Biomedical subjects

David I Perrett

Publications and source records attributed to David I Perrett.

At least 19 recordsLinked to original sources

PubMed2006

Reproductive strategy, sexual development and attraction to facial characteristics.

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics.

Adolescent↗

PubMed2006

Facial and bodily correlates of family background.

It has been suggested that absence of the father during early childhood has long-reaching effects on reproductive strategy and development of offspring. This paper reports two studies designed to investigate the physical characteristics of daughters associated with father absence. Study 1 used a facial averaging method to produce composite images of faces of women whose parents separated during their childhood (who were 'father absent'), women whose parents remained together, but had poor quality relationships and women whose parents were together and had good quality relationships. Images were then rated by male and female judges. Father absence and poor parental relationships were associated with apparent facial masculinity and reduced attractiveness in daughters. Poor parental relationships were also associated with reduced apparent health. Study 2 compared family background with body measurements and found that father absence or a poor quality relationship between parents were associated with body masculinity (high waist-to-hip ratio) and increased weight-for-height and adiposity. These results highlight the possibility of physical masculinization being associated with purported father absence 'effects'.

Adolescent↗

PubMed2006

Brain systems for assessing facial attractiveness.

Attractiveness is a facial attribute that shapes human affiliative behaviours. In a previous study we reported a linear response to facial attractiveness in orbitofrontal cortex (OFC), a region involved in reward processing. There are strong theoretical grounds for the hypothesis that coding stimulus reward value also involves the amygdala. The aim of the present investigation is to address whether the amygdala is also sensitive to reward value in faces, indexed as facial attractiveness. We hypothesized that contrary to the linear effects reported previously in OFC, the amygdala would show a non-linear effect of attractiveness by responding to both high and low attractive faces relative to middle attractive faces. Such a non-linear response would explain previous failures to report an amygdala response to attractiveness. Human subjects underwent fMRI while they were presented with faces that varied in facial attractiveness where the task was either to rate faces for facial attractiveness or for age. Consistent with our hypothesis, right amygdala showed a predicted non-linear response profile with greater responses to highly attractive and unattractive faces compared to middle-ranked faces, independent of task. Distinct patterns of activity were seen across different regions of OFC, with some sectors showing linear effects of attractiveness, others exhibiting a non-linear response profile and still others demonstrating activation only during age judgments. Significant effects were also seen in medial prefrontal and paracingulate cortices, posterior OFC, insula, and superior temporal sulcus during explicit attractiveness judgments. The non-linear response profile of the amygdala is consistent with a role in sensing the value of social stimuli, a function that may also involve specific sectors of the OFC.

Adult↗

PubMed2006

Correlated preferences for facial masculinity and ideal or actual partner's masculinity.

Studies of women's preferences for male faces have variously reported preferences for masculine faces, preferences for feminine faces and no effect of masculinity-femininity on male facial attractiveness. It has been suggested that these apparently inconsistent findings are, at least partly, due to differences in the methods used to manipulate the masculinity of face images or individual differences in attraction to facial cues associated with youth. Here, however, we show that women's preferences for masculinity manipulated in male faces using techniques similar to the three most widely used methods are positively inter-related. We also show that women's preferences for masculine male faces are positively related to ratings of the masculinity of their actual partner and their ideal partner. Correlations with partner masculinity were independent of real and ideal partner age, which were not associated with facial masculinity preference. Collectively, these findings suggest that variability among studies in their findings for women's masculinity preferences reflects individual differences in attraction to masculinity rather than differences in the methods used to manufacture stimuli, and are important for the interpretation of previous and future studies of facial masculinity.

Adolescent↗

PubMed2006

Neural representations of perceived bodily actions using a categorical frame of reference.

In object-centered, or categorical, visual representations of an agent's actions, the spatial positions of (parts of) the body action are defined with respect to the principal axis of the agent, rather than in relation to the observer. Some cells in the superior temporal sulcus (STS) of the macaque monkey have been reported to use such a categorical frame of reference to code for bodily postures and actions, but their small numbers prevented a detailed investigation. Here we report for the first time that anterior sites in the STS contain a relatively large number of cells that use an object-centered frame of reference to code for animate objects and their actions. We further show that these cells are selectively responsive to much more restricted sections of an action trajectory than previously thought, and that they generalize over highly unusual, hitherto untested, orientations (such as upside-down walking). Quite remarkably, some cells coded for the position of a body part not only with respect to the object's body structure, but also with respect to objects in the immediate surrounding, such as the supporting substrate the agent was standing on. We illustrate these properties using three cell populations: one responding to rotations of the upper body with respect to the lower body, one responding to forward or backward walking actions, and one responding to flexions of the knees. We discuss a possible role for the object-centered STS cell populations in representing the abstract object structure of flexible, animate objects, which could enable their recognition even when presented in highly unusual poses. We further discuss their possible role in representing goal-directed or intentional actions, and in imitation.

