Biomedical subjects

David I Perrett

Publications and source records attributed to David I Perrett.

29 records · Page 2Linked to original sources

PubMed2004

Demystifying social cognition: a Hebbian perspective.

For humans and monkeys, understanding the actions of others is central to survival. Here we review the physiological properties of three cortical areas involved in this capacity: the STS, PF and F5. Based on the anatomical connections of these areas, and the Hebbian learning rule, we propose a simple but powerful account of how the monkey brain can learn to understand the actions of others by associating them with self-produced actions, at the same time discriminating its own actions from those of others. As this system appears also to exist in man, this network model can provide a framework for understanding human social perception.

Animals↗

PubMed2004

When facial attractiveness is only skin deep.

Whilst the relationship between aspects of facial shape and attractiveness has been extensively studied, few studies have investigated which characteristics of the surface of faces positively influence attractiveness judgments. As many researchers have proposed a link between attractiveness and traits that appear healthy, apparent health of facial skin might be a property of the surface of faces that positively influences attractiveness judgments. In experiment 1 we tested for a positive correlation between ratings of the apparent health of small skin patches (extracted from the left and right cheeks of digital face images) and ratings of the attractiveness of male faces. By using computer-graphics faces, in experiment 2 we aimed to establish if apparent health of skin influences male facial attractiveness independently of shape information. Results suggest that apparent health of facial skin is correlated both with ratings of male facial attractiveness (experiment 1) and with being a visual cue for judgments of the attractiveness of male faces (experiment 2). These findings underline the importance of controlling for the influence of visible skin condition in studies of facial attractiveness and are consistent with the proposal that attractive physical traits are those that positively influence others' perceptions of an individual's health.

Adult↗

PubMed2004

Perception of facial expressions of emotion in bipolar disorder.

OBJECTIVES: Some studies have reported deficits in the perception of facial expressions among depressed individuals compared with healthy controls, while others have reported negative biases in expression perception. We examined whether altered perception of emotion reflects an underlying trait-like effect in affective disorder by examining facial expression perception in euthymic bipolar patients. METHODS: Sensitivity to six different facial expressions, as well as accuracy of emotion recognition, was examined among 17 euthymic bipolar patients and 17 healthy controls using an interactive computer program. RESULTS: No differences were found between euthymic bipolar patients and controls in terms of sensitivity to any particular emotion. Although initial analysis of the data suggested impairment in the recognition of fear among the patients, identification of this emotion was not relatively impaired compared with that of the other emotions. CONCLUSIONS: The study did not find any conclusive evidence for trait-like deficits in the perception of facially conveyed emotions in bipolar disorder. Altered perception of facial expressions that has been found to accompany depressed mood may instead reflect mood-congruent biases.

Adolescent↗

PubMed2003

Evidence from rhesus macaques suggests that male coloration plays a role in female primate mate choice.

Male animals of many species use conspicuous coloration to attract mates. Among mammals, primates possess the most brilliant secondary sexual coloration. However, whether colour plays a part in primate female mate choice remains unknown. Adult male rhesus macaques undergo a hormonally regulated increased reddening of facial and anogenital skin during their mating season. We experimentally investigated whether red male facial coloration is preferred by simultaneously presenting female rhesus macaques (n = 6) with computer-manipulated pale and red versions of 24 different male faces. The duration and direction of gaze were measured to discern visual preferences. Females exhibited preferences for the red versions of male faces. It is proposed that male coloration might provide a cue to male quality.

Animals↗

PubMed2003

Perceptual history influences neural responses to face and body postures.

We show that under natural viewing, the responses of cells the temporal lobe of the macaque to the sight of static head body postures is controlled by the sight of immediately actions. Cells in the anterior part of the superior sulcus responded vigorously to the sight of a face or posture that followed a particular body action, but not when it followed other actions. The effective action or posture presented in isolation or in different sequences failed to produce a response. Our results demonstrate that cells in the temporal cortex could support the formation of expectations about impending behavior of others.

Action Potentials↗

PubMed2003

Being the target of another's emotion: a PET study.

The eye region and gaze behaviour are known to play a major role in conveying information about direction of attention and emotional dispositions. Positron emission tomography scanning was used to explore the cerebral structures involved while subjects were asked to attribute hostile or friendly intentions to video-taped actors who directed attention towards or away from the subjects. As expected, a number of brain regions known to be involved in emotion processing was found activated when subjects had to attribute an emotion regardless of gaze direction. In addition, results indicate that gaze direction has an impact on the brain regions recruited to interpret emotions. The anterior region of the superior temporal gyrus (STG) was selectively activated during analysis of emotions through eye contact. This result provides neurophysiological evidence for privileged processing when an individual becomes personally involved as the object of another's emotions.

Adult↗

PubMed2003

Facial expression recognition in Williams syndrome.

