1
|
Meier EL, Sheppard SM, Sebastian R, Berube S, Goldberg EB, Shea J, Stein CM, Hillis AE. Resting state correlates of picture description informativeness in left vs. right hemisphere chronic stroke. Front Neurol 2023; 14:1288801. [PMID: 38145117 PMCID: PMC10744570 DOI: 10.3389/fneur.2023.1288801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023] Open
Abstract
Introduction Despite a growing emphasis on discourse processing in clinical neuroscience, relatively little is known about the neurobiology of discourse production impairments. Individuals with a history of left or right hemisphere stroke can exhibit difficulty with communicating meaningful discourse content, which implies both cerebral hemispheres play a role in this skill. However, the extent to which successful production of discourse content relies on network connections within domain-specific vs. domain-general networks in either hemisphere is unknown. Methods In this study, 45 individuals with a history of either left or right hemisphere stroke completed resting state fMRI and the Cookie Theft picture description task. Results Participants did not differ in the total number of content units or the percentage of interpretative content units they produced. Stroke survivors with left hemisphere damage produced significantly fewer content units per second than individuals with right hemisphere stroke. Intrinsic connectivity of the left language network was significantly weaker in the left compared to the right hemisphere stroke group for specific connections. Greater efficiency of communication of picture scene content was associated with stronger left but weaker right frontotemporal connectivity of the language network in patients with a history of left hemisphere (but not right hemisphere) stroke. No significant relationships were found between picture description measures and connectivity of the dorsal attention, default mode, or salience networks or with connections between language and other network regions. Discussion These findings add to prior behavioral studies of picture description skills in stroke survivors and provide insight into the role of the language network vs. other intrinsic networks during discourse production.
Collapse
Affiliation(s)
- Erin L. Meier
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Shannon M. Sheppard
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Rajani Sebastian
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, MD, United States
| | - Shauna Berube
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Emily B. Goldberg
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Jennifer Shea
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Colin M. Stein
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Argye E. Hillis
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, MD, United States
- Department of Cognitive Science, Johns Hopkins University, Baltimore, MD, United States
| |
Collapse
|
2
|
Li D, Hao J, Hao J, Cui X, Niu Y, Xiang J, Wang B. Enhanced Dynamic Laterality Based on Functional Subnetworks in Patients with Bipolar Disorder. Brain Sci 2023; 13:1646. [PMID: 38137094 PMCID: PMC10741828 DOI: 10.3390/brainsci13121646] [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: 10/19/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 12/24/2023] Open
Abstract
An ocean of studies have pointed to abnormal brain laterality changes in patients with bipolar disorder (BD). Determining the altered brain lateralization will help us to explore the pathogenesis of BD. Our study will fill the gap in the study of the dynamic changes of brain laterality in BD patients and thus provide new insights into BD research. In this work, we used fMRI data from 48 BD patients and 48 normal controls (NC). We constructed the dynamic laterality time series by extracting the dynamic laterality index (DLI) at each sliding window. We then used k-means clustering to partition the laterality states and the Arenas-Fernandez-Gomez (AFG) community detection algorithm to determine the number of states. We characterized subjects' laterality characteristics using the mean laterality index (MLI) and laterality fluctuation (LF). Compared with NC, in all windows and state 1, BD patients showed higher MLI in the attention network (AN) of the right hemisphere, and AN in the left hemisphere showed more frequent laterality fluctuations. AN in the left hemisphere of BD patients showed higher MLI in all windows and state 3 compared to NC. In addition, in the AN of the right hemisphere in state 1, higher MLI in BD patients was significantly associated with patient symptoms. Our study provides new insights into the understanding of BD neuropathology in terms of brain dynamic laterality.
Collapse
Affiliation(s)
- Dandan Li
- College of Computer Science and Technology, Taiyuan University of Technology, Jinzhong 030600, China; (J.H.)
| | | | | | | | | | | | | |
Collapse
|
3
|
Souter NE, Wang X, Thompson H, Krieger-Redwood K, Halai AD, Lambon Ralph MA, Thiebaut de Schotten M, Jefferies E. Mapping lesion, structural disconnection, and functional disconnection to symptoms in semantic aphasia. Brain Struct Funct 2022; 227:3043-3061. [PMID: 35786743 PMCID: PMC9653334 DOI: 10.1007/s00429-022-02526-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/12/2022] [Indexed: 01/03/2023]
Abstract
Patients with semantic aphasia have impaired control of semantic retrieval, often accompanied by executive dysfunction following left hemisphere stroke. Many but not all of these patients have damage to the left inferior frontal gyrus, important for semantic and cognitive control. Yet semantic and cognitive control networks are highly distributed, including posterior as well as anterior components. Accordingly, semantic aphasia might not only reflect local damage but also white matter structural and functional disconnection. Here, we characterise the lesions and predicted patterns of structural and functional disconnection in individuals with semantic aphasia and relate these effects to semantic and executive impairment. Impaired semantic cognition was associated with infarction in distributed left-hemisphere regions, including in the left anterior inferior frontal and posterior temporal cortex. Lesions were associated with executive dysfunction within a set of adjacent but distinct left frontoparietal clusters. Performance on executive tasks was also associated with interhemispheric structural disconnection across the corpus callosum. In contrast, poor semantic cognition was associated with small left-lateralized structurally disconnected clusters, including in the left posterior temporal cortex. Little insight was gained from functional disconnection symptom mapping. These results demonstrate that while left-lateralized semantic and executive control regions are often damaged together in stroke aphasia, these deficits are associated with distinct patterns of structural disconnection, consistent with the bilateral nature of executive control and the left-lateralized yet distributed semantic control network.
