Morphed Faces Research Articles

Measuring sexual dimorphism with a race-gender face space.

Faces are complex visual objects, and faces chosen to vary in 1 regard may unintentionally vary in other ways, particularly if the correlation is a property of the population of faces. Here, we present an example of a correlation that arises from differences in the degree of sexual dimorphism. In Experiment 1, paired similarity ratings were collected for a set of 40 real face images chosen to vary in terms of gender and race (Asian vs. White). Multidimensional scaling (MDS) placed these stimuli in a "face space," with different attributes corresponding to different dimensions. Gender was found to vary more for White faces, resulting in a negative or positive correlation between gender and race when only considering male or only considering female faces. This increased sexual dimorphism for White faces may provide an alternative explanation for differences in face processing between White and Asian faces (e.g., the own-race bias, face attractiveness biases, etc.). Studies of face processing that are unconfounded by this difference in the degree of sexual dimorphism require stimuli that are decorrelated in terms of race and gender. Decorrelated faces were created using a morphing technique, spacing the morphs uniformly around a ring in the 2-dimensional (2D) race-gender plane. In Experiment 2, paired similarity ratings confirmed the 2D positions of the morph faces. In Experiment 3, race and gender category judgments varied uniformly for these decorrelated stimuli. Our results and stimuli should prove useful for studying sexual dimorphism and for the study of face processing more generally.

The self prefers itself? Self-referential versus parental standards in face attractiveness.

Preference for phenotypic similarity in assortative mating may be influenced by either a preference for self-similarity or parent-similarity. The aim of the current study was to assess whether people’s preference in face attractiveness is influenced by resemblance to the opposite sex parent’s face (parental phenotype) or their own face (self-based phenotype or “self-imprinting”). We used computerized image manipulations of facial photographs of participants, their mothers and fathers. The original photographs were combined with 78% of the participants’ opposite sex prototype face (i.e., male and female prototypes made from equal contributions of a hundred faces), creating morphs where the contribution from the familiar faces went unnoticed. Female and male participants ranked these images together with the opposite-sex prototype different familiar morphs. Each participant did the same for the morphs generated with other same-sex participants’ faces and of their parents. We found that the female participants preferred the self-based morphs to the prototype faces. Male participants showed a general tendency towards self-referential standard. Parental face morphs were ranked low in attractiveness, which may be accounted for by the age difference of the faces blended into the self-based versus parental face morphs, since we used present-time photographs of both the participants and their parents.

How the human brain exchanges information across sensory modalities to recognize other people.

Recognizing the identity of other individuals across different sensory modalities is critical for successful social interaction. In the human brain, face- and voice-sensitive areas are separate, but structurally connected. What kind of information is exchanged between these specialized areas during cross-modal recognition of other individuals is currently unclear. For faces, specific areas are sensitive to identity and to physical properties. It is an open question whether voices activate representations of face identity or physical facial properties in these areas. To address this question, we used functional magnetic resonance imaging in humans and a voice-face priming design. In this design, familiar voices were followed by morphed faces that matched or mismatched with respect to identity or physical properties. The results showed that responses in face-sensitive regions were modulated when face identity or physical properties did not match to the preceding voice. The strength of this mismatch signal depended on the level of certainty the participant had about the voice identity. This suggests that both identity and physical property information was provided by the voice to face areas. The activity and connectivity profiles differed between face-sensitive areas: (i) the occipital face area seemed to receive information about both physical properties and identity, (ii) the fusiform face area seemed to receive identity, and (iii) the anterior temporal lobe seemed to receive predominantly identity information from the voice. We interpret these results within a prediction coding scheme in which both identity and physical property information is used across sensory modalities to recognize individuals.

Familiar face + novel face = familiar face? Uncanny valley? : Morphed face recognition in human and chimpanzee

Familiar face + novel face = familiar face? Uncanny valley? : Morphed face recognition in human and chimpanzee

The more-or-less morphing face illusion: a case of fixation-dependent modulation.

