Did you skip leg day? The neural mechanisms of muscle perception for body parts.

While the neural mechanisms underpinning the perception of muscularity are poorly understood, recent progress has been made using the psychophysical technique of visual adaptation. Prolonged visual exposure to high (low) muscularity bodies causes subsequently viewed bodies to appear less (more) muscular, revealing a recalibration of the neural populations encoding muscularity. Here, we use visual adaptation to further elucidate the tuning properties of the neural processes underpinning muscle perception for the upper and lower halves of the body. Participants manipulated the apparent muscularity of upper and lower bodies until they appeared 'normal', prior to and following exposure to a series of top/bottom halves of bodies that were either high or low in muscularity. In Experiment 1, participants were adapted to isolated own-gender body halves from one of four conditions; increased (muscularity) upper (body half), increased lower, decreased upper, or decreased lower. Despite the presence of muscle aftereffects when the body halves the participants viewed and manipulated were congruent, there was only weak evidence of muscle aftereffect transfer between the upper and lower halves of the body. Aftereffects were significantly weaker when body halves were incongruent, implying minimal overlap in the neural mechanisms encoding muscularity for body half. Experiment 2 examined the generalisability of Experiment 1's findings in a more ecologically valid context using whole-body stimuli, producing a similar pattern of results as Experiment 1, but with no evidence of cross-adaptation. Taken together, the findings are most consistent with muscle-encoding neural populations that are body-half selective. As visual adaptation has been implicated in cases of body size and shape misperception, the present study furthers our current understanding of how these perceptual inaccuracies, particularly those involving muscularity, are developed, maintained, and may potentially be treated.

Testing visual self-misperception in anorexia nervosa using a symmetrical body size estimation paradigm.

OBJECTIVE: Individuals diagnosed with anorexia nervosa (AN) often report seeing themselves as overweight. While body size estimation tasks suggest that such individuals overestimate their body size, these tasks have failed to establish whether this misestimation stems from visual misperception. Misestimation might, instead, be due to response bias. We designed a paradigm to distinguish between visual and response bias contributions to body size misestimation: the symmetrical body size estimation (s-BSE) paradigm. METHOD: The s-BSE paradigm involves two tasks. In the conventional task, participants estimate the width of their photographed body by adjusting the size of a rectangle to match. In the transposed task, participants adjust the size of a photograph of their body to match the rectangle. If overestimation stems exclusively from visual misperception, then errors in each task would be equal and opposite. Using this paradigm, we compared the performance of women diagnosed with AN (n = 14) against women without any eating disorder (n = 40). RESULTS: In the conventional task, we replicated previous findings indicating that both women with AN and women without any eating disorder overestimate their body size. In the transposed task, neither group adjusted the bodies to be narrower than the rectangle. Participants with AN set their photographs to be significantly wider. DISCUSSION: While we replicated previous findings of body size overestimation amongst women with AN and those without any eating disorder, our results are inconsistent with the hypothesis that such overestimation stems exclusively from visual misperception and instead suggest a substantial response bias effect. PUBLIC SIGNIFICANCE: Women with anorexia nervosa overestimate their own body size. Research has not yet determined whether this overestimation stems from them seeing themselves as larger or other, non-visual factors. We employ a new method for distinguishing these possibilities and find that non-visual factors influence size estimates for women with and without anorexia nervosa. This method can help future research control for non-perceptual influences on participant responses.

The valence-dominance model applies to body perception.

