Publication details for Dr Daniel SmithSmith, D.T., Ball, K. & Ellison, A. (2014). Covert visual search within and beyond the effective oculomotor range. Vision Research 95: 11-17.
- Publication type: Journal Article
- ISSN/ISBN: 0042-6989
- DOI: 10.1016/j.visres.2013.12.003
- Keywords: Attention, Exogenous, Eye movement, Endogenous, Oculomotor, Covert visual search.
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
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°. 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.