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Duñabeitia JA, Dimitropoulou M, Estévez A, Carreiras M. The influence of reading expertise in mirror-letter perception: Evidence from beginning and expert readers. MIND, BRAIN AND EDUCATION : THE OFFICIAL JOURNAL OF THE INTERNATIONAL MIND, BRAIN, AND EDUCATION SOCIETY 2013; 7:10.1111/mbe.12017. [PMID: 24273596 PMCID: PMC3836404 DOI: 10.1111/mbe.12017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The visual word recognition system recruits neuronal systems originally developed for object perception which are characterized by orientation insensitivity to mirror reversals. It has been proposed that during reading acquisition beginning readers have to "unlearn" this natural tolerance to mirror reversals in order to efficiently discriminate letters and words. Therefore, it is supposed that this unlearning process takes place in a gradual way and that reading expertise modulates mirror-letter discrimination. However, to date no supporting evidence for this has been obtained. We present data from an eye-movement study that investigated the degree of sensitivity to mirror-letters in a group of beginning readers and a group of expert readers. Participants had to decide which of the two strings presented on a screen corresponded to an auditorily presented word. Visual displays always included the correct target word and one distractor word. Results showed that those distractors that were the same as the target word except for the mirror lateralization of two internal letters attracted participants' attention more than distractors created by replacement of two internal letters. Interestingly, the time course of the effects was found to be different for the two groups, with beginning readers showing a greater tolerance (decreased sensitivity) to mirror-letters than expert readers. Implications of these findings are discussed within the framework of preceding evidence showing how reading expertise modulates letter identification.
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Affiliation(s)
| | | | | | - Manuel Carreiras
- Basque Center on Cognition, Brain and Language (BCBL); Donostia, Spain
- Ikerbasque, Basque Foundation for Science; Bilbao, Spain
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Lecourtier L, Antal MC, Cosquer B, Schumacher A, Samama B, Angst MJ, Ferrandon A, Koning E, Cassel JC, Nehlig A. Intact neurobehavioral development and dramatic impairments of procedural-like memory following neonatal ventral hippocampal lesion in rats. Neuroscience 2012; 207:110-23. [PMID: 22322113 DOI: 10.1016/j.neuroscience.2012.01.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 12/26/2011] [Accepted: 01/23/2012] [Indexed: 01/22/2023]
Abstract
Neonatal ventral hippocampal lesions (NVHL) in rats are considered a potent developmental model of schizophrenia. After NVHL, rats appear normal during their preadolescent time, whereas in early adulthood, they develop behavioral deficits paralleling symptomatic aspects of schizophrenia, including hyperactivity, hypersensitivity to amphetamine (AMPH), prepulse and latent inhibition deficits, reduced social interactions, and spatial working and reference memory alterations. Surprisingly, the question of the consequences of NVHL on postnatal neurobehavioral development has not been addressed. This is of particular importance, as a defective neurobehavioral development could contribute to impairments seen in adult rats. Therefore, at several time points of the early postsurgical life of NVHL rats, we assessed behaviors accounting for neurobehavioral development, including negative geotaxis and grip strength (PD11), locomotor coordination (PD21), and open-field (PD25). At adulthood, the rats were tested for anxiety levels, locomotor activity, as well as spatial reference memory performance. Using a novel task, we also investigated the consequences of the lesions on procedural-like memory, which had never been tested following NVHL. Our results point to preserved neurobehavioral development. They also confirm the already documented locomotor hyperactivity, spatial reference memory impairment, and hyperresponsiveness to AMPH. Finally, our rseults show for the first time that NVHL disabled the development of behavioral routines, suggesting dramatic procedural memory deficits. The presence of procedural memory deficits in adult rats subjected to NHVL suggests that the lesions lead to a wider range of cognitive deficits than previously shown. Interestingly, procedural or implicit memory impairments have also been reported in schizophrenic patients.
