A dissociation between similarity effects in episodic face recognition.

Memory similarity, the similarity between a test lure and memory traces, reduces confidence and accuracy in all forms of recognition memory. In contrast, Tulving (1981) showed that, in recognition memory for scenic pictures, choice similarity, the similarity between forced choice test alternatives, increased accuracy but decreased confidence. In the present study, we replicated both memory and choice similarity effects and the dissociation between accuracy and confidence with pictures of faces. State-trace analysis confirmed the dissociation and identified two dimensions underlying these effects, one associated with choice similarity and another associated with memory similarity. Further analysis showed that the effect of study-test lag was associated with the memory-similarity dimension.