Morphological variants of silent bared-teeth displays have different social interaction outcomes in crested macaques (Macaca nigra)

Objectives: While it has been demonstrated that even subtle variation in human facial expressions can lead to significant changes in the meaning and function of expressions, relatively few studies have examined primate facial expressions using similarly objective and rigorous analysis. Construction of primate facial expression repertoires may, therefore, be oversimplified, with expressions often arbitrarily pooled and/or split into subjective pigeonholes. Our objective is to assess whether subtle variation in primate facial expressions is linked to variation in function, and hence to inform future attempts to quantify complexity of facial communication. Materials and Methods: We used Macaque Facial Action Coding System, an anatomically based and hence more objective tool, to quantify “silent bared‐teeth” (SBT) expressions produced by wild crested macaques engaging in spontaneous behavior, and utilized discriminant analysis and bootstrapping analysis to look for morphological differences between SBT produced in four different contexts, defined by the outcome of interactions: Affiliation, Copulation, Play, and Submission. Results: We found that SBT produced in these contexts could be distinguished at significantly above‐chance rates, indicating that the expressions produced in these four contexts differ morphologically. We identified the specific facial movements that were typically used in each context, and found that the variability and intensity of facial movements also varied between contexts. Discussion: These results indicate that nonhuman primate facial expressions share the human characteristic of exhibiting meaningful subtle differences. Complexity of facial communication may not be accurately represented simply by building repertoires of distinct expressions, so further work should attempt to take this subtle variability into account

Electronic screening and brief intervention for risky drinking in Swedish university students -A randomized controlled trial

a b s t r a c t a r t i c l e i n f o Keywords: College student Alcohol Electronic screening Brief intervention Computer RCT Background: The limited number of electronic screening and brief intervention (e-SBI) projects taking place in young adult student populations has left knowledge gaps about the specific methods needed to motivate reduced drinking. The aim of the present study was to compare differences in alcohol consumption over time after a series of e-SBIs was conducted with two groups of young adult students who were considered risky drinkers. The intervention group (IG) (n = 80) received extensive normative feedback; the control group (CG) (n = 78) received very brief feedback consisting of only three statements. Method: An e-SBI project was conducted in naturalistic settings among young adult students at a Swedish university. This study used a randomized controlled trial design, with respondents having an equal chance of being assigned to either the IG or the CG. The study assessed changes comparing the IG with the CG on four alcohol-related measurements: proportion with risky alcohol consumption, average weekly alcohol consumption, frequency of heavy episodic drinking (HED) and peak blood alcohol concentration (BAC). Follow-up was performed at 3 and 6 months after baseline. Results: The study documented a significant decrease in the average weekly consumption for the IG over time but not for the CG, although the differences between the groups were non-significant. The study also found that there were significant decreases in HED over time within both groups; the differences were about equal in both groups at the 6-month follow-up. The proportion of risky drinkers decreased by about a third in both the CG and IG at the 3-and 6-month follow-ups. Conclusions: As the differences between the groups at 6 months for all alcohol-related outcome variables were not significant, the shorter, generic brief intervention appears to be as effective as the longer one including normative feedback. However, further studies in similar naturalistic settings are warranted with delayed assessment groups as controls in order to increase our understanding of reactivity assessment in email-based interventions among students

