Cohen Kadosh, R;
Cohen Kadosh, K;
Virtual dyscalculia induced by parietal lobe TMS impairs automatic magnitude processing.
People suffering from developmental dyscalculia encounter difficulties in automatically accessing numerical magnitudes [1-3]. For example, when instructed to attend to the physical size of a number while ignoring its numerical value, dyscalculic subjects, unlike healthy participants, fail to process the irrelevant dimension automatically and subsequently show a smaller size congruity effect (difference in reaction time between incongruent [e.g., 2 4] and congruent [e.g., 2 4] conditions), and no facilitation (neutral [e.g., 2 2] versus congruent) . Previous imaging studies determined the intraparietal sulcus (IPS) as a central area for numerical processing [4-11]. A few studies tried to identify the brain dysfunction underlying developmental dyscalculia but yielded mixed results regarding the involvement of the left  or the right  IPS. Here we applied fMRI-guided TMS neuronavigation to disrupt left or right IPS activation clusters in order to induce dyscalculic-like behavioral deficits in healthy volunteers. Automatic magnitude processing was impaired only during disruption of right IPS activity. When using the identical paradigm with dyscalculic participants, we reproduced a similar result pattern as obtained with non-dyscalculic volunteers during right IPS disruption. These findings provide direct evidence for the functional role of right IPS in automatic magnitude processing.
|Title:||Virtual dyscalculia induced by parietal lobe TMS impairs automatic magnitude processing|
|Additional information:||Imported via OAI, 15:41:43 19th Jul 2007|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Brain Sciences
UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Psychology and Language Sciences (Division of) > Institute of Cognitive Neuroscience
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
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