title: Salient sounds activate human visual cortex automatically.
abstract: Sudden changes in the acoustic environment enhance perceptual processing of subsequent visual stimuli that appear in close spatial proximity. Little is known, however, about the neural mechanisms by which salient sounds affect visual processing. In particular, it is unclear whether such sounds automatically activate visual cortex. To shed light on this issue, this study examined event-related brain potentials (ERPs) that were triggered either by peripheral sounds that preceded task-relevant visual targets (Experiment 1) or were presented during purely auditory tasks (Experiments 2-4). In all experiments the sounds elicited a contralateral ERP over the occipital scalp that was localized to neural generators in extrastriate visual cortex of the ventral occipital lobe. The amplitude of this cross-modal ERP was predictive of perceptual judgments about the contrast of colocalized visual targets. These findings demonstrate that sudden, intrusive sounds reflexively activate human visual cortex in a spatially specific manner, even during purely auditory tasks when the sounds are not relevant to the ongoing task.
authors.affiliation: Department of Psychology, Simon Fraser University, British Columbia V5A 1S6, Canada.
authors.forename: John J
authors.initials: JJ
authors.lastname: McDonald
authors.forename: Viola S
authors.initials: VS
authors.lastname: Störmer
authors.forename: Antigona
authors.initials: A
authors.lastname: Martinez
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Feng
authors.forename: Steven A
authors.initials: SA
authors.lastname: Hillyard
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001931:Brain Mapping; D003463:Cues; D004585:Electrooculography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D013016:Sound; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult