Harriet M. J. Smith

Concordant Cues in Faces and Voices: Testing the Backup Signal Hypothesis

Information from faces and voices combines to provide multimodal signals about a person. Faces and voices may offer redundant, overlapping (backup signals), or complementary information (multiple messages). This article reports two experiments which investigated the extent to which faces and voices deliver concordant information about dimensions of fitness and quality. In Experiment 1, participants rated faces and voices on scales for masculinity/femininity, age, health, height, and weight. The results showed that people make similar judgments from faces and voices, with particularly strong correlations for masculinity/femininity, health, and height. If, as these results suggest, faces and voices constitute backup signals for various dimensions, it is hypothetically possible that people would be able to accurately match novel faces and voices for identity. However, previous investigations into novel face–voice matching offer contradictory results. In Experiment 2, participants saw a face and heard a voice and were required to decide whether the face and voice belonged to the same person. Matching accuracy was significantly above chance level, suggesting that judgments made independently from faces and voices are sufficiently similar that people can match the two. Both sets of results were analyzed using multilevel modeling and are interpreted as being consistent with the backup signal hypothesis.

Matching novel face and voice identity using static and dynamic facial images

Research investigating whether faces and voices share common source identity information has offered contradictory results. Accurate face–voice matching is consistently above chance when the facial stimuli are dynamic, but not when the facial stimuli are static. We tested whether procedural differences might help to account for the previous inconsistencies. In Experiment 1, participants completed a sequential two-alternative forced choice matching task. They either heard a voice and then saw two faces or saw a face and then heard two voices. Face–voice matching was above chance when the facial stimuli were dynamic and articulating, but not when they were static. In Experiment 2, we tested whether matching was more accurate when faces and voices were presented simultaneously. The participants saw two face–voice combinations, presented one after the other. They had to decide which combination was the same identity. As in Experiment 1, only dynamic face–voice matching was above chance. In Experiment 3, participants heard a voice and then saw two static faces presented simultaneously. With this procedure, static face–voice matching was above chance. The overall results, analyzed using multilevel modeling, showed that voices and dynamic articulating faces, as well as voices and static faces, share concordant source identity information. It seems, therefore, that above-chance static face–voice matching is sensitive to the experimental procedure employed. In addition, the inconsistencies in previous research might depend on the specific stimulus sets used; our multilevel modeling analyses show that some people look and sound more similar than others.

Configural and component processing in simultaneous and sequential lineup procedures

Configural processing supports accurate face recognition, yet it has never been examined within the context of criminal identification lineups. We tested, using the inversion paradigm, the role of configural processing in lineups. Recent research has found that face discrimination accuracy in lineups is better in a simultaneous compared to a sequential lineup procedure. Therefore, we compared configural processing in simultaneous and sequential lineups to examine whether there are differences. We had participants view a crime video, and then they attempted to identify the perpetrator from a simultaneous or sequential lineup. The test faces were presented either upright or inverted, as previous research has shown that inverting test faces disrupts configural processing. The size of the inversion effect for faces was the same across lineup procedures, indicating that configural processing underlies face recognition in both procedures. Discrimination accuracy was comparable across lineup procedures in both the upright and inversion condition. Theoretical implications of the results are discussed.

The effect of inserting an inter-stimulus interval in face–voice matching tasks:

Voices and static faces can be matched for identity above chance level. No previous face–voice matching experiments have included an inter-stimulus interval (ISI) exceeding 1 s. We tested whether accurate identity decisions rely on high-quality perceptual representations temporarily stored in sensory memory, and therefore whether the ability to make accurate matching decisions diminishes as the ISI increases. In each trial, participants had to decide whether an unfamiliar face and voice belonged to the same person. The face and voice stimuli were presented simultaneously in Experiment 1, and there was a 5-s ISI in Experiment 2, and a 10-s interval in Experiment 3. The results, analysed using multilevel modelling, revealed that static face–voice matching was significantly above chance level only when the stimuli were presented simultaneously (Experiment 1). The overall bias to respond same identity weakened as the interval increased, suggesting that this bias is explained by temporal contiguity. Taken together, the findings highlight that face–voice matching performance is reliant on comparing fast-decaying, high-quality perceptual representations. The results are discussed in terms of social functioning.

Memory judgements: the contribution of detail and emotion to assessments of believability and reliability

ABSTRACT In legal settings, jury members, police, and legal professionals often have to make judgements about witnesses’ or victims’ memories of events. Without a scientific understanding of memory, (often erroneous) beliefs are used to make decisions. Evaluation of the literature identified two prevalent beliefs that could influence judgements: (1) memory operates like a video recorder therefore, accounts that are detailed are more believable than those containing vague descriptions, and (2) memories recalled with congruent emotion are more believable than those recalled with incongruent emotion. A 2 (emotionality: emotional, non-emotional) × 2 (detail: high, low) factorial design was generated. In line with previous research, participants made believability judgements (Experiment 1) but uniquely, participants were also asked to judge the reliability of the rememberer’s recall (Experiment 2). Self-reported confidence, personality measures, and political orientation were also recorded. Believability judgements did not vary as a function of detail or emotion but detailed accounts were judged as more reliable than vague accounts. Confidence and believability were positively correlated, whereas the confidence-reliability relationship was more complex. Personality and political measures were independent of judgements of both constructs. Our results suggest that believability and reliability are distinct constructs and should be examined as such in future research.