Collapse
Affiliation(s)
| | - Xiuyi Wang
- Department of Psychology, University of York, York, YO10 5DD, UK
- CAS Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Hannah Thompson
- School of Psychology and Clinical Language Sciences, University of Reading, Reading, UK
| | | | - Ajay D Halai
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
| | | | - Michel Thiebaut de Schotten
- Brain Connectivity and Behaviour Laboratory, Sorbonne Universities, Paris, France
- Groupe d'Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives-UMR 5293, CNRS, CEA, University of Bordeaux, Bordeaux, France
| | | |
Collapse
|
4
|
Thompson HE, Noonan KA, Halai AD, Hoffman P, Stampacchia S, Hallam G, Rice GE, De Dios Perez B, Lambon Ralph MA, Jefferies E. Damage to temporoparietal cortex is sufficient for impaired semantic control. Cortex 2022; 156:71-85. [PMID: 36183573 DOI: 10.1016/j.cortex.2022.05.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 04/07/2022] [Accepted: 05/16/2022] [Indexed: 01/26/2023]
Abstract
Semantic control allows us to focus semantic activation on currently relevant aspects of knowledge, even in the face of competition or when the required information is weakly encoded. Diverse cortical regions, including left prefrontal and posterior temporal cortex, are implicated in semantic control, however; the relative contribution of these regions is unclear. For the first time, we compared semantic aphasia (SA) patients with damage restricted to temporoparietal cortex (TPC; N = 8) to patients with infarcts encompassing prefrontal cortex (PF+; N = 22), to determine if prefrontal lesions are necessary for semantic control deficits. These SA groups were also compared with semantic dementia (SD; N = 10), characterised by degraded semantic representations. We asked whether TPC cases with semantic impairment show controlled retrieval deficits equivalent to PF+ cases or conceptual degradation similar to patients with SD. Independent of lesion location, the SA subgroups showed similarities, whereas SD patients showed a qualitatively distinct semantic impairment. Relative to SD, both TPC and PF+ SA subgroups: (1) showed few correlations in performance across tasks with differing control demands, but a strong relationship between tasks of similar difficulty; (2) exhibited attenuated effects of lexical frequency and concept familiarity, (3) showed evidence of poor semantic regulation in their verbal output - performance on picture naming was substantially improved when provided with a phonological cue, and (4) showed effects of control demands, such as retrieval difficulty, which were equivalent in severity across TPC and PF+ groups. These findings show that semantic impairment in SA is underpinned by damage to a distributed semantic control network, instantiated across anterior and posterior cortical areas.
Collapse
Affiliation(s)
- Hannah E Thompson
- School of Psychology and Counselling, The Open University, Milton Keynes, UK.
| | - Krist A Noonan
- School of Social and Community Medicine, University of Bristol, UK
| | - Ajay D Halai
- MRC Cognition & Brain Sciences Unit, University of Cambridge, UK
| | - Paul Hoffman
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh, UK
| | - Sara Stampacchia
- Laboratory of Neuroimaging and Innovative Molecular Tracers (NIMTlab), Geneva University Neurocenter and Faculty of Medicine, University of Geneva, Geneva, Switzerland; Department of Psychology and York Neuroimaging Centre, University of York, UK
| | - Glyn Hallam
- School of Human and Health Sciences, University of Huddersfield, UK
| | - Grace E Rice
- MRC Cognition & Brain Sciences Unit, University of Cambridge, UK
| | - Blanca De Dios Perez
- Division of Psychiatry and Applied Psychology, School of Medicine, University of Nottingham, UK
| | | | - Elizabeth Jefferies
- Department of Psychology and York Neuroimaging Centre, University of York, UK
| |
Collapse
|
5
|
Stampacchia S, Hallam GP, Thompson HE, Nathaniel U, Lanzoni L, Smallwood J, Lambon Ralph MA, Jefferies E. Training flexible conceptual retrieval in post-stroke aphasia. Neuropsychol Rehabil 2022; 32:1429-1455. [PMID: 33715583 PMCID: PMC7614451 DOI: 10.1080/09602011.2021.1895847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Semantic therapy in post-stroke aphasia typically focusses on strengthening links between conceptual representations and their lexical-articulatory forms to aid word retrieval. However, research has shown that semantic deficits in this group can affect both verbal and non-verbal tasks, particularly in patients with deregulated retrieval as opposed to degraded knowledge. This study, therefore, aimed to facilitate semantic cognition in a sample of such patients with post-stroke semantic aphasia (SA) by training the identification of both strong and weak semantic associations and providing explicit pictorial feedback that demonstrated both common and more unusual ways of linking concepts together. We assessed the effects of this training on (i) trained and untrained items; and (ii) trained and untrained tasks in eleven individuals with SA. In the training task, the SA group showed improvement with practice, particularly for trained items. A similar untrained task using pictorial stimuli (Camel and Cactus Test) also improved. Together, these results suggest that semantic training can be beneficial in patients with SA and may show some degree of generalization to untrained situations. Future research should seek to understand which patients are most likely to benefit from this type of training.