Animals↗

PubMed2006

The sensitivity of primate STS neurons to walking sequences and to the degree of articulation in static images.

We readily use the form of human figures to determine if they are moving. Human figures that have arms and legs outstretched (articulated) appear to be moving more than figures where the arms and legs are near the body (standing). We tested whether neurons in the macaque monkey superior temporal sulcus (STS), a region known to be involved in processing social stimuli, were sensitive to the degree of articulation of a static human figure. Additionally, we tested sensitivity to the same stimuli within forward and backward walking sequences. We found that 57% of cells that responded to the static image of a human figure was also sensitive to the degree of articulation of the figure. Some cells displayed selective responses for articulated postures, while others (in equal numbers) displayed selective responses for standing postures. Cells selective for static images of articulated figures were more likely to respond to movies of walking forwards than walking backwards. Cells selective for static images of standing figures were more likely to respond to movies of walking backwards than forwards. An association between form sensitivity and walking sensitivity could be consistent with an interpretation that cell responses to articulated figures act as an implied motion signal.

Action Potentials↗

PubMed2005

MHC-assortative facial preferences in humans.

Individuals tend to choose mates who are sufficiently genetically dissimilar to avoid inbreeding. As facial attractiveness is a key factor in human mate preference, we investigated whether facial preferences were related to genetic dissimilarity. We asked female volunteers to rate the attractiveness of men from photographs and compared these results with individual genotypes at the major histocompatibility complex (MHC). In contrast to previously reported preferences based on odour, we found a non-significant tendency for women to rate MHC-similar faces as more attractive, suggesting a preference for cues to a self-similar MHC in faces. Further analysis revealed that male faces received higher attractiveness scores when rated by women who were MHC-similar than by MHC-dissimilar women. Although unexpected, this MHC-similar facial preference is consistent with other studies documenting assortative preferences in humans, including for facial phenotype.

Adolescent↗

PubMed2005

Neural mechanisms of imitation and 'mirror neuron' functioning in autistic spectrum disorder.

An association between autistic spectrum disorder and imitative impairment might result from dysfunction in mirror neurons (MNs) that serve to relate observed actions to motor codings. To explore this hypothesis, we employed a functional magnetic resonance imaging (fMRI) protocol previously used to identify the neural substrate of imitation, and human MN function, to compare 16 adolescent males of normal intelligence with autistic spectrum disorder (ASD) and age, sex and IQ matched controls. In the control group, in accord with previous findings, we identified activity attributable to MNs in areas of the right parietal lobe. Activity in this area was less extensive in the ASD group and was absent during non-imitative action execution. Broca's area was minimally active during imitation in controls. Differential patterns of activity during imitation and action observation in ASD and controls were most evident in an area at the right temporo-parietal junction also associated with a 'theory of mind' (ToM) function. ASD participants also failed to show modulation of left amygdala activity during imitation that was evident in the controls. This may have implications for understanding the imitation of emotional stimuli in ASD. Overall, we suggest that ASD is associated with altered patterns of brain activity during imitation, which could stem from poor integration between areas serving visual, motor, proprioceptive and emotional functions. Such poor integration is likely to adversely affect the development of ToM through imitation as well as other aspects of social cognitive function in ASD.

Adolescent↗

PubMed2005

Is everybody always my friend? Perception of approachability in Williams syndrome.

Individuals with Williams syndrome (WS) are well known for their friendly behaviour and tendency to approach strangers indiscriminately as if everybody were their friend. This tendency to approach strangers is mirrored in their ratings of unfamiliar face stimuli. Here we examined their perception of unfamiliar expressive faces and found that individuals with WS do not always see faces as being highly approachable. Happy faces were rated as more approachable by individuals with WS than by controls. In contrast, the other less approachable face stimuli were rated lower on approachability by individuals with WS than by controls. Thus, it appears that although individuals with WS will discriminate people in terms of approachability, they have difficulty inhibiting their strong compulsion towards social interaction. The form of this strong pro-social compulsion is discussed both in terms of friendliness and in terms of the heightened salience of social stimuli (social stimulus attraction).

