Citation

Smith DT, Ball K, Ellison A. Vision Res. 2014; 95: 11-17.

Affiliation

Dept. of Psychology, Durham University, Queens Campus, Stockton-on-Tees, TS176BH, UK.

Copyright

(Copyright © 2014, Elsevier Publishing)

DOI

10.1016/j.visres.2013.12.003

PMID

24333751

Abstract

Covert spatial attention is tightly coupled to the eye-movement system, but the precise nature of this coupling remains contentious. Recent research has argued that covert attention and overt eye-movements many share a common biological limit, such that covert exogenous orienting of attention is limited to stimuli that fall within the range of possible eye movements (the effective oculomotor range: EOMR). However, this conclusion is based on a single experimental paradigm: The Posner cueing task. Here, we examine the extent to which covert spatial attention is limited to the EOMR in visual search. Exogenous attention was assessed using a feature search task and endogenous attention assessed using a conjunction search task. The tasks were performed monocularly with the dominant eye in the frontal position or abducted by 40 degrees. In the abducted position stimuli in the temporal hemispace could be seen, but could not become the goal of a saccadic eye-movement (i.e. they were beyond the EOMR). In contrast, stimuli in the nasal hemifield remained within the EOMR. We observed a significant effect of eye-abduction on feature search, such that search was slower when targets appeared beyond the EOMR. In contrast, eye-abduction had no effect on search times during conjunction search. Set size did not interact with target location or eye-position. It is concluded that optimal covert orienting of exogenous attention in visual search is restricted to locations within the effective oculomotor range.

Language: en