An exploration of visual behaviour in eyewitness identification tests

The contribution of internal (eyes, nose and mouth) and external (hair‐line, cheek and jawline) features across eyewitness identification tests was examined using eye tracking. In Experiment 1, participants studied faces and were tested with lineups, either simultaneous (test faces presented in an array) or sequential (test faces presented one at a time). In Experiment 2, the recognition of previously studied faces was tested in a showup (a suspect face alone was presented). Results indicated that foils were analysed for a shorter period of time in the simultaneous compared to the sequential condition, whereas a positively identified face was analysed for a comparable period of time across lineup procedures. In simultaneous lineups and showups, a greater proportion of time was spent analysing internal features of the test faces compared to sequential lineups. Different decision processes across eyewitness identification tests are inferred based on the results

The effects of acute alcohol intoxication on the cognitive mechanisms underlying false facial recognition

Rationale False face recognition rates are sometimes higher when faces are learned while under the influence of alcohol. Alcohol myopia theory (AMT) proposes that acute alcohol intoxication during face learning causes people to attend to only the most salient features of a face, impairing the encoding of less salient facial features. Yet, there is currently no direct evidence to support this claim. Objectives Our objective was to test whether acute alcohol intoxication impairs face learning by causing subjects to attend to a salient (i.e., distinctive) facial feature over other facial features, as per AMT. Methods We employed a balanced placebo design (N = 100). Subjects in the alcohol group were dosed to achieve a blood alcohol concentration (BAC) of 0.06 %, whereas the no alcohol group consumed tonic water. Alcohol expectancy was controlled. Subjects studied faces with or without a distinctive feature (e.g., scar, piercing). An old-new recognition test followed. Some of the test faces were “old” (i.e., previously studied), and some were “new” (i.e., not previously studied). We varied whether the new test faces had a previously studied distinctive feature versus other familiar characteristics. Results Intoxicated and sober recognition accuracy was comparable, but subjects in the alcohol group made more positive identifications overall compared to the no alcohol group. Conclusions The results are not in keeping with AMT. Rather, a more general cognitive mechanism appears to underlie false face recognition in intoxicated subjects. Specifically, acute alcohol intoxication during face learning results in more liberal choosing, perhaps because of an increased reliance on familiarity

The effect of lineup member similarity on recognition accuracy in simultaneous and sequential lineups.

Two experiments investigated whether remembering is affected by the similarity of the study face relative to the alternatives in a lineup. In simultaneous and sequential lineups, choice rates and false alarms were larger in low compared to high similarity lineups, indicating criterion placement was affected by lineup similarity structure (Experiment 1). In Experiment 2, foil choices and similarity ranking data for target present lineups were compared to responses made when the target was removed from the lineup (only the 5 foils were presented). The results indicated that although foils were selected more often in target-removed lineups in the simultaneous compared to the sequential condition, responses shifted from the target to one of the foils at equal rates across lineup procedures

Simultaneous v. sequential lineups: What do we really know?

Both conceptual and metaanalyses of the effects of simultaneous and sequential lineup testing procedures on false alarm and hit rates suggest that recent interest in moving to sequential lineups might be premature. A simple criterion-shift model based on signal detection analysis accounted for the results from the metaanalysis raising concern that the previously accepted relative v. absolute decision strategy view may be incorrect. The accepted view that hit rates will be unaffected by a change in procedure may be incorrect. Monte Carlo simulation results raise the possibility that serial position might play a much larger and more complicated role in performance on sequential lineups than has been considered. Much more research is needed before the sequential procedure is adopted

An examination of criminal face bias in a random sample of police lineups

Faces with a stereotypic criminal appearance are remembered better and identified more often than other faces according to past research. In the present project, a random sample of police lineups was evaluated using the mock witness paradigm to determine whether criminal appearance was associated with lineup choices. In Study 1, mock witnesses were either provided with a description of the culprit or they were not. Participants also self-reported why they had selected a given face. In Study 2, the line-up faces were rated with respect to criminal appearance, distinctiveness, typicality, and physical similarity. Criminal appearance was the primary reason self reported for face selection in the no description condition. Mock witness choices in the no description condition were associated with only criminal appearance. When provided with a description, mock witnesses based their choice on the description. These findings are discussed in relation to lineup fairness

Eye tracking and eyewitness memory.

