Covert Exogenous Cross-Modality Orienting between Audition and Vision

Control of visual attention by auditory stimuli is explored in seven previously unpublished experiments that were presented at conferences in the late 1980s. Reaction time (RT) to luminance targets was found to be affected by the spatial congruence between the target and a preceding or simultaneous, and non-informative, auditory event, suggesting that localizable auditory stimuli exogenously (rapidly and automatically) capture visual attention. These cuing effects were obtained in the absence of eye movements and do not appear to be mediated merely by criterion adjustments. When the information value of the auditory event was placed in conflict with its location (i.e., a tone on the right indicated that the visual target was likely to appear on the left), it was found that at short stimulus onset asynchronies (SOAs) reaction time (RT) was faster for targets at the stimulated location, an effect that disappeared within 500 ms and was reversed by 1000 ms. This demonstrates that it requires over 500 ms for endogenous orienting in response to probabilistic information about target location to overcome the powerful exogenous control of visual attention by localizable auditory stimulation. Simple RT to auditory stimuli was unaffected by the spatial congruence of a preceding or simultaneous visual stimulus. When uninformative, neither pitch contours (rising/falling tones) nor pitch (high/low tones) produced significant visual orienting along the vertical midline. When the direction of a pitch contour indicated the likely location of a visual target, participants were able to shift their attention if the relation between the natural meaning and the probabilistic information was compatible (e.g., rising contour signaled that a upper target was likely) but not when it was incompatible. The relation of these 30-year-old experiments to contemporary findings and ideas is discussed.