Adolescent↗

PubMed2005

Women's attractiveness judgments of self-resembling faces change across the menstrual cycle.

Two lines of reasoning predict that women's preferences for people exhibiting cues to kinship will be lower in the follicular phase than in the luteal phase of the menstrual cycle. Women may avoid kinship cues during the follicular phase when they are most fertile due to the costs of inbreeding. Alternatively, women may seek kinship cues during the luteal phase as a byproduct of the benefits of associating with kin during pregnancy, which is also characterized by high progesterone. We find that preferences for facial resemblance, a putative kinship cue, follow this predicted pattern and are positively correlated with estimated progesterone levels based on cycle day. Neither estimated estrogen levels nor conception risk predicted preferences for self-resemblance, and the cyclic shift was stronger for preferences for female faces than male faces. These findings lead to the possibility that this cyclic change in preference for self-resemblance may be a byproduct of a hormonal mechanism for increasing affiliative behavior toward kin during pregnancy rather than a mechanism for preventing inbreeding during fertile periods.

Adolescent↗

PubMed2005

An fMRI study of joint attention experience.

Although much is now known about eye movement detection, little is known about the higher cognitive processes involved in joint attention. We developed video stimuli which when watched, engender an experience of joint attention in the observer. This allowed us to compare an experience of joint attention to nonjoint attention within an fMRI scanning environment. Joint attention was associated with activity in the ventromedial frontal cortex, the left superior frontal gyrus (BA10), cingulate cortex, and caudate nuclei. The ventromedial frontal cortex has been consistently shown to be activated during mental state attribution tasks. BA10 may serve a cognitive integration function, which in this case seems to utilize a perception-action matching process. The activation we identified in BA10 overlaps with a location of increased grey matter density that we recently found to be associated with autistic spectrum disorder. This study therefore constitutes evidence that the neural substrate of joint attention also serves a mentalizing function. The developmental failure of this substrate in the left anterior frontal lobe may be important in the etiology of autistic spectrum disorder.

Adolescent↗

PubMed2005

Structural white matter deficits in high-functioning individuals with autistic spectrum disorder: a voxel-based investigation.

A number of imaging and neuropathological studies have reported structural abnormalities in white matter areas such as the corpus callosum in autism spectrum disorder (ASD). Differences in both global brain volume and the size of specific neural structures have been reported. In order to expand these previously reported findings and to describe more precisely the nature of such structural changes, we performed a voxel-based morphometric whole brain analysis, using a group-specific template, in male adolescents with ASD. Fifteen individuals with normal intelligence and ASD, and a group of 16 controls, matched for age, sex, and IQ, were investigated. High-resolution T1-weighted 3D data sets were acquired and analysed. Local white matter volume deficits were found in the corpus callosum, particularly in the anterior splenium and isthmus, and right hemisphere. White matter volume deficits were also found in the left middle temporal, right middle frontal, and left superior frontal gyri. No significant areas of increased white matter volume were found. Our findings support the hypothesis that reduced white matter volume in the corpus callosum and right hemisphere may play a role in the pathophysiology of ASD.

Adolescent↗

PubMed2005

Integration of visual and auditory information by superior temporal sulcus neurons responsive to the sight of actions.

Processing of complex visual stimuli comprising facial movements, hand actions, and body movements is known to occur in the superior temporal sulcus (STS) of humans and nonhuman primates. The STS is also thought to play a role in the integration of multimodal sensory input. We investigated whether STS neurons coding the sight of actions also integrated the sound of those actions. For 23% of neurons responsive to the sight of an action, the sound of that action significantly modulated the visual response. The sound of the action increased or decreased the visually evoked response for an equal number of neurons. In the neurons whose visual response was increased by the addition of sound (but not those neurons whose responses were decreased), the audiovisual integration was dependent upon the sound of the action matching the sight of the action. These results suggest that neurons in the STS form multisensory representations of observed actions.

Acoustic Stimulation↗

PubMed2004

Female facial attractiveness increases during the fertile phase of the menstrual cycle.

