Eye-movement parameters and pattern discrimination

Pattern discrimination was studied in a visual-search task by recordingan O’s eye movements while he determined how many of eight patterns, arranged in a square around a standardpattern, matched the standard pattern. The results demonstrate the role of eye movements in visual search and human pattern discrimination. The mean duration of an eye fixation on a pattern, the probability of fixating it, the probability ofrefixating it, and the sequence in which patterns were fixated were all systematically related to various pattern measures. Multivariateanalyses showed modest correlations between the duration of individual eye fixations and various pattern measures. Relative characteristics of patterns influenced performance more than absolute characteristics of patterns. Patterns that matched a standard were fixated more often and longer than patterns that did not match a standard. The order in which patterns were fixated depended upon their relative characteristics. The results were consistent with a model ofpattern discrimination consistingoftwo stagesin which (1) features of a fixated pattern are abstracted and encoded, and (2) these features are then compared with the features ofanother pattern.