A visual illusion is presented in which the perceived changes in a morphing sequence depend on eye movements. The phenomenon is illustrated using face morphs: when tracking a moving dot superimposed on a face morphing sequence, the changes in the morphing sequence seem rather small, but when the dot stops moving, the perceived extent of morphing suddenly becomes much larger. We explore this phenomenon further and discuss the observed effects.

Supra-additive contribution of shape and texture to individual face discrimination as revealed by electrophysiological periodic visual responses

Face perception depends on two sources of information 3D shape and surface-based cues (texture, color). According to behavioral studies, both of them equally contribute to discrimination of individual faces (O'Toole, Vetter & Blanz, 1999). However, these behavioral measures can be contaminated by many factors, not allowing to distinguish and to quantify the respective contribution of each source of information. Using an established method of manipulating facial images (Tiddeman, Burt, & Perrett, 2001), four individual faces (2 males) were morphed with another 10 same-sex faces varying shape only, texture only or both. Electroencephalogram (EEG) was recorded from 10 participants during a rapid periodic oddball visual stimulation, providing an objective, implicit and robust quantifiable measure of visual discrimination (Liu-Shuang, Norcia & Rossion, in press). Stimuli were presented in 80 sec long trials, in which the same face (one of the 4 faces) was shown four times consecutively and the fifth face (the oddball) was one of the corresponding morphed faces, thus resulting in a sequence AAAABAAAACAAAAD. The base frequency F was 5.88 Hz and the oddball frequency 1.18Hz (5.88Hz/5) and its harmonics (nF/5) were used to measure individual face discrimination. This individual face discrimination response was observed at occipito-temporal sites, particularly over the right hemisphere. While shape was also discriminated at right occipito-temporal electrode sites, surface information was coded bilaterally (Jiang et al., 2009). However, and most importantly, shape and texture changes alone were associated with much weaker responses than when both sources of information were combined, revealing a supra-additive effect of the contribution of the two facial aspects to the discrimination of individual faces. Thus, these results suggest that the two kinds of information combined are necessary to provide a full face identity, i.e. face identity being more than the sum of the contribution of shape and surface cues. Meeting abstract presented at VSS 2014

Neural response during explicit and implicit face processing varies developmentally in bipolar disorder

Both children and adults with bipolar disorder (BD) exhibit face emotion labeling deficits and neural circuitry dysfunction in response to emotional faces. However, few studies have compared these groups directly to distinguish effects of age and diagnosis. Such studies are important to begin to elucidate the developmental trajectory of BD and facilitate its diagnosis, prevention and treatment. This functional magnetic resonance imaging study compares 41 individuals with BD (19 children; 22 adults) and 44 age-matched healthy individuals (25 children; 19 adults) when making explicit or implicit judgments about angry or happy face morphs across a range of emotion intensity. Linear trend analyses revealed that BD patients, irrespective of age, failed to recruit the amygdala in response to increasing angry face. This finding was no longer significant when the group was restricted to euthymic youth or those without comorbid attention deficit hyperactivity disorder although this may reflect low statistical power. Deficits in subgenual anterior cingulate modulation were observed in both patient groups but were related to implicit processing for child patients and explicit processing for adult patients. Abnormalities in face emotion labeling and the circuitry mediating it may be biomarkers of BD that are present across development.

Panel perception of facial appearance of cleft patients generated by use of a morphing technique

Perception of the facial appearance of cleft patients has, until now, been evaluated on the basis of photographs of the patients. Research based on photographs generated by use of a morphing technique has not yet been reported. The purpose of this study was to investigate female and male raters' panel perception with regard to the following: (1) patient age, (2) attractiveness, (3) gender appearance, and (4) likeability of faces of cleft patients generated by the use of a morphing technique. The study was conducted at the Department of Oral, Craniomaxillofacial and Facial Plastic Surgery, University Hospital of Leipzig, Germany. We used photographs of 32 adult German nonsyndromic cleft patients, mean age 18.9 ± 1.3years, and surveyed 93 students, mean age 25.3 ± 3.2years, by use of a standardized questionnaire. All respondents rated the mean age of cleft patients equally in unmorphed and morphed pictures. For all respondents, attractiveness of morphed patient pictures was rated significantly higher than for unmorphed pictures (mean 4.8 ± 1.0 vs. 6.4 ± 2.4; p < 0.001), although significance was reached only if morphed pictures of eight patients were rated. Female respondents rated attractiveness significantly higher than did males, especially for pictures of female patients. Facial morphing of patient pictures is a suitable method for creation of standard cleft faces. Despite the modification of the pictures, the faces generated remain human and assessable by panel members. Perception of faces of cleft patients' depended on raters' gender.

