VENTRILOQUIST EFFECT REINSTATES RESPONSIVENESS TO AUDITORY-STIMULI INTHE IGNORED SPACE IN PATIENTS WITH HEMISPATIAL NEGLECT

We examined 6 patients with robust visual neglect following right hemi sphere damage. All of them had signs of auditory neglect as documented by the inferior identification of syllables delivered through a louds peaker on the left side. When the same stimuli on the left were admini stered in the presence of a fictitious source of sound (a dummy loudsp eaker) visible in the homolesional space, a significant increase in th e identification score of sounds was obtained (the ''ventriloquist'' e ffect). The result is in keeping with a notion of a strong coupling be tween auditory and visual systems. The effect is attributed to the act ivation by the fictitious source of sound of the audio-visual map in t he left hemisphere. We draw attention to the possibility that loss of awareness of auditory input may arise due to the disconnection of the visual input from the audio-visual template.