Flat affect (i.e., diminished expressivity) and self-reported anhedonia (i.e., lack of pleasure) are associated with many psychiatric disorders. There is a need to examine the relationship between specific anhedonia subtypes and flat affect in a non-clinical sample. Forty-seven undergraduate students (59% male; mean age 20.37; SD = 4.74) completed self-report questionnaires assessing four subtypes of anhedonia - consummatory/anticipatory by social/non-social. Participants then viewed 15 randomly-presented pictures (five neutral, ten negative) from the International Affective Pictures System while facial muscle activity (electromyography; EMG) was recorded. Male participants reporting a greater level of anhedonia, particularly consummatory social anhedonia, showed greater EMG activity change in the corrugator supercilii muscle to negative pictures, as compared with neutral pictures. Females showed the opposite pattern: more consummatory social anhedonia related to less EMG activity change in the corrugator muscle. In summary, consummatory social anhedonia in particular showed a strong relationship with facial expressivity that interacted with sex. In the presence of more consummatory social anhedonia, males show more negative facial reactions to negative stimuli while females show a more flattened affect. These findings may help explain discrepancies in existing research examining anhedonia and flat affect in clinical populations and have implications for etiology and treatments.

Schizotypy is a sub-threshold syndrome associated with schizophrenia. Much of the research on schizotypy concerns its component features, one of which being blunted or constricted affect. While several investigations have addressed this common “negative” symptom within the context of schizophrenia, few have focused on schizotypy directly, and none have utilized psychophysiological measurement to examine affective constriction. The present investigation uses facial electromyography (EMG) to measure patterns of affective expression within a psychometrically defined schizotypal population when presented threatening and distressing pictures from the IAPS. Twenty-eight individuals with elevated schizotypal features and 20 healthy controls were recruited for this investigation. The participants observed the series of pictures and provided self-report ratings of affective valance and arousal while their physiological responses were recorded. The protocol used here closely matched that used by Bradley and Lang (2007) and produced a similar pattern of results across all participants on selfreported ratings and physiological measures. Results further suggest that those with schizotypal features did not differ from control participants in self-reported ratings of negative affect or autonomic arousal. A three-way interaction in facial EMG measurement revealed that while schizotypic males demonstrated the expected pattern of blunted facial affective expression, schizotypic females displayed the opposite pattern. That is, females with psychometrically schizotypy demonstrated significant elevations in negative facial affective expression while viewing distressing pictures. We argue that these findings reflect unidentified sex differences in affective expression in schizotypy, and we discuss implications for assessment and diagnostic procedures among individuals with personality disorders

Research suggests that playing violent video games increases the likelihood of aggression. However, less clear is how individual characteristics influence the mechanisms that lead to aggression. Using Anderson and Bushman’s (2002) General Aggression Model as a framework, the present study examined the independent and joint effects of individual differences and situational factors on affective and physiological reactivity to playing a violent video game. One hundred thirty-three participants completed self-report measures of trait aggression and violent video game exposure. They were randomly assigned to groups instructed to play a video game using either violent or nonviolent strategies while facial electromyography, heart rate, and electrodermal activity were measured. Positive and negative affect was assessed via self-report prior to and following video game play. It was hypothesized that trait aggression and level of past exposure to violent video games would be positively related to increases in physiological arousal and negative affect among participants in a violent, relative to a nonviolent, condition. Hierarchical regression analyses failed to detect a significant relationship between trait aggression and changes in heart rate, facial electromyography, or self-reported affect as a function of game condition. However, significant positive relationships were found between trait aggression and skin conductance, but only in the nonviolent condition. Analyses revealed that past exposure to violent video games was positively related to increased skin conductance among participants in the non-violent, but not the violent video game condition. Past exposure to violent video games was also positively related to increased heart rate, but this was among participants in the violent, but not the non-violent condition. Significant relationships between past exposure to violent video games and changes in facial electromyography and self-reported affect as a function of video game condition were not found. Findings are discussed in terms of how trait aggression and past exposure to violent video games influence arousal, and potentially, the likelihood of aggressive behavior.

