Purchase this article with an account.
Vivian M. Ciaramitaro, Geoffrey M. Boynton; Visual-auditory spatial attention in human visual cortex. Journal of Vision 2005;5(8):171. doi: 10.1167/5.8.171.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To examine how auditory spatial attention influences responses in early visual areas.
Methods: Subjects were presented four stimuli simultaneously: two drifting gratings, one to the left and one to the right of central fixation, and two auditory tones, one to the left and one to the right ear. Auditory stimuli presented to the left ear was perceived as being on the left side of space, and vice versa. All four stimuli were presented in two successive intervals, with the speed of the visual gratings and the frequency of the auditory tones independently increased or decreased between the first and second interval. On any given trial, subjects were cued to attend the auditory stimulus in either the left or right ear and had to judge whether the attended stimulus contained the higher frequency tone in the first or second interval. Auditory frequency increment thresholds were determined prior to scanning, so as to maintain constant task difficulty throughout the scan. Subjects alternated between performing the task on the auditory stimulus in the left versus the right ear every 20-sec (6 blocks per scan, 8 trials per block). We measured fMRI responses to an unattended visual stimulus when attention was directed to an auditory stimulus on the same or the opposite side of space.
Results: In early visual areas we found a larger fMRI response to an unattended visual stimulus when auditory attention was directed to the same side of space, compared to when auditory attention was directed to the opposite side of space. These results are consistent with a cross-modal mechanism of spatial attention in which attention to a stimulus in one region of space leads to an enhancement of the response to any other stimulus in the same spatial region, regardless of modality. Thus, when visual and auditory stimuli share a common spatial region, even an unattended visual stimulus can gain a processing advantage, yielding a larger fMRI response.
This PDF is available to Subscribers Only