Access to identity-specific semantic codes from familiar faces.

Abstract

Information codes that can specify the surface form of a face are contrasted with semantic codes describing the properties of the person to whom the face belongs. Identity-specific semantic codes that specify characteristics of familiar people based on personal knowledge are in turn contrasted with the visually derived semantic codes and expression codes that can be derived even from unfamiliar faces. The idea that familiarity decisions (i.e., categorizing faces as belonging to known or unknown people) can be based on surface form, whereas certain types of semantic decision demand additional access to identity-specific semantic codes was investigated in four experiments. Experiments 1 and 3 showed that decisions based on identity-specific semantic codes (semantic decisions) usually take longer than decisions that do not demand access to an identity-specific semantic code (familiarity decisions). Experiment 2 showed that the use of familiar faces drawn from consistent or mixed categories affected reaction times for semantic decisions but not for familiarity decisions. Experiment 4 showed that semantic decisions to faces are taken more quickly (primed) when the faces have been recently seen, whereas there is no differential effect on semantic decisions to faces from previous semantic decisions involving the same people's names. These findings are consistent with the view that identity-specific semantic codes are accessed via face recognition units, and that outputs from face recognition units (which respond to the face's surface form) can be used as the basis for familiarity decisions.