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Barton JJ, Rubino C, Albonico A, Jackson M, Davies-Thompson J. Right hemi-alexia. Cortex 2022; 157:288-303. [PMID: 36370599 DOI: 10.1016/j.cortex.2022.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 09/02/2022] [Accepted: 09/26/2022] [Indexed: 12/15/2022]
Abstract
While pure alexia was long considered a disconnection syndrome, it may also be a selective visual word agnosia due to damage to the visual word form area. Disconnection is still the likely explanation of hemi-alexias, though, particularly when splenial lesions damage inter-hemispheric projections and cause left hemi-alexia. An intra-hemispheric disconnection causing right hemi-alexia is theoretically possible but seems very rare, with only a single report that has been challenged on the grounds of inadequate perimetry. We describe the case of PH, who had a severe reading deficit in her right hemifield. Detailed perimetry showed only a small relative hemi-scotoma along the horizontal meridian, while word reading was impaired over a much larger expanse of her right hemifield, in which object recognition was spared. Reading, lexical decisions, and perceptual discrimination of words were impaired in the right hemifield, and this extended to letters and numbers, with a trend to an effect on the perception of an unfamiliar script, namely Korean. On magnetic resonance imaging she had a large left lateral occipital meningioma with vasogenic edema of occipital white matter tracts. Functional magnetic resonance imaging showed that the visual word form area was located just anterior to the mass. Her perceptual abnormalities resolved after resection of the tumor. We conclude that right hemi-alexia exists and is most likely due to intra-hemispheric disconnection of occipital input to the visual word form area.
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Affiliation(s)
- Jason Js Barton
- Departments of Medicine (Neurology), Ophthalmology and Visual Science, University of British Columbia, Vancouver, Canada; Departments of Ophthalmology and Visual Science, University of British Columbia, Vancouver, Canada.
| | - Cristina Rubino
- Graduate Program in Rehabilitative Sciences, University of British Columbia, Vancouver, Canada.
| | - Andrea Albonico
- Departments of Medicine (Neurology), Ophthalmology and Visual Science, University of British Columbia, Vancouver, Canada; Departments of Ophthalmology and Visual Science, University of British Columbia, Vancouver, Canada.
| | - MaryLou Jackson
- Departments of Ophthalmology and Visual Science, University of British Columbia, Vancouver, Canada.
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Moore MJ, Shalev N, Gillebert CR, Demeyere N. Dissociations within neglect-related reading impairments: Egocentric and allocentric neglect dyslexia. J Clin Exp Neuropsychol 2020; 42:352-362. [PMID: 32063093 PMCID: PMC7175469 DOI: 10.1080/13803395.2020.1715926] [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] [Indexed: 12/18/2022]
Abstract
Consistently lateralized reading errors are commonly understood as side-effects of visuospatial neglect impairment. There is however a qualitative difference between systematically omitting full words presented on one side of passages (egocentric neglect dyslexia) and lateralized errors when reading single words (allocentric neglect dyslexia). This study aims to investigate the relationship between egocentric and allocentric neglect dyslexia and visuospatial neglect. 1209 stroke survivors completed standardized reading and cancellation tests. Stringent criteria identified unambiguous cases of allocentric neglect dyslexia (N = 17) and egocentric neglect dyslexia (N = 35). These conditions were found to be doubly dissociated with all cases of egocentric and allocentric neglect dyslexia occurring independently. Allocentric neglect dyslexia was dissociated from both egocentric and allocentric visuospatial neglect. Additionally, two cases of allocentric neglect dyslexia which co-occurred with oppositely lateralized domain-general visuospatial neglect were identified. Conversely, all cases of egocentric neglect dyslexia were found in the presence of domain-general visuospatial neglect. These findings suggest that allocentric neglect dyslexia cannot be fully understood as a consequence of visuospatial neglect. In contrast, we found no evidence for a dissociation between egocentric neglect dyslexia and visuospatial neglect. These findings highlight the need for new, neglect dyslexia specific rehabilitation strategies to be designed and tested.