Collapse
Affiliation(s)
- Sara Stampacchia
- Department of Psychology and York Neuroimaging Centre, University of York, York, UK.,Laboratory of Neuroimaging and Innovative Molecular Tracers (NIMTlab), Geneva University Neurocenter and Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Glyn P Hallam
- Department of Psychology and York Neuroimaging Centre, University of York, York, UK.,Department of Psychology, School of Human and Health Sciences, University of Huddersfield, Huddersfield, UK
| | | | - Upasana Nathaniel
- Department of Psychology and York Neuroimaging Centre, University of York, York, UK.,Psychology Department, University of Haifa, Haifa, Israel
| | - Lucilla Lanzoni
- Department of Psychology and York Neuroimaging Centre, University of York, York, UK
| | - Jonathan Smallwood
- Department of Psychology and York Neuroimaging Centre, University of York, York, UK.,Queen's University, Kingston, Canada
| | | | - Elizabeth Jefferies
- Department of Psychology and York Neuroimaging Centre, University of York, York, UK
| |
Collapse
|
6
|
Zhai J, Aryadoust V. The Metacognitive and Neurocognitive Signatures of Test Methods in Academic Listening. Front Psychol 2022; 13:930075. [PMID: 35783744 PMCID: PMC9245920 DOI: 10.3389/fpsyg.2022.930075] [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: 04/27/2022] [Accepted: 05/19/2022] [Indexed: 12/02/2022] Open
Abstract
This study aims to investigate whether and how test takers’ academic listening test performance is predicted by their metacognitive and neurocognitive process under different test methods conditions. Eighty test takers completed two tests consisting of while-listening performance (WLP) and post-listening performance (PLP) test methods. Their metacognitive awareness was measured by the Metacognitive Awareness Listening Questionnaire (MALQ), and gaze behavior and brain activation were measured by an eye-tracker and functional near-infrared spectroscopy (fNIRS), respectively. The results of automatic linear modeling indicated that WLP and PLP test performances were predicted by different factors. The predictors of WLP test performance included two metacognitive awareness measures (i.e., person knowledge and mental translation) and fixation duration. In contrast, the predictors of the PLP performance comprised two metacognitive awareness measures (i.e., mental translation and directed attention), visit counts, and importantly, three brain activity measures: the dmPFC measure in the answering phase, IFG measure in the listening phase, and IFG measure in the answering phase. Implications of these findings for language assessment are discussed.
Collapse
Affiliation(s)
- Jiayu Zhai
- School of English Studies, Sichuan International Studies University, Chongqing, China
- National Institute of Education, Nanyang Technological University, Singapore, Singapore
| | - Vahid Aryadoust
- National Institute of Education, Nanyang Technological University, Singapore, Singapore
- *Correspondence: Vahid Aryadoust,
| |
Collapse
|
7
|
Kristinsson S, den Ouden DB, Rorden C, Newman-Norlund R, Neils-Strunjas J, Fridriksson J. Predictors of Therapy Response in Chronic Aphasia: Building a Foundation for Personalized Aphasia Therapy. J Stroke 2022; 24:189-206. [PMID: 35677975 PMCID: PMC9194549 DOI: 10.5853/jos.2022.01102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 04/21/2022] [Indexed: 11/12/2022] Open
Abstract
Chronic aphasia, a devastating impairment of language, affects up to a third of stroke survivors. Speech and language therapy has consistently been shown to improve language function in prior clinical trials, but few clinicially applicable predictors of individual therapy response have been identified to date. Consequently, clinicians struggle substantially with prognostication in the clinical management of aphasia. A rising prevalence of aphasia, in particular in younger populations, has emphasized the increasing demand for a personalized approach to aphasia therapy, that is, therapy aimed at maximizing language recovery of each individual with reference to evidence-based clinical recommendations. In this narrative review, we discuss the current state of the literature with respect to commonly studied predictors of therapy response in aphasia. In particular, we focus our discussion on biographical, neuropsychological, and neurobiological predictors, and emphasize limitations of the literature, summarize consistent findings, and consider how the research field can better support the development of personalized aphasia therapy. In conclusion, a review of the literature indicates that future research efforts should aim to recruit larger samples of people with aphasia, including by establishing multisite aphasia research centers.
Collapse
Affiliation(s)
- Sigfus Kristinsson
- Center for the Study of Aphasia Recovery, University of South Carolina, Columbia, SC, USA
- Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC, USA
- Correspondence: Sigfus Kristinsson Department of Communication Sciences and Disorders, University of South Carolina, 915 Greene Street, Columbia, SC 29209, USA Tel: +1-803-553-4689 Fax: +1-803-777-9547 E-mail:
| | - Dirk B. den Ouden
- Center for the Study of Aphasia Recovery, University of South Carolina, Columbia, SC, USA
- Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC, USA
| | - Chris Rorden
- Center for the Study of Aphasia Recovery, University of South Carolina, Columbia, SC, USA
- Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Roger Newman-Norlund
- Center for the Study of Aphasia Recovery, University of South Carolina, Columbia, SC, USA
- Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Jean Neils-Strunjas
- Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC, USA
| | - Julius Fridriksson
- Center for the Study of Aphasia Recovery, University of South Carolina, Columbia, SC, USA
| |
Collapse
|
8
|
White matter microstructural damage in chronic ischemic stroke affecting the left inferior frontal gyrus: association with cognitive functions. Clin Neurol Neurosurg 2022; 217:107238. [DOI: 10.1016/j.clineuro.2022.107238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/18/2022] [Accepted: 03/31/2022] [Indexed: 01/01/2023]
|
9
|
Gao Z, Zheng L, Gouws A, Krieger-Redwood K, Wang X, Varga D, Smallwood J, Jefferies E. Context free and context-dependent conceptual representation in the brain. Cereb Cortex 2022; 33:152-166. [PMID: 35196710 PMCID: PMC9758583 DOI: 10.1093/cercor/bhac058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 11/13/2022] Open
Abstract
How concepts are coded in the brain is a core issue in cognitive neuroscience. Studies have focused on how individual concepts are processed, but the way in which conceptual representation changes to suit the context is unclear. We parametrically manipulated the association strength between words, presented in pairs one word at a time using a slow event-related fMRI design. We combined representational similarity analysis and computational linguistics to probe the neurocomputational content of these trials. Individual word meaning was maintained in supramarginal gyrus (associated with verbal short-term memory) when items were judged to be unrelated, but not when a linking context was retrieved. Context-dependent meaning was instead represented in left lateral prefrontal gyrus (associated with controlled retrieval), angular gyrus, and ventral temporal lobe (regions associated with integrative aspects of memory). Analyses of informational connectivity, examining the similarity of activation patterns across trials between sites, showed that control network regions had more similar multivariate responses across trials when association strength was weak, reflecting a common controlled retrieval state when the task required more unusual associations. These findings indicate that semantic control and representational sites amplify contextually relevant meanings in trials judged to be related.
