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Neural processes of reading| old_uid | 7488 |
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| title | Neural processes of reading |
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| start_date | 2009/10/20 |
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| schedule | 15h45-17h |
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| online | no |
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| summary | Based on magnetoencephalography (MEG) studies, cortical processing of single words proceeds from visual feature analysis in the occipital cortex at about 100 ms, through letter-string analysis at the base of the left occipitotemporal cortex at 150 ms, to analysis of the word meaning (and sound form) in the left superior temporal cortex at about 200 to 600 ms. The lexical-semantic activation in the left superior temporal cortex seems to reflect a supramodal processing stage. It turns out that, in MEG studies, the sustained left temporal activation from 200 ms onwards is the area and time window that most consistently reacts to various types of linguistic manipulations, such as syntactic errors in sentences, morphological complexity of single words and letter-string lexicality (together with length). Interestingly, functional magnetic resonance imaging (fMRI) studies rather tend to report left frontal activation in response to such manipulations. In principle, the apparent differences between the electrophysiological and hemodynamic imaging results could reflect differences in paradigms or choice of contrasts in fMRI, or they could be due to the different subject groups or even different languages. However, these differences in emphasis (MEG: left temporal, fMRI: left frontal) seem to persist even in direct comparisons of the same task on the same subjects. One can ask whether the temporal-frontal balance might reflect a difference in the way MEG evoked responses and fMRI BOLD signal pick up different nodes of anatomically and functionally connected networks. |
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| responsibles | Zondervan |
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