The role of context in the perception of orientation by the rat

Two experiments are reported which demonstrate the role of contextual factors in the rat's perception of orientation. Designed to eschew criticisms of an earlier study by McGonigle and Jones, the first experiment shows that the rat's perception of linear Gestalten is conditional upon the set of alternative patterns within which the (linear) pattern is embedded. The second experiment shows that the ecological framework of an orientational cue (rather than its position relative to retinocortical coordinates) determines the rat's perception of vertical and horizontal stimuli.