Collapse
Affiliation(s)
- Zhiyao Gao
- Department of Psychology, University of York, Heslington, NY YO10 5DD, United Kingdom
| | - Li Zheng
- Department of Psychology, University of Arizona, Tucson, AZ 85719, United States
| | - André Gouws
- Department of Psychology, University of York, Heslington, NY YO10 5DD, United Kingdom
| | - Katya Krieger-Redwood
- Department of Psychology, University of York, Heslington, NY YO10 5DD, United Kingdom
| | - Xiuyi Wang
- Department of Psychology, University of York, Heslington, NY YO10 5DD, United Kingdom
| | - Dominika Varga
- School of Psychology, University of Sussex, Brighton BN1 9RH, United Kingdom
| | - Jonathan Smallwood
- Department of Psychology, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Elizabeth Jefferies
- Corresponding author: Department of Psychology, University of York, Heslington, NY YO10 5DD, United Kingdom.
| |
Collapse
|
10
|
Meier EL. The role of disrupted functional connectivity in aphasia. HANDBOOK OF CLINICAL NEUROLOGY 2022; 185:99-119. [PMID: 35078613 DOI: 10.1016/b978-0-12-823384-9.00005-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Language is one of the most complex and specialized higher cognitive processes. Brain damage to the distributed, primarily left-lateralized language network can result in aphasia, a neurologic disorder characterized by receptive and/or expressive deficits in spoken and/or written language. Most often, aphasia is the consequence of stroke-termed poststroke aphasia (PSA)-yet, aphasia can also manifest due to neurodegenerative disease, specifically, a disorder called primary progressive aphasia (PPA). In recent years, functional connectivity neuroimaging studies have provided emerging evidence supporting theories regarding the relationships between language impairments, structural brain damage, and functional network properties in these two disorders. This chapter reviews the current evidence for the "network phenotype of stroke injury" hypothesis (Siegel et al., 2016) as it pertains to PSA and the "network degeneration hypothesis" (Seeley et al., 2009) as it pertains to PPA. Methodologic considerations for functional connectivity studies, limitations of the current functional connectivity literature in aphasia, and future directions are also discussed.
Collapse
Affiliation(s)
- Erin L Meier
- Department of Communication Sciences and Disorders, Northeastern University, Boston, MA, United States.
| |
Collapse
|
11
|
Flick G, Abdullah O, Pylkkänen L. From letters to composed concepts: A magnetoencephalography study of reading. Hum Brain Mapp 2021; 42:5130-5153. [PMID: 34402114 PMCID: PMC8449097 DOI: 10.1002/hbm.25608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 06/23/2021] [Accepted: 07/20/2021] [Indexed: 11/30/2022] Open
Abstract
Language comprehension requires the recognition of individual words and the combination of their meanings to yield complex concepts or interpretations. This combinatory process often requires the insertion of unstated semantic material between words, based on thematic or feature knowledge. For example, the phrase horse barn is not interpreted as a blend of a horse and a barn, but specifically a barn where horses are kept. Previous neuroscientific evidence suggests that left posterior and anterior temporal cortex underpin thematic and feature‐based concept knowledge, respectively, but much remains unclear about how these areas contribute to combinatory language processing. Using magnetoencephalography, we contrasted source‐localized responses to modifier‐noun phrases involving thematic relations versus feature modifications, while also examining how lower‐level orthographic processing fed composition. Participants completed three procedures examining responses to letter‐strings, adjective‐noun phrases, and noun–noun combinations that varied the semantic relations between words. We found that sections of the left anterior temporal lobe, posterior temporal lobe, and cortex surrounding the angular gyrus were all engaged in the minimal composition of adjective‐noun phrases, a more distributed network than in most prior studies of minimal composition. Of these regions, only the left posterior temporal lobe was additionally sensitive to implicit thematic relations between composing words, suggesting that it houses a specialized relational processing component in a wider composition network. We additionally identified a left occipitotemporal progression from orthographic to lexical processing, feeding ventral anterior areas engaged in the combination of word meanings. Finally, by examining source signal leakage, we characterized the degree to which these responses could be distinguished from one another using source estimation.