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Affiliation(s)
- L Lecourtier
- Laboratoire d'Imagerie et de Neurosciences Cognitives, UMR, 7237 Université de Strasbourg/CNRS, Strasbourg, France
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Gomar JJ, Pomarol-Clotet E, Sarró S, Salvador R, Myers CE, McKenna PJ. Procedural learning in schizophrenia: reconciling the discrepant findings. Biol Psychiatry 2011; 69:49-54. [PMID: 20817152 DOI: 10.1016/j.biopsych.2010.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Revised: 07/05/2010] [Accepted: 07/15/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND Studies of procedural learning in schizophrenia have been inconsistent, sometimes finding it to be preserved and sometimes impaired. This study examined three factors that could account for the variability among findings: type of task, presence of general intellectual impairment, and the extrapyramidal side effects of neuroleptic treatment. METHODS Forty-three patients with schizophrenia and 22 normal control subjects were examined with three different paradigms: the pursuit rotor, mirror reading, and probabilistic learning ("weather prediction"). A subgroup of intellectually preserved patients was also examined. Patients with and without tardive dyskinesia and with and without Parkinsonism were also compared. RESULTS The schizophrenic patients showed learning comparable to the control subjects on the pursuit rotor and mirror reading but were impaired on the probabilistic learning task. However, this last difference disappeared when the subgroup of intellectually preserved patients was compared with a subgroup of matched control subjects. Patients with and without tardive dyskinesia or Parkinsonism showed similar learning on all three tasks, but patients with tardive dyskinesia showed poorer overall performance than those without. CONCLUSIONS Procedural learning tends to be preserved in schizophrenia, and when impairment is found, differences in the overall level of intellectual function might be the determining factor.
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Affiliation(s)
- Jesús J Gomar
- Benito Menni Complex Assistencial en Salut Mental, Universitat Autònoma de Barcelona, Barcelona Spain.
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Kern RS, Hartzell AM, Izaguirre B, Hamilton AH. Declarative and nondeclarative memory in schizophrenia: What is impaired? What is spared? J Clin Exp Neuropsychol 2010; 32:1017-27. [PMID: 20446142 DOI: 10.1080/13803391003671166] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The study's aim was to assess a broad range of declarative and nondeclarative memory functions in schizophrenia to identify areas of impairment versus relative preservation. Participants included 40 schizophrenia outpatients and 30 demographically comparable community residents. All participants were administered a battery assessing declarative memory (verbal learning, working memory, semantic memory, remote memory, verbal retention) and nondeclarative memory (procedural learning, priming). To control for order effects, the battery was divided into three parts of approximately equal length with order of administration counterbalanced across study participants. The results showed persons with schizophrenia to be significantly impaired relative to community residents in verbal learning, working memory, semantic memory, remote memory, and priming. In contrast, the two groups were comparable in verbal retention and procedural learning. In the schizophrenia group, priming ability best discriminated past year's vocational status. In sum, the findings indicate a specific pattern of impairment and preservation of memory functioning in schizophrenia. Skill (procedural) learning and retention of learned, declarative verbal information across a delay appear intact, while all other areas measured appear impaired.
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Affiliation(s)
- Robert S Kern
- David Geffen School of Medicine, UCLA Semel Institute for Neuroscience and Human Behavior, Los Angeles, CA, USA.
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Abstract
Previous studies had revealed no specific effect under haloperidol (typical) and risperidone (atypical) neuroleptic (NLP) treatments for schizophrenia (SZ) on a variety of neurocognitive functions relying on the dopaminergic meso-cortico-limbic system (Rémillard et al., 2005, 2008). Considering the different affinities of D2 dopamine receptors for typical and atypical NLPs, these drugs may differentially affect the functions of the striatum, a determinant brain structure involved in procedural learning. The influence of risperidone (2-6 mg) and haloperidol (2-40 mg) on a nonmotor procedural task involving semantically related pairs of words with inverted letters was investigated in this double-blind study. The performance of 26 patients with SZ, randomly assigned to risperidone or haloperidol, was compared to that of 18 healthy controls at baseline, 3, 6, and 12 months. Results revealed that all patients with SZ exhibited slower reading speed of the word pairs than healthy controls at all assessment periods. In addition, procedural learning - characterized as a significant decrease in the time taken to read aloud the target word pairs - was more impaired in the haloperidol- than in the risperidone-treated group at all assessment periods. Healthy controls showed steady improvement in reading speed over the 12 months of the study, in contrast to SZ patients, who reached a plateau in their capacity to improve mirror-reading skill over time. However, all SZ participants in the study showed near normal learning profiles from exposure to semantic associations embedded in the procedural memory task, providing evidence for the preservation of associative connections in the semantic network of these patients. The observed impairment in procedural learning in SZ may thus reflect, at least in part, the influence of neuroleptic medication on striatal functions.
