Relative judgment in facial identity perception as revealed by sequential effects

Existing models of facial identity perception often assume that information conveyed by facial stimuli provides the sole basis for identity judgments, largely ignoring the involvement of contextual effects. Capitalizing on sequential effects, the present study investigates whether facial identity is judged relative to a context shaped by stimuli presented in previous trials. When categorizing a sequence of facial identities, our results demonstrated that participants' categorization of current faces varied according to the local sequential context provided by the immediately preceding faces and, to some extent, by the preceding stimuli presented two trials prior to the current trial. Moreover, this variation depended on the relative distance between the preceding and current faces. Notably, the nature of these identity-based sequential effects was qualitatively different between male and female participants. Female participants tended to respond to the current faces with the same category label as on the preceding faces. However, male participants responded with the same label only when the relative distance was small, but responded with a different label when the relative distance was increasingly large. The present study demonstrates that relative information between the preceding and current faces may be used as evidence to inform a judgment. However, this process is multifaceted rather than unitary and depends in part on participant gender.