Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FACE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources
PubMed1999

Evaluation of soft-tissue morphology of the face in 1,050 young adults.

Anthropometry of the face has always been an interesting subject for artists and plastic surgeons. Since ancient times, many rules have been proposed for the ideal face. The authors measured directly vertical and horizontal proportions of the face and inclinations of the soft-tissue facial profile in 1050 young Turkish adults. Differences between the facial measurements of subjects from seven different geographic regions were analyzed. Some of the measurements were compared further with the measurements of other populations in the literature, and the validity of the neoclassical canons were tested. The special head height measure was shorter than the special face height in the majority of our study group (women/men: equal height, 13%/15%; longer special head height, 28%/30%; shorter special head height, 59%/55%). Faces with three equally high-profile sections were not seen in women or in men. When the forehead height was compared with the nose height, equality was present in a small percentage of the population (women/men: equal height, 17%/18%; longer forehead, 41%/ 42%; shorter forehead, 42%/40%). The nose height was equal to the lower face height in a minority of the population (women/men: equal height, 10%/11%; longer nose, 9%/11%; shorter nose (81%/78%). The forehead height was shorter than the lower face height in the majority of the population (women/ men: equal height, 8%/9%; longer forehead, 12%/13%; shorter forehead, 79%/78%). The intercanthal distance was shorter than the nose width in the majority of the population (women/men: equal width, 20%/19%; wider intercanthal distance, 35%/37%; narrower intercanthal width, 65%/68%). The population was distributed evenly in regard to the variations of the orbital proportion canon (women/men: equal intercanthal width and eye fissure length, 31%/36%; wider intercanthal distance, 34%/27%; narrower intercanthal width, 35%/37%). The mouth width was greater than 1.5 times the nose width in the majority of the population (women/men: equal width, 6%/5%; wider mouth, 53%/54%; narrower mouth, 41%/41%). The nose width was narrower than one quarter of the face width in the majority of the population (women/men: equal width, 4%/3%; wider nose, 30%/39%; narrower nose, 66%/58%). The nose inclination was equal to the ear inclination in a very small fraction of subjects (women/ men: equal inclination, 3%/3%; greater nose inclination, 88%/87%; less nose inclination, 9%/9%). To sketch an outline of the average facial profile in the population studied, a convex facial profile is revealed, with the forehead and the chin retrodisplaced minimally with respect to the midface. The neoclassical canons were found to be invalid for the majority of the population in this study, and different proportional analytic results were obtained.

Adult↗
PubMed1999

Prosopagnosia and structural encoding of faces: evidence from event-related potentials.

Event-related brain potentials (ERPs) were recorded in response to unfamiliar faces and to houses from a severely prosopagnosic patient (PHD) and 24 control subjects. For all control subjects, faces elicited an enhanced negativity at lateral temporal electrodes (N170). This component was absent for PHD. Comparable results were obtained in response to inverted faces and houses. A selective deficit in face recognition is therefore reflected by abnormalities in ERP components specific to faces. As PHD was shown to have substantial deficits on tasks requiring the structural analysis of faces, these findings are consistent with the view that the N170 reflects processes involved in the structural encoding of faces, and may be a measure of selective impairments in the analysis of face components.

Adult↗
PubMed1999

Speed of face recognition in humans: an event-related potentials study.

Event-related potentials (ERPs) were measured while subjects passively looked at a line drawing of a normal face or a line drawing in which parts of the face were scattered so as not to be recognized as a face (scattered face) in order to estimate the speed of face recognition in humans. Because the spatial frequencies of these two types of line drawings were very similar, one could minimize the potentials due to the structure coding stage of the face processing. In addition, passive viewing of these stimuli eliminates the contribution of other processing such as discrimination or memory retrieval. Comparing these two conditions, statistically significant positive potentials were observed in frontal areas from 135ms after stimulus onset for the normal face. These early positive differences were probably due to the face processing per se in human visual recognition. Although statistically significant differences were observed in frontal areas, these are probably related to fusiform or inferior temporal area activation that is often reported using neuro-imaging technologies such as PET or fMRI.

