Both physical exercise and progressive muscle relaxation reduce the facing-the-viewer bias in biological motion perception

Social exclusion in psychotic disorders: An interactional processing model

Psychotic disorders are among the most highly stigmatized mental disorders, and individuals with psychosis experience significant exclusion from the community. Stigma reduction programs have done little to reduce social exclusion of individuals with psychosis, and there are significant limitations to the traditional stigma model as it applies to social exclusion. Herein, we present the Interactional Processing Model (IPM) of social exclusion towards individuals with psychosis. The IPM considers social exclusion to be the result of two interacting pathways with additional consideration for a feedback loop through which social exclusion sets in motion natural behavioural responses of individuals with psychosis that inadvertently perpetuates exclusion. The IPM considers initial social exclusion to be the result of an interaction between these two pathways. The first path aligns with the traditional stigma model and consists of the community becoming aware that an individual is diagnosed with a psychotic disorder and then excluding the individual based on pre-existing, generalized knowledge about the disorder. The second path to exclusion involves the observation of atypical behaviours from the individual, and generation of an individualized exclusion response. We provide initial empirical support for the IPM of social exclusion, outline testable hypotheses stemming from the model, and discuss implications for novel ways to consider both societal stigma reduction and personalized intervention.

Does anxiety induced by social interaction influence the perception of bistable biological motion?

When observing point light walkers orthographically projected onto a frontoparallel plane, the direction in which they are walking is ambiguous. Nevertheless, observers more often perceive them as facing towards than as facing away from them. This phenomenon is known as the "facing-the-viewer bias" (FTV). Two interpretations of the facing-the-viewer bias exist in the literature: a top-down and a bottom-up interpretation. Support for the top-down interpretation comes from evidence that social anxiety correlates with the FTV bias. However, the direction of the relationship between the FTV bias and social anxiety is inconsistent across studies and evidence for a correlation has mostly been obtained with relatively small samples. Therefore, the first aim of the current study was to provide a strong test of the hypothesized relationship between social anxiety and the facing-the-viewer bias in a large sample of 200 participants recruited online. In addition, a second aim was to further extend top-down accounts by investigating if the FTV bias is also related to autistic traits. Our results replicate the FTV bias, showing that people indeed tend to perceive orthographically projected point light walkers as facing towards them. However, no correlation between the FTV bias and social interaction anxiety (tau = -0.01, p = .86, BF = 0.18) or autistic traits (tau = -0.0039, p = .45, BF = 0.18) was found. As such, our data cannot confirm the top-down interpretation of the facing-the-viewer bias.

Divergent Thinking Influences the Perception of Ambiguous Visual Illusions

This study investigated the relationships between personality and creativity in the perception of two different ambiguous visual illusions. Previous research has suggested that Industriousness and Openness/Intellect (as measured by the Big Five Aspects Scale) are both associated with individual differences in perceptual switching rates for binocular rivalry stimuli. Here, we examined whether these relationships generalise to the Necker Cube and the Spinning Dancer illusions. In the experimental phase of this study, participants viewed these ambiguous figures under both static and dynamic, as well as free-view and fixation, conditions. As predicted, perceptual switching rates were higher: (a) for the static Necker Cube than the Spinning Dancer, and (b) in free-view compared with fixation conditions. In the second phase of the study, personality type and divergent thinking were measured using the Big Five Aspects Scale and the Alternate Uses Task, respectively. Higher creativity/divergent thinking (as measured by the Alternate Uses Task) was found to predict greater switching rates for the static Necker Cube (but not the Spinning Dancer) under both free-view and fixation conditions. These findings suggest that there are differences in the perceptual processing of creative individuals.