EquiFACS: the Equine Facial Action Coding System

Although previous studies of horses have investigated their facial expressions in specific contexts, e.g. pain, until now there has been no methodology available that documents all the possible facial movements of the horse and provides a way to record all potential facial configurations. This is essential for an objective description of horse facial expressions across a range of contexts that reflect different emotional states. Facial Action Coding Systems (FACS) provide a systematic methodology of identifying and coding facial expressions on the basis of underlying facial musculature and muscle movement. FACS are anatomically based and document all possible facial movements rather than a configuration of movements associated with a particular situation. Consequently, FACS can be applied as a tool for a wide range of research questions. We developed FACS for the domestic horse (Equus caballus) through anatomical investigation of the underlying musculature and subsequent analysis of naturally occurring behaviour captured on high quality video. Discrete facial movements were identified and described in terms of the underlying muscle contractions, in correspondence with previous FACS systems. The reliability of others to be able to learn this system (EquiFACS) and consistently code behavioural sequences was high—and this included people with no previous experience of horses. A wide range of facial movements were identified, including many that are also seen in primates and other domestic animals (dogs and cats). EquiFACS provides a method that can now be used to document the facial movements associated with different social contexts and thus to address questions relevant to understanding social cognition and comparative psychology, as well as informing current veterinary and animal welfare practices

Emotional Facial Expression Detection in the Peripheral Visual Field

BACKGROUND: In everyday life, signals of danger, such as aversive facial expressions, usually appear in the peripheral visual field. Although facial expression processing in central vision has been extensively studied, this processing in peripheral vision has been poorly studied. METHODOLOGY/PRINCIPAL FINDINGS: Using behavioral measures, we explored the human ability to detect fear and disgust vs. neutral expressions and compared it to the ability to discriminate between genders at eccentricities up to 40°. Responses were faster for the detection of emotion compared to gender. Emotion was detected from fearful faces up to 40° of eccentricity. CONCLUSIONS: Our results demonstrate the human ability to detect facial expressions presented in the far periphery up to 40° of eccentricity. The increasing advantage of emotion compared to gender processing with increasing eccentricity might reflect a major implication of the magnocellular visual pathway in facial expression processing. This advantage may suggest that emotion detection, relative to gender identification, is less impacted by visual acuity and within-face crowding in the periphery. These results are consistent with specific and automatic processing of danger-related information, which may drive attention to those messages and allow for a fast behavioral reaction

Social use of facial expressions in hylobatids

Non-human primates use various communicative means in interactions with others. While primate gestures are commonly considered to be intentionally and flexibly used signals, facial expressions are often referred to as inflexible, automatic expressions of affective internal states. To explore whether and how non-human primates use facial expressions in specific communicative interactions, we studied five species of small apes (gibbons) by employing a newly established Facial Action Coding System for hylobatid species (GibbonFACS). We found that, despite individuals often being in close proximity to each other, in social (as opposed to non-social contexts) the duration of facial expressions was significantly longer when gibbons were facing another individual compared to non-facing situations. Social contexts included grooming, agonistic interactions and play, whereas non-social contexts included resting and self-grooming. Additionally, gibbons used facial expressions while facing another individual more often in social contexts than non-social contexts where facial expressions were produced regardless of the attentional state of the partner. Also, facial expressions were more likely ‘responded to’ by the partner’s facial expressions when facing another individual than non-facing. Taken together, our results indicate that gibbons use their facial expressions differentially depending on the social context and are able to use them in a directed way in communicative interactions with other conspecifics

Association of self-reported bruxism with temporomandibular disorders:Northern Finland Birth Cohort (NFBC) 1966 study

Abstract Objective: To investigate the prevalence of self-reported bruxism and its association with temporomandibular disorders (TMD). The hypothesis of the study was that self-reported bruxism is associated with TMD. Methods: The data were gathered from 1962 subjects who participated in a field study in 2012–2013, including a questionnaire concerning bruxism and TMD symptoms as well as clinical sub-diagnoses of TMD using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Statistical method was chi-square test. Bonferroni correction was made, and a p-value of <0.003 was considered as significant. Results: The prevalence of self-reported bruxism was 39.6%: 34.0% in men and 44.5% in women. Those who reported sleep bruxism (SB) or awake bruxism (AB) had significantly more pain-related TMD symptoms and signs compared to those not reporting bruxism. Conclusions: The prevalence of self-reported bruxism is high among middle-aged adults and is associated with TMD pain-related symptoms and signs, as well as TMD diagnoses