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PubMed2005

The use of 3D information in face recognition.

Effects of shading in face recognition have often alluded to 3D shape processing. However, research to date has failed to demonstrate any use of important 3D information. Stereopsis adds no advantage in face encoding [Liu, C. H., Ward, J., & Young, A. W. (in press). Transfer between 2D and 3D representations of faces. Visual Cognition], and perspective transformation impairs rather than assists recognition performance [Liu, C. H. (2003). Is face recognition in pictures affected by the center of projection? In IEEE international workshop on analysis and modeling of faces and gestures (pp. 53-59). Nice, France: IEEE Computer Society]. Although evidence tends to rule out involvement of 3D information in face processing, it remains possible that the usefulness of this information depends on certain combinations of cues. We tested this hypothesis in a recognition task, where face stimuli with several levels of perspective transformation were either presented in stereo or without stereo. We found that even at a moderate level of perspective transformation where training and test faces were separated by just 30 cm, the stereo condition produced better performance. This provides the first evidence that stereo information can facilitate face recognition. We conclude that 3D information plays a role in face processing but only when certain types of 3D cues are properly combined.

Adolescent↗
PubMed2002

Human brain potential correlates of repetition priming in face and name recognition.

We investigated repetition priming in the recognition of famous people by recording event-related brain potentials (ERPs) and reaction times (RTs). Participants performed speeded two-choice responses depending on whether or not a stimulus showed a famous person. In Experiment 1, a facilitation was found in RTs to famous (but not to unfamiliar) faces when primed by the same face shown in an earlier priming phase of the experiment. In ERPs, an influence of repetition priming was observed neither for the N170 nor for a temporal N250 component which in previous studies had been shown to be sensitive to immediate face repetitions. ERPs to primed unfamiliar faces were more negative over right occipitotemporal areas than those to unprimed faces, but this effect was specific for repetitions of the same image, consistent with recent findings. In contrast, ERPs to primed familiar faces were more positive than those to unprimed faces at parietal sites from 500-600 ms after face onset, and these priming effects were comparable regardless of whether the same or a different image of the celebrity had served as prime. In Experiment 2, similar results were found for name recognition-a facilitation in RTs to primed familiar but not unfamiliar names, and a parietal positivity to primed names around 500-600 ms. ERP repetition effects showed comparable topographies for faces and names, consistent with the idea of a common underlying source. With reference to current models of face recognition, we suggest that these ERP repetition effects for familiar stimuli reflect a change in post-perceptual representations for people, rather than a neural correlate of recognition at a perceptual level.

Adolescent↗
PubMed2003

Event-related potentials (ERPs) to schematic faces in adults and children.

Event-related potentials (ERPs) were recorded from 4-year-old 8-10-year-old children and adults to a schematic face, inverted face and jumbled face. The subjects were instructed to fixate the stimuli and no other response was required. The schematic face and inverted face were shown with a frequency of 20% each and the remaining presentations (60%) were of the jumbled face. P1 and N170 peak latency were measurable in the children and adults. These peaks were at longer latencies in the children. P3 was measurable in the adults and 8-10-year-old children but not the 4-year-olds. The adults had larger and longer latency P1 and smaller amplitude N170 to the inverted face than the other faces. In contrast, the P1 was unaffected by inversion in the children and the N170 was not smaller to the inverted or jumbled face. It is concluded that this result reflects developmental differences in the processing of configuration, with the children relying on an under-specified configuration of the face.

Adolescent↗
PubMed1998

Brain potentials reveal the timing of face identity and expression judgments.

Event-related brain potentials (ERPs) were recorded from multiple scalp locations from young human subjects while they performed two different face processing tasks. The first task entailed the presentation of pairs of faces in which the second face was either a different view of the first face or a different view of a different face. The subjects had to decide whether or not the two faces depicted the same person. In the second task, pairs of faces (frontal views) were presented with the task of judging whether the expression of the second face matched that of the face. Incongruous faces in the view (identity) matching task gave rise to a negativity peaking at about 350 ms with a frontocentral maximum. This effect was similar to the N400 obtained in linguistic tasks. ERP effects in the expression matching task were much later and had a different distribution. This pattern of results corresponds well with neuropsychological and neuroimaging data suggesting specialized neuronal populations subserving identity and expression analysis but adds a temporal dimension to previous investigations.

