Body posture and gender impact neural processing of power-related words

Judging others’ power facilitates successful social interaction. Both gender and body posture have been shown to influence judgments of another’s power. However, little is known about how these two cues interact when they conflict or how they influence early processing. The present study investigated this question during very early processing of power-related words using event-related potentials (ERPs). Participants viewed images of women and men in dominant and submissive postures that were quickly followed by dominant or submissive words. Gender and posture both modulated neural responses in the N2 latency range to dominant words, but for submissive words they had little impact. Thus, in the context of dual-processing theories of person perception, information extracted from both behavior (i.e., posture) and from category membership (i.e., gender) are recruited side-by-side to impact word processing.     

Body posture and interpersonal perception in a dyadic interaction: A Big Two analysis

Body posture influences feelings about the self, but little is known about its impact on social cognition more generally. We apply the Big Two framework (Agency/Competence, Communion/Warmth) and study how body posture influences interpersonal perception in a dyadic interaction. In three experiments, we studied dyads with different body postures (Exps. 1 and 2: expanded/restricted; Exp. 3: expanded/neutral). Dyad members worked on a joint task, and rated self and other. Findings showed that participants in an expanded posture rated the self higher and the other lower on agency, whereas those in a submissive (or neutral) posture rated the self lower and the other higher on agency. In Experiment 2, participants in a submissive posture also rated their communion lower. Results are important both for the impact of body posture on interpersonal perception and for context effects in the relationship of Agency versus Communion ratings of self and others.     

Contributions of visual and embodied expertise to body perception

Recent research has demonstrated that our perception of the human body differs from that of inanimate objects. This study investigated whether the visual perception of the human body differs from that of other animate bodies and, if so, whether that difference could be attributed to visual experience and/or embodied experience. To dissociate differential effects of these two types of expertise, inversion effects (recognition of inverted stimuli is slower and less accurate than recognition of upright stimuli) were compared for two types of bodies in postures that varied in typicality: humans in human postures (human-typical), humans in dog postures (human-atypical), dogs in dog postures (dog-typical), and dogs in human postures (dog-atypical). Inversion disrupts global configural processing. Relative changes in the size and presence of inversion effects reflect changes in visual processing. Both visual and embodiment expertise predict larger inversion effects for human over dog postures because we see humans more and we have experience producing human postures. However, our design that crosses body type and typicality leads to distinct predictions for visual and embodied experience. Visual expertise predicts an interaction between typicality and orientation: greater inversion effects should be found for typical over atypical postures regardless of body type. Alternatively, embodiment expertise predicts a body, typicality, and orientation interaction: larger inversion effects should be found for all human postures but only for atypical dog postures because humans can map their bodily experience onto these postures. Accuracy data supported embodiment expertise with the three-way interaction. However, response-time data supported contributions of visual expertise with larger inversion effects for typical over atypical postures. Thus, both types of expertise affect the visual perception of bodies.     

Whole-body posture planning in anticipation of a manual prehension task: Prospective and retrospective effects

This study examined the extent to which the anticipation of a manual action task influences whole-body postural planning and orientation. Our participants walked up to a drawer, opened the drawer, then grasped and moved an object in the drawer to another location in the same drawer. The starting placement of the object within the drawer and the final placement of the object in the drawer were varied across trials in either a blocked design (i.e., in trials where the same start and end location were repeated consecutively) or in a mixed fashion. Of primary interest was the posture adopted at the moment of grasping the drawer handle before pulling it out prior to the object manipulation task. Of secondary interest was whether there were sequential effects such that postures adopted in preceding trials influenced postures in subsequent trials. The results indicated that the spatial properties of the forthcoming object manipulation influenced both the postures adopted by the participants and the degree to which the drawer was opened, suggesting a prospective effect. In addition, the adopted postures were more consistent in blocked trials than in mixed trials, suggesting an additional retrospective effect. Overall, our findings suggest that motor planning occurs at the level of the whole body, and reflects both prospective and retrospective influences.     

