Patterns of brain electrical activity during facial signs of emotion in 10-month-old infants.

This study examined electroencephalogram (EEG) asymmetries during the presence of discrete facial signs of emotion. Thirty-five 10-month-old infants were tested in a standard stranger- and mother-approach paradigm that included a brief separation from their mother. Infant facial expression was videotaped, and brain electrical activity from left and right frontal and parietal regions was recorded. The videotapes were coded with two different discrete facial coding systems. Artifact-free periods of EEG were extracted that were coincident with the expression of the emotions of joy, anger, and sadness. The data revealed different patterns of EEG asymmetry depending on the type of facial expression and vocal expression of affect that was observed. Expressions of joy that involved facial actions of both zygomatic and orbicularis oculi were seen more often in response to mother approach, whereas smiles that did not involve the action of orbicularis oculi were seen more often in response to approach of the stranger. The former type of smile was associated with relative left frontal activation, whereas the latter type was associated with right frontal activation. Facial expressions of anger and sadness exhibited in the absence of crying were associated with left frontal activation, whereas these same facial expressions during crying were associated with right frontal activation. These data underscore the usefulness of EEG measures of hemispheric activation in differentiating among emotional states associated with differences in facial and vocalic expressivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The value of genuine and polite smiles.

Humans show remarkable ability to adapt their social behavior to suit the changing requirements of their interactions. An interaction partner's social cues, particularly facial expressions, likely play an important role in motivating and reinforcing this behavioral adaptation. Over three studies, we test a key aspect of this idea. Specifically, we ask how the reinforcement value of facial expressions compares to that of nonsocial feedback and to what degree two frequently occurring expressions (genuine and polite smiles) differ in reinforcement value. Our findings show that social feedback is preferred over nonsocial feedback and that genuine smiles are preferred over polite smiles. Based on a logistic model of our data, we show that both monetary and social values of stimuli contribute significantly to participants' decisions. Indeed, participants were willing to sacrifice the chance of a monetary reward to receive a genuine smile and produced inflated estimates of the value of genuinely smiling faces. These findings suggest that genuine smiles, and potentially other social cues, may be useful social reinforcers and therefore important in the control of social behavior on a moment-to-moment basis during interaction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Jugement de l'authenticité des sourires et détection des indices faciaux.

The smile is one of the most often expressed emotions during social interactions. It can be authentic, that is, associated with a joyful emotional state in the person expressing it, but it can also be false, that is, deliberately produced in the absence of that emotional state in order to deceive one or more individuals (Ekman, 1993). Even though the fake smile very much resembles the authentic smile, it generally does not constitute the perfect smile. The fake smile more often has a certain degree of asymmetry than the authentic smile (Ekman, Hager, & Friesen, 1981) and it uses the cheek raiser action less often than with the authentic smile (Ekman, Friesen, & O'Sullivan, 1988; Frank, Ekman, & Friesen, 1993). This study looked at the knowledge that adults have of these differences as well as their perceptive ability to detect them. The visual stimuli presented to participants were prepared using the Facial Action Coding System (Ekman & Friesen, 1978). Results show that participants detected the differences between the two types of smile and that detection was better using smile asymmetry than with the cheek raiser action. Analysis of the use of response categories in the detection task indicated that participants underestimated the differences between smiles when they were different and that this tendency was more apparent with the cheek raiser detection method than for asymmetry detection. Participants also demonstrated a better knowledge of smile asymmetry than cheek raiser action. The knowledge gathered suggests that the ability of the receptor to judge smile authenticity is limited by perceptive factors. However, the mediation analyses that we conducted show the judging smile authenticity is not limited to simple perceptive detection of facial clues. Detecting facial clues is a necessary condition for correctly assessing smile authenticity, but it does not explain the variance in these assessments. We believe that this variance would be due more to the importance that participants give to facial clues. Finally, our results show that the capacity to detect differences between authentic and fake smiles is not easy to change. Participants who received modified information on changes of appearance linked to the two facial parameters were not more likely to detect the differences than participants who did not receive information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognition of posed and spontaneous dynamic smiles in young and older adults.

In 2 studies, we investigated age effects in the ability to recognize dynamic posed and spontaneous smiles. Study 1 showed that both young and older adult participants were above chance in their ability to distinguish between posed and spontaneous smiles in young adults. In Study 2, we found that young adult participant performance declined when judging a combination of both young and older adult target smiles, while older adult participants outperformed young adult participants in distinguishing between posed and spontaneous smiles. A synthesis of results across the 2 studies showed a small-to-medium age effect (d = ?0.40), suggesting that older adults have an advantage in discriminating between smile types. Mixed stimuli (i.e., a mixture of young and older adult faces) may impact accurate smile discrimination. In future research, both the sources (cues) and behavioral effects of age-related differences in the discrimination of positive expressions should be investigated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences between children and adults in the recognition of enjoyment smiles.