The relevance to social interaction modulates bistable biological-motion perception

Social interaction, the process through which individuals act and react toward each other, is arguably the building block of society. As the very first step for successful social interaction, we need to derive the orientation and immediate social relevance of other people: a person facing toward us is much more likely to initiate communications than a person who is back to us. Reversely, however, it remains elusive whether the relevance to social interaction modulates how we perceive the other's orientation. Here, we adopted the bistable point-light walker (PLW) which is ambiguous in its in-depth orientation. Participants were asked to report the orientation (facing the viewer or facing away from the viewer) of the PLWs. Three factors that are task-irrelevant but critically pertinent to social interaction, the distance, the speed, and the size of the PLW, were systematically manipulated. The nearer a person is, the more likely it initiates interactions with us. The larger a person is, the larger influence it may exert. The faster a person is, the shorter time is left for us to respond. Results revealed that participants tended to perceive the PLW as facing them more frequently than facing away when the PLW was nearer, faster, or larger. These same factors produced different patterns of effects on a non-biological rotating cylinder. These findings demonstrate that the relevance to social interaction modulates the visual perception of biological motion and highlight that bistable biological motion perception not only reflects competitions of low-level features but is also strongly linked to high-level social cognition.

Flexible Orientation Tuning of Visual Representations of Human Body Postures: Evidence From Long-Term Priming

The proficiency of human observers to identify body postures is examined in three experiments. We use a posture decision task in which participants are primed with either anatomically possible or impossible postures (in the latter case the upper and lower body face in opposite directions). In a long-term priming paradigm (i.e., in an initial priming block of trials and a subsequent test phase several minutes later), we manipulate the relation between priming and test postures with respect to the identity of the person in the body postures (Experiment 1), the prototypicality of the depth orientations (Experiment 2), and the variability of the priming orientations (Experiment 3). Reaction time to the test postures is the main dependent variable. In Experiment 1 it is found that priming of postures does not depend on the exact visual appearance of the actor (either same priming and test female or male figure or different figures), supporting the hypothesis that posture priming primarily is determined by the spatial relations between the body parts and much less by characteristics of the person involved. Long-term priming in our paradigm apparently is based on the reactivation of high-level posture representations that make abstraction of the identity of the human figure. In Experiment 2 we observe that privileged or prototypical orientations (e.g., 3/4 views) do not affect long-term priming of body postures. In Experiment 3, we find that increasing or decreasing the variability between the priming and test figures influences reaction time performance. Collectively, these results provide a better understanding of the flexibility (e.g., invariant to identity) and limits (e.g., depending on depth orientation) of the processes supporting human posture recognition.

Influencing Factors of Social Anxiety Disorder and Body Dysmorphic Disorder in a Nonclinical Brazilian Population

The aims of this study were twofold: (i) to investigate the prevalence of social anxiety disorder and body dysmorphic disorder in a nonclinical, Brazilian population and (ii) to examine the effects of selected factors such as sociodemographic characteristics (sex, age, marital status, workload, education, and income), body mass index, current diet, physical activity, and use of aesthetic treatment. A total of 428 adults (279 women and 149 men) aged 18 to 60 years ( M = 31.51, SD = 10.73) participated in the study. Social anxiety disorder was measured using a Brazilian version of the Social Phobia Inventory ( Osório, Crippa, & Loureiro, 2009 ). Body dysmorphic disorder by using a body dysmorphic symptoms scale validated for the Brazilian population ( Ramos & Yoshida, 2012 ). The main results showed that 28.7% of the sample reported symptoms of social anxiety disorder. Body dysmorphic disorder was more prevalent among women, individuals who had sought aesthetic treatment and individuals who were physically inactive. Moreover, lower levels of social anxiety disorder were observed in physically active individuals who had sought aesthetic treatment compared with physically inactive individuals who had sought aesthetic treatment. Social anxiety disorder was negatively correlated with age, daily workload, and income, while body dysmorphic disorder was positively associated with body mass index and negatively with income. These results show that social anxiety disorder and body dysmorphic disorder are differentially influenced by the selected factors investigated in this study.