The lack of obvious visible manifestations of ovulation in human females, compared with the prominent sexual swellings of many primates, has led to the idea that human ovulation is concealed. While human ovulation is clearly not advertised to the same extent as in some other species, we show here that both men and women judge photographs of women's faces that were taken in the fertile window of the menstrual cycle as more attractive than photographs taken during the luteal phase. This indicates the existence of visible cues to ovulation in the human face, and is consistent with similar cyclical changes observed for preferences of female body odour. This heightened allure could be an adaptive mechanism for raising a female's relative value in the mating market at the time in the cycle when the probability of conception is at its highest.

Beauty↗

PubMed2004

Smelling human sex hormone-like compounds affects face gender judgment of men.

Although strong cross-sensory interactions between visual, tactile and auditory modalities have already been shown, we know little about how chemosensory information affects processing in other sensory modalities. We studied whether smelling gender-specific odorous sex hormone-like steroids: 5-alpha-androgenst-16-en-3-one (androgen) or oestra-1, 3, 5 (10), 16-tetraen-3-ol (estrogen) can bias face gender discrimination. We found that, as a result of inhalation of androgen, men perceive faces to be more masculine as compared to when they are exposed to estrogen. Our results provide evidence for specific cross-sensory effects of the gender-specific chemosensory cues on the categorization of visual face gender.

Adult↗

PubMed2004

Single cell integration of animate form, motion and location in the superior temporal cortex of the macaque monkey.

This study investigated the cellular mechanisms in the anterior part of the superior temporal sulcus (STSa) that underlie the integration of different features of the same visually perceived animate object. Three visual features were systematically manipulated: form, motion and location. In 58% of a population of cells selectively responsive to the sight of a walking agent, the location of the agent significantly influenced the cell's response. The influence of position was often evident in intricate two- and three-way interactions with the factors form and/or motion. For only one of the 31 cells tested, the response could be explained by just a single factor. For all other cells at least two factors, and for half of the cells (52%) all three factors, played a significant role in controlling responses. Our findings support a reformulation of the Ungerleider and Mishkin model, which envisages a subdivision of the visual processing into a ventral 'what' and a dorsal 'where' stream. We demonstrated that at least part of the temporal cortex ('what' stream) makes ample use of visual spatial information. Our findings open up the prospect of a much more elaborate integration of visual properties of animate objects at the single cell level. Such integration may support the comprehension of animals and their actions.

Animals↗

PubMed2004

Concordant preferences for opposite-sex signals? Human pheromones and facial characteristics.

We have investigated whether preferences for masculine and feminine characteristics are correlated across two modalities, olfaction and vision. In study 1, subjects rated the pleasantness of putative male (4,16-androstadien-3-one; 5alpha-androst-16-en-3-one) and female (1,3,5 (10),16-estratetraen-3-ol) pheromones, and chose the most attractive face shape from a masculine-feminine continuum for a long- and a short-term relationship. Study 2 replicated study 1 and further explored the effects of relationship context on pheromone ratings. For long-term relationships, women's preferences for masculine face shapes correlated with ratings of 4,16-androstadien-3-one and men's preferences for feminine face shapes correlated with ratings of 1,3,5(10),16-estratetraen-3-ol. These studies link sex-specific preferences for putative human sex pheromones and sexually dimorphic facial characteristics. Our findings suggest that putative sex pheromones and sexually dimorphic facial characteristics convey common information about the quality of potential mates.

Adolescent↗

PubMed2004

A voxel-based investigation of brain structure in male adolescents with autistic spectrum disorder.

Autistic spectrum disorder (ASD) has been associated with abnormal neuroanatomy in many imaging and neuropathological studies. Both global brain volume differences and differences in the size of specific neural structures have been reported. Here, we report a voxel-based morphometric whole brain analysis, using a group specific template, on 16 individuals of normal intelligence with autistic spectrum disorder (ASD), and a group of 16 age-, sex- and IQ-matched controls. Total grey matter volume was increased in the ASD group relative to the control group, with local volume increases in the right fusiform gyrus, the right temporo-occipital region and the left frontal pole extending to the medial frontal cortex. A local decrease in grey matter volume was found in the right thalamus. A decrease in global white matter volume in the ASD group did not reach significance. We found the increase in grey matter volume in ASD subjects was greatest in those areas recognised for their role in social cognition, particularly face recognition (right fusiform gyrus), mental state attribution: 'theory of mind' (anterior cingulate and superior temporal sulcus) and perception of eye gaze (superior temporal gyrus). The picture as a whole may reflect an abnormally functioning social cognitive neural network. We suggest that increased grey matter volume may play a pivotal role in the aetiology of the autistic syndrome.

Adolescent↗