| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4312508 | Behavioural Brain Research | 2014 | 10 Pages |
•Oscillatory EEG signature of naturalistic navigation in blind and sighted participants differ.•Functional reorganization leads to stronger activity in the visual cortex in blind than in sighted participants.•Differences between blind and sighted participants were task-specific and cannot be explained by resting-state EEG or motor imagery performance.
The aim of the present study was to investigate functional reorganization of the occipital cortex for a mental navigation task in blind people. Eight completely blind adults and eight sighted matched controls performed a mental navigation task, in which they mentally imagined to walk along familiar routes of their hometown during a multi-channel EEG measurement. A motor imagery task was used as control condition. Furthermore, electrophysiological activation patterns during a resting measurement with open and closed eyes were compared between blind and sighted participants. During the resting measurement with open eyes, no differences in EEG power were observed between groups, whereas sighted participants showed higher alpha (8–12 Hz) activity at occipital sites compared to blind participants during an eyes-closed resting condition. During the mental navigation task, blind participants showed a stronger event-related desynchronization in the alpha band over the visual cortex compared to sighted controls indicating a stronger activation in this brain region in the blind. Furthermore, groups showed differences in functional brain connectivity between fronto-central and parietal–occipital brain networks during mental navigation indicating stronger visuo-spatial processing in sighted than in blind people during mental navigation. Differences in electrophysiological parameters between groups were specific for mental navigation since no group differences were observed during motor imagery. These results indicate that in the absence of vision the visual cortex takes over other functions such as spatial navigation.
