Abstract
Our senses generally complement each other: whereas vision gives us an uncontested spatial resolution, audition allows for localization in 360 degrees. To promote unity between sensory systems, sensory signals must be integrated into a multimodal coordinate system. Visual information is retinotopically encoded, and head-related auditory information is transformed into retinotopic coordinates in the superior colliculus. Because the eyes frequently move, the updating of spatial information with regards to the retina is crucial for the ability to localize sensory information after a saccade. This updating is known as remapping of spatial attention, the after-effects of which are reflected in facilitated post-saccadic reaction times to visual stimuli presented at the location of a retinotopic trace. However, whether auditory spatial attention is remapped in a similar manner is currently unclear. In the current study we investigated whether auditory spatial attention is remapped across eye movements. We designed a task in which participants allocated their attention to a peripheral location, followed by a saccade. After the saccade was completed, an auditory/visual target could either be presented at the location of the retinotopic trace or a novel location. Participants were tasked with reacting to this target as quickly as possible. We observe that auditory and visual targets presented at the location of the retinotopic trace were reacted to significantly faster immediately after the saccade than at the non-retinotopic locations. The facilitation of reaction times to post-saccadic targets at the location of the retinotopic trace diminished as the delay between saccade offset and target onset increased. Our study is the first to show that the effects of remapping spatial attention across saccades happens in retinotopic coordinates regardless of the sensory modality (i.e., audition or vision). Taken together, these results suggest that sensory unity is maintained across saccades by encoding audiovisual information into a retinotopic reference frame.
Meeting abstract presented at VSS 2017