Horses (<Emphasis Type="Italic">Equus caballus</Emphasis>) use human local enhancement cues and adjust to human attention

This study evaluates the horse (Equus caballus) use of human local enhancement cues and reaction to human attention when making feeding decisions. The superior performance of dogs in observing human states of attention suggests this ability evolved with domestication. However, some species show an improved ability to read human cues through socialization and training. We observed 60 horses approach a bucket with feed in a three-way object-choice task when confronted with (a) an unfamiliar or (b) a familiar person in 4 different situations: (1) squatting behind the bucket, facing the horse (2) standing behind the bucket, facing the horse (3) standing behind the bucket in a back-turned position, gazing away from the horse and (4) standing a few meters from the bucket in a distant, back-turned position, again gazing away from the horse. Additionally, postures 1 and 2 were tested both with the person looking permanently at the horse and with the person alternating their gaze between the horse and the bucket. When the person remained behind the correct bucket, it was chosen significantly above chance. However, when the test person was turned and distant from the buckets, the horses’ performance deteriorated. In the turned person situations, the horses approached a familiar person and walked towards their focus of attention significantly more often than with an unfamiliar person. Additionally, in the squatting and standing person situations, some horses approached the person before approaching the correct bucket. This happened more with a familiar person. We therefore conclude that horses can use humans as a local enhancement cue independently of their body posture or gaze consistency when the persons remain close to the food source and that horses seem to orientate on the attention of familiar more than of unfamiliar persons. We suggest that socialization and training improve the ability of horses to read human cues.     

Erectness of posture as an indicator of dominance or success in humans

Darwin and others have perceived parallels between the erect bearing of proud, successful humans and the expansive demeanor of dominant animals. Various additional parallels between man and other primates in the characteristics of dominance hierarchies, the facial and postural expression of dominance, and its possible neural mediation are described. In the present study, success by human subjects in various situations was found to be reflected by erect posture. In a longitudinal study, boys who had been ranked by peers as tough, or dominant in agonistic encounters, in early grade school were observed to have erect posture in high school. Further, high school students who were judged by peers as successful by group standards tended to have erect posture. Finally, erectness of posture was related to performance on a college examination, with students' posture changing in erectness upon their receiving their grade. These results are consistent with the hypothesis that human competition for social success is based upon a biological capacity for dominance hierarchization.This research was supported in part by a Wayne State University Faculty Research Award to the first author. Portions of this report were presented at the Animal Behavior Society meeting in June 1980 at Fort Collins, Colorado.     

Not all who stand tall are proud: Gender differences in the proprioceptive effects of upright posture

Research shows that individuals feel and later perform better when given positive feedback in the context of an upright posture, as opposed to a slumped one, even if unaware that their bodily position is meant to express emotion. We sought to determine whether proprioceptive feedback from body postures operate differently for women and men. Participants received success feedback when in either an upright or slumped posture, which was covertly manipulated. Results showed that for men the effects of posture were intuitive and appropriate: receiving success feedback while upright enhanced performance self-ratings. In contrast, after adopting an upright posture, women went on after success feedback to perform more poorly and make more negative self-ratings, than after adopting a slumped posture. A number of theories are offered as potential explanations for this gender effect.     

It hurts when I do this (or you do that): Posture and pain tolerance

Recent research (Carney, Cuddy, & Yap, 2010) has shown that adopting a powerful pose changes people's hormonal levels and increases their propensity to take risks in the same ways that possessing actual power does. In the current research, we explore whether adopting physical postures associated with power, or simply interacting with others who adopt these postures, can similarly influence sensitivity to pain. We conducted two experiments. In Experiment 1, participants who adopted dominant poses displayed higher pain thresholds than those who adopted submissive or neutral poses. These findings were not explained by semantic priming. In Experiment 2, we manipulated power poses via an interpersonal interaction and found that power posing engendered a complementary (Tiedens & Fragale, 2003) embodied power experience in interaction partners. Participants who interacted with a submissive confederate displayed higher pain thresholds and greater handgrip strength than participants who interacted with a dominant confederate.     

