Novel popout and familiar popout in a brightness discrimination task.

A single novel word among several familiarized words may be localized more effectively than the familiarized words (novel popout). Early demonstrations of novel popout attributed the effect to the capture of attentional resources by novel stimuli. Christie and Klein (1995, 1996) argued that differential recollection of novel versus familiar words could alternatively account for the popout effect. In the present experiments, participants judged which of four locations contained a physically brighter word. A bright novel word was localized significantly better than a bright familiar word in one-novel/three-familiar arrays, inconsistent with a retrievability account of novel popout. However, a bright familiar word was also localized better than a bright novel word in three-novel/one-familiar arrays, inconsistent with the mismatch theory proposed by Johnston and Hawley (1994). The results suggest that familiarity and novelty provide a perceptual segregation of the odd item; superior brightness discrimination at that location may be due either to attentional capture or to locational ambiguity within the larger group.