The Control of Spatial Attention

Researcher: William Bacon, PhD. in association with Roger Remington

For the past several years we have been investigating the conditions under which external visual stimuli of moderate intensity will capture spatial attention. We have shown that distractor stimuli will elicit involuntary shifts of spatial attention only when targets and distractors share properties that subjects are set to process. In this research we extend these results in two ways. First, we will examine the role that scene organization plays in modulating attentional capture. Objects will be defined by shape, color, and motion. If attention can be restricted to particular objects, then we should see no capture for distractors that belong to unattended objects. Second, we attempt to understand the mechanisms of selection by examining whether information from unattended objects is being processed even when attention has been captured by a distractor stimulus. Subjects will be exposed to targets and distractors that are defined by a unique motion, color, luminance, or onset. Varying these target and distractor properties will allow us to determine the level at which attentional control can be exerted, and the manner in which the processing of these features is organized.

In the current experiment we examine the pattern of reaction times between trials with abrupt onset and no-abrupt onset of the stimulus. Failure to find attentional capture in the onset condition would imply that the abrupt onset effect found in previous studies is dependent upon backward masking of the distractors.

For More Information: send inquiries to wfb3@columbia.edu

back to the home page