Abstract
Introduction. Previous studies suggest that spatially linked auditory and visual information has a higher likelihood to be further processed (Talsma, Senkowski, Soto-Faraco, & Woldorff, 2010) and that multisensory integration effects are more prominent in the elderly (Diaconescu, Hasher, & McIntosh, 2013; Laurienti, Burdette, Maldjian, & Wallace, 2006). These studies typically show that brief auditory stimuli affect detection of visual stimuli (e.g., Dalton & Spence, 2007). However, it is unclear whether multisensory stimuli can affect attentional weights when auditory and visual stimuli are integrated by their temporal synchronicity over a longer time period. To address this question, we developed a new paradigm examining whether we automatically assign higher attentional weights to stimuli with synchronous as opposed to asynchronous visual and auditory properties. Methods. Young (N=18) and elderly (N=28) volunteers participated in the study. They were asked to monitor two disks that continuously changed size either at the same or a different frequency. In 2/3 of the blocks, these visual disks were presented simultaneously with a sound that changed volume at either the same or a different frequency of one or both of the two disks. At random time intervals the luminance of one disk changed and participants had to detect this event as quickly as possible. Results. We predicted improved performance in the audiovisual synchronous compared to the audiovisual asynchronous and the no-sound condition. The results of 16 young observers illustrated an absence of this multisensory facilitating effect. The results were replicated in a group of elderly volunteers. Conclusion. Young and older observers do not automatically assign higher attentional weights to stimuli with synchronous audiovisual properties as compared to stimuli with asynchronous audiovisual properties.
Meeting abstract presented at VSS 2017