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Abstract The posterior extent of the human superior temporal sulcus (pSTS) is an important cortical region for detecting animacy, attributing agency to others, and decoding goal-directed behavior. Theoretical accounts attribute these cognitive skills to unique neural populations that have been difficult to identify empirically (Hein and Knight, 2008). The aim of this study is to evaluate the multivariate statistical structure of pSTS activation patterns when viewing different social cues. We identified a core conjunction region on pSTS from univariate responses with preference for point-light biological motion, faces and the attribution of social concepts to simple animated shapes. In a multivariate analysis, we characterized the similarity structure of the resulting activation patterns after controlling for variance in the activation profile elicited by form and motion features. We found strong antagonistic activation profiles between the social conditions and their localizer controls, a harbinger of why these canonical localizers are so effective, even in individual subjects. We also found unique patterns of similarity between the three core social conditions. Our findings are consistent with the Shultz et al. (2015) model of pSTS function in which separate neural populations exist for animacy detection from body parts versus for extracting intentional cues from movement. Highlights • There exists a conjunction pSTS selective for body cues and motion for agency. • There is statistical structure in the multivariate pSTS activation pattern. • Activation patterns along the pSTS differentiate social cues. • These findings support a model of pSTS topography for animacy by cue type. [ABSTRACT FROM AUTHOR]

Background Insufficient conspicuity of pedestrians at night is a fundamental contributor to injuries and fatalities. Retro-reflective clothing that enhances biological motion perception increases detection and identification of pedestrians at night. Objective To determine how speed of motion and body orientation affect observers’ judgments about the recognisability of pedestrians with bio-motion retro-reflectors. Method The stimuli used in this study were videos of a retro-reflectively outfitted pedestrian on a treadmill filmed in a nighttime road environment. Forty undergraduate students observed videos of pedestrians who were standing, walking or running with the side or back of their body oriented towards the observer. Participants decided which of the two pedestrians was most recognizable as a person. Judgments were made in high beams and low beams at 80 m, 160 m and 240 m. Results For both orientations, observers judged that walking and running pedestrians were more recognizable than standing pedestrians. Observers also judged that running pedestrians were more recognizable than walkers. The effect of pedestrian orientation was dependent on speed. When standing, pedestrians in the back orientation were selected more often, but when running, side-oriented pedestrians were selected as the most recognizable. Conclusions Speed of motion and body orientation affect observers’ judgments of the recognisability of pedestrians wearing retro-reflectors at night. Observers choose moving pedestrians (i.e., those who are walking or running) in biomo retro-reflectors as more recognizable as people than pedestrians who stand. The results fill several gaps in the literature and have practical and future research implications, which are discussed. [ABSTRACT FROM AUTHOR]

The eyes constitute a highly salient cue to communicate social intent. Previous research showed that direct eye contact between two individuals can readily evoke an increased propensity to ‘mirror’ other peoples’ actions. Considering the implicated role of the prosocial neuropeptide oxytocin (OXT) in enhancing the saliency of social cues and modulating approach/avoidance motivational tendencies, the current study adopted the non-invasive brain stimulation technique transcranial magnetic stimulation (TMS) to explore whether a single dose of intranasal OXT (24 IU) modulated (enhanced) a person’s propensity to show heightened mirroring or motor resonance upon salient social cues, such as eye contact. The study involved a double-blind, placebo-controlled, cross-over trial with twenty-seven healthy adult men (19–32 y). By applying single-pulse TMS over the primary motor cortex during movement observation, it was shown that motor resonance was significantly higher when movement observation was accompanied by direct, compared to averted gaze, but that a single dose of OXT did not uniformly enhance this effect. Significant moderations of the treatment effect were noted however, indicating that participants with high self-reports of attachment avoidance displayed a stronger OXT-treatment effect (enhancement of motor resonance upon direct eye contact), compared to participants with low attachment avoidance. Particularly, while participants with high attachment avoidance initially displayed a reduced propensity to increase their motor resonance upon direct eye contact, a single dose of OXT was able to promote an otherwise avoidant individual’s propensity to engage in motor resonance upon a salient social cue such as eye contact. [ABSTRACT FROM AUTHOR]