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Gold JM, Hahn B, Strauss GP, Waltz JA. Turning it upside down: areas of preserved cognitive function in schizophrenia. Neuropsychol Rev 2009; 19:294-311. [PMID: 19452280 DOI: 10.1007/s11065-009-9098-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 05/04/2009] [Indexed: 12/21/2022]
Abstract
Patients with schizophrenia demonstrate marked impairments on most clinical neuropsychological tests. These findings suggest that patients suffer from a generalized form of cognitive impairment, with little evidence of spared performance documented in several large meta-analytic reviews of the clinical literature. In contrast, we review evidence for relative sparing of aspects of attention, procedural memory, and emotional processing observed in studies that have employed experimental approaches adapted from the cognitive and affective neuroscience literature. These islands of preserved performance suggest that the cognitive deficits in schizophrenia are not as general as they appear to be when assayed with clinical neuropsychological methods. The apparent contradiction in findings across methods may offer important clues about the nature of cognitive impairment in schizophrenia. The documentation of preserved cognitive function in schizophrenia may serve to sharpen hypotheses about the biological mechanisms that are implicated in the illness.
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Affiliation(s)
- James M Gold
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, PO Box 21247, Baltimore, MD 21228, USA.
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Heerey EA, Bell-Warren KR, Gold JM. Decision-making impairments in the context of intact reward sensitivity in schizophrenia. Biol Psychiatry 2008; 64:62-9. [PMID: 18377874 PMCID: PMC2613513 DOI: 10.1016/j.biopsych.2008.02.015] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 02/17/2008] [Accepted: 02/22/2008] [Indexed: 10/22/2022]
Abstract
BACKGROUND Deficits in motivated behavior and decision-making figure prominently in the behavioral syndrome that characterizes schizophrenia and are difficult both to treat and to understand. One explanation for these deficits is that schizophrenia decreases sensitivity to rewards in the environment. An alternate explanation is that sensitivity to rewards is intact but that poor integration of affective with cognitive information impairs the ability to use this information to guide behavior. METHODS We tested reward sensitivity with a modified version of an existing signal detection task with asymmetric reinforcement and decision-making with a probabilistic decision-making task in 40 participants with schizophrenia and 26 healthy participants. RESULTS Results showed normal sensitivity to reward in participants with schizophrenia but differences in choice patterns on the decision-making task. A logistic regression model of the decision-making data showed that participants with schizophrenia differed from healthy participants in the ability to weigh potential outcomes, specifically potential losses, when choosing between competing response options. Deficits in working memory ability accounted for group differences in ability to use potential outcomes during decision-making. CONCLUSIONS These results suggest that the implicit mechanisms that drive reward-based learning are surprisingly intact in schizophrenia but that poor ability to integrate cognitive and affective information when calculating the value of possible choices might hamper the ability to use such information during explicit decision-making.
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Affiliation(s)
- Erin A Heerey
- School of Psychology, Bangor University, Gwynedd, United Kingdom.
