Eyewitness Memory

It has been estimated that eyewitness identification plays a critical role in upward of 80,000 criminal cases per year.  But eyewitnesses are not always accurate.  Some studies have found that 30-40% of identifications in actual police lineups are identifications of innocent persons.  The Law and Memory Processes lab conducts research examining factors that can help or hinder identification accuracy.  These include basic perceptual and memory variables like lighting, distance, and duration as well as social and cognitive variables such as stress and cross-race identifications.  We have also been involved in testing how police procedures can be modified to improve eyewitness performance. Topics include the instructions given to a witness prior to an identification attempt, feedback after an identification attempt, and proper selection of fillers.  The Law and Memory Processing Lab also conducts research on meta-cognitive variables that may help post-dict witness accuracy.  Our work on eyewitness memory is theoretically grounded in basic research in memory and cognition.

Missing and Wanted Persons

When someone goes missing or is wanted by authorities, police will sometimes release the person’s picture to the general public in hopes that someone will spot the individual and report the sighting to authorities.  Lampinen, Arnal and Hicks (2009) referred to the ability to spot someone you’ve been asked to be on the look out for as prospective person memory.  Prospective person memory is often quite poor.  In one early study, students in several classrooms were shown a picture of an individual and were asked to memorize the person’s face.  They were asked to imagine that the person was wanted by the police and were told that if they saw the person and alerted their instructor that they could win a cash prize.  Two days laler, under the guise of delivering copies to the instructor, the “wanted” individual showed up in the classroom.  After dropping off the copies, he turned to the class and in a loud voice said, “Hello class”, stood their for several seconds and then left.  Only about 5% of students reported the sighting to their instructor.  Our research team has been studying factors that can influence the probability of reporting a sighting including memory factors, face perception, attention, and response criterion.  We were the first lab to scientifically study the ability to spot and report missing or wanted persons. We also conduct research on forensic age progression. Forensic age progression refers to a set of techniques that are used to estimate the visual appearance of someone who has been missing for a long period of time.  Our work focuses on discovering way s of making age progressions more accurate so that they can be used to get more successful recoveries of missing and wanted persons.

False Memories

A false memory is a memory for a past event that diverges from historical reality.  False memories have been demonstrated for words, pictures, events, sentences, faces, and event entire autobiographical events.  The Law and Memory Processes lab has conducted research on false memories using a variety of different paradigms with both adult and child participants.  Our work has focused on two primary questions.  First, we have been interested in how it is that people can develop false memories that are subjectively compelling to them — that are confidently held, include contextual and perceptual details, and are impervious to discrediting.   We have proposed and tested a content borrowing account that says that false memories sometimes develop by errantly binding features from actually presented stimuli.   Second, we have been interested in the meta-cognitive strategies that people use to avoid false memories.  These strategies include recollection rejection, where people reject false memories because they remember something that is logically inconsistent with the false memory.  Another strategy is called diagnostic monitoring, where people set expectations for how distinctive they expect their memory to be. We have modeled the existence of these phenomenon in the Phantom ROC model.