How hand posture modulates interference from extraneous information in an Eriksen flanker task

Nicole M Murchison, Purdue University

Abstract

Davoli and Brockmole (2012) found that hand posture modulated the interference from distractor letters in an Eriksen flanker task: The flanking distractors produced less interference when the hands were placed around the position of the target letter (hands-near condition) than when the hands were placed below the display (hands-far condition). Davoli and Brockmole interpreted this result as indicating that visual attention can be focused better on the target when it is in the vicinity of the hands, reducing the processing of distractors. The experiments in this thesis were designed to test implications of this visual attention account and consider alternatives. The critical analyses throughout compared the influence of barrier condition on the flanker-compatibility effects (facilitation and interference) to determine whether using one's hands as barriers is efficient at focusing attention to block out extraneous information. Experiment 1 was a replication of Davoli and Brockmole's study, but with left and right foot presses as responses instead of presses of the index fingers. Flanker interference was less for the hands-near condition than for the hands-far condition, as in their study. In Experiment 2, a condition was tested in which the flankers occurred inside of the hands instead of outside of the hands: Reaction times were longer with the within-hand flankers, indicating that the flankers must be outside of the hands for there to be reduction of interference. In Experiment 3, participants responded to targets outside of the hands, as in the previous distractor positions, with the letter at the centered location being the "flanker." Results showed decreased interference for the hands-near condition, even though the flanker was supposedly in the region of enhanced attention. As to the question of whether hand placement is a consequence of enabling a tighter focus of visual attention or of some other mechanism, the hands likely provide a reference frame relative to which a person can decide where to focus attention in order to select the appropriate response.

Degree

M.S.

Advisors

Proctor, Purdue University.

Subject Area

Behavioral psychology|Experimental psychology

COinS