Adult↗
PubMed2004

Event-related potentials and time course of the "other-race" face classification advantage.

Other-race faces are less accurately recognized than same race faces but classified faster by race. Using event-related potentials (ERPs), we captured the brain temporal dynamics of face classification by race processing performed by 12 Caucasian participants. As expected, participants were faster to classify by race Asian than Caucasian faces. ERPs results identified the occurrence of the other-race face classification advantage at around 240 ms, in a stage related to the processing of visual information at the semantic level. The elaboration of individual face structural representation, reflected in the N170 face-sensitive component, was insufficient to achieve this process. Altogether, these findings suggest that the lesser experience of other-race faces engender fewer semantic representations, which in turn accelerate their speed of processing.

Abstracting and Indexing↗
PubMed2004

Concurrent processing reveals competition between visual representations of faces.

Scalp electrophysiological recordings in humans indicate that the processing of faces differs from other categories between 100 and 200 ms after stimulus onset, peaking at the N170. To test the effect of the addition of a second face stimulus in the visual field on the face-related N170, we measured this component in response to a laterally presented face stimulus while subjects were processing either a central face or a control stimulus. As early as 130 ms following the lateralized face stimulus, there was a strong (approximately 40% of signal) and specific reduction of the N170 amplitude when subjects were concurrently processing a central face. This observation suggests that the early stages of the N170 reflect the activation of individual faces having overlapping and competing neural representations in the human occipito-temporal cortex.

Adult↗
PubMed2004

Face pictures reduce behavioural, autonomic, endocrine and neural indices of stress and fear in sheep.

Faces are highly emotive stimuli and we find smiling or familiar faces both attractive and comforting, even as young babies. Do other species with sophisticated face recognition skills, such as sheep, also respond to the emotional significance of familiar faces? We report that when sheep experience social isolation, the sight of familiar sheep face pictures compared with those of goats or inverted triangles significantly reduces behavioural (activity and protest vocalizations), autonomic (heart rate) and endocrine (cortisol and adrenaline) indices of stress. They also increase mRNA expression of activity-dependent genes (c-fos and zif/268) in brain regions specialized for processing faces (temporal and medial frontal cortices and basolateral amygdala) and for emotional control (orbitofrontal and cingulate cortex), and reduce their expression in regions associated with stress responses (hypothalamic paraventricular nucleus) and fear (central and lateral amygdala). Effects on face recognition, emotional control and fear centres are restricted to the right brain hemisphere. Results provide evidence that face pictures may be useful for relieving stress caused by unavoidable social isolation in sheep, and possibly other animal species, including humans. The finding that sheep, like humans, appear to have a right brain hemisphere involvement in the control of negative emotional experiences also suggests that functional lateralization of brain emotion systems may be a general feature in mammals.

Animals↗
PubMed2006

Face and gaze processing in normally developing children: a magnetoencephalographic study.

Magnetoencephalography (MEG) was used to study the neural mechanisms underlying face and gaze processing in ten normally developing boys aged between 8 and 11 years and 12 adult males. The participants performed two tasks in which they had to decide whether images presented sequentially in pairs, depicted the same person or the same motorbike. In the first task, the participants saw pictures of faces in which the eyes were either open or shut and pictures of motorbikes. In the second task, participants saw pairs of faces with gaze averted to the left or right. In children there was no evidence of the face sensitive, low amplitude short latency (30-60 ms) activity seen previously in adults. A strong, midline posterior response at approximately 100 ms was observed in children, which was earlier and somewhat stronger to faces than to motorbikes; in adults the signal at this latency was weak. A clear face sensitive response was seen in adults at 135 ms, predominantly over the right inferior occipito-temporal regions. Although activity was observed in the children at the same latency, it was less prominent, not lateralized and was evoked similarly by faces and motorbikes. Averted gaze conditions evoked strong right-lateralized activity at approximately 245 ms in children only. These findings indicate that even in middle childhood the neural mechanisms underlying face processing are less specialized than in adults, with greater early activation of posterior occipital cortices and less specific activation of ventral occipito-temporal cortex.