First impressions of a person, including social judgements, are often based on appearance. The widely accepted valence-dominance model of face perception (Oosterhof and Todorov 2008 Proc. Natl Acad. Sci. USA 105, 11 087-11 092 (doi:10.1073/pnas.0805664105)) posits that social judgements of faces fall along two orthogonal dimensions: trustworthiness (valence) and dominance. The current study aimed to establish the principal components of social judgements based on the perception of bodies, hypothesizing that these would follow the same dimensions as face perception. Stimuli were black and white photographs showing bodies dressed in grey clothing, standing in their natural posture, in left profile. Raters (N = 237) judged the stimuli on the 14 traits used in Oosterhof and Todorov's original study (Oosterhof and Todorov 2008 Proc. Natl Acad. Sci. USA 105, 11 087-11 092 (doi:10.1073/pnas.0805664105)). Data were analysed using principal component analysis (PCA), as in the original study, with an additional exploratory factor analysis (EFA) using oblique rotation. While PCA produced a third dimension in line with several replications of the original study, results from the EFA produced two dimensions, representing trustworthiness and dominance, providing support for the hypothesis that social perceptions of bodies can be summarized using the valence-dominance model. These two factors could represent universal perceptions we have about people. Future research could explore social judgements of humans based on other stimuli, such as voices or body odour, to evaluate whether the trustworthiness and dominance dimensions are consistent across modalities.

Observing Provider Utilization of Electronic Health Records to Improve Clinical Quality Metrics.

Introduction: This study compared changes of healthcare quality in a Michigan Medicaid population before and after physician adoption of electronic health records (EHRs) via the Meaningful Use (MU) program for selected Healthcare Effectiveness Data and Information Set (HEDIS) quality of care measures. Methods: Healthcare measures included well-child visits, cancer screening, and chronic illness quality measures. Utilization data were obtained from Medicaid paid claims and encounter data with providers (N=291) receiving their first MU incentive in 2014 and at least one HEDIS-defined outpatient visit with a Michigan Medicaid enrollee. Paired t-tests with a repeated measures design were utilized to analyze the data. Results: Improvements in quality of infant well-child visits (mean difference = 10.2) and colorectal cancer screening (mean difference = 8.0 percent) were observed. We found no change or slight decreases for the other selected measures. Conclusion: These outcomes inform the performance and ability of EHRs to improve quality of healthcare standards particularly as technology continues to evolve under the Centers for Medicare & Medicaid Services (CMS) Interoperability and Patient Access final rule.

Visual body-size adaptation and estimation of tactile distance.

Estimating the size of bodies is crucial for interactions with physical and social environments. Body-size perception is malleable and can be altered using visual adaptation paradigms. However, it is unclear whether such visual adaptation effects also transfer to other modalities and influence, for example, the perception of tactile distances. In this study, we employed a visual adaptation paradigm. Participants were exposed to images of expanded or contracted versions of self- or other-identity bodies. Before and after this adaptation, they were asked to manipulate the width of body stimuli to appear as 'normal' as possible. We replicated an effect of visual adaptation such that the body-size selected as most 'normal' was larger after exposure to expanded and thinner after exposure to contracted adaptation stimuli. In contrast, we did not find evidence that this adaptation effect transfers to distance estimates for paired tactile stimuli delivered to the abdomen. A Bayesian analysis showed that our data provide moderate evidence that there is no effect of visual body-size adaptation on the estimation of spatial parameters in a tactile task. This suggests that visual body-size adaptation effects do not transfer to somatosensory body-size representations.

The "cheerleader effect" in facial and bodily attractiveness: A result of memory bias and not perceptual encoding.

Individual faces are rated as more attractive when presented in a group compared with when presented individually; a finding dubbed the "cheerleader effect." As a relatively recent discovery, the conditions necessary to observe the effect are not clearly understood. We sought to better define these conditions by examining two parameters associated with the effect. Our first aim was to determine whether the effect is specific to faces or occurs also for human bodies. Both face and body images were rated as being more attractive when presented in groups than when presented in isolation, demonstrating that the cheerleader effect is not restricted to faces. Furthermore, the effect was significantly larger for bodies than faces. Our second aim was to determine whether the cheerleader effect originates from a bias in memory or occurs during perceptual encoding. Participants in the "memory" condition provided attractiveness ratings after images had been removed from the testing screen, whereas participants in the "perceptual" condition provided ratings while the images remained visible, thereby eliminating the memory components of the paradigm. Significant cheerleader effects were only observed in the memory condition. We conclude that the cheerleader effect for faces and bodies is due to a bias in memory and does not occur at an initial stage of perceptual encoding.