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Affiliation(s)
- Margaret Jane Moore
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK
| | - Nir Shalev
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK
| | - Celine R Gillebert
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK.,Department of Brain and Cognition, KU Leuven, Leuven, Belgium
| | - Nele Demeyere
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK
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3
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Pure Alexia: A Combined First-Person Account and Neuropsychological Investigation. Cogn Behav Neurol 2019; 32:268-277. [DOI: 10.1097/wnn.0000000000000214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Visual attention in posterior stroke and relations to alexia. Neuropsychologia 2016; 92:79-89. [DOI: 10.1016/j.neuropsychologia.2016.02.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/29/2016] [Accepted: 02/29/2016] [Indexed: 11/22/2022]
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McAvinue LP, Vangkilde S, Johnson KA, Habekost T, Kyllingsbæk S, Bundesen C, Robertson IH. A Componential Analysis of Visual Attention in Children With ADHD. J Atten Disord 2015. [PMID: 23190613 DOI: 10.1177/1087054712461935] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Inattentive behaviour is a defining characteristic of ADHD. Researchers have wondered about the nature of the attentional deficit underlying these symptoms. The primary purpose of the current study was to examine this attentional deficit using a novel paradigm based upon the Theory of Visual Attention (TVA). METHOD The TVA paradigm enabled a componential analysis of visual attention through the use of a mathematical model to estimate parameters relating to attentional selectivity and capacity. Children's ability to sustain attention was also assessed using the Sustained Attention to Response Task. The sample included a comparison between 25 children with ADHD and 25 control children aged 9-13. RESULTS Children with ADHD had significantly impaired sustained attention and visual processing speed but intact attentional selectivity, perceptual threshold and visual short-term memory capacity. CONCLUSION The results of this study lend support to the notion of differential impairment of attentional functions in children with ADHD.
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Abstract
In combination with whole report and partial report tasks, the theory of visual attention (TVA) can be used to estimate individual differences in five basic attentional parameters: the visual processing speed, the storage capacity of visual short-term memory, the perceptual threshold, the efficiency of top-down selectivity, and the spatial bias of attentional weighting. TVA-based assessment has been used in about 30 studies to investigate attentional deficits in a range of neurological and psychiatric conditions: (a) neglect and simultanagnosia, (b) reading disturbances, (c) aging and neurodegenerative diseases, and most recently (d) neurodevelopmental disorders. The article introduces TVA based assessment, discusses its methodology and psychometric properties, and reviews the progress made in each of the four research fields. The empirical results demonstrate the general usefulness of TVA-based assessment for many types of clinical neuropsychological research. The method's most important qualities are cognitive specificity and theoretical grounding, but it is also characterized by good reliability and sensitivity to minor deficits. The review concludes by pointing to promising new areas for clinical TVA-based research.
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Affiliation(s)
- Thomas Habekost
- Department of Psychology, University of Copenhagen, Copenhagen Denmark
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Kraft A, Grimsen C, Kehrer S, Bahnemann M, Spang K, Prass M, Irlbacher K, Köhnlein M, Lipfert A, Brunner F, Kastrup A, Fahle M, Brandt SA. Neurological and neuropsychological characteristics of occipital, occipito-temporal and occipito-parietal infarction. Cortex 2014. [PMID: 23206528 DOI: 10.1016/j.cortex.2012.10.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Antje Kraft
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany.
| | - Cathleen Grimsen
- Department of Human Neurobiology, University of Bremen, Bremen, Germany
| | - Stefanie Kehrer
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Markus Bahnemann
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Karoline Spang
- Department of Human Neurobiology, University of Bremen, Bremen, Germany
| | - Maren Prass
- Department of Human Neurobiology, University of Bremen, Bremen, Germany
| | - Kerstin Irlbacher
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Martin Köhnlein
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Anika Lipfert
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Freimuth Brunner
- Medical Hospital Gesundheit Nord, Klinikum Bremen Mitte, Bremen, Germany
| | - Andreas Kastrup
- Medical Hospital Gesundheit Nord, Klinikum Bremen Mitte, Bremen, Germany
| | - Manfred Fahle
- Department of Human Neurobiology, University of Bremen, Bremen, Germany; The Henry Wellcome Laboratories of Vision Sciences, City University London, London, UK
| | - Stephan A Brandt
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany
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Barton JJS, Hanif HM, Eklinder Björnström L, Hills C. The word-length effect in reading: A review. Cogn Neuropsychol 2014; 31:378-412. [DOI: 10.1080/02643294.2014.895314] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Starrfelt R, Nielsen S, Habekost T, Andersen TS. How low can you go: spatial frequency sensitivity in a patient with pure alexia. BRAIN AND LANGUAGE 2013; 126:188-192. [PMID: 23774289 DOI: 10.1016/j.bandl.2013.05.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 05/14/2013] [Indexed: 06/02/2023]
Abstract
Pure alexia is a selective deficit in reading, following lesions to the posterior left hemisphere. Writing and other language functions remain intact in these patients. Whether pure alexia is caused by a primary problem in visual perception is highly debated. A recent hypothesis suggests that a low level deficit - reduced sensitivity to particular spatial frequencies - is the underlying cause. We tested this hypothesis in a pure alexic patient (LK), using a sensitive psychophysical paradigm to examine her performance with simple patterns of different spatial frequency. We find that both in a detection and a classification task, LK's contrast sensitivity is comparable to normal controls for all spatial frequencies. Thus, reduced spatial frequency sensitivity does not constitute a general explanation for pure alexia, suggesting that the core deficit in this disorder is at a higher level in the visual processing stream.