The authors investigated the differences between 8-year-olds (n = 80) and adults (n = 80) in recognition of felt versus faked enjoyment smiles by using a newly developed picture set that is based on the Facial Action Coding System. The authors tested the effect of different facial action units (AUs) on judgments of smile authenticity. Multiple regression showed that children base their judgment on AU intensity of both mouth and eyes, with relatively little distinction between the Duchenne marker (AU6 or "cheek raiser") and a different voluntary muscle that has a similar effect on eye aperture (AU7 or "lid tightener"). Adults discriminate well between AU6 and AU7 and seem to use eye-mouth discrepancy as a major cue of authenticity. Bared-teeth smiles (involving AU25) are particularly salient to both groups. The authors propose and discuss an initial developmental model of the smile recognition process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beyond smile dynamics: Mimicry and beliefs in judgments of smiles.

The judgment that a smile is based on “true,” usually positive, feelings affects social interaction. However, the processes underlying the interpretation of a smile as being more or less genuine are not well understood. The aim of the present research was to test predictions of the Simulation of Smiles Model (SIMS) proposed by Niedenthal, Mermillod, Maringer, and Hess (2010). In addition to the perceptual features that can guide the judgment of a smile as genuine, the model identifies the conditions that the judgments rely on: (a) the embodiment of the facial expression and its corresponding state, and (b) beliefs about the situations in which genuine smiles are most often expressed. Results of two studies are consistent with the model in that they confirm the hypotheses that facial mimicry provides feedback that is used to judge the meaning of a smile, and that beliefs about the situations in which a smile occurs guides such judgments when mimicry is inhibited. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Perceived differences between chimpanzee (Pan troglodytes) and human (Homo sapiens) facial expressions are related to emotional interpretation.

Human face perception is a finely tuned, specialized process. When comparing faces between species, therefore, it is essential to consider how people make these observational judgments. Comparing facial expressions may be particularly problematic, given that people tend to consider them categorically as emotional signals, which may affect how accurately specific details are processed. The bared-teeth display (BT), observed in most primates, has been proposed as a homologue of the human smile (J. A. R. A. M. van Hooff, 1972). In this study, judgments of similarity between BT displays of chimpanzees (Pan troglodytes) and human smiles varied in relation to perceived emotional valence. When a chimpanzee BT was interpreted as fearful, observers tended to underestimate the magnitude of the relationship between certain features (the extent of lip corner raise) and human smiles. These judgments may reflect the combined effects of categorical emotional perception, configural face processing, and perceptual organization in mental imagery and may demonstrate the advantages of using standardized observational methods in comparative facial expression research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smile intensity and warm touch as thin slices of child and family affective style.

The authors investigate the claim that thin slices of expressive behavior serve as reliable indicators of affective style in children and their families. Using photographs, the authors assessed smile intensity and tactile contact in kindergartners and their families. Consistent with claims that smiling and touch communicate positive emotion, measures of children’s smile intensity and warm family touch were correlated across classroom and family contexts. Consistent with studies of parent–child personality associations, parents’ warm smiles and negative facial displays resembled those of their children. Finally, consistent with observed relations between adult personality and positive display, children’s smiling behavior in the classroom correlated with parent ratings of children’s Extraversion/Surgency. These results highlight the utility of thin slices of smiling and touch as indicators of child and family affective style. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The diagnosis and treatment of the gummy smile

The diagnosis and treatment of the "gummy smile" (altered passive eruption, excessive gingival display) help the periodontist to provide the most beautiful smiles possible for patients. This article describes diagnosis, surgical planning, and case reports that show the benefits of treatment of this common clinical problem for the patient and restorative dentist who can now provide ideal cosmetic results for their patients.     

What's in a smile?

In positive social contexts, both adults and older infants show more Duchenne smiling (which involves high cheek raising) than non-Duchenne smiling (which does not). This study compared Duchenne and non-Duchenne smiles in early infancy for clues to their emotional significance. Infants (N?=?13) from 1 to 6 months of age were videotaped weekly for 5 min in 208 face-to-face interactions with their mothers. Levels of Duchenne and non-Duchenne smiling were correlated within interactive sessions, and the 2 smiles had similar developmental trajectories. Duchenne smiles were typically preceded by non-Duchenne smiles. The results suggest these frequently contrasted types of smiles occur in similar situations and are often different temporal phases of a continuous emotional process. In contrast to adults, infant Duchenne smiles had longer durations than non-Duchenne smiles, suggesting infant smiling does not fit adult models of emotional functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facial expression in adults with Down's Syndrome.