People use facial appearance to infer the social attributes of others. A primary indicator of facial attractiveness is prototypicality (the proximity of an object to its categorical central tendency); faces and objects closer to the central tendency are judged as more attractive. Perceptual fluency theory suggests that cognitive processing speed directly generates positive affect. This dissertation examined the relationships among attractiveness, prototypicality, and affective response in faces and non-face objects across adult and 8-year-old participants using a reaction time (RT) paradigm. RT predicted positive affect and disgust responses to facial stimuli. Of particular note are the series of complementary findings suggesting that reaction to unattractive faces may be both quantitatively (i.e., longer RT latencies) and qualitatively (i.e., judged to be less typical) different from high and medium attractive faces. These findings may help explain how appearance-based stereotypes are formed and maintained. / text

Several researchers in happiness studies have called for an increased sociopolitical interest in indicators of societal happiness. However, recent evidence for the proposed paradoxical effects of valuing happiness suggest that an increase in society’s perceived value of happiness may exert a detrimental, inverse influence on well-being. This notion is based on previous research demonstrating that manipulating participants to value happiness causes them to experience less positive emotions, compared to controls, when viewing positive film clips. Following the humanistic notion that the maximization of societal happiness is an advantageous sociopolitical endeavor, the proposed paradoxical effects of valuing happiness present a psychological barrier that researchers must strive to understand and, ideally, overcome. Previous experimental research on the paradoxical effects of valuing happiness has focused on participants’ emotionality as an operational definition of happiness. However, drawing from the Subjective Well-Being construct, emotionality is only one of several components of happiness. Building from this Subjective-Well Being framework, this study expands upon previous research by investigating whether a valuing happiness manipulation influences participants’ emotionality while they contemplate their own happiness. To examine this, nineteen participants were divided into two groups, one which received a valuing happiness manipulation (n=9) and the others served as a control group (n=10), and instructed to contemplate their personal happiness for 45 seconds. To measure participants’ emotions during this task, facial electromyography data were collected from the corrugator supercilii and the zygomaticus major facial muscles, a measure that previous research suggests is sensitive to the emotional value of thought. Results indicated that participants manipulated to value happiness did not experience significant differences in facial electromyography activation compared to controls. However, although non-significant, the correlation between facial electromyography activation and participants’ rating of happiness differed substantially for participants manipulated to value happiness (average r=.41 for corrugator, average r=-.09 for zygomaticus) and controls (average r=.-.29 for corrugator, average r=.14 for zygomaticus). The counterintuitive correlations for participants led to value happiness, despite not experiencing significant difference in the emotional value of the happiness contemplation task, provide preliminary evidence that these participants utilize the information retrieved from the contemplative stage in a qualitatively different way than controls when judging their own happiness. More specifically, the correlations for participants led to value happiness trend in the opposite direction of controls, demonstrating that increases in positive emotion during happiness contemplation actually are associated with lower scores on a self-report of happiness. This study suggests that the paradoxical effects of valuing happiness does not influence the retrieval of information when contemplating ones’ happiness, but may influence (in an apparently detrimental fashion) how this information is utilized when judging one’s happiness. Although the between-condition differences in correlations failed to reach statistical significance (more specifically, p=.09 for corrugator), this study provides preliminary evidence for the existence of a new dynamic of the proposed paradoxical effects of valuing happiness that is novel to the happiness studies discourse. Limitations, implications, and future directions are discussed.

Dans certaines circonstances, une personne peut être privée de ces capacités à des degrés divers, peut-être en raison de l'amputation des membres, lésions de la moelle épinière ou de maladies dégénératives. Dans ces cas, les appareils fonctionnels sont des outils pertinents pour aider les personnes à améliorer leurs capacités fonctionnelles. Particulièrement adapté dans le cas des personnes atteintes de déficience motrice grave, biosignaux électriques ont été utilisées avec succès pour faire fonctionner les appareils de communication alternatifs. Depuis plus d'un demi-siècle, l'information extraite du signal électromyographique pour operer un dispositif n'a pas examiné les informations fournies par l'unité de base du muscle: l'unité motrice. L'objectif de cette étude est d'examiner comment accéder à l'information au niveau de l'unité motrice permettrait d'améliorer les performances de l'opérateur au cours de la tâche de contrôle du curseur. L'objectif de cette étude est de déterminer si l'accès aux informations au niveau de l'unité motrice permettrait d'améliorer les performances de l'opérateur au cours de la tâche de contrôle du curseur. L'hypothèse est que la méthodologie proposée permettrait de générer des commandes de contrôle plus précises, par rapport aux approches traditionnelles en s'appuyant sur l'information globale obtenue par l'acquisition du signal sEMG conventionnel. Un système pour détecter les potentiels d'action d'unités motrices à partir du signal électromyographique a été conçu, y compris la conception de l'électrode, et la performance évaluée en mesurant le temps pris pour effectuer plusieurs tâches de contrôle du curseur. Les spécifications des tâches ont été extraites d'une étude précédente, qui a utilisé la méthode traditionnelle de traitement du signal électromyographique. La comparaison, basée sur la difficulté de la tâche estimée par la loi de Fitts, a indiqué que le signal de commande généré par la nouvelle méthode a fourni une meilleure précision que celle générée par l'approche traditionnelle, étant 27% plus rapide dans la tâche plus difficile / In some circumstances, a person may be deprived of natural abilities, such as walking and speaking, perhaps due to limb amputation, spinal cord injuries (SCI), or degenerative diseases. Assistive technology devices allows motor-impaired people to overcome their limitations promoting greater independence. Particularly suitable in the case of people with severe motor impairment, electrical biosignals have been successfully utilised to operate alternative communication devices. For over half a century, information extracted from the electromyographic signal for the purpose of operating a given device has not considered the information provided by the basic unit of the muscle: the motor unit. The objective of this study is to investigate how accessing information at motor unit level would improve the operator's performance during a given task. The hypothesis is that the proposed methodology would allow generating more precise control commands, when compared to traditional approaches relying on global information obtained by conventional electromyographic signal acquisition and processing. A system to detect motor unit action potentials from the electromyographic signal was devised, including the electrode design, and the performance evaluated by measuring the time taken to perform several cursor control tasks. The specifications of the cursor control task were extracted from a different study, which used the traditional electromyographic signal-processing approach. Comparing the results from both studies proved that the novel approach provides better control than the traditional one, being 27\% faster in the most difficult task

