The current study used an eye tracker to examine how auditory input affects the latency of visual saccades, fixations, and response times while using variations of a Serial Response Time (SRT) task. In Experiment 1, participants viewed a repeating sequence of visual stimuli that appeared in different locations on a computer monitor and they had to quickly determine if each visual stimulus was red or blue. The visual sequence was either presented in silence or paired with tones. Compared to the silent condition, the tones slowed down red/blue discriminations and delayed the latency of first fixations to the visual stimuli. To ensure the interference was not occurring during the decision/response phase and to better understand the nature of auditory interference, we removed the red/blue discrimination task in Experiment 2, manipulated cognitive load, and developed a gaze-contingent procedure where the timing of each visual stimulus was dependent on a saccade crossing a gaze-contingent boundary surrounding the target. Participants were slower at initiating their saccades/fixations and made more fixations under high load and auditory interference was found with participants being more likely to fixate on the visual images and were faster at fixating on the visual stimuli when the visual sequences were presented in silence. These findings suggest that auditory interference effects occur early in the course of processing and provide insights into potential mechanisms underlying modality dominance effects.
Listen to Your Heart: Examining Modality Dominance Using Cross-Modal Oddball Tasks
