Citation

Spering M, Gegenfurtner KR, Kerzel D. J. Exp. Psychol. Hum. Percept. Perform. 2006; 32(5): 1136-1154.

Affiliation

Justus-Liebig-Universitat Giessen, Allgemeine Psychologie, Giessen, Germany. miriam.spering@psychol.uni-giessen.de

Copyright

(Copyright © 2006, American Psychological Association)

DOI

10.1037/0096-1523.32.5.1136

PMID

17002527

Abstract

When 2 targets for pursuit eye movements move in different directions, the eye velocity follows the vector average (S. G. Lisberger & V. P. Ferrera, 1997). The present study investigates the mechanisms of target selection when observers are instructed to follow a predefined horizontal target and to ignore a moving distractor stimulus. Results show that at 140 ms after distractor onset, horizontal eye velocity is decreased by about 25%. Vertical eye velocity increases or decreases by 1 degrees /s in the direction opposite from the distractor. This deviation varies in size with distractor direction, velocity, and contrast. The effect was present during the initiation and steady-state tracking phase of pursuit but only when the observer had prior information about target motion. Neither vector averaging nor winner-take-all models could predict the response to a moving to-be-ignored distractor during steady-state tracking of a predefined target. The contributions of perceptual mislocalization and spatial attention to the vertical deviation in pursuit are discussed.

Language: en