How important are eye movements to visual pattern analysis? Previous findings indicate that at least one visual task (counting) is seriously impaired without them. We asked whether a comparable limitation applies to pattern recognition. Subjects were presented with pairs of randomly generated arrays composed of black and white pixels. The subjects indicated whether the arrays were identical or differed by one pixel. In one experiment, they were instructed to use normal eye movements, in another they were required to fixate on a point between the arrays. When eye movements were permitted, subjects' performance showed evidence for a search in which the discrepant pixel was eventually found, given adequate inspection time. When fixation was required, search was less efficient and the discrepant pixel was sometimes not found, despite prolonged inspection time. These results were independent of target size over a wide range. Our findings indicate that eye movements play a crucial role in pattern analysis that is not related to resolution.
Bibliographical noteFunding Information:
.4cX_no~~ied~emenrs-Thriess earch was supporteId” partb y U.S. Public Health Service Grants EY07S57 and EY02934 to Gordon E. Legge. K.-H. Schlingensiepen was supported by the Studienstiftung des deutschen Volkes. the DAAD and the Max-Planck-Gesellschaft. Timothy D. Walker was supported by the Center for Research in Human Learning. Some of the apparatus was provided by the Medtcal Research Council and the Wellcome Trust. We thank Clice Hood, Andrew Luebker and Gary Rubrn for technrcal help, Anne Gritfin for typing and Fiona Hake for artwork We also thank anonymous referees for therr particularly thorough comments.
- Eye movements
- Pattern recognition
- Visual resolution
- Visual search