Emotional cues and social anxiety resolve ambiguous perception of biological motion

Perceptions of ambiguous biological motion are modulated by different individual cognitive abilities (such as inhibition and empathy) and emotional states (such as anxiety). This study explored facing-the-viewer bias (FTV) in perceiving ambiguous directions of biological motion, and investigated whether task-irrelevant simultaneous face emotional cues in the background and the individual social anxiety traits could affect FTV. We found that facial motion cues as background affect sociobiologically relevant scenarios, including biological motion, but not non-biological situations (conveyed through random dot motion). Individuals with high anxiety traits demonstrated a more dominant FTV bias than individuals with low anxiety traits. Ensemble coding-like processing of task-irrelevant multiple emotional cues could magnify the facing-the-viewer bias than did in the single emotional cue. Overall, those findings suggest a correlation between high-level emotional processing and high-level motion perception (subjective to attentional control) contributes to facing-the-viewer bias.

It Is Not Just in Faces! Processing of Emotion and Intention from Biological Motion in Psychiatric Disorders

Social neuroscience offers a wide range of techniques that may be applied to study the social cognitive deficits that may underlie reduced social functioning—a common feature across many psychiatric disorders. At the same time, a significant proportion of research in this area has been conducted using paradigms that utilize static displays of faces or eyes. The use of point-light displays (PLDs) offers a viable alternative for studying recognition of emotion or intention inference while minimizing the amount of information presented to participants. This mini-review aims to summarize studies that have used PLD to study emotion and intention processing in schizophrenia (SCZ), affective disorders, anxiety and personality disorders, eating disorders and neurodegenerative disorders. Two main conclusions can be drawn from the reviewed studies: first, the social cognitive problems found in most of the psychiatric samples using PLD were of smaller magnitude than those found in studies presenting social information using faces or voices. Second, even though the information presented in PLDs is extremely limited, presentation of these types of stimuli is sufficient to elicit the disorder-specific, social cognitive biases (e.g., mood-congruent bias in depression, increased threat perception in anxious individuals, aberrant body size perception in eating disorders) documented using other methodologies. Taken together, these findings suggest that point-light stimuli may be a useful method of studying social information processing in psychiatry. At the same time, some limitations of using this methodology are also outlined.

Inverting the Facing-the-Viewer Bias for Biological Motion Stimuli

Depth-ambiguous point-light walkers are most frequently seen as facing-the-viewer (FTV). It has been argued that the FTV bias depends on recognising the stimulus as a person. Accordingly, reducing the social relevance of biological motion by presenting stimuli upside down has been shown to reduce FTV bias. Here, we replicated the experiment that reported this finding and added stick figure walkers to the task in order to assess the effect of explicit shape information on facing bias for inverted figures. We measured the FTV bias for upright and inverted stick figure walkers and point-light walkers presented in different azimuth orientations. Inversion of the stimuli did not reduce facing direction judgements to chance levels. In fact, we observed a significant facing away bias in the inverted stimulus conditions. In addition, we found no difference in the pattern of data between stick figure and point-light walkers. Although the results are broadly consistent with previous findings, we do not conclude that inverting biological motion simply negates the FTV bias; rather, inversion causes stimuli to be seen facing away from the viewer more often than not. The results support the interpretation that primarily low-level visual processes are responsible for the biases produced by both upright and inverted stimuli.

Distancing the Present Self from the past and the Future: Psychological Distance in Anxiety and Depression

Humans show a systematic tendency to perceive the future as psychologically closer than the past. Based on the clinical hypothesis that anxiety would be associated more with future threat life events, whereas depression with past loss events, here we explored whether people with anxiety- and depression-related personality traits perceive differently the psychological distance of temporal events. Results showed that the common tendency to perceive the future as psychologically closer than the past is exaggerated in individuals with anxiety-related personality traits, whereas this asymmetry drastically shrinks in individuals with depression-related personality traits. Beyond substantiating the hypothesis that the past and the future are differently faced by people with depression- and anxiety-related personality traits, the present findings suggest that temporal orientation of one's self may be greatly altered in anxiety and depression.