Adult↗
PubMed2003

Signs of REM sleep dependent enhancement of implicit face memory: a repetition priming study.

Faces are processed and stored in distinct neuroanatomical systems. Based on evidence of a critical role of sleep in memory processes, we investigated the impact of nocturnal sleep on implicit memories for faces in healthy men. Face repetition effects in reaction times were compared across sleep periods early in the night, which are dominated by slow wave sleep (SWS), and late in the night, where rapid eye movement (REM) sleep prevails, as well as across corresponding nocturnal intervals of wakefulness. An inverse priming effect was found selectively across REM sleep rich late sleep, as indicated by distinctly prolonged response latencies to previously presented faces compared with novel faces after this period of sleep (P<0.05). We assumed this inverse priming to reflect a facilitated identification of previously presented faces after extended REM sleep periods, thereby producing interference with the response generation in our task which did not require face identification but rather required recognizing formal features of the faces. This interpretation was supported by a supplementary experiment where enhanced positive repetition priming was found across late, REM sleep dominated sleep in a task requiring face identification. Together, these findings indicate that implicit face memories particularly benefit from REM sleep associated brain mechanisms.

Circadian Rhythm↗
PubMed2003

Spatial scale contribution to early visual differences between face and object processing.

Event-related potential (ERP) studies have highlighted an occipito-temporal potential, the N170, which is larger for faces than for other categories and delayed by stimulus inversion of faces, but not of other objects. We examined how high-pass and low-pass filtering modulate such early differences between the processing of faces and objects. Sixteen grey-scale pictures of faces and cars were filtered to preserve only relatively low (LSF) or high (HSF) spatial frequencies and were presented upright or upside-down. Subjects reported the orientation of the faces and cars in broad-pass and filtered conditions. In the broad-pass condition, we replicated typical N170 face-specific effects of amplitude and delay with inversion. These effects were also present in the LSF condition. However, a completely different pattern was revealed by the HSF condition: (1). a similar N170 amplitude for cars as compared to faces and (2). an absence of N170 latency delay with face inversion. These results show that the source of early processing differences between faces and objects is related to the extraction of information contained mostly in the LSF, which conveys coarse configuration cues particularly salient for face processing.

Adult↗
PubMed1999

A device for applying postsurgical pressure to the lateral face.

OBJECTIVE: The purpose of this study was to improve the effect of pressure applied on the lateral face after operations, particularly after parotid surgery for prevention of complications, especially the formation of salivary fistula. STUDY DESIGN: A pressure instrument (face pad) was designed to fit all types of facial morphology. The blood flow velocity of the superficial temporal artery was measured by means of a Doppler detector in 30 healthy volunteers under 2 different conditions, with and without the face pad. Values for 2 parameters, peak velocity and average peak velocity, were determined for the purpose of selecting an appropriate pressure. Each of 47 patients who had undergone regional parotidectomy received pressure with the face pad for 3 days; the results were compared with those in a control group of 44 patients who had undergone similar operations but received traditional packing dressings. RESULTS: The peak velocities of the superficial temporal artery with and without the face pad were not significantly different (t = 1.541, P = .132) when a pressure value of 4 to 5 N was applied. However, the average peak velocity of the superficial temporal artery increased significantly (t = 3.678, P = .001) with the face pad. The 47 patients with the face pad had no postoperative parotid fistula; in contrast, salivary fistula developed in 5 of the 44 control cases, for an overall fistula rate of 11.36%. A significant difference existed between the 2 groups (P = .023). CONCLUSIONS: The face pad worked quantitatively and was stable and comfortable. A pressure of 4 to 5 N on the lateral face did not influence the blood flow of the superficial temporal artery. The higher peak velocity was correlated with regional stenosis of the temporal vein caused by pressure. Evidently, the face pad can reduce postoperative complications after parotidectomy; moreover, it makes pressure dressing easy and shortens the in-hospital days of the patient as well.

Adult↗
PubMed2000

Making features relevant: learning faces and event-related potentials recording using an analytic procedure.

