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PubMed1989

Face cooling-induced reduction of plasma prolactin response to exercise as part of an integrated response to thermal stress.

This study was designed to verify if the decrease in blood prolactin (PRL) induced by selective face cooling during exercise could be part of a response to specific body thermal stress. Five healthy trained male cyclists presenting a significant plasma PRL elevation to exercise were, on three occasions and at weekly interval, submitted to a submaximal exercise (approx. 65% VO2max) on ergocycle with and without selective face cooling. In absence of face cooling a first trial served to establish reference values for workload, heart rate and plasma PRL levels, the latter increasing markedly (450% of resting values) in these conditions. On a second trial but with workload maintained at reference values (222 +/- 9 W), a significant bradycardia was observed with face cooling; furthermore, plasma PRL response to exercise was significantly reduced (to 31% of original response). On a third trial with face cooling, workload had to be significantly augmented (242 +/- 10 W) to maintain heart rate at reference level (78% HRmax); in addition, plasma PRL response to exercise was almost unchanged compared to the reference-value level. The absence of a significant face cooling-induced decrease in sympathetic tonus, as evaluated through peripheral plasma catecholamines response, does not indicate a role for the autonomic nervous system in the face cooling-induced reduction of both heart rate and PRL responses during exercise. Assay of circulating peripheral beta-endorphins could indicate that the face cooling-induced PRL blunted response does not necessarily involve an opioid mediation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Event-related brain potentials differentiate priming and recognition to familiar and unfamiliar faces.

Recent studies from our laboratory have resulted in the identification of an event-related potential (ERP) correlate of a visual memory process. This memory process is reflected by a reduction in the voltage of the visual memory potential (VMP) to repeated pictures of unfamiliar faces compared to novel pictures of faces. In the current experiment we used unfamiliar and famous faces in an identical repetition priming paradigm, while the subject differentially recognized famous from non-famous faces. Significant differences in response times were obtained between primed and unprimed familiar faces, but not between primed and unprimed unfamiliar faces. The VMP was reduced to primed unfamiliar faces and significantly diminished to primed familiar faces compared to unprimed stimuli. Priming was typically reflected by a reduction of the VMP at the occipito-temporal region, whereas recognition resulted in a diminution of the VMP at both the occipito-temporal region and at the frontal region. These data support the involvement of differential neural systems for priming and recognition of visual stimuli.

Adult↗
PubMed1996

Face recognition under varying poses: the role of texture and shape.

Although remarkably robust, face recognition is not perfectly invariant to pose and viewpoint changes. It has long been known that both profile and full-face views result in poorer recognition performance than a 3/4 view. However, little data exist which investigate this phenomenon in detail. The present work provides such data using a high angular resolution and a large range of poses. Since there are inconsistencies in the literature concerning these issues, we emphasize the different roles of the learning view and the testing view in the recognition experiment. We also emphasize the roles of information contained in the texture and in the shape of a face. Our stimuli were generated from laser-scanned head models and contained either the natural texture or only Lambertian shading and no texture. The results of our same/different face recognition experiments are: (1) only the learning view but not the testing view affects recognition performance. (2) For textured faces the optimal learning view is closer to the full-face view than for the shaded faces. (3) For shaded faces, we find a significantly better recognition performance for the symmetric view. The results can be interpreted in terms of different strategies to recover invariants from texture and from shading.

Adult↗
PubMed1991

Effects of processing speed on cerebral asymmetry for left- and right-oriented faces.

A free-vision chimeric facial emotion judgment task and a tachistoscopic face-recognition reaction time task were administered to 20 male right-handed subjects. The tachistoscopic task involved judgments of whether a poser in the centrally presented full-face photograph was the same or different poser than in a profile photograph presented in the left or right visual field (LVF, RVF). The free-vision task was that used by J. Levy, W. Heller, M. Banich, and L. Burton (1983, Brain and Cognition, 2, 404-419) and involved judging which of two chimeric faces appeared happier, in which the two chimeras were mirror images of each other and each chimera consisted of a smiling half-face joined at the midline to a neutral half-face of the same poser. For the tachistoscopic task, subjects were divided into groups of Fast and Slow responders by a median split of the mean reaction times. For the Fast subjects, judgments were faster in the LVF than in the RVF, and there was a significant interaction between visual field and profile direction, such that responses were faster for medially oriented profiles; i.e., LVF responses were faster for right-facing than for left-facing profiles, with the reverse relationship in the RVF. The Slow responders did not show these effects. Only the Fast group showed the bias for choosing the chimera with the smile on the left as happier, and mean response speed and the LVF advantage on the tachistoscopic test correlated with the leftward bias on the free-vision task for all subjects combined. It was suggested that overall response speed on the face-matching task reflected the extent to which specialized and more efficient right hemisphere functions were activated.