Enhanced sensitivity and response bias for male anger in women with borderline personality disorder

Interpersonal difficulties, which are characteristic of Borderline personality disorder (BPD), may be related to problems with social cognition. We explored facial emotion recognition in 44 women (15 with BPD, 15 healthy controls, and 14 with a history of childhood trauma but no BPD) examining the role of BPD and abuse history in the ability to detect fearful, angry and happy cues in emotional faces. In Task 1, participants viewed pictures of morphed faces containing different percentages of specific emotions and reported the emotion they saw. In Task 2, participants were asked to increase the intensity of a specific emotion on an initially neutral face until they could detect that emotion in the face. Across both tasks, BPD predicted the earlier detection of anger in male faces. BPD symptoms also predicted the misidentification of anger in male faces containing no anger cues. Although participants with BPD were slower to recognize happiness in male faces, their overall ability to recognize happiness was unimpaired. Abuse history did predict problems with happiness recognition. Finally, recognition of fear was unrelated to abuse history and BPD. Findings suggest that BPD is associated with a bias toward seeing anger in males and that this is independent of abuse history.

EPA-1514 - Processing of facial anger in borderline personality disorder

Patients with borderline personality disorder (BPD) are hypersensitive for social threat and are unable to regulate emotion. One reason for this might be deficits in facial emotion recognition. Although they do not show a general deficit in facial emotion recognition, previous studies have revealed a bias towards the perception of anger in morphed faces with low intensity of this emotion. The aim of this study was to further investigate the processing and recognition of ambiguous facial expressions BPD patients using bimodal social stimuli. Male and female BPD patients as well as matched healthy men and women were presented emotionally intonated sentences (auditory stimuli) and thereafter had to classify in a forced-choice decision task morphed faces displaying blends of happy and angry facial expressions (e.g., 80% angry/ 20% happy). Besides behavioral responses, we recorded and analyzed the electroencephalogramm. In the behavioral data, we found a bias for anger when BPD patients are confronted with ambiguous bimodal stimuli. The ERP analyses revealed enhanced amplitudes for non-ambiguous emotional faces (i.e., 80%-angry/20%-happy, 80%-happy/20%-angry) compared with ambiguous faces (50%-angry/50%-happy) at components reflecting early (parietooccipital N170, frontocentral N200), and later (parietal P300) stages of emotional face processing. BPD patients had decreased amplitudes particularly in the emotion-sensitive parietalP300. These results confirm a hypersensitivity for subtle signals of facial anger and a reduced accuracy in anger recognition in faces clearly displaying anger in BPD patients maybe because of an enhanced early processing of and reduced regulation of the emotional reaction to facial anger.

Emotional recognition of children with high-functioning autism spectrum disorder

Individuals with autism spectrum disorder have difficulties recognizing emotional information, especially from facial expressions. The present study investigated facial expression recognition ability among 17 children with high-functioning autism spectrum disorder and 26 typically developing children. Three facial expression tasks were used: the Eyes Task, the Morphed Faces Task, and the Movie Stills Task with and without faces. Children were asked to adapt emotional words for stimuli (eye stimuli and emotional scenes) or rate emotional intensity from facial expressions. Results showed that children with high-functioning autism spectrum disorder had difficulties perceiving subtle fear, complex emotions, and using contextual information appropriately in the absence of faces. These findings suggest that difficulty in recognizing emotional information from not only facial expressions but also contextual cues could provide a basis for understanding to social deficits among children with high-functioning autism spectrum disorder.