Adult↗
PubMed2004

Face inversion and contrast-reversal effects across development: in contrast to the expertise theory.

To determine the role of configural changes on the development of face encoding and memory, we investigated face recognition in an n-back repetition task with upright, inverted and contrast-reversed unfamiliar faces in adults and children (8-16 years). Repetitions occurred immediately (0-lag) or after one intervening face (1-lag). Face recognition continued to develop beyond 14-16 years, as shown with hit rates, d' scores and reaction times that all improved with age. Inversion and contrast-reversal effects were found in all subjects but were not more pronounced with increasing age, suggesting no increased reliance on configural processing and thus arguing against the expertise theory of Diamond and Carey (1986). Recognition improved with age in upright but also in inverted and contrast-reversed faces, suggesting a quantitative rather than a qualitative developmental change in face processing. For all age groups, performances decreased and reaction times increased from 0- to 1-lag conditions similarly, suggesting a similar memory component involved in adults' and children's processing. These data suggest gradual quantitative improvements in face processing with age, mainly due to increasing working memory processing capacity.

Adult↗
PubMedDate not supplied

Newborns' face recognition: role of inner and outer facial features.

Existing data indicate that newborns are able to recognize individual faces, but little is known about what perceptual cues drive this ability. The current study showed that either the inner or outer features of the face can act as sufficient cues for newborns' face recognition (Experiment 1), but the outer part of the face enjoys an advantage over the inner part (Experiment 2). Inversion of the face stimuli disrupted recognition when only the inner portion of the face was shown, but not when the whole face was fully visible or only the outer features were presented (Experiment 3). The results enhance our picture of what information newborns actually process and encode when they discriminate, learn, and recognize faces.

Face↗
PubMed2005

Variation in perceived attractiveness: differences between dynamic and static faces.

Studies that attempt to define facial attractiveness often do so in terms of structural features of the face (e.g., symmetry, averageness). However, these studies typically use static images of faces that may not be analogous to dynamic faces that are frequently used in other areas of attractiveness research, such as research investigating the impact of attractiveness on social interaction. The current studies investigated similarities and differences in how dynamic and static faces are perceived and evaluated. Study 1 demonstrated that dynamic and static faces are judged by different evaluative standards. Study 2 demonstrated that perceived emotion may be more salient in judging the attractiveness of dynamic faces than in judging the attractiveness of static faces. These findings illustrate the need to more fully explore the differences between dynamic and static faces to facilitate a better understanding of the characteristics underlying perceived attractiveness.

Beauty↗
PubMed2006

View-specific coding of face shape.

Monkey and human cortex contain view-specific face neurons, but it remains unclear whether they code face shape. We tested the view specificity of face-shape coding by inducing figural face aftereffects at one viewpoint (3/4 left) and testing generalization to different viewpoints (front view and 3/4 right). The aftereffects were induced by adaptation to consistent figural distortions (contracted or expanded), which shifts the distortion perceived as most normal toward the adapting distortion. The strong aftereffect that was observed at the adapting view was significantly and substantially reduced for both front-view test faces and mirror-image (3/4 right) test faces, indicating view specificity. The limited transfer across mirror views is strong evidence of view specificity, given their figural similarity. The aftereffects survived a size change between adaptation and test faces (Experiment 2), a result that rules out low-level adaptation as an explanation. These results provide strong evidence that face-shape coding is view-specific.

Face↗
PubMed1986

Understanding face recognition.

