Yong Min Choi¹ (), Viola Störmer¹; ¹Dartmouth College

Real-world behavior rarely relies on a single sensory modality. Instead, multi-sensory inputs are concurrently processed and integrated to guide complex behavioral goals. For example, orienting spatial attention to a transient, peripheral sound enhances visual processing, as reflected in improved visual discrimination performance and amplified visual-cortical responses for stimuli at the sound’s location (e.g., Keefe & Störmer, 2021). Meanwhile, auditory processing often requires sustained, rather than transient, attentional engagement (e.g., listening to a speech). Therefore, in the present study, we examined whether sustained auditory spatial attention enhances visual processing at spatially congruent locations. Participants (N = 24) performed a dual task combining a dichotic listening paradigm with a visual discrimination task. In the auditory task, participants listened to two streams of digits presented from speakers located at the left and right side of the monitor, with each digit randomly spoken in either a male or female voice. Before each block, they were instructed to attend to the stream from (1) the left speaker, (2) the right speaker, or (3) a specific voice (male or female) regardless of location, and to detect immediate digit repetitions (auditory 1-back) while maintaining fixation. Concurrently, brief subthreshold Gabor patches appeared intermittently in either visual hemifield, and participants reported their orientation (clockwise vs. counterclockwise). We found significantly enhanced visual discrimination accuracy when directing auditory attention to the speaker located at the same hemifield, compared to when attending to the opposite location (pbonf = .008) or to a non-spatial voice cue (pbonf = .048). Exploratory analyses of eye-tracking data revealed small but systematic gaze shifts toward the attended hemifield, which did not explain the observed effect of auditory spatial attention on visual task performance. These findings demonstrate that sustained auditory spatial attention selectively enhances visual processing at corresponding locations, revealing robust cross-modal attentional facilitation under prolonged attentional demands.

Acknowledgements: This study was supported by National Science Foundation under BCS-2446115.