La grande majorité de nos actions et décisions s’élaborent en présence d’autres individus. De nombreux travaux en psychologie sociale attestent de l’existence d’influences sociales sur les comportements observables par autrui. Nos travaux ont pour objectif de déterminer dans quelles mesures des informations sociales influencent également les processus internes de monitoring métacognitif qui accompagnent les actions cognitives et les prises de décisions. Les indices sociaux non-verbaux (tels que des directions de regards et les expressions faciales) constituent une part importante de la communication humaine. Nos études ont ainsi testé si i) les indices sociaux non-verbaux sont intégrés aux processus de monitoring métacognitif rétrospectif (i.e. à l’élaboration de jugement de confiance); ii) des mécanismes de filtrage permettent de moduler l’impact de ces indices sur les jugements de confiance, en fonction de la pertinence des indices iii) la culture des participants (collectiviste versus individualiste) module l’impact de ces indices sur les jugements de confiance. Nos travaux explorent ces questions à travers quatre ensemble d’études comportementales, dont deux explorant également l’électromyographie faciale des participants, et deux explorant les différences interculturelles (en comparant des participants japonais et français). Dans leur ensemble, ces résultats indiquent que des indices sociaux non-verbaux qui confortent les choix des individus augmentent automatiquement le sentiment de confiance des individus en leur choix, alors même que ces indices ne sont pas fiables. Le traitement de ces indices sociaux particuliers, dans le contexte d’élaboration d’un jugement de confiance, semble reposer sur une voie de type heuristique. Les effets sont très similaires chez les participants Japonais et Français, bien que partiellement plus marqués chez les participants Japonais (i.e. dans les cultures collectivistes). Les réactions électromyographiques faciales suscitées par des expressions faciales signifiantes dans le contexte de réalisation de la tâche cognitive refléteraient différents mécanismes en fonction des valeurs culturelles des individus. Nous discutons des implications de nos résultats dans les domaines cliniques et de l’apprentissage. / Actions and decisions most often take place in the presence of others. Previous social psychology studies have shown the effects of social information on external and observable behaviors. In this work, we aim to determine to what extent social information also influences the internal metacognitive monitoring processes underlying cognitive actions and decision-making. Non-verbal social cues (such as gaze direction and facial expressions) constitute an important part of human communication. Here, we have tested (i) whether non-verbal social cues are integrated into the processes of retrospective metacognitive monitoring (i.e. into the assessment of confidence-based judgment); (ii) whether filtering mechanisms are used to modulate the impact of these cues on confidence-based judgment, depending on cue relevance; and (iii) whether participants’ culture (collectivist versus individualist) modulates the impact of these cues on confidence-based judgment. Our work explores these issues through four sets of behavioral studies, two of which also exploring facial expressions using electromyography, and two of which exploring intercultural differences (comparing Japanese and French participants). Overall, we observed that non-verbal social cues that reinforce individuals' choices automatically increase their confidence in those choices, even when the cues are unreliable. The processing of these particular social cues (in the context of the assessment of confidence-based judgment) follow a heuristic pathway. The effects are similar among Japanese and French participants, although somewhat more marked among Japanese participants (i.e. the collectivist culture). The electromyographic recordings of significant facial expressions during the cognitive task likely reflect different mechanisms depending on individuals’ cultural values. We discuss our findings in the context of their clinical and learning applications.

