EVENT: Psychology Colloquium: John Wixted (UCSD) on models of lineup memory

Psychology Colloquium

Tuesday 20th June 4:30-5:30pm in Bayliss MCS G.33

Presenter: Prof John Wixted (UCSD)

Title: Models of Lineup Memory

Abstract:

Both in the lab and in the field, face recognition memory is often tested using a photo lineup. A photo lineup typically consists of six or more photos, one of a suspect, who is either guilty (previously seen) or innocent (not previously seen), and several others of physically similar fillers, all of whom are known to be innocent. For many years, different photo lineup formats, such as presenting the photos simultaneously or sequentially, have been tested to determine if one format is diagnostically superior to the other. Recently, and inspired by signal detection theory, competing lineup formats have been compared using receiver operating characteristic (ROC) analysis. The results generally show that presenting faces simultaneously improves the ability of eyewitnesses to discriminate between innocent and guilty suspects. Here, we present three competing signal-detection models of lineup recognition memory, derive their likelihood functions, and fit them to empirical ROC data from a variety of recent studies. The model that most accurately characterizes the ROC data incorporates an established principle from basic cognitive science known as "ensemble encoding," a principle that naturally applies to the presentation of a set of similar items (such as the faces in a lineup). The ensemble model also accords with a previously proposed theory of eyewitness identification according to which the simultaneous presentation of faces in a lineup enhances discriminability compared to when faces are presented in isolation by permitting witnesses to detect and discount non-diagnostic facial features (the same features that comprise the ensemble representation).

Speaker Bio:

John Wixted received his Ph.D. in 1987 from Emory University in clinical psychology and is now a Distinguished Professor of experimental psychology at the University of California, San Diego. His research is concerned with understanding the mechanisms of human memory, focusing on the neuroscience of memory and amnesia, signal-detection analyses of recognition memory, and, eyewitness memory. Professionally, he has served as editor-in-chief of Psychonomic Bulletin & Review, and he is the current editor-in-chief of the 4th Edition of the venerable Stevens' Handbook, now entitled the Stevens' Handbook of Experimental Psychology and Cognitive Neuroscience. He has won several teaching awards over the years, and in 2011, he was the recipient of the Howard Crosby Warren Medal for outstanding achievement in experimental psychology.

Ullrich Ecker, PhD Associate Professor Director, Community and Engagement School of Psychological Science University of Western Australia +61 (0)8 6488 3257 www.uwa.edu.au/people/ullrich.ecker www.cogsciwa.com