Adult↗
PubMed2006

Face presentation: predictors and delivery route.

OBJECTIVE: We sought to identify associated characteristics of face presentation and to examine factors that were associated with mode of delivery in the setting of face presentation. STUDY DESIGN: This was a retrospective cohort study of women who were diagnosed with face presentation during labor. We examined maternal, fetal, and labor characteristics to determine the associations and predictors of cesarean delivery. RESULTS: Fetuses in face presentation were more likely preterm, < 2500 g, and black. An Apgar score of < 7 at 5 minutes was more common in face presentation (10.9%) compared with vertex presentation (4.4%; P = .018). Rates of umbilical artery base excess < -12 or pH < 7.0 were not different. Cesarean delivery was less common in women who received oxytocin (adjusted odds ratio, 0.18; 95% CI, 0.03-0.95) and in women with mentum anterior (14%) as compared with mentum posterior presentation (85%; P < .001). CONCLUSION: This study confirms the association between face presentation and prematurity. The association with black ethnicity may be related to differences in pelvic anatomy. Although face presentation was associated with decreased Apgar scores, no other indicators of fetal asphyxia were identified. Cesarean delivery rates were higher in women with mentum posterior face presentation and in women who did not receive oxytocin.

Apgar Score↗
PubMed2005

Asymmetrical activation in the human brain during processing of fearful faces.

Traditional split-field studies and patient research indicate a privileged role for the right hemisphere in emotional processing [1-7], but there has been little direct fMRI evidence for this, despite many studies on emotional-face processing [8-10](see Supplemental Background). With fMRI, we addressed differential hemispheric processing of fearful versus neutral faces by presenting subjects with faces bilaterally [11-13]and orthogonally manipulating whether each hemifield showed a fearful or neutral expression prior to presentation of a checkerboard target. Target discrimination in the left visual field was more accurate after a fearful face was presented there. Event-related fMRI showed right-lateralized brain activations for fearful minus neutral left-hemifield faces in right visual areas, as well as more activity in the right than in the left amygdala. These activations occurred regardless of the type of right-hemifield face shown concurrently, concordant with the behavioral effect. No analogous behavioral or fMRI effects were observed for fearful faces in the right visual field (left hemisphere). The amygdala showed enhanced functional coupling with right-middle and anterior-fusiform areas in the context of a left-hemifield fearful face. These data provide behavioral and fMRI evidence for right-lateralized emotional processing during bilateral stimulation involving enhanced coupling of the amygdala and right-hemispheric extrastriate cortex.

Amygdala↗
PubMed1999

Head turning and face-down positioning in prone-sleeping premature infants.

BACKGROUND: Term infants may die of sudden infant death syndrome (SIDS) when they assume the face-straight-down or the face-near-straight-down head positions. Preterm infants have a higher SIDS rate, but it is not known how often they assume the face-straight-down and face-near-straight-down positions. OBJECTIVES: To determine the frequency and cardiorespiratory consequences of head turning and face-down head positioning in prone-sleeping premature infants. STUDY DESIGN: Supervised overnight cardiorespiratory and audiovisual recordings were conducted in 15 prone-sleeping preterm infants nearing hospital discharge: birth weight, 1178 101 (SEM) g, postconceptional age, 40 1.0 weeks. RESULTS: The preterm infants, studied at a younger postconceptional age than previously reported term infants, seldom turned their heads during sleep; therefore they rarely assumed the face-straight-down position (6 episodes in 3 infants) or the face-near-straight-down position (30 episodes in 6 infants). CONCLUSIONS: Prematurely born infants, known to be at increased risk of SIDS, rarely assume face-down positions when sleeping prone at approximately 40 weeks' postconceptional age. These results suggest that head turning during sleep is developmentally regulated and may have relevance to understanding the age distribution of SIDS.