Shining a Light on Race: Contrast and Assimilation Effects in the Perception of Skin Tone and Racial Typicality.

Researchers have long debated the extent to which an individual's skin tone influences their perceived race. Brooks and Gwinn (2010) demonstrated that the race of surrounding faces can affect the perceived skin tone of a central target face without changing perceived racial typicality, suggesting that skin lightness makes a small contribution to judgments of race compared to morphological cues (the configuration and shape of the facial features). However, the lack of a consistent light source may have undermined the reliability of skin tone cues, encouraging observers to rely disproportionately on morphological cues instead. The current study addresses this concern by using 3D models of male faces with typically Black African or White European appearances that are illuminated by the same light source. Observers perceived target faces surrounded by White faces to have darker skin than those surrounded by Black faces, particularly for faces of intermediate lightness. However, when asked to judge racial typicality, a small assimilation effect was evident, with target faces perceived as more stereotypically White when surrounded by White than when surrounded by Black faces at intermediate levels of typicality. This evidence of assimilation effects for perceived racial typicality despite concurrent contrast effects on perceived skin lightness supports the previous conclusion that perceived skin lightness has little influence on judgments of racial typicality for racially ambiguous faces, even when lighting is consistent.

Looking at the Figures: Visual Adaptation as a Mechanism for Body-Size and -Shape Misperception.

Many individuals experience body-size and -shape misperception (BSSM). Body-size overestimation is associated with body dissatisfaction, anxiety, depression, and the development of eating disorders in individuals who desire to be thinner. Similar symptoms have been noted for those who underestimate their muscularity. Conversely, individuals with high body mass indices (BMI) who underestimate their adiposity may not recognize the risks of or seek help for obesity-related medical issues. Although social scientists have examined whether media representations of idealized bodies contribute to the overestimation of fat or underestimation of muscle, other scientists suggest that increases in the prevalence of obesity could explain body-fat underestimation as a form of renormalization. However, these disparate approaches have not advanced our understanding of the perceptual underpinnings of BSSM. Recently, a new unifying account of BSSM has emerged that is based on the long-established phenomenon of visual adaptation, employing psychophysical measurements of perceived size and shape following exposure to "extreme" body stimuli. By inducing BSSM in the laboratory as an aftereffect, this technique is rapidly advancing our understanding of the underlying mental representation of human bodies. This nascent approach provides insight into real-world BSSM and may inform the development of therapeutic and public-health interventions designed to address such perceptual errors.

Muscle and fat aftereffects and the role of gender: Implications for body image disturbance.

Body image disturbance - a cause of distress amongst the general population and those diagnosed with various disorders - is often attributed to the media's unrealistic depiction of ideal bodies. These ideals are strongly gendered, leading to pronounced fat concern amongst females, and a male preoccupation with muscularity. Recent research suggests that visual aftereffects may be fundamental to the misperception of body fat and muscle mass - the perceptual component of body image disturbance. This study sought to establish the influence of gender on these body aftereffects. Male and female observers were randomly assigned to one of four adaptation conditions (low-fat, high-fat, low-muscle, and high-muscle bodies) and were asked to adjust the apparent fat and muscle levels of male and female bodies to make them appear as 'normal' as possible both before adaptation and after adaptation. While neither the gender of observers nor of body stimuli had a direct effect, aftereffect magnitude was significantly larger when observers viewed own-gender (compared with other-gender) stimuli. This effect, which may be due to attentional factors, could have implications for the development of body image disturbance, given the preponderance of idealized own-gender bodies in media marketed to male and female consumers.

The Thin White Line: Adaptation Suggests a Common Neural Mechanism for Judgments of Asian and Caucasian Body Size.