The aim of this paper is to develop a theoretical model and a set of terms for understanding and discussing how we recognize familiar faces, and the relationship between recognition and other aspects of face processing. It is suggested that there are seven distinct types of information that we derive from seen faces; these are labelled pictorial, structural, visually derived semantic, identity-specific semantic, name, expression and facial speech codes. A functional model is proposed in which structural encoding processes provide descriptions suitable for the analysis of facial speech, for analysis of expression and for face recognition units. Recognition of familiar faces involves a match between the products of structural encoding and previously stored structural codes describing the appearance of familiar faces, held in face recognition units. Identity-specific semantic codes are then accessed from person identity nodes, and subsequently name codes are retrieved. It is also proposed that the cognitive system plays an active role in deciding whether or not the initial match is sufficiently close to indicate true recognition or merely a 'resemblance'; several factors are seen as influencing such decisions. This functional model is used to draw together data from diverse sources including laboratory experiments, studies of everyday errors, and studies of patients with different types of cerebral injury. It is also used to clarify similarities and differences between processes for object, word and face recognition.

Attention↗
PubMed1998

Comparison of nose and face mask CPAP therapy for sleep apnoea.

BACKGROUND: Many patients with sleep apnoea/hypopnoea syndrome (SAHS) find nasal continuous positive airway pressure (CPAP) treatment unsatisfactory due to side effects related to mouth air leakage. A study was performed to compare side effects with face mask and nose mask CPAP therapy in patients with SAHS, with and without uvulopalatopharyngoplasty (U3P). METHODS: Twenty newly diagnosed patients with SAHS took part in a randomised double limb trial of face or nose mask CPAP therapy (four weeks per limb) in which CPAP compliance in terms of machine run time was measured and patients answered a symptom questionnaire on side effects resulting from the mask. Ten patients with SAHS with U3P (SAHS/U3P) who were already regular users of nasal CPAP were also given a four week trial of face mask CPAP to compare compliance and symptoms. Ten patients with SAHS were matched with the 10 SAHS/U3P patients for body mass index, age, apnoea/hypopnoea index, and CPAP pressure. Long term compliance was estimated one year after the mask comparison studies. RESULTS: For patients with SAHS nightly compliance was higher with a nose mask (mean (SE) 5.3 (0.4) hours/night CPAP) than with a face mask (4.3 (0.5) hours/night CPAP), p = 0.01 (mean difference 1.0 hour/night, 95% CI 1.8 to 0.3). Nose masks were rated more comfortable by 19 of 20 patients (p < 0.001) despite more mouth leak related symptoms. For SAHS/U3P patients compliance was marginally higher with nose masks (5.1 (0.7) hours/night CPAP) than with face masks (4.0 (0.8) hours/night CPAP), p = 0.07 (mean difference 1.1 hour/night, 95% CI 2.1 to 0.1). Nose masks were rated more comfortable by seven of 10 patients. There were no significant differences in side effect scores with face and nose masks. At one year nine of 10 SAHS patients and nine of 10 SAHS/U3P patients were still using CPAP. Compliance was 5.4 (0.6) hours/night for the SAHS patients and 3.5 (0.4) hours/night for the SAHS/U3P patients, p = 0.02 (mean difference 1.9 hour/night, 95% CI 3.6 to 0.3). CONCLUSIONS: Compliance is greater with nose mask CPAP than with face mask CPAP because the overall comfort is better and compensates for increased symptoms associated with mouth leakage. Improved face mask design is needed.

Double-Blind Method↗
PubMed2000

Fine discrimination of faces can be performed rapidly.

Here we measure the smallest change in a face that can be discriminated. A morphing algorithm mixed two faces in variable proportions to create a series of synthetic faces that each differed by a tiny amount. By selecting from this series, a test face could be chosen so as to reach a just noticeable difference from a sample face. Face-discrimination thresholds were about 7% of the average difference between two faces, as quantified by coefficients of a principal components decom position. This threshold remained constant as the duration of the test face was reduced from 1,000 to 100 msec, and rose quickly for shorter stimulus durations. The behavioral evidence presented here indicates that complex visual processing can be completed within the first 100 msec of the signal, suggesting involvement of feedforward neural mechanisms, and placing constraints on possible computational algorithms employed within the ventral visual pathways.

