Otto H. MacLin

Eyewitness decisions in simultaneous and sequential lineups: a dual-process signal detection theory analysis.

Many eyewitness researchers have argued for the application of a sequential alternative to the traditional simultaneous lineup, given its role in decreasing false identifications of innocent suspects (sequential superiority effect). However, Ebbesen and Flowe (2002) have recently noted that sequential lineups may merely bring about a shift in response criterion, having no effect on discrimination accuracy. We explored this claim, using a method that allows signal detection theory measures to be collected from eyewitnesses. In three experiments, lineup type was factorially combined with conditions expected to influence response criterion and/or discrimination accuracy. Results were consistent with signal detection theory predictions, including that of a conservative criterion shift with the sequential presentation of lineups. In a fourth experiment, we explored the phenomenological basis for the criterion shift, using the remember—know—guess procedure. In accord with previous research, the criterion shift in sequential lineups was associated with a reduction in familiarity-based responding. It is proposed that the relative similarity between lineup members may create a context in which fluency-based processing is facilitated to a greater extent when lineup members are presented simultaneously.

RACE, AROUSAL, ATTENTION, EXPOSURE, AND DELAY An Examination of Factors Moderating Face Recognition

Otto H. MacLin, M. Kimberly MacLin, and Roy S. MalpassUniversity of Texas at El PasoA large percentage of people recently exonerated by DNA evidence were impris-oned on the basis of faulty eyewitness identification. Many of these cases involvedvictims and suspects of different races. Two studies examined the recognition ofHispanic and Black target faces by Hispanic participants under nonoptimal viewingconditions. When viewing time decreased, recognition performance for same- andother-race faces systematically shifted downward. Recognition accuracy for faces ofboth races decreased under conditions of high negative arousal and attention load;however, recognition of same-race faces was differentially affected by attentiondistractors. Face recognition accuracy was not affected by a delay between initialpresentation of the faces and the face recognition test. An understanding of howrecognition of other-race persons differs from that of same-race persons can assistby reducing misidentifications and ensuring that the perpetrator rather than aninnocent person is imprisoned.Eyewitness testimony often serves as direct evidence in a courtroom settingand can have a strong influence on juries (Loftus, 1974; Penrod & Cutler, 1995).Unfortunately, eyewitness identification is imperfect and can at times lead to theconviction of innocent people, as evidenced by a series of recent DNA exoner-ation cases. Breakthroughs in DNA testing have facilitated the isolation of factorsthat lead to false imprisonment. Of 62 cases examined, 52 involved mistakenidentifications (Connors, Lundregan, Miller, & McEwan, 1996; Scheck, Neufeld,& Dwyer, 2000). In 69% of the misidentification cases, the victim was White,whereas in 57% of those cases the exonerated defendant was Black, whichindicates that a proportionally greater number of misidentifications occurredacross racial lines.This finding may come as no surprise to anyone familiar with the phenom-enon commonly known as the own-race effect, cross-race effect, or own-race bias(Chance & Goldstein, 1996; Malpass & Kravitz, 1969; Brigham & Malpass,1985), which posits that people perform poorly when attempting to recognize aperson of a different race (Meissner & Brigham, 2001). A large body of literatureexists that examines factors affecting the recognition of own-race faces, such asdistinctiveness of the face, sex of the face, age of the witness, attention, arousal,exposure, and delay between observation and testing; however, only 18% of the

Using a computer simulation of three slot machines to investigate a gambler’s preference among varying densities of near-miss alternatives

The present article describes a software program in Visual Basic .NET designed to simulate three slot machines on a computer screen. This software is described in detail regarding utility, downloading, and usage; and data are presented illustrating the software’s potential for researchers interested in gambling behavior. A simulation of multiple slot machines such as this enables researchers to evaluate players’ preferences across various machines. In the highlighted experiment, 18 recreational slot machine players played the software for extra course credit and a chance at cash prizes. All participants played a version of the simulation in which every 5th response on average was a win, whereas the remaining trials were a loss. However, on those loss trials, a varying distribution of almost wins or near misses (i.e., two winning symbols on the payoff line and the final winning symbol directly above or below the payoff line) were presented in percentages of 15, 30, or 45. While no preferences across the three options could be predicted on the basis of reinforcement history alone, deviations from equal choices across the games were noted and appeared to be the result of the presentations of near-miss losing trials. Implications for a greater understanding of pathological gambling are presented.

An evaluation of response allocations to concurrently available slot machine simulations.

Gambling behavior often involves making choices between concurrently available game options. With regard to slot machine gambling, multiple games allow for choices to be made with respect to which game to play. The authors of the present study used a slot machine simulation created in Visual Basic. NET to examine gambling preference. The specific question addressed was whether gamblers prefer a smaller payout more often (averaging around every 10 spins) over a larger payout less often (averaging around every 50 spins). Two types of reinforcement were examined during the study: frequency of payouts and the amount of credits won. The results indicate that participants had a preference for a slot machine with the more frequent payout as opposed to one with more intermittent payout. These results support existing literature on theories of choice and provide a step toward understanding human gambling behavior.