Trunk posture affects upper extremity function of adults

This study examined the effects of various seated trunk postures on upper extremity function. 59 adults were tested using the Jebsen Taylor Hand Function Test while in three different trunk postures. Significant mean differences between the neutral versus the flexed and laterally flexed trunk postures were noted during selected tasks. Specifically, dominant hand performance during the tasks of feeding and lifting heavy cans was significantly slower while the trunk was flexed and laterally flexed than when performed in the neutral trunk position. Performance of the nondomi nant hand during the tasks of picking up small objects, page turning, as well as the total score was slower while the trunk was flexed compared to performance in the neutral trunk position. These findings support the assumption that neutral trunk posture improves upper extremity performance during daily activities although the effect is not consistent across tasks. Findings are discussed along with limitations and recommendations for research.     

Embodied mood regulation: the impact of body posture on mood recovery,negative thoughts,and mood-congruent recall

Previous work has shown that a stooped posture may activate negative mood. Extending this work, the present experiments examine how stooped body posture influences recovery from pre-existing negative mood. In Experiment 1 (n?=?229), participants were randomly assigned to receive either a negative or neutral mood induction, after which participants were instructed to take either a stooped, straight, or control posture while writing down their thoughts. Stooped posture (compared to straight or control postures) led to less mood recovery in the negative mood condition, and more negative mood in the neutral mood condition. Furthermore, stooped posture led to more negative thoughts overall compared to straight or control postures. In Experiment 2 (n?=?122), all participants underwent a negative mood induction, after which half received cognitive reappraisal instructions and half received no instructions. Mood-congruent cognitions were assessed through autobiographical memory recall. Again, stooped (compared to straight) position led to less mood recovery. Notably, this was independent of regulation instruction. These findings demonstrate for the first time that posture plays an important role in recovering from negative mood.     

Upright and left out: Posture moderates the effects of social exclusion on mood and threats to basic needs

Adopting a powerful posture leads individuals to feel more confident and dominant. Social exclusion can strongly impact individuals' mood and basic social needs. The current research combines these bodies of research, investigating the effects of dominant and submissive poses on responses to social exclusion and inclusion. In two experiments, participants held a slouching or upright pose and were either socially included or excluded using the Cyberball social exclusion manipulation. Social exclusion only affected participants' mood when individuals took a powerful posture: Excluded participants in powerful postures had more negative mood after exclusion than included power‐posing participants, but effects of exclusion and inclusion did not differ among submissive‐posing participants (Experiments 1 and 2). Similarly, it was also found that social exclusion affected basic needs only when participants' adopted powerful poses (Experiment 2). Copyright © 2013 John Wiley & Sons, Ltd.     

赢分与输分运动员面孔表情和身体姿势情绪的加工机制*

本研究采用中国运动员赢分和输分后的表情, 通过行为学和脑电技术比较面孔表情和身体姿势的加工机制。实验1探讨了赢分与输分面孔和身体的效价和强度, 实验2考察了图片的情绪类型(中性、快乐、悲伤、愤怒、恐惧、厌恶), 实验3采用脑电技术比较了赢分和输分情绪的神经机制。3个实验的行为结果表明, 相比面孔, 身体信息更能区分赢分和输分的效价, 而且身体姿势传递的情绪内容相对单一, 面孔表情传递的情绪内容相对复杂和多样化。脑电实验的结果表明, 身体的情绪信息能更早地被大脑识别, 表现在N170成分上, 面孔表情的情绪效应, 反映在EPN成分上。在加工的晚期, 面孔和身体条件下, 均观测到胜利比失败表情诱发了更大的LPP成分。结果表明, 大脑在多个阶段对身体姿势进行情绪评估与分类, 为行为上身体对效价的高区分性提供了证据。     