Female↗
PubMed2001

Human face recognition in sheep: lack of configurational coding and right hemisphere advantage.

Face recognition in sheep is qualitatively similar to that in humans in terms of its left visual field bias, and the effects of expertise and configural coding. The current study was designed to determine whether such effects are species specific by investigating the case of sheep recognising humans. It was found that the sheep could identify human faces and while they showed a small inversion-induced decline in discriminatory performance, this was significantly less than seen with sheep faces. In other aspects, there were qualitative differences with human face recognition compared with conspecific recognition. In contrast with sheep faces there was no left visual field advantage in the recognition of human faces and the internal features were not used at all as visual cues. The data suggest that these sheep, whilst being extensively exposed to interactions with humans, were unable to identify them with all the same 'expert' methods as were used to discriminate other sheep. This suggests that different neural systems may, to some extent, be used for recognition of sheep as opposed to human faces. The relative contribution to differential neural processing of the faces of the different species and the role of expertise are discussed.

Journal Article↗
PubMed1994

Variation in maxillary and mandibular molar and incisor vertical dimension in 12-year-old subjects with excess, normal, and short lower anterior face height.

Maxillary and mandibular molar and incisor vertical dimensions were evaluated in subjects who had excessive, normal, and short lower anterior face height in relation to upper face height. Sexual dimorphism was also investigated. The dentoalveolar heights were compared between Class I and Class II, dental and skeletal malocclusions. The sample was drawn from the Burlington Growth Centre sample and consisted of 188 male and 156 female subjects at age 12 years, for whom lateral head films were available. This sample was classified into excessive, normal, and short lower anterior face height, using the ratio upper anterior face height/lower anterior face height (UAFH/LAFH). The results showed that the dentoalveolar heights are significantly different between faces with excessive, normal, and short lower anterior face heights, except for the lower posterior dental height, which showed no difference between short and normal lower anterior face height subjects. All dentoalveolar heights are larger for male subjects except for the upper posterior dental height. Dentoalveolar heights are similar between Class I and Class II dental and skeletal malocclusions. The upper teeth present a higher correlation to the UAFH/LAFH ratio than the lower teeth. Stepwise regression analysis shows that 22% of the variation in the ratio is explained by the maxillary and mandibular molars and 41% is explained by the maxillary and mandibular incisors.

Cephalometry↗
PubMed2001

Effects of attention and emotion on face processing in the human brain: an event-related fMRI study.

We used event-related fMRI to assess whether brain responses to fearful versus neutral faces are modulated by spatial attention. Subjects performed a demanding matching task for pairs of stimuli at prespecified locations, in the presence of task-irrelevant stimuli at other locations. Faces or houses unpredictably appeared at the relevant or irrelevant locations, while the faces had either fearful or neutral expressions. Activation of fusiform gyri by faces was strongly affected by attentional condition, but the left amygdala response to fearful faces was not. Right fusiform activity was greater for fearful than neutral faces, independently of the attention effect on this region. These results reveal differential influences on face processing from attention and emotion, with the amygdala response to threat-related expressions unaffected by a manipulation of attention that strongly modulates the fusiform response to faces.

Adult↗
PubMed2000

The distributed human neural system for face perception.

Face perception, perhaps the most highly developed visual skill in humans, is mediated by a distributed neural system in humans that is comprised of multiple, bilateral regions. We propose a model for the organization of this system that emphasizes a distinction between the representation of invariant and changeable aspects of faces. The representation of invariant aspects of faces underlies the recognition of individuals, whereas the representation of changeable aspects of faces, such as eye gaze, expression, and lip movement, underlies the perception of information that facilitates social communication. The model is also hierarchical insofar as it is divided into a core system and an extended system. The core system is comprised of occipitotemporal regions in extrastriate visual cortex that mediate the visual analysis of faces. In the core system, the representation of invariant aspects is mediated more by the face-responsive region in the fusiform gyrus, whereas the representation of changeable aspects is mediated more by the face-responsive region in the superior temporal sulcus. The extended system is comprised of regions from neural systems for other cognitive functions that can be recruited to act in concert with the regions in the core system to extract meaning from faces.

Journal Article↗
PubMed1996

Two loci of repetition priming in the recognition of familiar faces.