Perceptual identification and the cross-race effect

The current research examined whether the cross-race effect (CRE) was evident in perceptual identification tasks and the extent to which certain boundary conditions moderated the effect. Across two experiments, a significant CRE was observed in measures of accuracy and response latency. As predicted, Experiment 1 showed that the CRE was exacerbated when encoding time was brief and test set size was increased. Experiment 2 replicated the effect of set size, but also showed that the CRE was more pronounced when the retention interval was lengthened. The theoretical and practical implications of the results are discussed.

Coding observational data: A software solution

The analysis of observational data, particularly from social interactions, is often made difficult by the process of transcribing the verbal and behavioral interactions, having observers code on the transcriptions, and then transferring those codes to a statistical analysis program. The advent of computeraided coding schemes has, to some extent, eliminated this laborious and time-consuming process. However, existing programs may not fulfill the needs of all of the researchers interested in this methodology, and furthermore, the expense of current systems may put these tools out of reach for some. The Observational Data Coding System (ODCS) software package presented here is a flexible coding tool designed to make efficient the process of coding observational data. A control panel allows the researcher to customize the program and coding system to suit his or her research questions. A variety of media (including video, audio, image, and text) can be read directly into the Windows-based program; trained observers can then code a variety of factors via buttons on the screen while the file is playing. An example of using the program to analyze conversation is provided. ODCS is a flexible, free tool for the coding of observational data.

PC_Eyewitness: A computerized framework for the administration and practical application of research in eyewitness psychology

Eyewitness identification evidence is an important aspect of our legal system. Society relies on witnesses to identify suspects whom they have observed during the commission of a crime. Because a witness has only a mental representation of the individual he or she observed, law enforcement must rely on verbal descriptions and identification procedures to document eyewitness evidence. The present article introduces and details a computer program, referred to asPC_Eyewitness (PCE), which can be used in laboratories to conduct research on eyewitness memory. PCE is a modular program written in Visual Basic 6.0 that allows a researcher to present stimuli to a participant, to conduct distractor tasks, to elicit verbal descriptors regarding a target individual, and to present a lineup for the participant to provide an identification response. To illustrate the versatility of the program, several classic studies in the eyewitness literature are recreated in the context of PC E. The program is also shown to have applications in the conduct of field research and for use by law enforcement to administer lineups in everyday practice. PCE is distributed at no cost.

A computerized simulation for investigating gambling behavior during roulette play

The present paper describes a computerized roulette program for the conducting of psychological research on gambling behavior. The program was designed to simulate an actual roulette game found in casinos and gambling riverboats throughout North America. The roulette program collects detailed trial-by-trial data on player/participant behavior that can easily be transferred into data analysis and graphics programs. This multimedia simulation was designed in the Visual Basic programming language, and it is capable of running on any IBM-compatible personal computer running the Windows 2000 or higher operating system.

PC_Eyewitness: Evaluating the New Jersey method

One important variable in eyewitness identification research is lineup administration procedure. Lineups administered sequentially (one at a time) have been shown to reduce the number of false identifications in comparison with those administered simultaneously (all at once). As a result, some policymakers have adopted sequential administration. However, they have made slight changes to the method used in psychology laboratories. Eyewitnesses in the field are allowed to take multiple passes through a lineup, whereas participants in the laboratory are allowed only one pass. PC_Eyewitness (PCE) is a computerized system used to construct and administer simultaneous or sequential lineups in both the laboratory and the field. It is currently being used in laboratories investigating eyewitness identification in the United States, Canada, and abroad. A modified version of PCE is also being developed for a local police department. We developed a new module for PCE, the New Jersey module, to examine the effects of a second pass. We found that the sequential advantage was eliminated when the participants were allowed to view the lineup a second time. The New Jersey module, and steps we are taking to improve on the module, are presented here and are being made available to the research and law enforcement communities.

Social psychophysics: Using psychophysics to answer “social” questions with PsychoPro

Complex social stimuli (like faces) can be studied using a methodology typically reserved for studying lights, tones, and colors: psychophysics. Given that psychophysics examines how humans detect and respond to stimuli in their environment, we can extend that to the study of how humans detect social stimuli in the environment. Using psychophysical methodology to answer “social” questions provides another dimension of experimental manipulation and control to the diverse array of methodologies already used by social psychologists. In this article, we review psychophysical methodology, provide a rationale for social psychophysics, describe an easy-touse software program called PsychoPro, for collecting psychophysical data, and present data collected using this program to examine racial thresholds that provide evidence for a cognitive gating mechanism for racial information that impacts face processing (MacLin & MacLin, 2007, in press; MacLin, MacLin, & Peterson, 2008).