Detecting biological motion is essential for adaptive social behavior. Previous research has revealed the brain processes underlying this ability. However, brain activity during biological motion perception captures a multitude of processes. As a result, it is often unclear which processes reflect movement processing and which processes reflect secondary processes that build on movement processing. To address this issue, we developed a new approach to measure brain responses directly coupled to observed movements. Specifically, we showed 30 male and female adults a point-light walker moving at a pace of 2.4 Hz and used EEG frequency tagging to measure the brain response coupled to that pace ('movement tagging'). The results revealed a reliable response at the walking frequency that was reduced by two manipulations known to disrupt biological motion perception: phase scrambling and inversion. Interestingly, we also identified a brain response at half the walking frequency (i.e., 1.2 Hz), corresponding to the rate at which the individual dots completed a cycle. In contrast to the 2.4 Hz response, the response at 1.2 Hz was increased for scrambled (vs. unscrambled) walkers. These results show that frequency tagging can be used to capture the visual processing of biological movements and can dissociate between global (2.4 Hz) and local (1.2 Hz) processes involved in biological motion perception, at different frequencies of the brain signal. • We measure brain responses coupled to a point-light figure walking in place. • Responses coupled to the walking cycle were reduced by scrambling and inversion. • Responses coupled to local dot movements were increased by scrambling. • Movement tagging can isolate brain responses coupled to movement processing. • Movement tagging can disentangle global and local stages of movement processing. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Schizophrenia patients have impairments at several levels of cognition including visual attention (eye movements), perception, and social cognition. However, it remains unclear how lower-level cognitive deficits influence higher-level cognition. To elucidate the hierarchical path linking deficient cognitions, we focused on biological motion perception, which is involved in both the early stage of visual perception (attention) and higher social cognition, and is impaired in schizophrenia. Seventeen schizophrenia patients and 18 healthy controls participated in the study. Using point-light walker stimuli, we examined eye movements during biological motion perception in schizophrenia. We assessed relationships among eye movements, biological motion perception and empathy. In the biological motion detection task, schizophrenia patients showed lower accuracy and fixated longer than healthy controls. As opposed to controls, patients exhibiting longer fixation durations and fewer numbers of fixations demonstrated higher accuracy. Additionally, in the patient group, the correlations between accuracy and affective empathy index and between eye movement index and affective empathy index were significant. The altered gaze patterns in patients indicate that top-down attention compensates for impaired bottom-up attention. Furthermore, aberrant eye movements might lead to deficits in biological motion perception and finally link to social cognitive impairments. The current findings merit further investigation for understanding the mechanism of social cognitive training and its development. [ABSTRACT FROM AUTHOR]

Migraine ranks as the third most common disease in the world and has caused significant losses of daily life abilities. Previously, people gave more attention to the pain of migraines and usually ignored the impairments of cognitive function in migraineurs. In the present study, a duration discrimination paradigm was used to assess the global and local biological motion perception in migraineurs and healthy controls. In the experiment, biological motion sequences and inanimate motion sequences (the inverted biological motion sequences) were sequentially presented on a screen. Observers were instructed to make a two-alternative forced choice to accurately indicate which interval (the first or the second) appeared longer. The stimuli involved global biological motion sequences and local biological motion sequences. The statistical analyses were conducted on the points of subjective equality that were obtained by fitting a psychometric function to each individual observer’s data. In migraineurs, global biological motion signals lengthened the perceived temporal duration (as occurs in normal people), whereas local biological motion signals did not have this temporal dilation effect. The results indicated that patients with migraine showed a deficit in local biological motion perception, whereas their global biological motion perception was comparable to that of healthy subjects. [ABSTRACT FROM AUTHOR]

