title: On the relative contributions of multisensory integration and crossmodal exogenous spatial attention to multisensory response enhancement.
abstract: Two processes that can give rise to multisensory response enhancement (MRE) are multisensory integration (MSI) and crossmodal exogenous spatial attention. It is, however, currently unclear what the relative contribution of each of these is to MRE. We investigated this issue using two tasks that are generally assumed to measure MSI (a redundant target effect task) and crossmodal exogenous spatial attention (a spatial cueing task). One block of trials consisted of unimodal auditory and visual targets designed to provide a unimodal baseline. In two other blocks of trials, the participants were presented with spatially and temporally aligned and misaligned audiovisual (AV) targets (0, 50, 100, and 200ms SOA). In the integration block, the participants were instructed to respond to the onset of the first target stimulus that they detected (A or V). The instruction for the cueing block was to respond only to the onset of the visual targets. The targets could appear at one of three locations: left, center, and right. The participants were instructed to respond only to lateral targets. The results indicated that MRE was caused by MSI at 0ms SOA. At 50ms SOA, both crossmodal exogenous spatial attention and MSI contributed to the observed MRE, whereas the MRE observed at the 100 and 200ms SOAs was attributable to crossmodal exogenous spatial attention, alerting, and temporal preparation. These results therefore suggest that there may be a temporal window in which both MSI and exogenous crossmodal spatial attention can contribute to multisensory response enhancement.
authors.affiliation: Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands. Electronic address: N.VanderStoep@uu.nl.
authors.forename: N
authors.initials: N
authors.lastname: Van der Stoep
authors.affiliation: Oxford University, Department of Experimental Psychology, Oxford, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Spence
authors.affiliation: Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands; Brain Center Rudolf Magnus, and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and De Hoogstraat Rehabilitation, The Netherlands.
authors.forename: T C W
authors.initials: TC
authors.lastname: Nijboer
authors.affiliation: Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Van der Stigchel
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D055815:Young Adult
keywords: Crossmodal; Cueing; Exogenous spatial attention; Multisensory integration; Multisensory response enhancement; Race model