Collapse
Affiliation(s)
- Graham Flick
- Department of Psychology, New York University, New York, New York, USA.,NYUAD Research Institute, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Osama Abdullah
- NYUAD Research Institute, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Liina Pylkkänen
- Department of Psychology, New York University, New York, New York, USA.,NYUAD Research Institute, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.,Department of Linguistics, New York University, New York, New York, USA
| |
Collapse
|
12
|
Jedidi Z, Manard M, Balteau E, Degueldre C, Luxen A, Philips C, Collette F, Maquet P, Majerus S. Incidental Verbal Semantic Processing Recruits the Fronto-temporal Semantic Control Network. Cereb Cortex 2021; 31:5449-5459. [PMID: 34180511 DOI: 10.1093/cercor/bhab169] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/21/2021] [Accepted: 05/25/2021] [Indexed: 11/12/2022] Open
Abstract
The frontoparietal semantic network, encompassing the inferior frontal gyrus and the posterior middle temporal cortex, is considered to be involved in semantic control processes. The explicit versus implicit nature of these control processes remains however poorly understood. The present study examined this question by assessing regional brain responses to the semantic attributes of an unattended stream of auditory words while participants' top-down attentional control processes were absorbed by a demanding visual search task. Response selectivity to semantic aspects of verbal stimuli was assessed via a functional magnetic resonance imaging response adaptation paradigm. We observed that implicit semantic processing of an unattended verbal stream recruited not only unimodal and amodal cortices in posterior supporting semantic knowledge areas, but also inferior frontal and posterior middle temporal areas considered to be part of the semantic control network. These results indicate that frontotemporal semantic networks support incidental semantic (control) processes.
Collapse
Affiliation(s)
- Z Jedidi
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium.,Department of Neurology, CHU Liège, Domaine Universitaire du Sart-Tilman, 4000 Liège, Belgium
| | - M Manard
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium
| | - E Balteau
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium
| | - C Degueldre
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium
| | - A Luxen
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium
| | - C Philips
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium
| | - F Collette
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium
| | - P Maquet
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium.,Department of Neurology, CHU Liège, Domaine Universitaire du Sart-Tilman, 4000 Liège, Belgium
| | - S Majerus
- GIGA - Cyclotron Research Centre in vivo imaging, University of Liège, 4000 Liège, Belgium.,Psychology & Neuroscience of Cognition Research Unit, University of Liège, 4000 Liège, Belgium.,Fund for Scientific Research - FNRS, 1000 Brussels, Belgium
| |
Collapse
|
13
|
Stefaniak JD, Alyahya RSW, Lambon Ralph MA. Language networks in aphasia and health: A 1000 participant activation likelihood estimation meta-analysis. Neuroimage 2021; 233:117960. [PMID: 33744459 DOI: 10.1016/j.neuroimage.2021.117960] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/28/2021] [Accepted: 03/08/2021] [Indexed: 12/20/2022] Open
Abstract
Aphasia recovery post-stroke is classically and most commonly hypothesised to rely on regions that were not involved in language premorbidly, through 'neurocomputational invasion' or engagement of 'quiescent homologues'. Contemporary accounts have suggested, instead, that recovery might be supported by under-utilised areas of the premorbid language network, which are downregulated in health to save neural resources ('variable neurodisplacement'). Despite the importance of understanding the neural bases of language recovery clinically and theoretically, there is no consensus as to which specific regions are more likely to be activated in post-stroke aphasia (PSA) than healthy individuals. Accordingly, we performed an Activation Likelihood Estimation (ALE) meta-analysis of language functional neuroimaging studies in PSA. We obtained coordinate-based functional neuroimaging data for 481 individuals with aphasia following left-hemisphere stroke and 530 linked controls from 33 studies that met predefined inclusion criteria. ALE identified regions of consistent, above-chance spatial convergence of activation, as well as regions of significantly different activation likelihood, between participant groups and language tasks. Overall, these findings dispute the prevailing theory that aphasia recovery involves recruitment of novel right hemisphere territory into the language network post-stroke. Instead, multiple regions throughout both hemispheres were consistently activated during language tasks in both PSA and controls. Regions of the right anterior insula, frontal operculum and inferior frontal gyrus (IFG) pars opercularis were more likely to be activated across all language tasks in PSA than controls. Similar regions were more likely to be activated during higher than lower demand comprehension or production tasks, consistent with them representing enhanced utilisation of spare capacity within right hemisphere executive-control related regions. This provides novel evidence that 'variable neurodisplacement' underlies language network changes that occur post-stroke. Conversely, multiple undamaged regions were less likely to be activated across all language tasks in PSA than controls, including domain-general regions of medial superior frontal and paracingulate cortex, right IFG pars triangularis and temporal pole. These changes might represent functional diaschisis, and demonstrate that there is not global, undifferentiated upregulation of all domain-general neural resources during language in PSA. Such knowledge is essential if we are to design neurobiologically-informed therapeutic interventions to facilitate language recovery.
Collapse
Affiliation(s)
- James D Stefaniak
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK; Department of Psychiatry, University of Cambridge, Cambridge, UK; Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, UK.
