Multisensory Interactions across Spatial Location and Temporal Synchrony

Abstract

The process of integrating information across sensory modalities is highly dependent upon a number of stimulus characteristics, including spatial and temporal coincidence, as well as effectiveness. Typically, these properties have been studied in isolation, but recent evidence suggests that they are interactive. This study focuses on interactions between the spatial location and temporal synchrony of stimuli. Participants were presented with simple audiovisual in parametrically varied locations, and with parametrically varied stimulus onset asynchronies (SOAs). Participants performed spatial location and perceived simultaneity tasks (PSS). Accuracies and response times were measured. Accuracies of spatial localization were dependent upon spatial location, with no effect of SOA and interaction seen, however, RT analysis showed an effect of SOA and an interaction; more peripheral presentations showed greater slowing of RT in asynchronous conditions, and fewer violations of the race model. With the PSS tasks, effects of SOA and spatial location were found in the responses, as well as an interaction between the two. Peripheral stimuli were more likely to be judged as synchronous, a difference seen particularly with long SOAs. These results suggest that the commonly studied principles of integration are indeed interactive, and that these interactions have measureable behavioral implications.