460-76. [PMID: 23920029 PMCID: PMC3784964 DOI: 10.1016/j.ridd.2013.07.017] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/04/2013] [Accepted: 07/09/2013] [Indexed: 05/23/2023]
Abstract
A number of studies have investigated procedural learning in dyslexia using serial reaction time (SRT) tasks. Overall, the results have been mixed, with evidence of both impaired and intact learning reported. We undertook a systematic search of studies that examined procedural learning using SRT tasks, and synthesized the data using meta-analysis. A total of 14 studies were identified, representing data from 314 individuals with dyslexia and 317 typically developing control participants. The results indicate that, on average, individuals with dyslexia have worse procedural learning abilities than controls, as indexed by sequence learning on the SRT task. The average weighted standardized mean difference (the effect size) was found to be 0.449 (CI95: .204, .693), and was significant (p<.001). However, moderate levels of heterogeneity were found between study-level effect sizes. Meta-regression analyses indicated that studies with older participants that used SRT tasks with second order conditional sequences, or with older participants that used sequences that were presented a large number of times, were associated with smaller effect sizes. These associations are discussed with respect to compensatory and delayed memory systems in dyslexia.
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Vlachos F, Andreou E, Delliou A. Brain hemisphericity and developmental dyslexia. RESEARCH IN DEVELOPMENTAL DISABILITIES 2013; 34:1536-1540. [PMID: 23475004 DOI: 10.1016/j.ridd.2013.01.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/29/2013] [Accepted: 01/29/2013] [Indexed: 06/01/2023]
Abstract
The present study examined the link between brain hemisphericity and dyslexia in secondary school students, using the Preference Test (PT), a widely used self-report index of preferred hemisphere thinking styles. The hypothesis was that differences would be revealed between the dyslexic group and their peers in hemispheric preference. A total of 45 secondary school students who were diagnosed with dyslexia and attended regular public schools formed the learning disabled group. A comparison group was formed of pupils who attended the same classes (N=90), and these were matched for age and sex with dyslexics (1 dyslexic: 2 control). The results revealed that significantly more dyslexic pupils displayed a preference for a right hemisphere thinking style compared to their peers who adopted a left hemisphere thinking style. This finding is in line with the suggestion of the greater right hemisphere involvement in the expression of developmental dyslexia.
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Affiliation(s)
- Filippos Vlachos
- University of Thessaly, Department of Special Education, Argonafton & Filellinon, 38221 Volos, Greece.
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Kapoula Z, Gaertner C, Matheron E. Spherical lenses and prisms lead to postural instability in both dyslexic and non dyslexic adolescents. PLoS One 2012; 7:e46739. [PMID: 23144786 PMCID: PMC3489872 DOI: 10.1371/journal.pone.0046739] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 09/07/2012] [Indexed: 02/06/2023] Open
Abstract
There is controversy as to whether dyslexic children present systematic postural deficiency. Clinicians use a combination of ophthalmic prisms and proprioceptive soles to improve postural performances. This study examines the effects of convergent prisms and spherical lenses on posture. Fourteen dyslexics (13-17 years-old) and 11 non dyslexics (13-16 years-old) participated in the study. Quiet stance posturography was performed with the TechnoConcept device while subjects fixated a target at eye-level from a distance of 1_m. Four conditions were run: normal viewing; viewing the target with spherical lenses of -1 diopter (ACCOM1) over each eye; viewing with -3 diopters over each eye (ACCOM3); viewing with a convergent prism of 8 diopters per eye. Relative to normal viewing, the -1 lenses increased the surface of body sway significantly whereas the -3 diopter lenses only resulted in a significant increase of antero-posterior body sway. Thus, adolescents would appear to cope more effectively with stronger conflicts rather than subtle ones. The prism condition resulted in a significant increase in both the surface and the antero-posterior body sway. Importantly, all of these effects were similar for the two groups. Wavelet analysis (time frequency domain) revealed high spectral power of antero-posterior sway for the prism condition in both groups. In the ACCOM3 condition, the spectral power of antero-posterior sway decreased for non dyslexics but increased for dyslexics suggesting that dyslexics encounter more difficulty with accommodation. The cancelling time for medium range frequency (believed to be controlled by the cerebellum), was shorter in dyslexics, suggesting fewer instances of optimal control. We conclude that dyslexics achieve similar postural performances albeit less efficiently. Prisms and lenses destabilize posture for all teenagers. Thus, contrary to adults, adolescents do not seem to use efferent, proprioceptive ocular motor signals to improve their posture, at least not immediately when confronted to convergence accommodation conflict.
