A narrow band of image dimensions is critical for face recognition.

A key challenge in human and computer face recognition is to differentiate information that is diagnostic for identity from other sources of image variation. Here, we used a combined computational and behavioural approach to reveal critical image dimensions for face recognition. Behavioural data were collected using a sorting and matching task with unfamiliar faces and a recognition task with familiar faces.

Perception of threat and intent to harm from vocal and facial cues.

What constitutes a "threatening tone of voice"? There is currently little research exploring how listeners infer threat, or the intention to cause harm, from speakers' voices. Here, we investigated the influence of key linguistic variables on these evaluations (Study 1). Results showed a trend for voices perceived to be lower in pitch, particularly those of male speakers, to be evaluated as sounding more threatening and conveying greater intent to harm.

The effect of pre-event instructions on eyewitness identification.

Research on eyewitness identification often involves exposing participants to a simulated crime and later testing memory using a lineup. We conducted a systematic review showing that pre-event instructions, instructions given before event exposure, are rarely reported and those that are reported vary in the extent to which they warn participants about the nature of the event or tasks. At odds with the experience of actual witnesses, some studies use pre-event instructions explicitly warning participants of the upcoming crime and lineup task.

Trait impressions from voices are formed rapidly within 400 ms of exposure.

When seeing a face or hearing a voice, perceivers readily form first impressions of a person's characteristics-are they trustworthy, do they seem aggressive? One of the key claims about trait impressions from faces and voices alike is that these impressions are formed rapidly. For faces, studies have systematically mapped this rapid time course of trait impressions, finding that they are well formed and stable after approximately 100 ms of exposure. For voices, however, no systematic investigation of the time course of trait perception exists.

Trait evaluations of faces and voices: Comparing within- and between-person variability.

Human faces and voices are rich sources of information that can vary in many different ways. Most of the literature on face/voice perception has focused on understanding how people look and sound different to each other (between-person variability). However, recent studies highlight the ways in which the same person can look and sound different on different occasions (within-person variability).

Multiple-image arrays in face matching tasks with and without memory.

Previous research has shown that exposure to within-person variability facilitates face learning. A different body of work has examined potential benefits of providing multiple images in face matching tasks. Viewers are asked to judge whether a target face matches a single face image (as when checking photo-ID) or multiple face images of the same person.

How does familiarity with a voice affect trait judgements?

From only a single spoken word, listeners can form a wealth of first impressions of a person's character traits and personality based on their voice. However, due to the substantial within-person variability in voices, these trait judgements are likely to be highly stimulus-dependent for unfamiliar voices: The same person may sound very trustworthy in one recording but less trustworthy in another. How trait judgements differ when listeners are familiar with a voice is unclear: Are listeners who are familiar with the voices as susceptible to the effects of within-person variability? Does the semantic knowledge listeners have about a familiar person influence their judgements? In the current study, we tested the effect of familiarity on listeners' trait judgements from variable voices across 3 experiments.

Facial identity across the lifespan.

We can recognise people that we know across their lifespan. We see family members age, and we can recognise celebrities across long careers. How is this possible, despite the very large facial changes that occur as people get older? Here we analyse the statistical properties of faces as they age, sampling photos of the same people from their 20s to their 70s.

Face search in CCTV surveillance.

Background: We present a series of experiments on visual search in a highly complex environment, security closed-circuit television (CCTV). Using real surveillance footage from a large city transport hub, we ask viewers to search for target individuals. Search targets are presented in a number of ways, using naturally occurring images including their passports and photo ID, social media and custody images/videos.

The Role of Face and Voice Cues in Predicting the Outcome of Student Representative Elections.

First impressions formed after seeing someone's face or hearing their voice can affect many social decisions, including voting in political elections. Despite the many studies investigating the independent contribution of face and voice cues to electoral success, their integration is still not well understood. Here, we examine a novel electoral context, student representative ballots, allowing us to test the generalizability of previous studies.

Understanding facial impressions between and within identities.

A paradoxical finding from recent studies of face perception is that observers are error-prone and inconsistent when judging the identity of unfamiliar faces, but nevertheless reasonably consistent when judging traits. Our aim is to understand this difference. Using everyday ambient images of faces, we show that visual image statistics can predict observers' consensual impressions of trustworthiness, attractiveness and dominance, which represent key dimensions of evaluation in leading theoretical accounts of trait judgement.

Social Evaluation of Faces Across Gender and Familiarity.

Models of social evaluation aim to capture the information people use to form first impressions of unfamiliar others. However, little is currently known about the relationship between perceived traits across gender. In Study 1, we asked viewers to provide ratings of key social dimensions (dominance, trustworthiness, etc.

Inter-rater agreement in trait judgements from faces.

Researchers have long been interested in how social evaluations are made based upon first impressions of faces. It is also important to consider the level of agreement we see in such evaluations across raters and what this may tell us. Typically, high levels of inter-rater agreement for facial judgements are reported, but the measures used may be misleading.

Smiles in face matching: Idiosyncratic information revealed through a smile improves unfamiliar face matching performance.

Unfamiliar face matching is a surprisingly difficult task, yet we often rely on people's matching decisions in applied settings (e.g., border control).

Audiovisual integration in social evaluation.

Our social evaluation of other people is influenced by their faces and their voices. However, rather little is known about how these channels combine in forming "first impressions." Over 5 experiments, we investigate the relative contributions of facial and vocal information for social judgments: dominance and trustworthiness.