Attention Effects on Form Discrimination at Different Eccentricities
Abstract
Considerable disagreement exists in the visual attention literature about how attention is allocated over the visual fields. One frequently expressed metaphor is that attention moves like a spotlight and, thus would take longer to shift to targets further from fixation. In order to test this metaphor, five experiments were conducted in which target location was precured and form discrimination accuracy was assessed. By varying the interval between the precue and the target (stimulus onset asynchrony, SOA), a time course of attention effects was obtained for targets at 2deg,6deg, and 10deg eccentricity, In the first three experiments, precuing effects were found, but there were no differences in performance as a function of eccentricity for very short SOAs, with either a peripheral cue or a foveal arrow cue. For long SOAs, however, performance was better for targets that were closer to fixation. In experiments 4 (peripheral cue) and (foveal cue), the targets were scaled to make them equally discriminable at all eccentricities. Again precuing effect were found, but there were no differences in accuracy as a function of eccentricity for most SOAs. These results suggest that attention shifting is not analogous to a moving spotlight. Keywords: Cortical magnification factor, Eccentricity, Shifting of attention, Spotlight metaphor, Visual attention.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1989
- Accession Number
- ADA205865
Entities
People
- Don R. Lyon
- Marylou Cheal
Organizations
- University of Dayton