Memory for faces: evidence of retrieval-based impairment.

Four experiments investigated whether and how interpolated faces cause impairment to memories for related target faces. Participants viewed target faces and then saw a presentation of interpolated faces that were related to some of the targets. Modified tests, which offered target and novel faces as recognition alternatives, detected impairment effects after short retention intervals but not after 48-hr intervals, indicating that spontaneous recovery had occurred. For the interpolated presentations, some participants were misled to believe that the faces were the same as the targets, and others were informed that they were similar but different. The impairment and recovery effects were not moderated by participants' beliefs about the interpolated faces. The recovery effects suggest that interpolated faces affected the retrieval but not the storage of memories for targets, even for participants who were successfully misled about the interpolated faces.