For more than a century psychologists have utilized eye tracking as a window into how we think and how we feel, and to test theories of the mind and its mental processes. A range of forensic topics has been investigated with eye tracking, such as the effect of weapon exposure (e.g., Hope & Wright, 2008), visual attention in anti-social personality disorder (e.g., Ceballos & Bauer, 2004), and the role of expertise in deception detection (Bond, 2008). Recently, researchers have begun to use eye tracking to study eyewitness decision processes in criminal lineup identification (e.g., Mansour, Lindsay, Brewer, & Munhall, 2009). This paper reviews the application of eye tracking technology in criminal identification lineup research and discusses issues that arise in translating eye movements to reveal eyewitness decision processes

An examination of simultaneous lineup identification decision processes using eye tracking

An examination of simultaneous lineup identification decision processes using eye trackin

Receiver operating characteristic analysis of eyewitness memory: comparing the diagnostic accuracy of simultaneous versus sequential lineups.

A police lineup presents a real-world signal-detection problem because there are two possible states of the world (the suspect is either innocent or guilty), some degree of information about the true state of the world is available (the eyewitness has some degree of memory for the perpetrator), and a decision is made (identifying the suspect or not). A similar state of affairs applies to diagnostic tests in medicine because, in a patient, the disease is either present or absent, a diagnostic test yields some degree of information about the true state of affairs, and a decision is made about the presence or absence of the disease. In medicine, Receiver Operating Characteristic (ROC) analysis is the standard method for assessing diagnostic accuracy. By contrast, in the eyewitness memory literature, this powerful technique has never been used. Instead, researchers have attempted to assess the diagnostic performance of different lineup procedures using methods that cannot identify the better procedure (e.g., by computing a diagnosticity ratio). Here, we describe the basics of ROC analysis, explaining why it is needed and showing how to use it to measure the performance of different lineup procedures. To illustrate the unique advantages of this technique, we also report three ROC experiments that were designed to investigate the diagnostic accuracy of simultaneous vs. sequential lineups. According to our findings, the sequential procedure appears to be inferior to the simultaneous procedure in discriminating between the presence vs. absence of a guilty suspect in a lineup

The effects of masculinity and suspect gender on perceptions of guilt

This study investigated whether perceptions of guilt for both male and female suspects co-­varied with masculine physical appearance. In addition, the study tested whether the relationship between masculine physical appearance and perceptions of guilt was dependent upon whether the crime is stereotypically male perpetrated. Participants read one of three crime scenarios (burglary, child abuse and neglect, fraud and forgery) and evaluated the likelihood that suspects of varying masculine appearance committed the crime in question. Masculine physical appearance significantly affected guilt ratings across all crime types for both male and female suspects. Additionally, guilt ratings for male compared to female suspects were higher for burglary, a crime that was viewed as stereotypically male perpetrated by research participants. The results are discussed in relation to applied implications and future research directions

The role of eyewitness identification evidence in felony case dispositions.

We addressed the question of whether felony case dispositions are associated with eyewitness identification evidence. Toward this end, 725 felony cases (rape, robbery, and assault) were randomly sampled from the archives of a District Attorney’s Office in a large south-western city in the United States. Positive eyewitness identification evidence was more likely in cases issued compared to those rejected for prosecution although other case factors were associated with issuing outcomes to a larger extent. Additionally, eyewitness identification evidence was stronger in prosecuted compared to rejected cases in which eyewitness testimony was the sole evidence against the defendant. Neither the presence of multiple identifications nor non-identifications of the suspect varied across issuing outcomes. The findings are discussed in relation to additional research that is needed at the police and prosecution stages to advance public policy development with respect to the evaluation of eyewitness identification evidence