Cognitive empathy modulates the visual perception of human-like body postures without imitation

To examine the mechanism of visual perception of human-like body postures, we conducted a posture recognition task, a questionnaire survey, and the Interpersonal Reactivity Index (IRI). The majority of participants perceived the pseudo-posture as a human posture in the early stage (78%), but only approximately half of them reported the imagination of bodily movement (66%). These results suggest that the majority of observers perceive pseudo-postures as human postures in the early stage of perception, but this human posture perception does not necessarily lead to the visualisation of bodily movement. In a group of who received the pseudo posture as a human-posture regardless of the perception stages, the participants who imagined bodily movement (64%) showed significantly higher scores than those who did not on the Fantasy subscale of the IRI. Highly empathic participants are more likely to detect a kinematic relation between the pseudo-postures.     

Body posture effects on self‐evaluation: A self‐validation approach

Building on the notion of embodied attitudes, we examined how body postures can influence self‐evaluations by affecting thought confidence, a meta‐cognitive process. Specifically, participants were asked to think about and write down their best or worse qualities while they were sitting down with their back erect and pushing their chest out (confident posture) or slouched forward with their back curved (doubtful posture). Then, participants completed a number of measures and reported their self‐evaluations. In line with the self‐validation hypothesis, we predicted and found that the effect of the direction of thoughts (positive/negative) on self‐related attitudes was significantly greater when participants wrote their thoughts in the confident than in the doubtful posture. These postures did not influence the number or quality of thoughts listed, but did have an impact on the confidence with which people held their thoughts. Copyright © 2009 John Wiley & Sons, Ltd.     

Attributing attention: the use of human-given cues by domestic horses (Equus caballus)

Recent research has shown that domestic dogs are particularly good at determining the focus of human attention, often outperforming chimpanzees and hand-reared wolves. It has been suggested that the close evolutionary relationship between humans and dogs has led to the development of this ability; however, very few other domestic species have been studied. We tested the ability of 36 domestic horses to discriminate between an attentive and inattentive person in determining whom to approach for food. The cues provided were body orientation, head orientation or whether the experimenters’ eyes were open or closed. A fourth, mixed condition was included where the attentive person stood with their body facing away from the subjects but their head turned towards the subject while the inattentive person stood with their body facing the subject but their head turned away. Horses chose the attentive person significantly more often using the body cue, head cue, and eye cue but not the mixed cue. This result suggests that domestic horses are highly sensitive to human attentional cues, including gaze. The possible role of evolutionary and environmental factors in the development of this ability is discussed.     

Impact of lumbar spine posture on thoracic spine motion and muscle activation patterns

Complex motion during standing is typical in daily living and requires movement of both the thoracic and lumbar spine; however, the effects of lumbar spine posture on thoracic spine motion patterns remain unclear. Thirteen males moved to six positions involving different lumbar (neutral and flexed) and thoracic (flexed and twisted) posture combinations. The thoracic spine was partitioned into three segments and the range of motion from each posture was calculated. Electromyographical data were collected from eight muscles bilaterally. Results showed that with a flexed lumbar spine, the lower-thoracic region had 14.83° and 15.61° more flexion than the upper- and mid-thoracic regions, respectively. A flexed lumbar spine significantly reduced the mid-thoracic axial twist angle by 5.21° compared to maximum twist in the mid-thoracic region. Functional differences emerged across muscles, as low back musculature was greatest in maintaining flexed lumbar postures, while thoracic erector spinae and abdominals showed bilateral differences with greater activations to the ipsilateral side. Combined postures have been previously identified as potential injury modulators and bilateral muscle patterns can have an effect on loading pathways. Overall, changes in thoracic motion were modified by lumbar spine posture, highlighting the importance of considering a multi-segmented approach when analyzing trunk motion.     