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Affiliation(s)
- Randi Starrfelt
- Center for Visual Cognition, Department of Psychology, University of Copenhagen, Denmark.
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Caspersen ID, Habekost T. Selective and sustained attention in children with spina bifida myelomeningocele. Child Neuropsychol 2013; 19:55-77. [DOI: 10.1080/09297049.2011.639753] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Habekost T, Vogel A, Rostrup E, Bundesen C, Kyllingsbaek S, Garde E, Ryberg C, Waldemar G. Visual processing speed in old age. Scand J Psychol 2012; 54:89-94. [PMID: 23121639 DOI: 10.1111/sjop.12008] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mental speed is a common concept in theories of cognitive aging, but it is difficult to get measures of the speed of a particular psychological process that are not confounded by the speed of other processes. We used Bundesen's (1990) Theory of Visual Attention (TVA) to obtain specific estimates of processing speed in the visual system controlled for the influence of response latency and individual variations of the perception threshold. A total of 33 non-demented old people (69-87 years) were tested for the ability to recognize briefly presented letters. Performance was analyzed by the TVA model. Visual processing speed decreased approximately linearly with age and was on average halved from 70 to 85 years. Less dramatic aging effects were found for the perception threshold and the visual apprehension span. In the visual domain, cognitive aging seems to be most clearly related to reductions in processing speed.
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Affiliation(s)
- Thomas Habekost
- Center for Visual Cognition, Department of Psychology, University of Copenhagen, Copenhagen, Denmark.
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Sustained attention, attentional selectivity, and attentional capacity across the lifespan. Atten Percept Psychophys 2012; 74:1570-82. [DOI: 10.3758/s13414-012-0352-6] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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McAvinue LP, Vangkilde S, Johnson KA, Habekost T, Kyllingsbæk S, Robertson IH, Bundesen C. The relationship between sustained attention, attentional selectivity, and capacity. JOURNAL OF COGNITIVE PSYCHOLOGY 2012. [DOI: 10.1080/20445911.2011.628653] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Bundesen C, Habekost T, Kyllingsbæk S. A neural theory of visual attention and short-term memory (NTVA). Neuropsychologia 2010; 49:1446-57. [PMID: 21146554 DOI: 10.1016/j.neuropsychologia.2010.12.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 11/10/2010] [Accepted: 12/02/2010] [Indexed: 11/17/2022]
Abstract
The neural theory of visual attention and short-term memory (NTVA) proposed by Bundesen, Habekost, and Kyllingsbæk (2005) is reviewed. In NTVA, filtering (selection of objects) changes the number of cortical neurons in which an object is represented so that this number increases with the behavioural importance of the object. Another mechanism of selection, pigeonholing (selection of features), scales the level of activation in neurons coding for a particular feature. By these mechanisms, behaviourally important objects and features are likely to win the competition to become encoded into visual short-term memory (VSTM). The VSTM system is conceived as a feedback mechanism that sustains activity in the neurons that have won the attentional competition. NTVA accounts both for a wide range of attentional effects in human performance (reaction times and error rates) and a wide range of effects observed in firing rates of single cells in the primate visual system.
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Affiliation(s)
- Claus Bundesen
- Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
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Barban F, Zannino GD, Santangelo V, Macaluso E, Serra L, Caltagirone C, Carlesimo GA. Amblyopic dyslexia: a little investigated reading disorder. Neurocase 2010; 16:397-407. [PMID: 20401806 DOI: 10.1080/13554791003620298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
We present a case of a little investigated reading disorder we call 'amblyopic dyslexia'. The reading impairment in this patient resulted from a left extrastriate and white matter lesion causing a scotomatic area of partial deficit within the right visual field. The visual deficit was consistent with cerebral amblyopia, that is, reduced form, colour, and light sensitivity without a complete loss of vision. The patient's reading deficit was characterized by accurate single letter naming and almost accurate but effortful single word reading, with no letter-by-letter strategy. The criteria for distinguishing amblyopic dyslexia from other reading disorders and the most appropriate treatment are discussed.