Visual adaptation has been proposed as a mechanism linking viewing images of thin women's bodies with body size and shape misperception (BSSM). Non-Caucasian populations appear less susceptible to BSSM, possibly because adaptation to thin Caucasian bodies in Western media may not fully transfer to own-race bodies. Experiment 1 used a cross-adaptation paradigm to examine the transfer of body size aftereffects across races. Large aftereffects were found in the predicted directions for all conditions. The strength of aftereffects was statistically equivalent when the race of test stimuli was congruent vs. incongruent with the race of adaptation stimuli, suggesting complete transfer of aftereffects across races. Experiment 2 used a contingent-adaptation paradigm, finding that simultaneous adaptation to wide Asian and narrow Caucasian women's bodies (or vice versa) results in no significant aftereffects for either congruent or incongruent conditions and statistically equivalent results for each. Equal and opposite adaptation effects may therefore transfer completely across races, canceling each other out. This suggests that body size is encoded by a race-general neural mechanism. Unexpectedly, Asian observers showed reduced body size aftereffects compared to Caucasian observers, regardless of the race of stimulus bodies, perhaps helping to explain why Asian populations appear less susceptible to BSSM.

Gender and the Body Size Aftereffect: Implications for Neural Processing.

Prolonged exposure to wide (thin) bodies causes a perceptual aftereffect such that subsequently viewed bodies appear thinner (wider) than they actually are. This phenomenon is known as visual adaptation. We used the adaptation paradigm to examine the gender selectivity of the neural mechanisms encoding body size and shape. Observers adjusted female and male test bodies to appear normal-sized both before and after adaptation to bodies digitally altered to appear heavier or lighter. In Experiment 1, observers adapted simultaneously to bodies of each gender distorted in opposite directions, e.g., thin females and wide males. The direction of resultant aftereffects was contingent on the gender of the test stimulus, such that in this example female test bodies appeared wider while male test bodies appeared thinner. This indicates at least some separation of the neural mechanisms processing body size and shape for the two genders. In Experiment 2, adaptation involved either wide females, thin females, wide males or thin males. Aftereffects were present in all conditions, but were stronger when test and adaptation genders were congruent, suggesting some overlap in the tuning of gender-selective neural mechanisms. Given that visual adaptation has been implicated in real-world examples of body size and shape misperception (e.g., in anorexia nervosa or obesity), these results may have implications for the development of body image therapies based on the adaptation model.

Meaningful Use: Does Physician Participation Move the Needle on Quality Metrics?

INTRODUCTION: To determine the association between pattern of participation in the Meaningful Use (MU) initiative and self-reported clinical quality metrics. METHODS: We used state-level Medicaid electronic health record (EHR) incentive program data to categorize physicians based on receipt of MU payments (single year vs. multiple years) and self-reported quality metrics from 2011 to 2016. RESULTS: Among 4,198 participating physicians, only 36% received more than one EHR incentive payment. Physicians participating for a single year had better cancer-screening metrics. By comparison, physicians who participated for multiple years reported better medication-related metrics and chronic disease management metrics. CONCLUSIONS: Nature of participation may have varying degrees of influence on types of clinical quality metrics. Sustained participation may support management of chronic conditions. Administrative claims data will help to elucidate our findings.

Health Information Exchange of Medication Lists: Hospital Discharge to Home Healthcare.

Nurses report significant gaps in communication among patients discharged from the hospital with home healthcare (HHC) services. The aim of this pilot study was to quantify the contents of HHC admission packets used to guide nurses' first home visit after hospital discharge. We evaluated 20 randomly selected charts of older adults admitted to HHC after a hospitalization for heart failure. Admission packets contained nearly 50 pages of material, which frequently included duplicate documents printed from the hospital-based electronic health record (EHR). Despite the plethora of documents, most packets omitted key information, such as patients' cognitive and functional status, and even discharge summaries, which would be relevant and actionable for HHC nurses. Moreover, admission packets contained multiple, often discordant, EHR-generated medication lists, which makes reconciliation challenging for nurses and puts vulnerable patients at risk for adverse drug events. Overall, there is an urgent need to improve health information exchange between hospitals and HHC agencies, which will simultaneously promote nurse efficiency and patient safety.

Eliciting nurses' perspectives to improve health information exchange between hospital and home health care.

