Effects of post-exposure description and imaging on subsequent face recognition performance

After viewinga crime, witnessesare frequentlyaskedby police investigatorsto give a verbaldescriptionof the perpetrator. At a later time, witnesses may be asked to try to recognize the perpetrator in a lineup or a mugfile. The purpose of this research was to determine whetherperformanceon a later recognitiontest is influencedby an earlier verbal descriptiontest of the targeL Participantsviewedsix targetfaces, and aftereach, performedone of fourpost-exposureactivities. Twowereverbal description tasks. The descriptorchecklist task had participantsindicate, using a list of potential adjectives,those descriptors that best described the most recently seen face. The descriptor generate task had participants recall descriptors that best describedthe most recently seen face. Both descriptiontasks were accomplishedusinga questionnairethat was identicalexcept for the presenceor absenceof specificadjectives. Otherparticipantswere instructedto image the targetface or theyperformed an irrelevant task during the post-exposureperiod. In a later recognition test, participants tried to find the targets in a set of faces containing 134 distractors. The results showed that participantsusing the checklistproduced lower performanceon the recognitiontest than participantswho generatedtheir own descriptors. Imagingproducedthe highestrecognitionperformance but was not significantly different from the irrelevant condition. The recognition decrement of the descriptor checklist is explainedin terms of interferencecaused by the presenceof irrelevantface descriptorsthat added noise to participants'memory of the targets. Implications for testing witness memory by police investigators are discussed. For example, if verbal descriptionsof faces are requestedfrom eyewitnesses,descriptorrecall may be preferredover a descriptorrecognitionbecause the formertask does not degradelater recognitionof theperpetrator.