Auditory deficits in visuospatial neglect patients.

Since the pioneering experimental work of Bisiach et al. (1984) on deficits in sound localisation associated with unilateral brain lesions and visual neglect, a number of systematic investigations have examined auditory processing in visuospatial neglect patients. Evidence from a variety of experimental paradigms has revealed some auditory deficits in detection and identification tasks, during bilateral stimulation; plus localisation deficits for single sounds. These deficits emerge predominantly for contra-lesional sounds, although some auditory disturbances applying to both contra- and ipsilesional sounds have also been documented. Here we review evidence suggesting that some of these auditory deficits arise in relatively high-level stages of spatial processing. In addition, we present new analyses showing that auditory deficits in identification and localisation tasks often correlate with clinical measures of visual neglect, across a variety of different studies and tasks. This empirical relation suggests that a disturbance of multisensory spatial processing may often account for the joint auditory and visual spatial deficits in neglect patients, although rarer dissociations between the modalities should also be considered.