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Ventral and dorsal visual pathways support auditory motion processing in the blind: evidence from electrical neuroimaging
Author(s) -
Lewald Jörg,
Getzmann Stephan
Publication year - 2013
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12306
Subject(s) - neuroimaging , dorsum , neuroscience , psychology , visual processing , vision for perception and vision for action , visual system , audiology , visual cortex , medicine , anatomy , perception
Blindness induces processes of neural plasticity, resulting in recruitment of the deafferentated visual areas for non‐visual sensory functions. These processes are related to superior abilities of blind compared with sighted individuals for specific auditory and tactile tasks. Recently, an exceptional performance of the blind has been demonstrated for auditory motion perception, with a minimum audible movement angle that was half that of sighted controls (J. Lewald (2013) Neuropsychologia , 51 , 181–186). The present study revealed an electrophysiological correlate of this finding by analysing the so‐called motion‐onset response, a prominent auditory‐evoked potential to the onset of motion. The c N 1 component of this response, appearing about 170 ms after motion onset, was two times higher in amplitude for blind compared with matched sighted control subjects. At the time of the c N 1, electrical neuroimaging using s LORETA revealed stronger activation in blind than sighted subjects primarily in ventral visual areas ( V 1v, V 2v, VP , V 4v) of the right occipital lobe. Activation was also obtained in middle temporal area V 5. These findings suggest that blindness results in stronger involvement of both non‐motion areas of the ventral visual stream and motion areas of the dorsal visual stream in processing of auditory motion at the same point in time after motion onset. This argues against the view that visual motion areas, such as area V 5, are preferentially recruited for auditory motion analysis in the blind. Rather, cross‐modal reorganization of cortical areas induced by blindness seems to be largely independent of the specific visual functions of the same areas in sighted persons.