We present a procedure designed for the learning of faces (represented by realistic drawings) and a task for the subsequent recording of Event-Related Potentials (ERPs), with the aim of investigating the psychobiological mechanisms involved in the recognition of familiar (or known) faces. The learning procedure consisted in a series of six sessions in which subjects familiarized themselves with the faces through a forced-choice features task: after the study of a set of 40 faces, each of these was presented at random in an incomplete way (without the eyes/eyebrows fragment), together with two sets of eyes and eyebrows for the subject to decide which of them corresponded to each face. This procedure is thought to facilitate for subjects the acquisition of the information related to the structural description of the faces (that is, without associated verbal/semantic information) using preferentially analytic processing strategies. The parameter d' of the Theory of Signal Detection allowed us to evaluate in the course of the learning sessions the degree of familiarization achieved with the studied faces. Subsequently, an ERPs' recording session was carried out, during which subjects executed a face-feature matching task. In this task, similar in structure to that carried out in the learning sessions, the subject had to decide whether the automatic completion of the faces that was made was correct or incorrect. ERPs' effects related to mismatching features were obtained, which indicate the existence of specific cerebral mechanisms involved in the recognition of faces.

Adult↗
PubMed2002

Generators of visual evoked potentials for faces and eyes in the human brain as determined by dipole localization.

Human visual evoked potentials were recorded during presentation of photos of human and animal faces and various face features. Negative waves with approximate peak latencies of 165 msec (N170) were bilaterally recorded from the occipito-temporal regions. Mean peak latencies of the N170 were shorter for faces than eyes only. Analyses of amplitudes of evoked potentials indicated that the N170 elicited by faces reflected activity of a specific neural system which was insensitive to detailed differences among individual faces regardless of species, and consequently suggest that this system might function to detect existence of faces in general. On the other hand, the mean amplitude of the N170 elicited by human eyes was significantly larger than those by animal eyes. These differences in response latencies and amplitudes of the N170 suggest existence of at least 2 different visual evoked potentials with similar latencies (i.e., N170) which are sensitive to faces in general and human eyes, respectively. Dipole source localization analysis indicated that dipoles for the N170 elicited by eyes were located in the posterior inferior temporal gyrus, and those for faces, located initially in the same region, but moved toward the fusiform and lingual gyri at the late phase of the N170. The results indicated that information processing of faces and eyes separated at least as early as the latency of the N170 at the posterior inferior temporal gyrus as well as the fusiform and lingual gyri, and might provide neurophysiological and anatomical bases to an initial structural encoding stage of human faces.

Adult↗
PubMed1986

Face-name interference.

Interference effects between the processing of simultaneously presented photographs of faces of familiar people and printed names of familiar people were investigated. Printed names interfered with identifying faces, whereas faces did not interfere with saying printed names (Experiments 1 and 3). In contrast, faces interfered more with name categorization than names interfered with face categorization (Experiments 2 and 4). Despite a priori reasons as to why faces might be thought to possess functional properties different from those of other visual objects, the observed effects are comparable to those found in object-word interference studies, with photographs of faces behaving like pictures of objects and printed people's names behaving like printed names of objects. In face naming tasks, the presence of related names produced more interference than did the presence of unrelated names (Experiment 1). This effect was examined in greater detail in Experiment 3, where we found that the effect arises when the face and the name belong to people of similar appearance. An effect of common category membership was not found in Experiment 3. Experiment 5, however, showed that names of people highly associated with the person whose face is presented also produce more interference than do names of unrelated people.

Association↗
PubMed2003

Holistic processing of faces in preschool children and adults.

Contrary to the encoding-switch hypothesis, recent research demonstrates that 6-year-olds do not rely solely on parts-based encoding to recognize upright faces. This research shows better recognition of face parts presented in the whole face than in isolation, indicating use of holistic encoding. The present study examined whether children younger than 6 years also recognize faces holistically. Four-year-olds, 5-year-olds, and adults were administered a part-whole face recognition task. Children below the age of 6 remembered parts from upright faces better when tested in the whole-face context than in isolation. This whole-face advantage did not occur when faces were inverted. Although children showed a smaller inversion decrement than adults and generally performed more poorly than adults, the different age groups showed similar patterns of performance, indicating that young preschoolers, like older children and adults, are able to recognize faces holistically.

Adolescent↗
PubMed2003

Development and testing of a Faces Scale for the assessment of anxiety in critically ill patients.