Four experiments examining the repetition priming of familiar face recognition are reported. The experiments showed that the speed of deciding whether a face is familiar was facilitated by prior presentation of the face, but not by reading the written name or by producing the name in response to a definition. In contrast, reading names and producing names to definitions both primed subsequent naming of the corresponding faces (Experiments 1 and 2). Face naming was primed more by face naming than by either familiarity decisions or naming from description (Experiments 3 and 4). The authors propose that repetition priming of familiar face recognition occurs at 2 distinct loci. The first involves the perceptual recognition of a face as familiar and is domain-specific. The second involves name retrieval and is susceptible to both within- and cross-domain priming.

Adult↗
PubMed2000

Differences in the coding of spatial relations in face identification and basic-level object recognition.

The purpose of this investigation was to determine if the relations among the primitives used in face identification and in basic-level object recognition are represented using coordinate or categorical relations. In 2 experiments the authors used photographs of famous people's faces as stimuli in which each face had been altered to have either 1 of its eyes moved up from its normal position or both of its eyes moved up. Participants performed either a face identification task or a basic-level object recognition task with these stimuli. In the face identification task, 1-eye-moved faces were easier to recognize than 2-eyes-moved faces, whereas the basic-level object recognition task showed the opposite pattern of results. Results suggest that face identification involves a coordinate shape representation in which the precise locations of visual primitives are specified, whereas basic-level object recognition uses categorically coded relations.

Adult↗
PubMed2003

Attending to faces: change detection, familiarization, and inversion effects.

We tested detection of changes to eye position, eye color (brightness), mouth position, and mouth color in frontal views of faces. Two faces were presented sequentially for 555 ms each, with a blank screen of 120 ms separating the two. Faces were presented either both upright or both inverted. Measures of detection (d') were calculated for several different degrees of change for each of the four dimensions of change. We first compared results to an earlier experiment that used an oddity design, in which subjects indicated which of three simultaneously viewed and otherwise identical faces had been altered on one of these four dimensions. Subjects in both of these experiments were partially cued, in that they knew the four possible types of changes that could occur on a given trial. The change-detection results correlated well with the oddity data. They confirmed that face inversion had little effect upon detection of changes in eye color, a moderate effect upon detection of eye-position or mouth-color changes, and caused a drastic reduction in the detection of mouth-position changes. An experiment in which uncued and fully cued subjects were compared showed that cueing significantly improved detection of feature color changes, but there was little difference between upright and inverted faces. Full cueing eliminated all effects of inversion. Compared to partial cueing, changes in mouth color were poorly detected by uncued subjects. Last, a change in the frequency of the base (unaltered) face in an experiment from 75% to 40% showed that increased short-term familiarity decreased the detection of eye changes and increased the detection of mouth changes, regardless of face orientation and the type of change made (color or position). We conclude that uncued subjects encode the spatial relations of features more than the colors of features, that mouth color in particular is not considered a relevant dimension for encoding, and that familiarization redistributes attention from more to less salient facial regions. Inversion effects are not simply an exaggeration of the salience effects revealed by withdrawing cueing, but represent an interaction of spatial encoding with salience, in that the greatest inversion effects occur for spatial shifts in less salient facial regions, and can be eliminated through the use of focused attention.

Adolescent↗
PubMed1993

Parts and wholes in face recognition.

Are faces recognized using more holistic representations than other types of stimuli? Taking holistic representation to mean representation without an internal part structure, we interpret the available evidence on this issue and then design new empirical tests. Based on previous research, we reasoned that if a portion of an object corresponds to an explicitly represented part in a hierarchical visual representation, then when that portion is presented in isolation it will be identified relatively more easily than if it did not have the status of an explicitly represented part. The hypothesis that face recognition is holistic therefore predicts that a part of a face will be disproportionately more easily recognized in the whole face than as an isolated part, relative to recognition of the parts and wholes of other kinds of stimuli. This prediction was borne out in three experiments: subjects were more accurate at identifying the parts of faces, presented in the whole object, than they were at identifying the same part presented in isolation, even though both parts and wholes were tested in a forced-choice format and the whole faces differed only by one part. In contrast, three other types of stimuli--scrambled faces, inverted faces, and houses--did not show this advantage for part identification in whole object recognition.

Adult↗
PubMed2001

Deep venous thrombosis and pulmonary embolus after face lift: a study of incidence and prophylaxis.