Brief relaxation training is not sufficient to alter tolerance to experimental pain in novices

Relaxation techniques, such as deep breathing and muscle relaxation, are aspects common to most forms of mindfulness training. There is now an abundance of research demonstrating that mindfulness training has beneficial effects across a wide range of clinical conditions, making it an important tool for clinical intervention. One area of extensive research is on the beneficial effects of mindfulness on experiences of pain. However, the mechanisms of these effects are still not well understood. One hypothesis is that the relaxation components of mindfulness training, through alterations in breathing and muscle tension, leads to changes in parasympathetic and sympathetic nervous system functioning which influences pain circuits. The current study seeks to examine how two of the relaxation subcomponents of mindfulness training, deep breathing and muscle relaxation, influence experiences of pain in healthy individuals. Participants were randomized to either a 10 minute deep breathing, progressive muscle relaxation, or control condition after which they were exposed to a cold pain task. Throughout the experiment, measures of parasympathetic and sympathetic nervous system activity were collected to assess how deep breathing and progressive muscle relaxation alter physiological responses, and if these changes moderate any effects of these interventions on responses to pain. There were no differences in participants’ pain tolerances or self-reported pain ratings during the cold pain task or in participants’ physiological responses to the task. Additionally, individual differences in physiological functioning were not related to differences in pain tolerance or pain ratings. Overall this study suggests that the mechanisms through which mindfulness exerts its effects on pain are more complex than merely through physiological changes brought about by altering breathing or muscle tension. This indicates a need for more research examining the specific subcomponents of mindfulness, and how these subcomponents might be acting, to better understand their utility as a clinical treatment.

The interaction of perceptual biases in bistable perception

When viewing ambiguous stimuli, people tend to perceive some interpretations more frequently than others. Such perceptual biases impose various types of constraints on visual perception, and accordingly, have been assumed to serve distinct adaptive functions. Here we demonstrated the interaction of two functionally distinct biases in bistable biological motion perception, one regulating perception based on the statistics of the environment – the viewing-from-above (VFA) bias, and the other with the potential to reduce costly errors resulting from perceptual inference – the facing-the-viewer (FTV) bias. When compatible, the two biases reinforced each other to enhance the bias strength and induced less perceptual reversals relative to when they were in conflict. Whereas in the conflicting condition, the biases competed with each other, with the dominant percept varying with visual cues that modulate the two biases separately in opposite directions. Crucially, the way the two biases interact does not depend on the dominant bias at the individual level, and cannot be accounted for by a single bias alone. These findings provide compelling evidence that humans robustly integrate biases with different adaptive functions in visual perception. It may be evolutionarily advantageous to dynamically reweight diverse biases in the sensory context to resolve perceptual ambiguity.

Visual preference for social stimuli in individuals with autism or neurodevelopmental disorders: an eye-tracking study

BACKGROUND

Recent research has identified differences in relative attention to competing social versus non-social video stimuli in individuals with autism spectrum disorder (ASD). Whether attentional allocation is influenced by the potential threat of stimuli has yet to be investigated. This is manipulated in the current study by the extent to which the stimuli are moving towards or moving past the viewer. Furthermore, little is known about whether such differences exist across other neurodevelopmental disorders. This study aims to determine if adolescents with ASD demonstrate differences in attentional allocation to competing pairs of social and non-social video stimuli, where the actor or object either moves towards or moves past the viewer, in comparison to individuals without ASD, and to determine if individuals with three genetic syndromes associated with differing social phenotypes demonstrate differences in attentional allocation to the same stimuli.

METHODS

In study 1, adolescents with ASD and control participants were presented with social and non-social video stimuli in two formats (moving towards or moving past the viewer) whilst their eye movements were recorded. This paradigm was then employed with groups of individuals with fragile X, Cornelia de Lange, and Rubinstein-Taybi syndromes who were matched with one another on chronological age, global adaptive behaviour, and verbal adaptive behaviour (study 2).