BACKGROUND: Many patients experience anxiety during treatment in an intensive care unit, but intensive care patients are often not able to respond to existing validated measures of anxiety such as the Brief Symptom Inventory. We have developed a new single item Faces Anxiety Scale made up of drawings of five faces. AIMS: The aims of this study were to: (i) assess the ability of intensive care patients to respond to the Faces Anxiety Scale; and (ii) investigate whether the scale yields ordinal and interval data. ETHICS: The project was approved by two Human Research Ethics Committees. Patients were included in the study if they gave informed consent. INSTRUMENTS AND METHODS: (i) Intensive care patients (n = 40) were asked to respond to the Faces Anxiety Scale, the anxiety subscale of the Brief Symptom Inventory, and a numerical analogue anxiety scale; and (ii) Hospital and University staff and students (n = 75) were asked to place the five faces in rank order. A further 100 staff members and students were asked to place each face at a point on a 60-cm triangular wedge according to the level of anxiety they thought the face showed. RESULTS: The Faces Anxiety Scale elicited more responses from intensive care patients than the numerical analogue anxiety scale the or anxiety subscale of the Brief Symptom Inventory (36 vs. 25 vs. 17, respectively, P < 0.0001). In the testing of the order of the scale items, 93% of respondents independently placed the scale items in the order of least to most anxiety as intended in the design of the scale. In the testing for equality of intervals respondents placed the faces relatively equidistant, with no overlap of 95% confidence intervals around the mean distances. CONCLUSION: The Faces Anxiety Scale has minimal subject burden, elicits self report from intensive care patients more often than other simple scales, and has evidence of the interval scale properties of rank order and equality between the points on the scale.

Adult↗
PubMed1993

What gives a face its gender?

An experiment is reported in which the attribution of gender to isolated facial features and to faces whose features have been interchanged with those of a face of the opposite gender has been examined. Sixteen male faces were averaged to create a prototype male face and sixteen female faces averaged to create a prototype female face. The prototypes were then masked to exclude ears, neck, hair, and hairline. Individual features (brows, eyes, nose, mouth, and chin) and pairs of features (brows & eyes, eyes & nose, nose & mouth, mouth & chin) from the prototypes were then presented in isolation for classification according to their perceived gender. The results showed that, for the faces used, the brows & eyes, brows alone, eyes alone, the whole jaw, the chin, the nose & mouth, the mouth alone (in descending order), ie all the features except the nose, carried some information about gender when they were seen in isolation. In the second part of the experiment different features from one prototype face were grafted into the prototype of the opposite gender and the resulting composite faces classified by their perceived gender. The results of this feature substitution showed the jaw, brows & eyes, chin, and brows (in descending order) effecting significant change in perceived gender. The difference in gender information carried by feature(s) when they were viewed in isolation from that when they were substituted for each other is attributed to the role of configuration in the perception of the gender of a face.

Adolescent↗
PubMed1994

Impact of quality of the image, orientation, and similarity of the stimuli on visual search for faces.

Evidence from a series of visual-search experiments suggests that detecting an upright face amidst face-like distractors elicits a pattern of reaction times that is consistent with serial search. In four experiments the impact of orientation, number of stimuli in the display, and similarity of stimuli on search rates was examined. All displays were homogeneous. Trials were blocked by distractor type for three experiments. In the first experiment search rates for faces amidst identical faces rotated by 180 degrees were examined. No advantage was evidenced in searching for an upright face. The impact of the quality of the face representation was examined in the second experiment. Search rates are reported for a line-drawn and a digitized image of a face amidst identical faces rotated by 180 degrees. Search was faster for digitized than for line-drawn faces. The findings of the first experiment for orientation were replicated. In the third and fourth experiments the impact of disrupting the facial configuration in distractors was examined and performance was contrasted for blocked and mixed trials, respectively, with the same stimulus set. Reaction times increased with the number of distractors in the display in all but the nonface condition, which produced a shallow slope suggestive of parallel search. Search amidst other distractors appeared to involve the conjoining of a specific set of features with specific spatial relations. The hierarchy of relevant configural dimensions was inconsistent across these two experiments, suggesting that the symmetry, top-down order of features, orientation of the face, and predictability of the distractor type may have an interactive effect on search strategies.