| | - Reem S W Alyahya
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK; King Fahad Medical City, Riyadh, Saudi Arabia; Alfaisal University, Riyadh, Saudi Arabia
| | | |
Collapse
|
14
|
Wilson SM, Schneck SM. Neuroplasticity in post-stroke aphasia: A systematic review and meta-analysis of functional imaging studies of reorganization of language processing. NEUROBIOLOGY OF LANGUAGE (CAMBRIDGE, MASS.) 2021; 2:22-82. [PMID: 33884373 PMCID: PMC8057712 DOI: 10.1162/nol_a_00025] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
Abstract
Recovery from aphasia is thought to depend on neural plasticity, that is, functional reorganization of surviving brain regions such that they take on new or expanded roles in language processing. We carried out a systematic review and meta-analysis of all articles published between 1995 and early 2020 that have described functional imaging studies of six or more individuals with post-stroke aphasia, and have reported analyses bearing on neuroplasticity of language processing. Each study was characterized and appraised in detail, with particular attention to three critically important methodological issues: task performance confounds, contrast validity, and correction for multiple comparisons. We identified 86 studies describing a total of 561 relevant analyses. We found that methodological limitations related to task performance confounds, contrast validity, and correction for multiple comparisons have been pervasive. Only a few claims about language processing in individuals with aphasia are strongly supported by the extant literature: first, left hemisphere language regions are less activated in individuals with aphasia than neurologically normal controls, and second, in cohorts with aphasia, activity in left hemisphere language regions, and possibly a temporal lobe region in the right hemisphere, is positively correlated with language function. There is modest, equivocal evidence for the claim that individuals with aphasia differentially recruit right hemisphere homotopic regions, but no compelling evidence for differential recruitment of additional left hemisphere regions or domain-general networks. There is modest evidence that left hemisphere language regions return to function over time, but no compelling longitudinal evidence for dynamic reorganization of the language network.
Collapse
Affiliation(s)
- Stephen M. Wilson
- Address for correspondence: Stephen M. Wilson, Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, 1215 21st Ave S, MCE 8310, Nashville, TN 37232. Phone: 615-936-5810.
| | | |
Collapse
|
15
|
Qiao J, Zhao X, Wang S, Li A, Wang Z, Cao C, Wang Q. Functional and Structural Brain Alterations in Encephalitis With LGI1 Antibodies. Front Neurosci 2020; 14:304. [PMID: 32317923 PMCID: PMC7146067 DOI: 10.3389/fnins.2020.00304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/16/2020] [Indexed: 01/17/2023] Open
Abstract
Objective: The purpose of this study was to examine the neural substrates and mechanisms that generate memory deficits, seizures and neuropsychiatric abnormalities in encephalitis with LGI1 antibodies using a data-driven, multimodal magnetic resonance imaging (MRI) approach. Methods: Functional MRI data were acquired from 14 anti-LGI1 encephalitis patients and 14 age and gender matched normal controls. Independent component analysis with hierarchical partner matching (HPM-ICA) was used to assess the whole-brain intrinsic functional connectivity. Granger causality (GC) was applied to investigate the effective connectivity among the brain regions that identified by HPM-ICA. Diffusion tensor imaging (DTI) was utilized to investigate white matter microstructural changes of the patients. Results: Participants with LGI1 antibodies encephalitis presented reduced functional connectivity in the brain areas associated with memory, cognition and motion circuits, while increased functional connectivity in putamen and caudate in comparison to the normal controls. Moreover, the effective connectivity in patients was decreased from the frontal cortex to supplementary motor area. Finally, patients had significant reductions in fractional anisotropy (FA) for the corpus callosum, internal capsule, corona radiata and superior longitudinal fasciculus, accompanied by increases in mean diffusivity (MD) for these regions as compared to controls. Conclusion: Our findings suggest that the neural disorder and behavioral deficits of anti-LGI1 encephalitis may be associated with extensive changes in brain connectivity and microstructure. These pathological alterations affect the basal ganglia and limbic system besides the temporal and frontal lobe.
Collapse
Affiliation(s)
- Jianping Qiao
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Data Science and Technology, School of Physics and Electronics, Shandong Normal University, Jinan, China
| | - Xiuhe Zhao
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Shengjun Wang
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Anning Li
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China
| | - Zhishun Wang
- Department of Psychiatry, Columbia University, New York, NY, United States
| | - Chongfeng Cao
- Department of Emergency, Jinan Central Hospital Affiliated to Shandong University, Jinan, China
| | - Qing Wang
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China
| |
Collapse
|
16
|
Marino Dávolos J, Arias JC, Jefferies E. Linking individual differences in semantic cognition to white matter microstructure. Neuropsychologia 2020; 141:107438. [PMID: 32171737 DOI: 10.1016/j.neuropsychologia.2020.107438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 02/28/2020] [Accepted: 03/10/2020] [Indexed: 12/15/2022]
Abstract
Semantic cognition is thought to involve the interaction of heteromodal conceptual representations with control processes that (i) focus retrieval on currently-relevant information, and (ii) suppress dominant yet irrelevant features and associations. Research suggests that semantic control demands are higher when retrieving a link between weakly-associated word pairs, since there is a mismatch between the pattern of semantic retrieval required by the task and the dominant associations of individual words. In addition, given that heteromodal concepts are thought to reflect the integration of vision, audition, valence and other features, the control demands of semantic tasks should be higher when there is less consistency between these features. In the present study, 62 volunteers completed a semantic decision task, where association strength and semantic-affective congruence were manipulated. We used diffusion tensor magnetic resonance imaging to obtain fractional anisotropy (FA) measures of white matter tracts hypothesized to be part of the semantic network. The behavioural data revealed an interaction between semantic-affective congruence and strength of association, suggesting these manipulations both contribute to semantic control demands. Next we considered how individual differences in these markers of semantic control relate to the microstructure of canonical white matter tracts, complementing previous studies that have largely focused on measures of intrinsic functional connectivity. Repeated-measures analysis of covariance showed opposing interactions between semantic control markers and FA of two tracts: left inferior longitudinal fasciculus (ILF) and right inferior fronto-occipital fasciculus (IFOF). Participants with higher FA in left ILF showed more efficient retrieval of weak associations, and more accurate performance for weak associations when meaning and valence were incongruent, consistent with the hypothesis that this left hemisphere tract supports semantic control. In contrast, participants with higher FA in right IFOF were more accurate for trials in which meaning and valence were congruent, and consequently when semantic control demands were minimised. These findings are consistent with recent studies showing that semantic control processes are strongly left-lateralised. In contrast, long-range connections from vision to semantic regions in the right hemisphere might support relatively automatic patterns of semantic retrieval.
