Involuntary attention to sound modulates visual temporal perception: An electrophysiological study
Single Paper Presentation

John J. McDonald
Department of Psychology, Simon Fraser University

Wolfgang A. Teder-Sälejärvi
Department of Neurosciences, University of California San Diego

Francesco Di Russo
IRCCS Fondazione Santa Lucia

Steven A. Hillyard
Department of Neurosciences, University of California San Diego

     Abstract ID Number: 136
     Full text: Not available
     Last modified: April 15, 2003

Abstract
The law of prior entry states that attended objects are perceived more rapidly than unattended objects (Titchener, 1908). Evidence for prior entry has come from studies involving temporal order judgments: When attended and unattended stimuli occur simultaneously, the attended stimulus usually appears to occur first. Such findings suggest that sensory information arising from attended locations is processed before sensory information arising from unattended locations. Here, we investigated this issue by recording event-related potentials (ERPs) in a temporal-order-judgment task. A spatially uninformative sound was used to attract attention prior to the appearance of a pair of visual targets. Consistent with previous studies, participants often reported that the target at the cued location appeared to occur before a simultaneously presented target on the opposite side of fixation. This suggests that an involuntary shift of attention to the sound modulated the speed of visual processing. However, the auditory cue influenced the amplitudes of the early ERP components but had no influence on the latencies of the early ERP components. These findings indicate that the sound-induced changes in visual temporal perception were mediated by enhancements of neural activity in visual cortex rather than changes in the speed of information transmission in the visual system.