HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Handy, T. C. Articles by Khoe, W. Search for Related Content PubMed PubMed Citation Articles by Handy, T. C. Articles by Khoe, W.

Attention and Sensory Gain Control: A Peripheral Visual Process?

¹ University of British Columbia, ² University of California, San Diego

Reprint requests should be sent to Todd C. Handy, Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, BC Canada V6T 1Z4, or via e-mail: tchandy{at}psych.ubc.ca.

Attention-related sensory gain control in human extrastriate cortex is believed to improve the acuity of visual perception. Yet given wide variance in the spatial resolution of vision across the retina, it remains unclear whether sensory gain operates homogenously between foveal and nonfoveal retinotopic locations. To address this issue, we used event-related potentials (ERPs) in a variant of the canonical spatial attention task. Participants were cued to expect targets at either fixation (foveal targets) or at a location several degrees above fixation (parafoveal targets). At both target locations, manual reaction times were shorter for cued relative to uncued targets, indicating that attention was consistently oriented to the cued location. Nevertheless, attention-related increases in sensory-evoked cortical activity were only observed at the parafoveal target location, as measured by the amplitude of the lateral occipital P1 ERP component. A second experiment replicated this data pattern using targets with lower stimulus contrast, indicating that the absence of a P1 effect for foveal targets could not be attributed to a saturated P1 response under higher-contrast stimulus conditions. When considered in light of retinogeniculate projections to cortex showing systematic changes in their physiological organization beginning within a degree of visual angle of the fovea, our findings support the proposal that the strategic functions of visual attention may vary with the retinotopic location involved.

This article has been cited by other articles:

				S. Yeap, S. P. Kelly, P. Sehatpour, E. Magno, D. C. Javitt, H. Garavan, J. H. Thakore, and J. J. Foxe Early Visual Sensory Deficits as Endophenotypes for Schizophrenia: High-Density Electrical Mapping in Clinically Unaffected First-Degree Relatives. Arch Gen Psychiatry, November 1, 2006; 63(11): 1180 - 1188. [Abstract] [Full Text] [PDF]