Visual sensitivity in search tasks depends on the response requirement.

Full Abstract

This paper reports a comparison between two tasks of visual search. Two observers carried out, in separate blocks, a saccade-to-target task and a manual-target-detection task. The displays, which were identical for the two tasks, consisted of a ring of eight equally spaced Gabor patches. The target could be defined by a difference from the distractors along four possible dimensions:
orientation, spatial frequency, contrast or size. These four dimensions were used as variables in separate experiments. In each experiment, performance was measured over an extensive range of values of the particular dimension. Thresholds were thus obtained for the saccade and the manual response tasks. The nature of the response was found to modify the relative visual sensitivity. For orientation differences, manual response performance was better than saccade-to-target performance. The reverse was true for spatial frequency and contrast differences, where saccade-to-target performance was better than manual response performance. We conclude that saccade-selection in a search task draws on different visual information from that used for manual responding in the equivalent task. The two tasks thus differ in more than the different response systems used:
the results suggest the action of different underlying neural visual mechanisms as well as different neural motor mechanisms.

Learn Faster Today Improve your study skills

Author information

Author/s: Gilchrist, Iain D (ID); Heywood, Charles A (CA); Findlay, John M (JM);

Affiliation: Department of Experimental Psychology, University of Bristol, 8 Woodland Road, Bristol BS8 1TN, UK. I.D.Gilchrist@bristol.ac.uk

Journal and publication information

Publication Type: Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't

Journal: Spatial vision (Spat Vis), published in Netherlands. (Language: eng)

Reference: 2003-; vol 16 (issue 3-4) : pp 277-93

Dates: Created 2003/07/15; Completed 2003/09/10; Revised 2007/08/21;

PMID: 12858952, status: MEDLINE (last retrieval date: 11/6/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article (including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

This article has not been indexed for related articles as yet, however you can still use the live related article search links below.

See 100+ related articles.