Despite patient safety initiatives to improve care transitions, prior research largely neglects to elicit feedback from home health nurses regarding health information exchange. The goal of this quality improvement study was to identify opportunities to facilitate information transfer during hospital-to-home-health-care transitions for older adults with heart failure. We conducted focus groups with 19 nurses employed by a single healthcare system using two commercially available electronic health record (EHR) vendors. We analyzed interview transcripts following an immersion/crystallization approach to identify themes. Average participants were females in their mid-fifties with 15 years of home health experience. Nurses reported challenges with hospital-to-home-health-care information exchange, specifically: 1) poor medication management, 2) ineffective communication, 3) technology issues, and 4) patient factors. Nurses identified several opportunities for improvement, including discordant EHR-generated medication lists, which may be amenable to technological solutions. Local quality improvement efforts should incorporate nurses' suggestions and leverage existing best practices.

Vection strength increases with simulated eye-separation.

Research has previously shown that adding consistent stereoscopic information to self-motion displays can improve the vection in depth induced in physically stationary observers. In some past studies, the simulated eye-separation was always close to the observer's actual eye-separation, as the aim was to examine vection under ecological viewing conditions that provided consistent binocular and monocular self-motion information. The present study investigated whether large discrepancies between the observer's simulated and physical eye-separations would alter the vection-inducing potential of stereoscopic optic flow (either helping, hindering, or preventing the induction of vection). Our self-motion displays simulated eye-separations of 0 cm (the non-stereoscopic control), 3.25 cm (reduced from normal), 6.5 cm (approximately normal), and 13 cm (exaggerated relative to normal). The rated strength of vection in depth was found to increase systematically with the simulated eye-separation. While vection was the strongest in the 13-cm condition (stronger than even the 6.5-cm condition), the 3.25-cm condition still produced superior vection to the 0-cm control (i.e., it had significantly stronger vection ratings and shorter onset latencies). Perceptions of scene depth and object motion-in-depth speed were also found to increase with the simulated eye-separation. As expected based on the findings of previous studies, correlational analyses suggested that the stereoscopic advantage for vection (found for all of our non-zero eye-separation conditions) was due to the increase in perceived motion-in-depth.

Experimental manipulation of visual attention affects body size adaptation but not body dissatisfaction.

OBJECTIVE: Prolonged exposure to large/small bodies causes aftereffects in perceived body size. Outside the laboratory, individuals repeatedly exposed to small (large) bodies tend to over- (under-) estimate their size and exhibit increased (decreased) body dissatisfaction. Why, among individuals exposed to approximately equivalent distributions of body sizes, only some develop body size and shape misperception and/or body dissatisfaction is not yet fully understood. METHOD: We exposed 61 women to high and low adiposity bodies simultaneously, instructing half to attend to high, and half to low adiposity bodies. RESULTS: Participants in the high adiposity attention condition's perception of "normal" body size significantly increased in adiposity, and vice versa. DISCUSSION: This suggests that visual attention moderates body size aftereffects. Interventions encouraging visual attention to more realistic ranges of bodies may therefore reduce body misperception. No change in body dissatisfaction was found, suggesting that changes in the perceptual component (misperception) may not necessarily affect the attitudinal component (dissatisfaction) of body image distortion.

The high-level basis of body adaptation.

Prolonged visual exposure, or 'adaptation', to thin (wide) bodies causes a perceptual aftereffect such that subsequently seen bodies appear wider (thinner) than they actually are. Here, we conducted two experiments investigating the effect of rotating the orientation of the test stimuli by 90° from that of the adaptor. Aftereffects were maximal when adapting and test bodies had the same orientation. When they differed, the axis of the perceived distortion changed with the orientation of the body. Experiment 1 demonstrated a 58% transfer of the aftereffect across orientations. Experiment 2 demonstrated an even greater degree of aftereffect transfer when the influence of low-level mechanisms was reduced further by using adaptation and test stimuli with different sizes. These results indicate that the body aftereffect is mediated primarily by high-level object-based processes, with low-level retinotopic mechanisms playing only a minor role. The influence of these low-level processes is further reduced when test stimuli differ in size from adaptation stimuli.