Collapse
Affiliation(s)
- Julián Marino Dávolos
- Department of Psychology and York Neuroimaging Centre, University of York, YO10 5DD, York, UK.
| | - Juan Cruz Arias
- Instituto de Investigación Oulton, Córdoba, Córdoba, Argentina.
| | - Elizabeth Jefferies
- Department of Psychology and York Neuroimaging Centre, University of York, YO10 5DD, York, UK.
| |
Collapse
|
17
|
Effects of white noise on word recall performance and brain activity in healthy adolescents with normal and low auditory working memory. Exp Brain Res 2020; 238:945-956. [PMID: 32179941 DOI: 10.1007/s00221-020-05765-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/29/2020] [Indexed: 10/24/2022]
Abstract
The present study examined the impact of white noise on word recall performance and brain activity in 40 healthy adolescents, split in two groups (normal and low) depending on their auditory working memory capacity (AWMC). Using functional magnetic resonance imaging, participants performed a backward recall task under four different signal-to-noise ratio (SNR) conditions: 15, 10, 5, and 0-dB SNR. Behaviorally, normal AWMC individuals scored significantly higher than low AWMC individuals across noise levels. Whole-brain analyses showed brain activation not to be statistically different between groups across noise levels. In the normal group, a significant positive relationship was found between performance and number of activated voxels in the right superior frontal gyrus. In the low group, significant positive correlations were found between performance and number of activated voxels in left superior frontal gyrus, left inferior frontal gyrus, and left anterior cingulate cortex. These findings suggest that the strategic structure involved in the enhancement of AWM performance may differ in normal and low AWMC individuals.
Collapse
|
18
|
Jefferies E, Thompson H, Cornelissen P, Smallwood J. The neurocognitive basis of knowledge about object identity and events: dissociations reflect opposing effects of semantic coherence and control. Philos Trans R Soc Lond B Biol Sci 2019; 375:20190300. [PMID: 31840592 DOI: 10.1098/rstb.2019.0300] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Semantic memory encompasses knowledge of specific objects and their diverse associations, but the mechanisms that allow us to retrieve aspects of knowledge required for a given task are poorly understood. The dual hub theory suggests that separate semantic stores represent knowledge of (i) taxonomic categories (in the anterior temporal lobes, ATL) and (ii) thematic associations (in angular gyrus, AG or posterior middle temporal gyrus, pMTG). Alternatively, the controlled semantic cognition (CSC) framework suggests that semantic processing emerges from the flexible interaction of heteromodal semantic representations in ATL with a semantic control network, which includes pMTG as well as prefrontal regions. According to this view, ATL supports patterns of coherent auto-associative retrieval, while semantic control sites respond when ongoing conceptual activation needs to be altered to suit the task or context. These theories make different predictions about the nature of functional dissociations within the semantic network. We review evidence for these claims across multiple methods. First, we show ATL is sensitive to the strength of thematic associations as well as taxonomic relations. Next, we document functional dissociations between AG and pMTG: rather than these regions acting as comparable thematic hubs, AG is allied to the default mode network and supports more 'automatic' retrieval, while pMTG responds when control demands are high. However, the semantic control network, including pMTG, also shows a greater response to events/actions and verbs, supporting the claims of both theories. We propose that tasks tapping event semantics often require greater shaping of conceptual retrieval than comparison tasks, because these elements of our knowledge are inherently flexible, with relevant features depending on the context. In this way, the CSC account might be able to account for findings that suggest both a process and a content distinction within the semantic network. This article is part of the theme issue 'Towards mechanistic models of meaning composition'.