Algorithms↗
PubMed2000

Hemispheric asymmetries for whole-based and part-based face processing in the human fusiform gyrus.

Behavioral studies indicate a right hemisphere advantage for processing a face as a whole and a left hemisphere superiority for processing based on face features. The present PET study identifies the anatomical localization of these effects in well-defined regions of the middle fusiform gyri of both hemispheres. The right middle fusiform gyrus, previously described as a face-specific region, was found to be more activated when matching whole faces than face parts whereas this pattern of activity was reversed in the left homologous region. These lateralized differences appeared to be specific to faces since control objects processed either as wholes or parts did not induce any change of activity within these regions. This double dissociation between two modes of face processing brings new evidence regarding the lateralized localization of face individualization mechanisms in the human brain.

Adult↗
PubMed2005

Detailed exploration of face-related processing in congenital prosopagnosia: 2. Functional neuroimaging findings.

Specific regions of the human occipito-temporal cortex are consistently activated in functional imaging studies of face processing. To understand the contribution of these regions to face processing, we examined the pattern of fMRI activation in four congenital prosopagnosic (CP) individuals who are markedly impaired at face processing despite normal vision and intelligence, and with no evidence of brain damage. These individuals evinced a normal pattern of fMRI activation in the fusiform gyrus (FFA) and in other ventral occipito-temporal areas, in response to faces, buildings, and other objects, shown both as line drawings in detection and discrimination tasks and under more naturalistic testing conditions when no task was required. CP individuals also showed normal adaptation levels in a block-design adaptation experiment and, like control subjects, exhibited evidence of global face representation in the FFA. The absence of a BOLD-behavioral correlation (profound behavioral deficit, normal face-related activation in the ventral occipito-temporal cortex) challenges existing accounts of face representation, and suggests that activation in these cortical regions per se is not sufficient to ensure intact face processing.

Adult↗
PubMed2003

Illumination encoding in face recognition: effect of position shift.

Recognition of faces and objects is impaired when illumination direction varies. Three experiments explore whether this impairment can be explained by display changes (Biederman & Bar, 1999), and whether cast shadows help or hinder face recognition. Observers judged whether two sequentially-presented faces, shown with or without cast shadows, were the same person. The faces were illuminated from the same or different directions, and were presented in the same or different positions on the screen. In Experiment 1, performance was illumination-dependent only on same-position trials, suggesting that observers used display changes. Experiment 2 tested whether this could be explained by peripheral viewing on different-position trials. A fixation cross cued each face's location, such that observers could move their eyes to view each face centrally. Performance was illumination-dependent regardless of whether position changed. In both experiments, shadows did not affect performance, in contrast to earlier findings (Braje, Kersten, Tarr, & Troje, 1998). In Experiment 3, all faces were presented peripherally without shadows. Changing the illumination direction did not affect performance. These results demonstrate that peripheral viewing, rather than display changes, can explain why changes in illumination direction do not affect performance when position changes. The results also suggest that face representations retain illumination information.

Adult↗
PubMed2005

Honeybee (Apis mellifera) vision can discriminate between and recognise images of human faces.

Recognising individuals using facial cues is an important ability. There is evidence that the mammalian brain may have specialised neural circuitry for face recognition tasks, although some recent work questions these findings. Thus, to understand if recognising human faces does require species-specific neural processing, it is important to know if non-human animals might be able to solve this difficult spatial task. Honeybees (Apis mellifera) were tested to evaluate whether an animal with no evolutionary history for discriminating between humanoid faces may be able to learn this task. Using differential conditioning, individual bees were trained to visit target face stimuli and to avoid similar distractor stimuli from a standard face recognition test used in human psychology. Performance was evaluated in non-rewarded trials and bees discriminated the target face from a similar distractor with greater than 80% accuracy. When novel distractors were used, bees also demonstrated a high level of choices for the target face, indicating an ability for face recognition. When the stimuli were rotated by 180 degrees there was a large drop in performance, indicating a possible disruption to configural type visual processing.

Animals↗