Individuals with Williams syndrome (WS) excel in face recognition and show both a remarkable concern for social stimuli and a linguistic capacity for, in particular, emotionally referenced language. The animated full facial expression comprehension test (AFFECT), a new test of emotional expression perception, was used to compare participants with WS with both chronological and mental age-matched controls. It was found that expression recognition in WS was worse than that of chronologically age-matched controls but indistinguishable from that of mental age controls. Different processing strategies are thought to underlie the similar performance of individuals with WS and mental age controls. The expression recognition performance of individuals with WS did not correlate with age, but was instead found to correlate with IQ. This is compared to earlier findings, replicated here, that face recognition performance on the Benton test correlates with age and not IQ. The results of the Benton test have been explained in terms of individuals with WS being good at face recognition; since a piecemeal strategy can be used, this strategy is improved with practice which would explain the correlation with age. We propose that poor expression recognition of the individuals with WS is due to a lack of configural ability since changes in the configuration of the face are an important part of expressions. Furthermore, these reduced configural abilities may be due to abnormal neuronal development and are thus fixed from an early age.

Adolescent↗

PubMed2003

Cells in monkey STS responsive to articulated body motions and consequent static posture: a case of implied motion?

We show that populations of visually responsive cells in the anterior part of the superior temporal sulcus (STSa) of the macaque monkey code for the sight of both specific articulated body actions and the consequent articulated static body postures. We define articulated actions as actions where one body part (e.g. a limb or head) moves with respect to the remainder of the body which remains static; conversely non-articulated actions are actions where the equivalent body parts do not move with respect to each other but move as one. Similarly, articulated static body postures contain a torsion or rotation between parts, while non-articulated postures do not. Cells were tested with the sight of articulated and non-articulated actions followed by the resultant articulated or non-articulated static body postures. In addition, the static body postures that formed the start and end of the actions were tested in isolation. The cells studied did not respond to the sight of non-articulated static posture, which formed the starting-point of the action, but responded vigorously to the articulated static posture that formed the end-point of the action. Other static postures resembling the articulated end-point posture, but which were in a more relaxed muscular state (i.e. non-articulated), did not evoke responses. The cells did not respond to body actions that were less often associated with the effective static articulated postures. Our results suggest that the cells' responses were related to the implied action rather than the static posture per se. We propose that the neural representations in STSa for actual biological motion may also extend to biological motion implied from static postures. These representations could play a role in producing the activity in the medial temporal/medial superior temporal (V5(MT)/MST) areas reported in fMRI studies when subjects view still photographs of people in action.

Action Potentials↗

PubMed2003

Perceptual judgements of others' tasting experiences: are they enjoying their food?

Motivated by previous work suggesting that infants make stereotypic facial reactions to different tastes, we assessed communicative signals that might enable an adult to interpret the strength, taste, and hedonic value of a liquid flavour another adult is consuming. Four subjects (tasters) were overtly videoed consuming drinks that varied in strength (low, medium, and high concentrations), taste (sweet, sour, bitter, and salty), and hedonic value (taster-rated enjoyment). 26 observers assessed the strength, taste, and taster's enjoyment of the drink from video clips of the tasters. Observers perceived the hedonic value of the drinks to the taster and the drinks' strength based on the tasters' reactions but were generally poor at assessing the specific taste of the drink. For all tastes except the bitter ones, observers might have based their judgements of taste on how much the taster appeared to enjoy the drink. These findings are discussed in terms of communication of food's value.

Adult↗

PubMed2002

Facial affect perception in alcoholics.

Satisfactory interpersonal interaction involves understanding others' facial expressions. Alcoholic individuals often have severe interpersonal difficulties that may relate to poor and distorted perception of facial expressions. The importance of attention direction has been highlighted by the finding, in recent primate studies, of neurons responsible for the detection of attention direction. Studies on humans suggest that expression perception is modulated by attention direction (whether the expression is directed towards or away from the observer). Here, for the first time, the relationship between attention direction and perception of expression (anger, sadness, happiness and disgust) in alcoholic and control subjects is investigated. We used animated facial stimuli depicting different emotions to give measures of recognition accuracy and of perceptual sensitivity. Our study demonstrated that alcoholics made more errors than control subjects in recognising expressions generally and had a tendency to mis-label sad expressions directed towards them as being hostile (angry/disgusted). When asked to select the point when they started to see the expression, alcoholics, especially female alcoholics, chose higher expression intensities. This study highlights the importance of investigating the modulating effects of attention direction when studying the perception of expressions and provides an indication of how alcoholics' inappropriate social reactions may be triggered.

Adult↗

PubMed2002

Facial attractiveness judgements reflect learning of parental age characteristics.

Mate preferences are shaped by infant experience of parental characteristics in a wide variety of species. Similar processes in humans may lead to physical similarity between parents and mates, yet this possibility has received little attention. The age of parents is one salient physical characteristic that offspring may attend to. The current study used computer-graphic faces to examine how preferences for age in faces were influenced by parental age. We found that women born to 'old' parents (over 30) were less impressed by youth, and more attracted to age cues in male faces than women with 'young' parents (under 30). For men, preferences for female faces were influenced by their mother's age and not their father's age, but only for long-term relationships. These data indicate that judgements of facial attractiveness in humans reflect the learning of parental characteristics.

Adult↗