| | | | - James M Gold
- Maryland Psychiatric Research Center, University of Maryland, Baltimore
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Boulay LJ, Labelle A, Bourget D, Robertson S, Habib R, Tessier P, Tombaugh T, Milin R. Dissociating medication effects from learning and practice effects in a neurocognitive study of schizophrenia: Olanzapine versus haloperidol. Cogn Neuropsychiatry 2007; 12:322-38. [PMID: 17558641 DOI: 10.1080/13546800601069534] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To contrast the effect of a typical antipsychotic (haloperidol) and an atypical antipsychotic (olanzapine) on neurocognitive functioning in schizophrenia when learning and practice (LP) effects are controlled. METHODS Two groups of participants were recruited, 27 schizophrenia patients in their first 5 years of illness and 13 normal controls. Prior to double-blind randomisation, all subjects were assessed on four occasions within 5 days (prerandomisation period) on the same neurocognitive battery. Repeated assessment prior to randomisation was chosen as a method to control for LP effects. Patients were then randomised to 56 days of treatment with haloperidol or olanzapine (postrandomisation). All subjects were assessed on neurocognitive measures at Days 28 and 56. RESULTS LP effects were present during the prerandomisation period on motor tasks, verbal and visual short-term memory, attention, and on a measure of verbal working memory. There were no changes in performance for patients randomised to treatment with olanzapine or haloperidol or the normal control group during the postrandomisation period. CONCLUSIONS Once LP effects are controlled, olanzapine and haloperidol do not affect performance on measures of motor functioning, verbal short-term memory, attention, verbal working memory, reaction time, visuospatial short-term memory, and visual working memory beyond that observed from LP effects.
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Affiliation(s)
- Luc J Boulay
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Hospital. Ottawa, Ontario. Canada
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Zedkova L, Woodward ND, Harding I, Tibbo PG, Purdon SE. Procedural learning in schizophrenia investigated with functional magnetic resonance imaging. Schizophr Res 2006; 88:198-207. [PMID: 16945506 DOI: 10.1016/j.schres.2006.06.039] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 06/16/2006] [Accepted: 06/19/2006] [Indexed: 11/16/2022]
Abstract
A cerebral basis for the acquisition and retention of procedural knowledge in schizophrenia was examined with 1.5 T functional MRI during an embedded sequence Serial Reaction Time Task (SRTT) in 10 chronic medicated patients and 15 healthy controls. Comparable procedural learning was observed in both groups, suggesting that the impairment reported in previous schizophrenia samples may not be robust. Consistent with previous fMRI reports, procedural learning in the control group was associated with activity in the dorsal striatum, anterior cingulate, parietal cortex and frontal cortex. Greater procedural learning related activity was observed in the control relative to the schizophrenia group in the bilateral frontal, left parietal and bilateral caudate regions. Patients did not activate frontal or parietal areas while responding to the embedded sequence within the SRTT, but greater activation during procedural learning was observed relative to the control sample in the right anterior cingulate, left globus pallidus and the right superior temporal gyrus. Thus, despite comparable instantiation of procedural learning in schizophrenia, the cerebral activation associated with this cognitive skill was abnormal. The paucity of activity in bilateral frontal cortex, left parietal cortex and bilateral caudate nucleus may represent cerebral dysfunction associated with schizophrenia, whereas the hyperactivation of the right superior temporal gyrus, the right anterior cingulate cortex and the left globus pallidus may represent a compensatory cerebral action capable of facilitating near-normal task performance. The results are thus consistent with a neurodevelopmental pathology impinging on fronto-subcortical circuitry.
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Affiliation(s)
- Lenka Zedkova
- Department of Psychiatry and Bebensee Schizophrenia Research Unit, University of Alberta, Edmonton, Alberta, Canada
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Abstract
Despite a growing number of studies that have investigated the relationship between neurocognition and psychosocial outcome in schizophrenia, no studies have looked at the relationship between procedural memory and social skills measures in schizophrenia. The goal of this study was to investigate whether procedural memory, often preserved in schizophrenia, could predict nonverbal social skills in chronic patients with schizophrenia. Fourteen outpatients with schizophrenia participated in our study. Procedural memory was evaluated using the Mirror Reading Test, and nonverbal and verbal social skills were evaluated using a structured role play test. As predicted, there was a significant positive correlation between the learning index of the Mirror Reading Test and nonverbal skills (Spearman rho=0.559, p = 0.038), but not for verbal communication skills or processing skills. Although preliminary, these results provide the first evidence of an association between procedural memory and nonverbal social skills in patients with schizophrenia.
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Affiliation(s)
- Yuki Kawakubo
- Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
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