RESULTS

Adolescents with ASD demonstrated reduced looking-time to social versus non-social videos only when stimuli were moving towards them. Individuals in the three genetic syndrome groups showed similar looking-time but differences in fixation latency for social stimuli moving towards them. Across both studies, we observed within- and between-group differences in attention to social stimuli that were moving towards versus moving past the viewer.

CONCLUSIONS

Taken together, these results provide strong evidence to suggest differential visual attention to competing social versus non-social video stimuli in populations with clinically relevant, genetically mediated differences in socio-behavioural phenotypes.

Converging Evidence of Ubiquitous Male Bias in Human Sex Perception

Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males-an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers' race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli--while still tending to accept stimuli as male--were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception.

Direction of Biological Motion Affects Early Brain Activation: A Link with Social Cognition

A number of EEG studies have investigated the time course of brain activation for biological movement over this last decade, however the temporal dynamics of processing are still debated. Moreover, the role of direction of movement has not received much attention even though it is an essential component allowing us to determine the intentions of the moving agent, and thus permitting the anticipation of potential social interactions.

In this study, we examined event-related responses (ERPs) in 15 healthy human participants to light point walkers and their scrambled counterparts, whose movements occurred either in the radial or in the lateral plane. Compared to scrambled motion (SM), biological motion (BM) showed an enhanced negativity between 210 and 360ms. A source localization algorithm (sLORETA) revealed that this was due to an increase in superior and middle temporal lobe activity. Regarding direction, we found that radial BM produced an enhanced P1 compared to lateral BM, lateral SM and radial SM. This heightened P1 was due to an increase in activity in extrastriate regions, as well as in superior temporal, medial parietal and medial prefrontal areas. This network is known to be involved in decoding the underlying intentionality of the movement and in the attribution of mental states. The social meaning signaled by the direction of biological motion therefore appears to trigger an early response in brain activity.

The relationship between social anxiety and the perception of depth-ambiguous biological motion stimuli is mediated by inhibitory ability

Orthographically projected biological motion stimuli are depth-ambiguous. Consequently, their projection when oriented towards the viewer is the same as when oriented away. Despite this, observers tend to interpret such stimuli as facing the viewer more often. Some have speculated that this facing-the-viewer bias may exist for sociobiological reasons: Mistaking another human as retreating when they are actually approaching could have more severe consequences than the opposite error. An implication of this theory is that the facing-towards percept may be perceived as more threatening than the facing-away percept. Given this, as well as the finding that anxious individuals have been found to display an attentional bias towards threatening stimuli, we reasoned that more anxious individuals might have stronger facing-the-viewer biases. Furthermore, since anxious individuals have been found to perform poorer on inhibition tasks, we hypothesized that inhibitory ability would mediate the relationship between anxiety and the facing-the-viewer bias (i.e., difficulty inhibiting the threatening percept). Exploring individual differences, we asked participants to complete anxiety questionnaires, to perform a Go/No-Go task, and then to complete a perceptual task that allowed us to assess their facing-the-viewer biases. As hypothesized, we found that both greater anxiety and weaker inhibitory ability were associated with greater facing-the-viewer biases. In addition, we found that inhibitory ability significantly mediated the relationship between anxiety and facing-the-viewer biases. Our results provide further support that the facing-the-viewer bias is sensitive to the sociobiological relevance of biological motion stimuli, and that the threat bias for ambiguous visual stimuli is mediated by inhibitory ability.

