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 demonstration s of novel popout attributed the effect to the capture of attentional resou rces by novel stimuli. Christie and Klein (1995, 1996) argued that differen tial recollection of novel versus familiar words could alternatively accoun t for the popout effect. At the present experiments, participants judged wh ich 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 tha n a bright novel word in three-novel/one-familiar arrays, inconsistent with the mismatch theory proposed by Johnston and Hawley (1994). The results su ggest that familiarity and novelty provide a perceptual segregation of the odd item; superior brightness discrimination at that location may be due ei ther to attentional capture or to locational ambiguity within the larger gr oup.