title: Auditory peripersonal space in humans.
abstract: In the present study we report neuropsychological evidence of the existence of an auditory peripersonal space representation around the head in humans and its characteristics. In a group of right brain-damaged patients with tactile extinction, we found that a sound delivered near the ipsilesional side of the head (20 cm) strongly extinguished a tactile stimulus delivered to the contralesional side of the head (cross-modal auditory-tactile extinction). By contrast, when an auditory stimulus was presented far from the head (70 cm), cross-modal extinction was dramatically reduced. This spatially specific cross-modal extinction was most consistently found (i.e., both in the front and back spaces) when a complex sound was presented, like a white noise burst. Pure tones produced spatially specific cross-modal extinction when presented in the back space, but not in the front space. In addition, the most severe cross-modal extinction emerged when sounds came from behind the head, thus showing that the back space is more sensitive than the front space to the sensory interaction of auditory-tactile inputs. Finally, when cross-modal effects were investigated by reversing the spatial arrangement of cross-modal stimuli (i.e., touch on the right and sound on the left), we found that an ipsilesional tactile stimulus, although inducing a small amount of cross-modal tactile-auditory extinction, did not produce any spatial-specific effect. Therefore, the selective aspects of cross-modal interaction found near the head cannot be explained by a competition between a damaged left spatial representation and an intact right spatial representation. Thus, consistent with neurophysiological evidence from monkeys, our findings strongly support the existence, in humans, of an integrated cross-modal system coding auditory and tactile stimuli near the body, that is, in the peripersonal space.
authors.affiliation: CNC Centro Neuroscienze Cognitive, Dipartimento di Psicologia, Università di Bologna, Italy. farne@psibo.unibo.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Farnè
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Làdavas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology; D005108:Extinction, Psychological; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010550:Personal Space; D013017:Sound Localization; D013028:Space Perception / Q000502:physiology*; D014110:Touch