Abstract: While recent studies indicate that observers are able to use dynamic information to anticipate whole-body actions like tennis shots, it is less clear whether the action’s amplitude may also allow for anticipation. We therefore examined the role of movement dynamics and amplitude for the anticipation of tennis-shot direction. In a previous study, movement dynamics and amplitude were separated from the kinematics of tennis players’ forehand groundstrokes. In the present study, these were manipulated and tennis shots were simulated. Three conditions were created in which shot-direction differences were either preserved or removed: Dynamics-Present–Amplitude-Present (DPAP), Dynamics-Present–Amplitude-Absent (DPAA), and Dynamics-Absent–Amplitude-Present (DAAP). Nineteen low-skill and 15 intermediate-skill tennis players watched the simulated shots and predicted shot direction from movements prior to ball-racket contact only. Percent of correctly predicted shots per condition was measured. On average, both groups’ performance was superior when the dynamics were present (the DPAP and DPAA conditions) compared to when it was absent (the DAAP condition). However, the intermediate-skill players performed above chance independent of amplitude differences in shots (i.e., both the DPAP and DPAA conditions), whereas the low-skill group only performed above chance when amplitude differences were absent (the DPAA condition). These results suggest that the movement’s dynamics but not their amplitude provides information from which tennis-shot direction can be anticipated. Furthermore, the successful extraction of dynamical information may be hampered by amplitude differences in a skill-dependent manner. [Copyright &y& Elsevier]

Abstract: In this study, the first to explore the cortical correlates of signed language (SL) processing under point-light display conditions, the observer identified either a signer or a lexical sign from a display in which different signers were seen producing a number of different individual signs. Many of the regions activated by point-light under these conditions replicated those previously reported for full-image displays, including regions within the inferior temporal cortex that are specialised for face and body-part identification, although such body parts were invisible in the display. Right frontal regions were also recruited – a pattern not usually seen in full-image SL processing. This activation may reflect the recruitment of information about person identity from the reduced display. A direct comparison of identify-signer and identify-sign conditions showed these tasks relied to a different extent on the posterior inferior regions. Signer identification elicited greater activation than sign identification in (bilateral) inferior temporal gyri (BA 37/19), fusiform gyri (BA 37), middle and posterior portions of the middle temporal gyri (BAs 37 and 19), and superior temporal gyri (BA 22 and 42). Right inferior frontal cortex was a further focus of differential activation (signer>sign). These findings suggest that the neural systems supporting point-light displays for the processing of SL rely on a cortical network including areas of the inferior temporal cortex specialized for face and body identification. While this might be predicted from other studies of whole body point-light actions () it is not predicted from the perspective of spoken language processing, where voice characteristics and speech content recruit distinct cortical regions () in addition to a common network. In this respect, our findings contrast with studies of voice/speech recognition (). Inferior temporal regions associated with the visual recognition of a person appear to be required during SL processing, for both carrier and content information. [Copyright &y& Elsevier]

Others' action observation activates in the observer a coordinated hand-eye motor program, covert for the hand (i.e. motor resonance), and overt for the eye (i.e. proactive gaze), similar to that of the observed agent. The biological motion hypothesis of action anticipation claims that proactive gaze occurs only in the presence of biological motion, and that kinematic information is sufficient to determine the anticipation process. The results of the present study did not support the biological motion hypothesis of action anticipation. Specifically, proactive gaze was present during observation of both a biological accelerated-decelerated motion and a non-biological constant velocity motion (Experiment 1), in the presence of a barrier able to restrict differences between the two kinematics to the motion profile of individual markers prior to contact (Experiment 2), but only if an object was present at the end point of the movement trajectory (Experiment 3). Furthermore, proactive gaze was found independently of the presence of end effects temporally congruent with the instant in which the movement stopped (Experiments 4, and 5). We propose that the involvement of the observer's motor system is not restricted to when the agent moves with natural kinematics, and it is mandatory whenever the presence of an agent or a goal is evident, regardless of physical appearance, natural kinematics, and the possibility to identify the action behind the stimulus. [ABSTRACT FROM AUTHOR]