Agnosia↗
PubMed1995

Factors influencing the accuracy of age estimates of unfamiliar faces.

Factors affecting the accuracy with which adults could assess the age of unfamiliar male faces aged between 5 and 70 years were examined. In the first experiment twenty-five 'young' adult subjects, aged 16-25, and twenty-five 'old' adults, aged 51-60, were used. Each subject saw five versions of three different faces: these consisted of an original version of each face and four manipulated versions of it. The manipulations consisted of mirror reversal, pseudo-cardioidal strain, thresholding, and elimination of all but the internal features of the face. The second experiment was similar except that a between-subjects design was used: each subject saw three faces for each age category of target face, but was exposed to only a single type of manipulation (plus a set of 'original' faces which were identical for all groups, so that the comparability of the different groups in age estimation could be checked). Results from both experiments were similar. Age estimates for unmanipulated 'original' faces were highly accurate, although subjects were most accurate with target faces that were within their own age range. Results for the manipulated faces implied that the importance of cardioidal strain as a necessary and sufficient cue to age may have been overestimated in previous reports: subjects' age estimates were accurate when cardioidal strain was absent from the stimulus, and poor when cardioidal strain was the only cue available.

Adolescent↗
PubMed1996

An 'other-race effect' for categorizing faces by sex.

It is well-known that people recognize faces of their own race more accurately than faces of other races-a phenomenon often referred to as the 'other-race effect'. Using brief presentations of faces, we show a similar effect for the task of discriminating the sex of a face. Specifically, Caucasian observers discriminated male and female Caucasian faces more accurately/efficiently than did Oriental observers, and Oriental observers discriminated male and female Japanese faces more accurately/efficiently than did Caucasian observers. This result indicates that, under suboptimal viewing conditions, the identification of even the most salient of facial characteristics-face sex-is impaired for other-race faces. This finding suggests, also, that the nature and diversity of our experience with faces may affect not only the quality of the face representation for later access by recognition processes, but also the efficiency of a perceptual discrimination process. Intriguingly, too, we found that female observers, for both races tested, were considerably more accurate at the sex classification task than were male observers.

Adult↗
PubMed1999

Effects of the height of the internal features of faces on adults' aesthetic ratings and 5-month-olds' looking times.

We examined the influence of the height of the internal features of faces on adults' ratings of attractiveness and on 5-month-olds' looking times. Subjects viewed drawings or coloured photographs of faces presented in pairs that were identical except that the internal features were at a low height, with a large forehead and small chin; at a high height, with a small forehead and large chin; or at a medium height. Adults rated faces with their features at the medium and low heights as more attractive than faces with their features at the high height, and, at least for drawings, rated faces with medium features as more attractive than faces with low features. Babies looked equally long at faces with their features at various heights except for looking slightly longer at faces with high rather than low features. The results suggest that the influence of feature height on reactions to faces is different for adults and 5-month-olds, and hence that it may be shaped by cultural learning and/or experience with faces sometime after early infancy.

Adolescent↗
PubMed2000

Testing a two-component model of face identification: effects of inversion, contrast reversal, and direction of lighting.

Enns and Shore (1997 Perception & Psychophysics 59 23-31) found additive effects of test orientation (upright or inverted) and direction of lighting (brow or chin lit) when they studied the inversion effect on face identification. A two-stage model was inferred in which inversion was processed by an orientation-sensitive component after which chin-lighting was processed by a lighting-sensitive component. Face identification is also strongly influenced by contrast reversal. A study is reported which aimed to (i) determine if contrast reversal interacts with lighting direction or orientation, findings that would support Enns and Shore's model; and (ii) to test their assumption that holistic encoding is prerequisite for their model by inducing featural encoding through training names to inverted faces. Names for unfamiliar brow-lit positive-contrast faces were trained with the faces upright or inverted. Identification accuracy was measured with combinations of orientation, lighting, and contrast. Consistent with their model, test orientation and direction of lighting were additive after training on upright faces and lighting and contrast reversal interacted. When holistic encoding was prevented following training on inverted faces, test orientation and lighting direction interacted for positive-contrast faces. Negative faces showed only an effect of direction of lighting. These results support Enns and Shore's two-stage model and their interpretation that orientation and direction of lighting interact following featural encoding of faces.

Analysis of Variance↗