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Affiliation(s)
- Francesco Barban
- Clinical and Behavioural Neurology Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy.
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Dubois M, Kyllingsbæk S, Prado C, Musca SC, Peiffer E, Lassus-Sangosse D, Valdois S. Fractionating the multi-character processing deficit in developmental dyslexia: Evidence from two case studies. Cortex 2010; 46:717-38. [PMID: 20116054 DOI: 10.1016/j.cortex.2009.11.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 11/13/2008] [Accepted: 10/26/2009] [Indexed: 11/25/2022]
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Starrfelt R, Habekost T, Gerlach C. Visual processing in pure alexia: A case study. Cortex 2010; 46:242-55. [DOI: 10.1016/j.cortex.2009.03.013] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 03/20/2009] [Accepted: 03/27/2009] [Indexed: 11/25/2022]
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Starrfelt R, Habekost T, Leff AP. Too little, too late: reduced visual span and speed characterize pure alexia. Cereb Cortex 2009; 19:2880-90. [PMID: 19366870 PMCID: PMC2774391 DOI: 10.1093/cercor/bhp059] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Whether normal word reading includes a stage of visual processing selectively dedicated to word or letter recognition is highly debated. Characterizing pure alexia, a seemingly selective disorder of reading, has been central to this debate. Two main theories claim either that 1) Pure alexia is caused by damage to a reading specific brain region in the left fusiform gyrus or 2) Pure alexia results from a general visual impairment that may particularly affect simultaneous processing of multiple items. We tested these competing theories in 4 patients with pure alexia using sensitive psychophysical measures and mathematical modeling. Recognition of single letters and digits in the central visual field was impaired in all patients. Visual apprehension span was also reduced for both letters and digits in all patients. The only cortical region lesioned across all 4 patients was the left fusiform gyrus, indicating that this region subserves a function broader than letter or word identification. We suggest that a seemingly pure disorder of reading can arise due to a general reduction of visual speed and span, and explain why this has a disproportionate impact on word reading while recognition of other visual stimuli are less obviously affected.
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Affiliation(s)
- Randi Starrfelt
- Department of Psychology, Center for Visual Cognition, Copenhagen University, DK-1361 Copenhagen, Denmark.
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Affiliation(s)
- Thomas Habekost
- Center for Visual Cognition, Department of Psychology, Copenhagen University, Denmark.
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Bundesen C. The Broadbent Lecture at the XVth Congress of the European Society for Cognitive Psychology, Marseilles, France, 2007. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/09541440701880374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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The significance of visual information processing in reading: Insights from hemianopic dyslexia. Neuropsychologia 2008; 46:2445-62. [DOI: 10.1016/j.neuropsychologia.2008.04.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2007] [Revised: 04/18/2008] [Accepted: 04/25/2008] [Indexed: 11/22/2022]
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Habekost T, Rostrup E. Visual attention capacity after right hemisphere lesions. Neuropsychologia 2007; 45:1474-88. [PMID: 17174988 DOI: 10.1016/j.neuropsychologia.2006.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 11/05/2006] [Accepted: 11/17/2006] [Indexed: 11/28/2022]
Abstract
Recently there has been a growing interest in visual short-term memory (VSTM) including the neural basis of the function. Processing speed, another main aspect of visual attention capacity, has received less investigation. For both cognitive functions human lesion studies are sparse. We used a whole report experiment for estimation of these two parameters in 22 patients with right side stroke. Psychophysical performance was analyzed using Bundesen's [Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97, 523-547] Theory of Visual Attention (TVA) and compared statistically to lesion location and size measured by MRI. Visual processing speed was impaired in the contralesional hemifield for most patients, but typically preserved ipsilesionally, even after large cortico-subcortical lesions. When bilateral deficits in processing speed occurred, they were related to damage in the right middle frontal gyrus or leukoaraiosis. The storage capacity of VSTM was also normal for most patients, but deficits were found after severe leukoaraiosis or large strokes extending deep into white matter. Thus, the study demonstrated the importance of white-matter connectivity for both VSTM capacity and ipsilesional processing speed. The study also showed that lesions in a large region of the right hemisphere, including the putamen, insula, and inferior frontal cortex, do not lead to general deficits in the capacity of visual attention.
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Affiliation(s)
- Thomas Habekost
- Center for Visual Cognition, Department of Psychology, University of Copenhagen, Linnesgade 22, 1361 Copenhagen K, Denmark.
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