The influence of time constraints on posture choices during an end-state comfort task

People adopt comfortable postures for the end states of motor actions (end-state comfort; Rosenbaum & Jorgensen, 1992). The choice to end comfortably often elicits adoption of uncomfortable beginning states, demonstrating that a sequence of movement is planned in advance of movement onset. Many factors influence the choice of comfortable end-state postures including the greater precision and speed afforded by postures at joint angle mid-ranges (Short & Cauraugh, 1999). To date, there has been little evaluation of the hypothesis that postures are chosen based on minimizing the time spent in uncomfortable postures. The aim of this experiment was to examine how the relative time required to hold beginning and end-state postures influenced the choice of posture. Participants moved a two-toned wooden dowel from one location to another with the requirement to grasp the object and place a specified color down. Participants completed four conditions where no postures were held, only one posture was held, or both postures were held. We predicted more thumb-up postures for positions held longer regardless of whether these postures were at the end or beginning state. Results verified that the constraint of holding the initial posture led to decreased end-state comfort supporting the hypothesis that estimation of time spent in postures is an important constraint in planning. We also note marked individual differences in posture choices, particularly when the object was moved to the left.     

Social learning across species: horses (<Emphasis Type="Italic">Equus caballus</Emphasis>) learn from humans by observation

This study examines whether horses can learn by observing humans, given that they identify individual humans and orientate on the focus of human attention. We tested 24 horses aged between 3 and 12. Twelve horses were tested on whether they would learn to open a feeding apparatus by observing a familiar person. The other 12 were controls and received exactly the same experimental procedure, but without a demonstration of how to operate the apparatus. More horses from the group with demonstration (8/12) reached the learning criterion of opening the feeder twenty times consecutively than horses from the control group (2/12), and younger horses seemed to reach the criterion more quickly. Horses not reaching the learning criteria approached the human experimenters more often than those that did. The results demonstrate that horses learn socially across species, in this case from humans.     

The effect of body posture on long-range time-to-contact estimation

On Earth, gravity accelerates freely moving objects downward, whereas upward-moving objects are being decelerated. Do humans take internalised knowledge of gravity into account when estimating time-to-contact (TTC, the time remaining before the moving object reaches the observer)? To answer this question, we created a motion-prediction task in which participants saw the initial part of an object's trajectory moving on a collision course prior to an occlusion. Observers had to judge when the object would make contact with them. The visual scene was presented with a head-mounted display. Participants lay either supine (looking up) or prone (looking down), suggestive of the ball either rising up or falling down toward them. Results showed that body posture had a significant effect on time-to-contact estimation, but only when occlusion times were long (2.5 s). The effect was also rather small. This lack of immediacy in the posture effect suggests that TTC estimation is initially robust toward the effect of gravity, which comes to bear only as more time is allowed for post-processing of the visual information.     

Prediction of postural risk of fall initiation based on a two-variable description of body dynamics: Position and velocity of center of mass

This research addresses the question: what is the risk of fall initiation at a certain human posture? There are postures from which no one is able to keep their balance and a fall will surely initiate (risk = 1), and others from which everyone may regain their stability (risk = 0). In other postures, only a portion of people can control their stability. One may interpret risk to chance of a fall to be initiated, and based on the portion of fallers assign a risk value to a given human posture (postural risk). Human posture can be mapped to a point in a 2-dimensional space: the x − v plane, the axes of which are horizontal components of the position and velocity of the center of mass of the body. For every pair of (x, v), the outcome of the balance recovery problem defines whether a person with a given strength level is able to regain their stability when released from a posture corresponding to that point. Using strength distribution data, we estimated the portion of the population who will initiate a fall if starting at a certain posture. A fast calculation approach is also introduced to replace the time-consuming method of solving the recovery problem many times. Postural risk of fall initiation for situations expressed by (x, v) pairs for the entire x − v plane is calculated and shown in a color-map.