Onset asynchrony influences audio-visual interaction in temporal modulation discrimination tasks

Abstract

A target stimulus in one sensory modality influenced by an unattended stimulus in an- other sensory modality is called cross-modal interaction. Based on previous studies, temporal correlation and information from the unattended stimulus can cause cross-modal interaction. However, the attentional cue provided by the unattended stimuli can also be a way that unattended stimuli influence participants' performance in multisensory tasks. In this study audio-visual oscillated stimuli was used, and the congruency of the oscillations in audio-visual stimuli and the onset asynchrony of the two stimuli were manipulated. We used diffusion decision model (DDM) to analyze the result as a decision making process. I found no increase of accuracy in different onset asynchrony conditions, but the responses were faster when unattended stimuli have earlier onset than the target stimuli. The DDM analysis have shown that when the unattended stimuli present earlier than the target stimuli, the drift rate was faster but the boundary separation was also larger than other onset asynchrony conditions. The conclusion is that the unattended stimuli can act as an attentional cue and can provide information to influence our judgment on the target stimuli.