Reliable perception of self-motion and orientation requires the central nervous system (CNS) to adapt to changing environments, stimuli, and sensory organ function. The proposed computations required of neural systems for this adaptation process remain conceptual, limiting our understanding and ability to quantitatively predict adaptation and mitigate any resulting impairment prior to completing adaptation. Here, we have implemented a computational model of the internal calculations involved in the orientation perception system’s adaptation to changes in the magnitude of gravity. In summary, we propose that the CNS considers parallel, alternative hypotheses of the parameter of interest (in this case, the CNS’s internal estimate of the magnitude of gravity) and uses the associated sensory conflict signals (i.e., difference between sensory measurements and the expectation of them) to sequentially update the posterior probability of each hypothesis using Bayes rule. Over time, an updated central estimate of the internal magnitude of gravity emerges from the posterior probability distribution, which is then used to process sensory information and produce perceptions of self-motion and orientation. We have implemented these hypotheses in a computational model and performed various simulations to demonstrate quantitative model predictions of adaptation of the orientation perception system to changes in the magnitude of gravity, similar to those experienced by astronauts during space exploration missions. These model predictions serve as quantitative hypotheses to inspire future experimental assessments.

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Objectives: Evaluate the relationship of nutrition parameters and the modified frailty index (mFI) on postsurgical complications within a young patient population sustaining lower extremity orthopaedic trauma. Design: Retrospective observational cohort study. Setting: Urban, American College of Surgeons-Verified, Level-1, Trauma Center. Patients/Participants: Seventeen-thousand one hundred nine adult patients under the age of 65 sustaining lower extremity fractures undergoing operative intervention from 2006 to 2018. Main Outcome Measures: On admission, mFI and albumin levels were obtained, as well as complication data. Statistical analysis was used to analyze the association between frailty, malnutrition, and postoperative complications. Patients were stratified, healthy (mFI ≤1, albumin ≥3.5 g/dL), malnourished (mFI ≤1, albumin <3.5 g/dL), frail (mFI ≥2, albumin ≥3.5 g/dL), and frail and malnourished (mFI ≥2, albumin <3.5 g/dL). Results: 60.4% of patients were healthy, 18.8% were malnourished, 11.7% were frail, and 9.0% were frail and malnourished. Frailty and/or malnourishment on admission predicted significantly higher odds of postoperative complications and mortality when compared with healthy patients. Frailty and malnourishment in conjunction predicted a significantly higher odds ratio of 1.46 (1.22–1.75) for developing postoperative complications when compared with the only malnourished. This was also observed when compared with the only frail (odd ratio: 1.61, P < 0.001); however, there was also a 2.72 (P < 0.001) increased odds of mortality. Conclusions: Frailty and malnutrition in conjunction predicts a subset of patients with a higher risk of postoperative complications beyond that of frailty or malnutrition in isolation. Identification of these physiological states on admission allows for interventional opportunities during hospitalization. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background:Demographic differences among surgical trainees regarding intrapersonal traits, such as imposter syndrome and assertiveness, have become widely acknowledged. However, many of these characteristics have not been examined in tandem, nor among both trainees and surgeons in practice. This study aimed to address these knowledge gaps.Methods:This was an anonymous, voluntary survey study comprised of validated measures of (1) self-efficacy, (2) imposter syndrome, (3) assertiveness, (4) perfectionism, and (5) self-rated likeability. A multimodal recruitment strategy was used and surgeons across all subspecialties were eligible for inclusion.Results:A total of 296 participants were included, with 54% identifying as female (n = 161) and 72% between the ages of 25 and 40 years of age (n = 212). Imposter syndrome, assertiveness, and perfectionism scales were normally distributed; self-efficacy and self-rated likeability scales demonstrated slight negative skew. Self-identified male sex was associated with less imposter syndrome (P < 0.001) and perfectionism (P = 0.035) and higher assertiveness (P < 0.001). Imposter syndrome was less common among older age groups (P = 0.001).Conclusions:Surgeons are a self-efficacious group of perfectionists with widespread variability in imposter syndrome and assertiveness. Female sex and younger age were associated with more imposter syndrome and less assertiveness, highlighting an opportunity for early career coaching.