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Proceedings Paper

Modeling the time course of attention signals in human primary visual cortex
Author(s): Michael A. Silver
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Paper Abstract

Previous neuroimaging studies have documented the existence of attention signals in human visual cortex, but little is known about the time course of these signals. A recent study reported persistent activity in early visual cortex whose duration was correlated with the duration of sustained attention1. The present study extends these findings by modeling the time course of sustained attention signals with a linear function with duration equal to the period of sustained attention but with variable amplitude and slope. Subjects performed a visual detection task in which a variable-duration delay period occurred before every target presentation. This design required the subjects to allocate visuospatial attention throughout the delay period. Functional magnetic resonance imaging (fMRI) was used to record activity in primary visual cortex (cortical area V1) during performance of the task. There were significant individual differences in the time course of attention signals, with some subjects displaying time courses consistent with constant amplitude attention signals, while others showed decreasing amplitude of attention-related activity during the delay period. These individual differences in time course of attention signals were correlated with behavioral response bias, suggesting that they may reflect differences in the types of attention used by the subjects to perform the detection task. In particular, those subjects who had constant amplitude sustained attention signals may have been employing relatively more endogenous, or top-down attention, while the subjects who exhibited attention signals that decreased over time may have been using relatively more exogenous, or bottom-up attention.

Paper Details

Date Published: 9 February 2006
PDF: 8 pages
Proc. SPIE 6057, Human Vision and Electronic Imaging XI, 605714 (9 February 2006); doi: 10.1117/12.674149
Show Author Affiliations
Michael A. Silver, Univ. of California, Berkeley (United States)

Published in SPIE Proceedings Vol. 6057:
Human Vision and Electronic Imaging XI
Bernice E. Rogowitz; Thrasyvoulos N. Pappas; Scott J. Daly, Editor(s)

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