Identity-lineup location influences target selection: evidence from eye movements

Eyewitnesses often have to recognize the perpetrators of an observed crime from identity lineups. In the construction of these lineups, a decision must be made concerning where a suspect should be placed, but whether location in a lineup affects the identification of a perpetrator has received little attention. This study explored this problem with a face-matching task, in which observers decided if pairs of faces depict the same person or two different people (Experiment 1), and with a lineup task in which the presence of a target had to be detected in an identity parade of five faces (Experiment 2). In addition, this study also explored if high accuracy is related to a perceptual pop-out effect, whereby the target is detected rapidly among the lineup. In both experiments, observers' eye movements revealed that location determines the order in which people were viewed, whereby faces on the left side were consistently viewed first. This location effect was reflected also in observers' responses, so that a foil face on the left side of a lineup display was more likely to be misidentified as the target. However, identification accuracy was not related to a pop-out effect. The implications of these findings are discussed.