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Affiliation(s)
- Zoi Kapoula
- IRIS Group, Centre d'Etudes SensoriMotrices UMR8194, CNRS, Université Paris Descartes, Paris, France.
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Sela I, Karni A. Differences in learning volitional (manual) and non-volitional (posture) aspects of a complex motor skill in young adult dyslexic and skilled readers. PLoS One 2012; 7:e43488. [PMID: 23049736 PMCID: PMC3458875 DOI: 10.1371/journal.pone.0043488] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 07/20/2012] [Indexed: 11/18/2022] Open
Abstract
The 'Cerebellar Deficit Theory' of developmental dyslexia proposes that a subtle developmental cerebellar dysfunction leads to deficits in attaining 'automatic' procedures and therefore manifests as subtle motor impairments (e.g., balance control, motor skill learning) in addition to the reading and phonological difficulties. A more recent version of the theory suggests a core deficit in motor skill acquisition. This study was undertaken to compare the time-course and the nature of practice-related changes in volitional (manual) and non-volitional (posture) motor performance in dyslexic and typical readers while learning a new movement sequence. Seventeen dyslexic and 26 skilled young adult readers underwent a three-session training program in which they practiced a novel sequence of manual movements while standing in a quiet stance position. Both groups exhibited robust and well-retained gains in speed, with no loss of accuracy, on the volitional, manual, aspects of the task, with a time-course characteristic of procedural learning. However, the dyslexic readers exhibited a pervasive slowness in the initiation of volitional performance. In addition, while typical readers showed clear and well-retained task-related adaptation of the balance and posture control system, the dyslexic readers had significantly larger sway and variance of sway throughout the three sessions and were less efficient in adapting the posture control system to support the acquisition of the novel movement sequence. These results support the notion of a non-language-related deficit in developmental dyslexia, one related to the recruitment of motor systems for effective task performance rather than to a general motor learning disability.
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Affiliation(s)
- Itamar Sela
- Edmond J. Safra Brain Research Center for the Study of Learning Disabilities, University of Haifa, Haifa, Israel.
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Sensory integration, sensory processing, and sensory modulation disorders: putative functional neuroanatomic underpinnings. THE CEREBELLUM 2012; 10:770-92. [PMID: 21630084 DOI: 10.1007/s12311-011-0288-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This paper examines conditions that have variously been called sensory integration disorder, sensory processing disorder, and sensory modulation disorder (SID/SPD/SMD). As these conditions lack readily and consistently agreed-upon operational definitions, there has been confusion as to how these disorders are conceptualized. Rather than addressing various diagnostic controversies, we will instead focus upon explaining the symptoms that are believed to characterize these disorders. First, to clarify the overall context within which to view symptoms, we summarize a paradigm of adaptation characterized by continuous sensorimotor interaction with the environment. Next, we review a dual-tiered, integrated model of brain function in order to establish neuroanatomic underpinnings with which to conceptualize the symptom presentations. Generally accepted functions of the neocortex, basal ganglia, and cerebellum are described to illustrate how interactions between these brain regions generate both adaptive and pathological symptoms and behaviors. We then examine the symptoms of SID/SPD/SMD within this interactive model and in relation to their impact upon the development of inhibitory control, working memory, academic skill development, and behavioral automation. We present likely etiologies for these symptoms, not only as they drive neurodevelopmental pathologies but also as they can be understood as variations in the development of neural networks.
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Nicolson RI, Fawcett AJ, Brookes RL, Needle J. Procedural learning and dyslexia. DYSLEXIA (CHICHESTER, ENGLAND) 2010; 16:194-212. [PMID: 20680991 DOI: 10.1002/dys.408] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Three major 'neural systems', specialized for different types of information processing, are the sensory, declarative, and procedural systems. It has been proposed (Trends Neurosci., 30(4), 135-141) that dyslexia may be attributable to impaired function in the procedural system together with intact declarative function. We provide a brief overview of the increasing evidence relating to the hypothesis, noting that the framework involves two main claims: first that 'neural systems' provides a productive level of description avoiding the underspecificity of cognitive descriptions and the overspecificity of brain structural accounts; and second that a distinctive feature of procedural learning is its extended time course, covering from minutes to months. In this article, we focus on the second claim. Three studies-speeded single word reading, long-term response learning, and overnight skill consolidation-are reviewed which together provide clear evidence of difficulties in procedural learning for individuals with dyslexia, even when the tasks are outside the literacy domain. The educational implications of the results are then discussed, and in particular the potential difficulties that impaired overnight procedural consolidation would entail. It is proposed that response to intervention could be better predicted if diagnostic tests on the different forms of learning were first undertaken.
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Affiliation(s)
- R I Nicolson
- Department of Psychology, University of Sheffield, UK
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