Poster B7, Sunday, March 26, 8:00 – 10:00 am, Pacific Concourse
Temporal Expectation Weights Visual Signals Over Auditory Signals
Marcia Grabowecky1, Melisa Menceloglu1, Satoru Suzuki1; 1Northwestern University
Temporal expectation occurs when temporally structured sensory information explicitly or implicitly predicts the onset or duration of future events, and influences behavioral responses. Less is known about temporal expectation effects on multisensory processing. We investigated how temporal expectation influenced auditory-visual interaction, using an auditory-visual congruity effect as a measure of crossmodal interaction. On each trial, participants received a modality cue indicating whether a target letter, B or D, would be presented auditorily or visually. The task was to identify the letter in the cued modality as rapidly and as accurately as possible. Each target was simultaneously accompanied by a congruent or an incongruent letter presented through the other modality. Temporal expectation was block-wise manipulated: in the short-interval-expected block, short-interval stimuli were presented 80% of the time and the long-interval stimuli 20% of the time; in the long-interval-expected block, the probabilities were reversed. For auditory identification, an incongruent visual stimulus produced stronger interference when the bimodal stimulus was presented with expected than with unexpected timing. In contrast, for visual identification, an incongruent auditory stimulus produced weaker interference when the bimodal stimulus was presented with expected than with unexpected timing. The fact that temporal expectation made visual distracters more potent and visual targets less susceptible to auditory interference suggests that temporal expectation increases perceptual weight on visual signals.
Topic Area: ATTENTION: Multisensory