The facial expressions of adults with Down's syndrome (DS; n?=?15) as they watched happy, sad, and neutral videotapes were compared with those of a healthy age-matched control group (n?=?20). Facial movements were analyzed with the Facial Action Coding System (P. E. Ekman & W. V. Friesen, 1978). While watching happy stimuli, the 10 DS adults who were able to appropriately rate their reactions smiled with a cheek raise as frequently as control adults, suggesting that the expression of positive affect in these individuals is normal. Contrary to predictions, however, the DS group exhibited fewer smiles without cheek raises than did control adults and were more likely not to smile. Neither group showed prototypic sad facial expressions in response to sad stimuli. Independent of emotion, DS participants made more facial movements, including more tongue shows, than did control participants. Differences in facial expression in DS adults may confuse others' interpretations of their emotional responses and may be important for understanding the development of abnormal emotional processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Treatment of severe physiologic gingival pigmentation with free gingival autograft

Melanin is normally found in the skin of all people, and normal pigmentation of the intraoral tissues is a relatively frequent finding. The highest rate of gingival pigmentation has been observed at the incisors. Until recently, however, very little attention has been paid to the esthetic treatment of severe gingival pigmentation. To answer the cosmetic demand for a pleasing smile, pigmented gingiva was replaced with an unpigmented free gingival autograft in 10 patients. At least two areas in each patient were grafted. In all 10 areas in which the recipient site received full-thickness bed preparation, no evidence of repigmentation was found after 4.5 years. Of the 10 areas that received partial-thickness bed preparation, only one exhibited repigmentation (after 1 year).     

Duchenne smile, emotional experience, and autonomic reactivity: A test of the facial feedback hypothesis.

This study examined the modulatory function of Duchenne and non-Duchenne smiles on subjective and autonomic components of emotion. Participants were asked to hold a pencil in their mouth to either facilitate or inhibit smiles and were not instructed to contract specific muscles. Five conditions--namely lips pressing, low-level non-Duchenne smiling, high-level non-Duchenne smiling, Ducherme smiling, and control--were produced while participants watched videoclips that were evocative of positive or negative affect. Participants who displayed Duchenne smiles reported more positive experience when pleasant scenes and humorous cartoons were presented. Furthermore, they tended to exhibit different patterns of autonomic arousal when viewing positive scenes. These results support the facial feedback hypothesis and suggest that facial feedback has more powerful effects when facial configurations represent valid analogs of basic emotional expressions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of normal and perturbed social play on the duration and amplitude of different types of infant smiles.

Different types of smiling varying in amplitude of lip corner retraction were investigated during 2 mother-infant games--peekaboo and tickle--at 6 and 12 months and during normally occurring and perturbed games. Using Facial Action Coding System (FACS), infant smiles were coded as simple (lip corner retraction only), Duchenne (simple plus cheek raising), play (simple plus jaw drop), and duplay (Duchenne plus jaw drop). In addition, again using FACS, the amplitude of lip corner retraction was coded on a 5-point scale. Rather than a single smile expression that differs only in amplitude, the authors found a complex family of different smile expressions differing in their duration and amplitude as a function of game, setup versus climax of the game, and perturbation. Both type of smiling and amplitude of smiling appear to be controlled independently by the infant in relation to the context. These findings reveal systematic and context-specific nuances in infant smiles in the 2nd half of the first year. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gold weights for the treatment of lagophthalmos caused by facial paralysis. Our experience and review of the literature

Paralysis of the orbicularis oculi muscle in patients with facial palsy can originate serious functional and esthetic problems. The implantation of a gold weight in the upper eyelid is one of the many surgical techniques that have been described for the correction of lagophthalmos in these patients. In this article we review the literature and present our experience with gold weight implantation for eyelid reanimation in patients with facial palsy. This procedure is technically simple to perform, produces good functional and cosmetic results, has a relatively low complication rate and is reversible should facial function return.     

Esthetics and vertical tooth position: orthodontic possibilities

Throughout the 1990s, esthetic dentistry has become a prominent part of the treatment protocol of most dentists. Patients have become more conscious of the benefits of a beautiful smile and are willing to invest time and money to improve the appearance of their teeth. Many of these patients can be treated with routine restorative procedures (crowns, composites, laminates) to achieve the desired results. However, some patients have problems with tooth position that create significant discrepancies in gingival levels which can compromise the esthetic result of restorative dentistry. Prerestorative orthodontic therapy can often resolve these tooth position problems and enhance the esthetic restoration. This article describes the indication, methods, and results achieved when orthodontics preceded restorative dentistry in the treatment of various esthetic challenges.     

Judgments of facial expressions of emotion in profile.

Despite the fact that facial expressions of emotion have signal value, there is surprisingly little research examining how that signal can be detected under various conditions, because most judgment studies utilize full-face, frontal views. We remedy this by obtaining judgments of frontal and profile views of the same expressions displayed by the same expressors. We predicted that recognition accuracy when viewing faces in profile would be lower than when judging the same faces from the front. Contrarily, there were no differences in recognition accuracy as a function of view, suggesting that emotions are judged equally well regardless of from what angle they are viewed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The relationship between smile type and play type during parent-infant play.

This study examined the relationship between smile type and play type during parent–infant interactions in the home. Thirty-six mother–infant and father–infant dyads were videotaped playing for 10 min. Smile type (basic, Duchenne, and duplay smiles) and play type (object, physical, vocal, and book reading) were coded. Results of loglinear analysis indicated that different types of smiles occur during different types of play more often than expected if distributed equally. In addition, different smile-type and play-type patterns occurred for father–infant dyads compared with mother–infant dyads. Qualitative analyses were used to generate hypotheses about the reasons why different types of smiles occurred during various play activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)