In some circumstances, a person may be deprived of natural abilities, such as walking and speaking, perhaps due to limb amputation, spinal cord injuries (SCI), or degenerative diseases. Assistive technology devices allows motor-impaired people to overcome their limitations promoting greater independence. Particularly suitable in the case of people with severe motor impairment, electrical biosignals have been successfully utilised to operate alternative communication devices. For over half a century, information extracted from the electromyographic signal for the purpose of operating a given device has not considered the information provided by the basic unit of the muscle: the motor unit. The objective of this study is to investigate how accessing information at motor unit level would improve the operator's performance during a given task. The hypothesis is that the proposed methodology would allow generating more precise control commands, when compared to traditional approaches relying on global information obtained by conventional electromyographic signal acquisition and processing. A system to detect motor unit action potentials from the electromyographic signal was devised, including the electrode design, and the performance evaluated by measuring the time taken to perform several cursor control tasks. The specications of the cursor control task were extracted from a dierent study, which used the traditional electromyographic signal-processing approach. Comparing the results from both studies proved that the novel approach provides better control than the traditional one, being 27% faster in the most dificult task. / Em determinadas circunstâncias, um indivíduo pode ser privado de suas habilidades naturais, tais como andar e falar, no caso de amputações, lesões na medula espinhal ou doenças degenerativas. Dispositivos de tecnologia assistiva permitem que indivíduos com restrições motoras a superem suas limitações promovendo maior independência. Particularmente adequados ao quadro de restrição motora severa, sinais bioelétricos tem sido usados com sucesso para operar dispositivos de comunicação alternativa. Por mais de meio século, informações extraídas do sinal eletromiográfico com o propósito de operar um determinado dispositivo não considera a unidade básica do músculo: a unidade motora. O objetivo deste estudo é investigar como a performance do operador é afetada ao utilizar informações do sinal eletromiográfico provenientes diretamente de unidades motoras. A hipótese é que a metodologia proposta seja capaz de gerar sinais de controle mais precisos quando comparados com a abordagem tradicional que usa informações globais obtidas por métodos tradicionais de aquisição e tratamento do sinal eletromiográfico. Um sistema capaz de detectar e tratar os potenciais de ação de unidades motoras em tempo real foi desenvolvido, incluindo o projeto do eletrodo e a performance foi avaliada ao medir o tempo para execução de tarefas de controle de cursor. As especificações da tarefa de controle de cursor foram retiradas de um estudo anterior, que usava métodos tradicionais de processamento do sinal eletromiográfico. A comparação dos resultados dos dois estudos demonstrou que o novo método oferece melhor controle, sendo até 27% mais rápido na tarefa mais difícil. / Doutor em Ciências

La problématique de cette thèse est de comprendre et d’expliquer l’influence de l’activation des composantes périphérique efférente, expressive motrice et des sentiments subjectifs de l’émotion sur la formation des attitudes et des intentions comportementales du consommateur exposé à l’annonce. Cette recherche s’inscrit dans le modèle des processus composants de l’émotion développé en neurosciences affectives. Pour tester nos hypothèses, nous avons réalisé une étude selon laquelle les épisodes émotionnels du consommateur résultent de l’évaluation cognitive et dynamique des évènements mis en scène dans l’annonce. Notre protocole expérimental est fondé sur la mesure verbale des sentiments subjectifs et sur la mesure de l’activité électrophysiologique du système nerveux autonome et du système nerveux somatique des participants exposés à 6 annonces publicitaires télévisées (3 annonces commerciales / 3 annonces sociales). Les résultats obtenus montrent que l’exposition à l’annonce suscite chez le consommateur une activation des composantes périphérique efférente, expressive motrice et des sentiments subjectifs de l’émotion. La prise en compte de l’activation de ces trois composantes permet alors d’expliquer la formation de l’attitude envers l’annonce, de l’attitude envers la marque et des intentions comportementales du consommateur. Les résultats indiquent également que les annonces ne suscitent pas systématiquement des épisodes émotionnels chez les consommateurs ; c’est la présence d’évènements pertinents dans l’annonce pour un consommateur qui déclenche un processus d’évaluation cognitif à l’origine des épisodes émotionnels / The issue of this thesis is to understand and explain the influence of the activation of peripheral efference, motor expression, and subjective feeling components on the behavioural and attitude intentions of the consumer exposed to advertising. This research belongs to the components process model which is part of the developed emotion in affective neurosciences. To test our hypotheses, we have carried out a study where the emotional episodes of the consumer result from the cognitive appraisal of salient events highlighted in the advertising. Our experimental protocol is based on the verbal measure of subjective feelings and on the measure of the electrophysiological activity of the autonomous nervous system and also the somatic nervous system of the participants exposed to six television commercials (three commercial ads/ three social ads). The achieved results show that the exposure to advertising reveals in the consumer an activation of the peripheral efference, motor expression, and subjective feeling components of emotion. The awareness of the activation of those three components leads then to explain the attitude formation towards the advertising and towards the brand as well as behavioural intentions of the consumer. The results illustrate as well that the advertising do not systematically awake emotional episodes among the consumers; it is the presence of salient events in the advertising for a consumer that triggers a cognitive appraisal process to the origin of the emotional episodes