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More to dyslexia than deficits in visual attention?

Karelse, J.W. (2007) More to dyslexia than deficits in visual attention?

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Abstract:Samenvatting The aim of the experiment reported in this paper was to establish whether dyslectics have specific attentional problems. To this end the performance between a group of 12 adult dyslectics and 14 adult controls on a Posner task with endogenous attentional cuing was compared. In addition participants also made a number of clinically used pen and paper tasks. During the Posner task, EEG was measured. For the cue target interval lateralized event related potentials associated with attentional shifting were compared. One recent theory states that dyslexia is caused by abnormal functioning of the magnocellular pathways. The magnocellular system is responsible for handling fast sensory information and projects, in the case of visual information, onto the posterior parietal cortex. Therefore it is reasoned that dyslectics would suffer in tasks involving the posterior parietal cortex, like directing visual attention. Our results do not confirm the attentional hypothesis. No behavioral differences between dyslectics and controls were found for both the psychological tests and the Posner task On the Posner task both groups benefited equally from attentional cues and subsequent attentional shifts. Analysis of EEG data in the cue target interval revealed the early directing attention component (EDAN) to be 40 ms longer in dyslectics. Reasoned is that his reflects different functioning of the posterior parietal cortex in dyslectics, unrelated to specific attentional problems but instead related to task-related aspects of the cue.
Item Type:Essay (Bachelor)
Faculty:BMS: Behavioural, Management and Social Sciences
Subject:05 communication studies
Programme:Psychology BSc (56604)
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