Tactile input and empathy modulate the perception of ambiguous biological motion

Evidence has shown that task-irrelevant auditory cues can bias perceptual decisions regarding directional information associated with biological motion, as indicated in perceptual tasks using point-light walkers (PLWs) (Brooks et al., 2007). In the current study, we extended the investigation of cross-modal influences to the tactile domain by asking how tactile input resolves perceptual ambiguity in visual apparent motion, and how empathy plays a role in this cross-modal interaction. In Experiment 1, we simulated the tactile feedback on the observers' fingertips when the (upright or inverted) PLWs (comprised of either all red or all green dots) were walking (leftwards or rightwards). The temporal periods between tactile events and critical visual events (the PLW's feet hitting the ground) were manipulated so that the tap could lead, synchronize, or lag the visual foot-hitting-ground event. We found that the temporal structures between tactile (feedback) and visual (hitting) events systematically biases the directional perception for upright PLWs, making either leftwards or rightwards more dominant. However, this effect was absent for inverted PLWs. In Experiment 2, we examined how empathy modulates cross-modal capture. Instead of giving tactile feedback on participants' fingertips, we gave taps on their ankles and presented the PLWs with motion directions of approaching (facing toward observer)/receding (facing away from observer) to resemble normal walking postures. With the same temporal structure, we found that individuals with higher empathy were more subject to perceptual bias in the presence of tactile feedback. Taken together, our findings showed that task-irrelevant tactile input can resolve the otherwise ambiguous perception of the direction of biological motion, and this cross-modal bias was mediated by higher level social-cognitive factors, including empathy.

Both right- and left-handers show a bias to attend others' right arm

The common-coding hypothesis suggests that the more similar an observed action is to the way the observer would perform it, the stronger is the ensuing activation of motor representations. Therefore, producing actions could prime perception so that observers would be particularly responsive to (i.e. biased to perceive) actions that are related to, and share features with, their own actions. If this similarity principle also applies to handedness, right- and left-handers should be more likely to perceive actions as performed with their dominant rather than non-dominant hand. In two experiments, participants were required to indicate the perceived orientation (front or back view) of pictures of ambiguous human silhouettes performing one-handed manual actions. Experiment 1, in which 300 right-handers and 60 left-handers reported the orientation of a single silhouette seen for as much as they wished, showed that participants perceived the figures more frequently in an orientation congruent with a movement performed with the right rather than the left hand. Experiment 2, in which 12 right-handers and 12 left-handers reported the orientation of 52 silhouettes seen for 300 ms, showed similar results when multiple responses per participant were collected rather than only one. Contrary to our expectations, no difference was observed between right- and left-handers, which might suggest an attentional bias towards the right arm of human bodies in both groups. Moreover, participants were more likely to perceive the figure as front-facing than as back-facing, possibly due to the greater adaptive relevance of approaching compared to receding individuals.

Assessing threat responses towards the symptoms and diagnosis of schizophrenia using visual perceptual biases

Stigma towards individuals diagnosed with schizophrenia continues despite increasing public knowledge about the disorder. Questionnaires are used almost exclusively to assess stigma despite self-report biases affecting their validity. The purpose of this experiment was to implicitly assess stigma towards individuals with schizophrenia by measuring visual perceptual biases immediately after participants conversed with a confederate. We manipulated both the diagnostic label attributed to the confederate (peer vs. schizophrenia) and the presence of behavioural symptoms (present vs. absent). Immediately before and after conversing with the confederate, we measured participants' facing-the-viewer (FTV) biases (the preference to perceive depth-ambiguous stick-figure walkers as facing towards them). As studies have suggested that the FTV bias is sensitive to the perception of threat, we hypothesized that FTV biases would be greater after participants conversed with someone that they believed had schizophrenia, and also after they conversed with someone who presented symptoms of schizophrenia. We found partial support for these hypotheses. Participants had significantly greater FTV biases in the Peer Label/Symptoms Present condition. Interestingly, while FTV biases were lowest in the Schizophrenia Label/Symptoms Present condition, participants in this condition were most likely to believe that people with schizophrenia should face social restrictions. Our findings support that both implicit and explicit beliefs help develop and sustain stigma.