Impact of total sleep deprivation on behavioural neural processing of emotionally expressive faces

Sleep deprivation impacts subjective mood states, but very little research has examined the impact on processing emotional information. In the current study, we investigated the impact of total sleep deprivation on neural responses to emotional facial expressions as well as the accuracy and speed with which these faces were categorized. Forty-nine participants completed two tasks in which they were asked to categorize emotional facial expressions as Happy, Sad, Angry, or Fearful. They were shown the 'full' expression of the emotions in one task and more subtle expressions in a second task in which expressions were 'morphed' with neutral faces so that the intensity of emotion varied. It was expected that sleep deprivation would lead to greater reactivity (indexed by larger amplitude N170 event-related potentials), particularly for negative and more subtle facial expressions. In the full face task, sleep-deprived (SD) participants were significantly less accurate than controls (C) at identifying Sad faces and slower to identify all emotional expressions. P1 was smaller and N170 was larger for the SD compared to C group, but for all emotions, indicating generalized impairment in low-level visual processing. In the more difficult morphed face task, SD participants were less accurate than C participants for Sad faces; as well, the group difference in reaction time was greatest for Sad faces. For the SD group, N170 increased in amplitude with increasing perceptual difficulty for the Fearful and Angry faces, but decreased in amplitude with increasing difficulty for Sad faces. These data illustrate that sleep deprivation led to greater neural reactivity for the threat-related negative emotions as they became more subtle; however, there was a failure to engage these perceptual resources for the processing of Sad faces. Sleep loss preferentially impacted the processing of Sad faces; this has widespread implications for sleep-deprived groups.

Group membership alters the threshold for mind perception: The role of social identity, collective identification, and intergroup threat

Human faces are used as cues to the presence of social agents, and the ability to detect minds and mental states in others occupies a central role in social interaction. In the current research, we present evidence that the human propensity for mind perception is bound by social group membership. Specifically, we show how identification with different social groups influences the threshold for mind perception. In three experiments, participants assessed a continuum of face morphs that ranged from human to doll faces. These faces were described as in-group or out-group members. Participants had higher (i.e., more stringent) thresholds for perceiving minds behind out-group faces, both in minimal (Experiment 1) and real-world groups (Experiment 2). In other words, out-group members required more humanness than in-group members to be perceived as having minds. This intergroup bias in mind perception was moderated by collective identification, such that highly identified group members had the highest threshold for perceiving minds behind out-group relative to in-group faces. In contrast, Democrats and Republicans who perceived the other party as threatening had lower thresholds for perceiving minds behind out-group faces (Experiment 3). These experiments suggest that mind perception is a dynamic process in which relevant contextual information such as social identity and out-group threat change the interpretation of physical features that signal the presence of another mind. Implications for mind perception, dehumanization, and intergroup relations are discussed. (229 words)

Face and Object Discrimination in Autism, and Relationship to IQ and Age

The current study tested fine discrimination of upright and inverted faces and objects in adolescents with Autism Spectrum Disorder (ASD) as compared to age- and IQ-matched controls. Discrimination sensitivity was tested using morphed faces and morphed objects, and all stimuli were equated in low-level visual characteristics (luminance, contrast, spatial frequency make-up). Participants with ASD exhibited slight, non-significant impairments in discrimination sensitivity for faces, yet significantly enhanced discrimination sensitivity for objects. The ASD group also showed a protracted development of face and object inversion effects. Finally, for ASD participants, face sensitivity improved with increasing IQ while object sensitivity improved with age. By contrast, for controls, face sensitivity improved with age, but neither face nor object sensitivity was influenced by IQ. These findings suggest that individuals with ASD follow a qualitatively different path in the development of face and object processing abilities.

