title: Multisensory signalling enhances pupil dilation.
abstract: Detecting and integrating information across the senses is an advantageous mechanism to efficiently respond to the environment. In this study, a simple auditory-visual detection task was employed to test whether pupil dilation, generally associated with successful target detection, could be used as a reliable measure for studying multisensory integration processing in humans. We recorded reaction times and pupil dilation in response to a series of visual and auditory stimuli, which were presented either alone or in combination. The results indicated faster reaction times and larger pupil diameter to the presentation of combined auditory and visual stimuli than the same stimuli when presented in isolation. Moreover, the responses to the multisensory condition exceeded the linear summation of the responses obtained in each unimodal condition. Importantly, faster reaction times corresponded to larger pupil dilation, suggesting that also the latter can be a reliable measure of multisensory processes. This study will serve as a foundation for the investigation of auditory-visual integration in populations where simple reaction times cannot be collected, such as developmental and clinical populations.
authors.affiliation: Centre for Brain Science, Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Rigato
authors.affiliation: Social and Health Psychology, Department of Psychology University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Gerulf
authors.initials: G
authors.lastname: Rieger
authors.affiliation: Centre for Brain Science, Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Romei
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception; D004106:Dilatation; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011680:Pupil / Q000502:physiology*; D014796:Visual Perception; D055815:Young Adult