Deep venous thrombosis and pulmonary embolus are known risks of surgery. However, the incidence of these conditions in face lift is unknown. In this study, the incidence of deep venous thrombosis/pulmonary embolus after face lift is studied and factors associated with thromboembolic complications are evaluated. One-third of the active members of the American Society for Aesthetic Plastic Surgery were randomly selected. Participating surgeons completed a one-page survey providing information on face-lift procedures during a 12-month study period. A response rate of 80 percent was achieved, with 273 of the 342 surgeons responding to the survey. A total of 9937 face-lift procedures were reported in the 1-year study period. There were 35 patients with deep venous thrombosis (0.35 percent), 14 patients with pulmonary embolus (0.14 percent), and 1 patient death in the series. Although 43.5 percent of patients underwent face lift under general anesthesia, 83.7 percent of deep venous thrombosis/pulmonary embolus events occurred with general anesthesia. For prophylaxis for deep venous thrombosis/pulmonary embolus, 19.7 percent of the surgeons used intermittent compression devices, 19.6 percent used thromboembolic disease hose or Ace wraps, and 60.7 percent used no prophylaxis. Of patients developing deep venous thrombosis/pulmonary embolus, 4.1 percent were treated prophylactically with intermittent compression devices, 36.7 percent with thromboembolic disease hose/Ace wraps, and 59.2 percent with no prophylaxis. It was found that deep venous thrombosis/pulmonary embolus after face lift is a measurable complication experienced by one of nine surgeons surveyed. Deep venous thrombosis/pulmonary embolus is more likely to occur when the procedure is performed under general anesthesia. The majority of plastic surgeons surveyed used no prophylaxis for deep venous thrombosis when performing face-lift procedures. Intermittent compression devices were associated with significantly fewer thromboembolic complications, whereas Ace wrap/thromboembolic disease hose afforded no protection against deep venous thrombosis/pulmonary embolus when used alone. In conclusion, aesthetic surgeons should consider adopting intermittent compression devices when performing face lift under general anesthesia.

Bandages↗
PubMed2005

Familiarity facilitates the corticocortical processing of face perception.

The visual evoked potentials elicited by mosaic pictures were used to elucidate the initial step of face perception. Three different mosaic levels (subthreshold, threshold, suprathreshold) for familiar and unfamiliar faces and objects were randomly presented for 250 ms. The latencies of occipital N1 and posterior-temporal N2 were shortened by decreasing the mosaic levels of faces but not for object. The N2 amplitude significantly increased at threshold and suprathreshold levels for familiar and unfamiliar faces. The latency difference between N1 and N2 at threshold level for a familiar face was significantly shortened compared with that for an unfamiliar face. Our findings suggest the initial step of face perception is already set in the primary visual cortex, and familiarity can facilitate the corticocortical processing of face information.

Adult↗
PubMed2004

Dissociable roles of the human somatosensory and superior temporal cortices for processing social face signals.

Faces are multi-dimensional stimuli bearing important social signals, such as gaze direction and emotion expression. To test whether perception of these two facial attributes recruits distinct cortical areas within the right hemisphere, we used single-pulse transcranial magnetic stimulation (TMS) in healthy volunteers while they performed two different tasks on the same face stimuli. In each task, two successive faces were presented with varying eye-gaze directions and emotional expressions, separated by a short interval of random duration. TMS was applied over either the right somatosensory cortex or the right superior lateral temporal cortex, 100 or 200 ms after presentation of the second face stimulus. Participants performed a speeded matching task on the second face during one of two possible conditions, requiring judgements about either gaze direction or emotion expression (same/different as the first face). Our results reveal a significant task-stimulation site interaction, indicating a selective TMS-related interference following stimulations of somatosensory cortex during the emotional expression task. Conversely, TMS of the superior lateral temporal cortex selectively interfered with the gaze direction task. We also found that the interference effect was specific to the stimulus content in each condition, affecting judgements of gaze shifts (not static eye positions) with TMS over the right superior temporal cortex, and judgements of fearful expressions (not happy expressions) with TMS over the right somatosensory cortex. These results provide for the first time a double dissociation in normal subjects during social face recognition, due to transient disruption of non-overlapping brain regions. The present study supports a critical role of the somatosensory and superior lateral temporal regions in the perception of fear expression and gaze shift in seen faces, respectively.

Adult↗