Abstract
Purpose. This study investigated the ways in which observers can combine dynamic visual and auditory information. Method. The observer viewed a quick stream of 18 gray disks (83 ms per disk), each accompanied by a simultaneous burst of auditory white noise. Three levels of disk brightness and of noise loudness were used to produce 9 different types of audiovisual pairing. In the brightness-only (and loudness-only) attention condition, participants attempted to ignore variations in loudness (brightness) and judged with feedback whether the mean brightness (loudness) of the disks in the stimulus stream was higher versus lower than the usual. In the correlation condition, participants judged (with feedback) whether the stimulus stream contained a greater number of correlated (brightest/loudest plus dimmest/quietest) or anticorrelated (brightest/quietest plus dimmest/loudest) pairings. In each condition, a probit model was used to measure the impact exerted on the observer's judgments by each of the 9 types of pairings. Results. In the brightness-only and loudness-only conditions, observers succeeded in ignoring the irrelevant modality. In the correlation condition, the impact of a pairing was a separable function of its brightness and loudness. Conclusions. Depending on task demands, observers can achieve a range of different attention filters for processing these audiovisual displays: they can extract either the mean loudness (uninfluenced by brightness variations) or the mean brightness (uninfluenced by loudness variations); however, they can also achieve an attention filter that correlates the loudness with the brightness variations in the stimulus stream.