P.1.j.010 Neuropsychological impairment: the disturbed effect of self-processing in major depressive disorder

Background: Neuropsychological impairment (mainly focus on executive function, attention, verbal and nonverbal learning and memory) has long been established as a fundamental characteristic in major depressive disorder, but a specific pattern of neuropsychological impairment generally accepted has not been summarized. Different studies generally adopted different methodological issues (such as clinical status, samples, the measures of neuropsychological task and statistical methods, etc) to investigate on account of the considerable variability in the heterogeneity of depression. However, compared with other types of cognitive function, self-face recognition was considered as may help us to clearly understand the process of self-related information. Besides, it is always believed that the self-experience ability is unique for human beings, and the self-face symbolizes distinct self-characteristics of humans. The purpose of this research was to explore whether the self was impaired in major depressive disorder with the classic neuropsychological paradigm of self-face recognition (SFR). Methods: A total of 18 depressive patients and 20 healthy subjects participated in this SFR study. Morphed faces were basic materials in this experiment. We presented three types of face stimuli: self-face stimuli, famous-face stimuli (the face of a famous star who was able to be recognized by the participants at first sight), and stranger-face stimuli. Here, we mixed the features of any two of the three types of faces based on a certain proportion and got three serious of morphed faces. We directly tested the bias by instructing participants to recognize the identity of the morphed faces created by blending face features between any of two identities. All the experimental results would be automatically recorded on the computer immediately. Results: RM-ANOVA showed a significant main effect between different test groups [F(1,36) = 7.388, P = 0.01). The independent t-test further revealed that self (t = 2.636, P = 0.012) and selfrecognition bias (t = 2.190, P = 0.035) observed in self-famous task and self-stranger task for depressive patients were significantly greater than that for healthy control. In contrast, there was no significant difference between two groups in famous-stranger task (t = 0.892, P = 0.378), that was to say, there was no impairment on familiarity-processing in depression. Conclusions: The results in SFR study showed that the tendency of both self (self-famous task) and self-recognition (selfstranger task) were impaired in patients with major depressive disorder, i.e., there might be a specific deficit in the effect of selfprocessing, and therefore influencing the ability of face recognition. This kind of self-disturbance is consistent with the clinical phenomenon and the neural basis of depression in some respects. The findings provide a new perspective for our further study on etiology and pathological mechanisms of major depressive disorder. In addition, the study only involves some behavioral levels of data and future empirical research should combine various techniques, such as MRI and ERP, to explore neural basis of self-disturbance in major depressive disorder. P.1.j.011 Synthesis and pharmacological evaluation of irreversible allosteric ligands for the M1 muscarinic acetylcholine receptor B.J. Davie1 °, C. Valant1, B. Capuano2, P.J. Scammells2, A. Christopoulos1 1Monash Institute of Pharmaceutical Sciences, Drug Discovery Biology, Melbourne, Australia; 2Monash Institute of Pharmaceutical Sciences, Medicinal Chemistry, Melbourne, Australia

Oxytocin sharpens self-other perceptual boundary

Recent cross-species research has demonstrated that the neurohormone oxytocin plays a key role in social interaction and cognitive processing of others' emotions. Whereas oxytocin has been shown to influence social approach, trust, and bond formation, a potential role of the oxytocinergic system in blurring or enhancing the ability to differentiate between one's self and other's related stimuli is unknown. Thus, we investigated whether oxytocin affects the ability to differentiate between self- and other-related stimuli using a facial morphing procedure. In a placebo-controlled, double-blind study, 44 healthy men received either 24 IU oxytocin or placebo intranasally. After 45 min, we measured participants' ability to differentiate their own identity while viewing a photo of themselves morphing into the photo of an unfamiliar face. Oxytocin administration shortened the latency of self-other differentiation. Additionally, when asked to rate the pleasantness of the unmorphed photos, the oxytocin-treated participants rated their own and the unfamiliar face as comparably pleasant. Oxytocin increases the ability to recognize differences between self and others and increases positive evaluation of others. Our findings are consistent with the hypothesis that impaired oxytocin signaling may be involved in the development and manifestation of human psychopathologies in which self-recognition is altered.

Was "seeing the mean emotion" indeed a high level analysis?