Collapse
|
19
|
Othman EA, Yusoff AN, Mohamad M, Abdul Manan H, Abd Hamid AI, Giampietro V. Hemispheric Lateralization of Auditory Working Memory Regions During Stochastic Resonance: An fMRI Study. J Magn Reson Imaging 2019; 51:1821-1828. [DOI: 10.1002/jmri.27016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/22/2019] [Accepted: 11/22/2019] [Indexed: 01/12/2023] Open
Affiliation(s)
- Elza Azri Othman
- Department of Medical Imaging, Faculty of Health SciencesUniversiti Sultan Zainal Abidin Kuala Terengganu Malaysia
- Centre for Health and Applied Sciences, Faculty of Health SciencesUniversiti Kebangsaan Malaysia Kuala Lumpur Malaysia
| | - Ahmad Nazlim Yusoff
- Centre for Health and Applied Sciences, Faculty of Health SciencesUniversiti Kebangsaan Malaysia Kuala Lumpur Malaysia
| | - Mazlyfarina Mohamad
- Centre for Health and Applied Sciences, Faculty of Health SciencesUniversiti Kebangsaan Malaysia Kuala Lumpur Malaysia
| | - Hanani Abdul Manan
- Department of RadiologyUniversiti Kebangsaan Malaysia Medical Centre Kuala Lumpur Malaysia
| | - Aini Ismafairus Abd Hamid
- Department of NeurosciencesSchool of Medical Sciences, Universiti Sains Malaysia, Health Campus Kelantan Malaysia
| | - Vincent Giampietro
- Department of NeuroimagingInstitute of Psychiatry, Psychology & Neuroscience, King's College London UK
| |
Collapse
|
20
|
Degrees of lateralisation in semantic cognition: Evidence from intrinsic connectivity. Neuroimage 2019; 202:116089. [DOI: 10.1016/j.neuroimage.2019.116089] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/27/2019] [Accepted: 08/08/2019] [Indexed: 11/15/2022] Open
|
21
|
Dressing A, Kaller CP, Nitschke K, Beume LA, Kuemmerer D, Schmidt CS, Bormann T, Umarova RM, Egger K, Rijntjes M, Weiller C, Martin M. Neural correlates of acute apraxia: Evidence from lesion data and functional MRI in stroke patients. Cortex 2019; 120:1-21. [DOI: 10.1016/j.cortex.2019.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 02/28/2019] [Accepted: 05/07/2019] [Indexed: 10/26/2022]
|
22
|
Mensen A, Pigorini A, Facchin L, Schöne C, D'Ambrosio S, Jendoubi J, Jaramillo V, Chiffi K, Eberhard-Moscicka AK, Sarasso S, Adamantidis A, Müri RM, Huber R, Massimini M, Bassetti C. Sleep as a model to understand neuroplasticity and recovery after stroke: Observational, perturbational and interventional approaches. J Neurosci Methods 2018; 313:37-43. [PMID: 30571989 DOI: 10.1016/j.jneumeth.2018.12.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 11/19/2018] [Accepted: 12/16/2018] [Indexed: 01/28/2023]
Abstract
Our own experiences with disturbances to sleep demonstrate its crucial role in the recovery of cognitive functions. This importance is likely enhanced in the recovery from stroke; both in terms of its physiology and cognitive abilities. Decades of experimental research have highlighted which aspects and mechanisms of sleep are likely to underlie these forms of recovery. Conversely, damage to certain areas of the brain, as well as the indirect effects of stroke, may disrupt sleep. However, only limited research has been conducted which seeks to directly explore this bidirectional link between both the macro and micro-architecture of sleep and stroke. Here we describe a series of semi-independent approaches that aim to establish this link through observational, perturbational, and interventional experiments. Our primary aim is to describe the methodology for future clinical and translational research needed to delineate competing accounts of the current data. At the observational level we suggest the use of high-density EEG recording, combined analysis of macro and micro-architecture of sleep, detailed analysis of the stroke lesion, and sensitive measures of functional recovery. The perturbational approach attempts to find the causal links between sleep and stroke. We promote the use of transcranial magnetic stimulation combined with EEG to examine the cortical dynamics of the peri-infarct stroke area. Translational research should take this a step further using optogenetic techniques targeting more specific cell populations. The interventional approach focuses on how the same clinical and translational perturbational techniques can be adapted to influence long-term recovery of function.
Collapse
|
23
|
Meier EL, Johnson JP, Kiran S. Left frontotemporal effective connectivity during semantic feature judgments in patients with chronic aphasia and age-matched healthy controls. Cortex 2018; 108:173-192. [PMID: 30243049 PMCID: PMC6234086 DOI: 10.1016/j.cortex.2018.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 08/01/2018] [Accepted: 08/08/2018] [Indexed: 12/15/2022]
Abstract
Traditional models of neural reorganization of language skills in patients with chronic stroke-induced aphasia (PWA) propose activation of reperfused or spared left hemisphere tissue results in the most favorable language outcomes. However, these models do not fully explain variable behavioral recovery patterns observed in chronic patients. Instead, investigation of connectivity patterns of critical network nodes may elucidate better-informed recovery models. In the present study, we combined fMRI and dynamic causal modeling (DCM) to examine effective connectivity of a simple three-node left hemisphere network during a semantic feature decision task in 25 PWA and 18 age-matched neurologically intact healthy controls. The DCM model space utilized in Meier, Kapse, & Kiran (2016), which was organized according to exogenous input to one of three regions (i.e., left inferior frontal gyrus, pars triangularis [LIFGtri], left posterior middle temporal gyrus [LpMTG], or left middle frontal gyrus [LMFG]) implicated in various levels of lexical-semantic processing, was interrogated. This model space included all possible combinations of uni- and bidirectional task-modulated connections between LIFGtri, LMFG and LpMTG, resulting in 72 individual models that were partitioned into three separate families (i.e., Family #1: Input to LIFGtri, Family #2: Input to LMFG, Family #3: Input to LpMTG). Family-wise Bayesian model selection revealed Family #2: Input to LMFG best fit both patient and control data at a group level. Both groups relied heavily on LMFG's modulation of the other two model regions. By contrast, between-group differences in task-modulated coupling of LIFGtri and LpMTG were observed. Within the patient group, the strength of activity in LIFGtri and connectivity of LpMTG → LIFGtri were positively associated with lexical-semantic abilities inside and outside of the scanner, whereas greater recruitment of LpMTG was associated with poorer lexical-semantic skills.
Collapse
Affiliation(s)
- Erin L Meier
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States.
| | - Jeffrey P Johnson
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
| | - Swathi Kiran
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
| |
Collapse
|
24
|
Wang X, Bernhardt BC, Karapanagiotidis T, De Caso I, Gonzalez Alam TRDJ, Cotter Z, Smallwood J, Jefferies E. The structural basis of semantic control: Evidence from individual differences in cortical thickness. Neuroimage 2018; 181:480-489. [DOI: 10.1016/j.neuroimage.2018.07.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 06/11/2018] [Accepted: 07/17/2018] [Indexed: 12/23/2022] Open
|