Research

If someone showed you a picture of your mother and asked who was pictured, you would probably say "my mother." This decision would be almost automatic; but why is that? What if the picture showed your mother when she was eight years old? Would the decision still be automatic? What if you had to pick your mother out of a set of six pictures? What if it was a police officer you were speaking with and he was asking you to pick a criminal out of a lineup? Decision making underlies much of our behaviour and the impact of those decisions varies from negligible to changing lives. My research broadly concerns applied decision making, and more specifically concerns how people make decisions about faces.

Eyewitness Memory: Lineups

Eyewitness memory refers to memory for a criminal event. When someone witnesses a crime, the police often ask them to describe the criminal, and then they search for a suspect. Once a suspect is found, witnesses are often asked to view police lineups. Criminal investigations and convictions rely heavily on eyewitness testimony in court. In particular, the conviction of a perpetrator may depend on whether a witness selects the suspect from a police lineup. This decision includes whether to identify anyone at all, the choice of a particular person, and the confidence associated with these decisions. I am interested in how this decision process occurs.

Much of my research concerns how the decision to identify someone from a lineup varies under different circumstances, such as when the criminal was wearing a disguise at the time of the crime, when the lineup members were presented one at a time (simultaneous) versus all at once (sequentially), when the witness viewed the criminal for a short versus a long time, when different kinds of instructions about how to make the decision are given to witnesses, etc.

Eyewitness Memory: The Weapon Focus Effect

The Weapon Focus Effect refers to findings that witnesses have poorer eyewitness memories when they witness events involving a weapon than when they witness events not involving a weapon. Witnesses may focus on a weapon to the exclusion of other items such as the face of a perpetrator or other witnesses. However, the weapon focus effect has found differential support. Laboratory research reliably shows the Weapon Focus Effect but reviews of actual eyewitness testimony paint a different picture. Eyewitnesses to real crimes have much better memory for peripheral details in the presence versus absence of weapons than participants in most studies. I am currently testing possible reasons for this discrepancy.

Face Recognition

Quality of memory is obviously related to recognition accuracy: you are much more likely to recognize your mother than your waiter from dinner last week. How are good quality memories produced? Should this be defined in terms of duration, frequency, or pattern of encoding? What constitutes a single exposure to a face? In order to understand how faces move from being unfamiliar to familiar, it is important to define what the unit of exposure that produces memory.

Friendly Fire

Pat Tillman was a well-known football player for the Arizona Cardinals who quit his career in the NFL to join the US Army Rangers. In April of 2004 he was shot and killed by fellow American soldiers. Friendly fire is a concern for police forces and the military. One line of research I am following concerns the cues that lead to friendly fire. Some that have been looked at by myself and others include individual factors (impulsivity, stereotypes), perceptual factors (motion), and appearance (pose, presence of an object, clothing).