Introduction Previous research found that observers could precisely extract summary statistics from a broad range of visual stimuli, including facial emotion. However, it is controversial whether the results found in the mean emotion discrimination task indeed showed a kind of high level analysis. The task was adapted from the low level ensemble coding, like mean size (Ariely, 2001; Chong, & Treisman, 2003). Does it really reflect the high level extraction of mean emotion? Methods Two experiments were designed to address this question. Fifty morphed faces were created from two emotionally extreme faces (neutral to disgust) of the same person. In Experiment 1, the same task of Haberman and Whitney (2007, 2009) was used. Observers were asked to judge whether a single test face was more neutral than the preceding set of four faces with identical or different emotions displayed for 2000ms. In Experiment 2, observers made similar comparison, but based on the size of eyes within the faces. Results The threshold analysis used by Haberman and Whitney (2007, 2009) didn’t show a consistent pattern for every subject. Therefore, A’, the nonparametric sensibility index of signal detection theory, was calculated as the index of discrimination performance. The results showed that although observers could indeed precisely discriminate the mean emotion of four hetero faces from the emotion of the test face, discriminating the emotion of homo faces was much better. Besides, compared with previous results (Haberman, & Whitney, 2007, 2009), the mean discrimination performance showed no differences among upright, inverted and scrambled faces (Haberman, & Whitney, 2007, 2009). More importantly, the mean extraction of eye size was as precise as that of emotions. Conclusion It was possible that the summary representation of facial expressions might be based on low level, instead of high level, visual analysis of faces. Meeting abstract presented at VSS 2013

Something to smile about: The interrelationship between attractiveness and emotional expression

Previous studies have suggested a link between the processing of the emotional expression of a face and how attractive it appears. In two experiments we investigated the interrelationship between attractiveness and happiness. In Experiment 1 we presented morphed faces varying in attractiveness and happiness and asked participants to choose the more attractive of two simultaneously presented faces. In the second experiment we used the same stimuli as in Experiment 1 and asked participants to choose the happier face. The results of Experiment 1 revealed that the evaluation of attractiveness is strongly influenced by the intensity of a smile expressed on a face: A happy facial expression could even compensate for relative unattractiveness. Conversely, the findings of Experiment 2 showed that facial attractiveness also influences the evaluation of happiness: It was easier to choose the happier of two faces if the happier face was also more attractive. We discuss the interrelationship of happiness and attractiveness with regard to evolutionary relevance of positive affective status and rewarding effects.

Abrupt category shifts during real-time person perception

Previous studies have suggested that real-time person perception relies on continuous competition, in which partially active categories smoothly compete over time. Here, two studies demonstrated the involvement of a different kind of competition. In Study 1, before participants selected the correct sex category for morphed faces, their mouse trajectories often exhibited a continuous attraction toward the incorrect category that increased with sex-category ambiguity, indicating continuous competition. On other trials, however, trajectories initially pursued the incorrect category and then abruptly redirected toward the correct category, suggesting early incorrect category activation that was rapidly reversed later in processing. These abrupt category reversals also increased with ambiguity. In Study 2, participants were presented with faces containing a sex-typical or sex-atypical hair cue, in a context in which the norm was either sex-typical targets (normative context) or sex-atypical targets (counternormative context). Sex-atypical targets induced greater competition in the normative context, but sex-typical targets induced greater competition in the counternormative context. Together, these results demonstrate that categorizing others involves both smooth competition and abrupt category shifts, and that these flexibly adapt to the social context.

On the ideology of hypodescent: Political conservatism predicts categorization of racially ambiguous faces as Black

According to the principle of hypodescent, multiracial individuals are categorized according to their most socially subordinate group membership. We investigated whether the tendency to apply this principle is related to political ideology. In three studies, participants categorized a series of morphed faces that varied in terms of racial ambiguity. In each study, self-reported conservatism (vs. liberalism) was associated with the tendency to categorize ambiguous faces as Black. Consistent with the notion that system justification motivation helps to explain ideological differences in racial categorization, the association between conservatism and hypodescent was mediated by individual differences in opposition to equality (Study 2) and was stronger when U.S. participants categorized American than Canadian faces (Study 3). We discuss ways in which the categorization of racially ambiguous individuals in terms of their most subordinate racial group may exacerbate inequality and vulnerability to discrimination.