Initial development of skill with a reversed bicycle and a case series of experienced riders.

Riding a bicycle is considered a durable skill that cannot be forgotten. Here, novice participants practiced riding a reversed bicycle, in which a reversing gear inverted the handlebar's rotation. Although learning to ride the reversed bicycle was possible, it was slow, highly variable, implicit, and followed an S-shape pattern. In the initial learning phase, failed attempts to ride the normal bicycle indicated strong interference between the two bicycle skills. While additional practice decreased this interference effect, a subset of learners could not ride either bicycle after eight sessions of practice. Experienced riders who performed extensive practice could switch bicycles without failed attempts and exhibited similar performance (i.e., similar handlebar oscillations) on both bicycles. However, their performance on the normal bicycle was worse than that of the novice bicycle riders at baseline. In conclusion, "unlearning" of the normal bicycle skill precedes the initial learning of the reversed bicycle skill, and a signature of such unlearning is still present following extensive practice.

The spatial contrast sensitivity function and its neurophysiological bases.

Contrast processing is a fundamental function of the visual system, and contrast sensitivity as a function of spatial frequency (CSF) provides critical information about the integrity of the system. Here, we used a novel iPad-based instrument to collect CSFs and fitted the data with a difference of Gaussians model to investigate the neurophysiological bases of the spatial CSF. The reliability of repeat testing within and across sessions was evaluated in a sample of 22 adults for five spatial frequencies (0.41-13 cycles/degree) and two temporal durations (33 and 500 ms). Results demonstrate that the shape of the CSF, lowpass versus bandpass, depends on the temporal stimulus condition. Comparisons with previous psychophysical studies and with single-cell data from macaques and humans indicate that the major portion of the CSF, spatial frequencies >1.5 cycles/degree regardless of temporal condition, is determined by a 'sustained' mechanism (presumably parvocellular input to primary visual cortex [V1]). Contrast sensitivity to the lowest spatial frequency tested appears to be generated by a 'transient' mechanism (presumably magnocellular input to V1). The model fits support the hypothesis that the high spatial frequency limb of the CSF reflects the receptive field profile of the center mechanism of the smallest cells in the parvocellular pathway. These findings enhance the value of contrast sensitivity testing in general and increase the accessibility of this technique for use by clinicians through implementation on a commercially-available device.

Implementation of a Comprehensive Anti-Racism Plan in an Academic Physical Therapy Department: An Administrative Case Report.

OBJECTIVE: Transforming the University of Southern California health care system requires that institutions and organizations position equity, diversity, inclusion (EDI), and anti-racism as central to their missions. The purpose of this administrative case report was to describe a systematic approach taken by an academic physical therapy department to develop a comprehensive antiracism plan that engages all interested and affected parties and includes processes for sustainable, long-term engagement. METHODS: Four strategies contributed to organizational change toward anti-racism: Holding Ourselves Accountable; Developing a Plan; Building Consensus; and Providing Education, Support, and Resources. The attitudes of faculty and staff about racism and anti-racist actions were assessed through surveys at the start of the process and after 1 year. Engagement in activities, meetings, and trainings related to EDI and anti-racism was logged for faculty and staff. RESULTS: From November 2020 through November 2021, several outcomes were achieved, including: making structural organizational changes; updating faculty merit review to include EDI; developing a bias reporting mechanism; establishing faculty development activities, resources, and groups; and implementing structured efforts to recruit a diverse cohort. Within that year, faculty and staff engaged in 99.32 hours of EDI and anti-racism trainings, workshops, and resource groups. Survey data showed persistent high support and commitment to EDI and anti-racism. Faculty and staff reported that they felt more equipped to identify and address individual and institutional racism and they reported risking their reputations to talk about race more often. Confidence in their ability to identify and resolve conflicts related to microaggressions, cultural insensitivity, and bias improved. However, their self-reported ability to identify and address structural racism remained unchanged. CONCLUSION: By approaching anti-racism as transformative rather than performative, an academic physical therapy department was able to develop and implement a comprehensive anti-racism plan with high support and engagement. IMPACT: The physical therapy profession has not been immune to racism and health injustice. Organizational change to become anti-racist is imperative for excellence and a necessary challenge to undertake if the physical therapy profession is to transform society and improve the human experience.

Frequency-domain analysis of transient visual evoked potentials in schizophrenia.

PURPOSE: Frequency-domain measures were applied to characterize neural deficits in individuals with schizophrenia using transient visual evoked potentials (tVEP). These measures were compared with conventional time-domain measures to elucidate underlying neurophysiological mechanisms and examine the value of frequency analysis. METHODS: Four frequency bands of activity identified in previous work were explored with respect to magnitude (spectral power), timing (phase), a combined measure, magnitude-squared coherence (MSC), and compared to amplitudes and times of prominent deflections in the response. RESULTS: Band 2 power/MSC (14-28 Hz) captured the major deflections in the waveform and its power predicted N75-P100 amplitude for patients and controls. Band 3 power/MSC (30-40 Hz) correlated highly with the earliest deflection (P60-N75), reflecting input to primary visual cortex (V1) and produced the largest magnitude effect. Phase of the 24th harmonic component predicted P100 peak time for patients and controls and yielded the largest group difference. Cluster analyses including time- and frequency-domain measures identified subgroups of patients with differential neurophysiological effects. A small but significant difference in visual acuity was found between groups that appears to be neurally based: Acuity (range 0.63-1.6) was not correlated with any tVEP measures in controls nor with input timing to V1 (P60 peak time) in patients, but was correlated with later tVEP measures in patients. All but two of the patients were on antipsychotic medication: Medication level (chlorpromazine equivalents) was correlated negatively with tVEP time measures and positively with certain magnitude measures yielding responses similar to controls at high levels. CONCLUSIONS: Overall, frequency-domain measures were shown to be objective and recommended as an alternative to conventional, subjective time-domain measures for analyzing tVEPs and in distinguishing between groups (patients vs. controls and patient subgroups). The findings implicated a loss of excitatory input to V1 in schizophrenia. Acuity as measured in the current study reflected disease status, and medication level was associated with improved tVEP responses. These novel tVEP techniques may be useful in revealing neurophysiological processes affected in schizophrenia and as a clinical tool.

Adaptive control is reversed between hands after left hemisphere stroke and lost following right hemisphere stroke.

Human motor adaptability is of utmost utility after neurologic injury such as unilateral stroke. For successful adaptive control of movements, the nervous system must learn to correctly identify the source of a movement error and predictively compensate for this error. The current understanding is that in bimanual tasks, this process is flexible such that errors are assigned to, and compensated for, by the limb that is more likely to produce those errors. Here, we tested the flexibility of the error assignment process in right-handed chronic stroke survivors using a bimanual reaching task in which the hands jointly controlled a single cursor. We predicted that the nondominant left hand in neurotypical adults and the paretic hand in chronic stroke survivors will be more responsible for cursor errors and will compensate more within a trial and learn more from trial to trial. We found that in neurotypical adults, the nondominant left hand does compensate more than the right hand within a trial but learns less trial-to-trial. After a left hemisphere stroke, the paretic right hand compensates more than the nonparetic left hand within-trial but learns less trial-to-trial. After a right hemisphere stroke, the paretic left hand neither corrects more within-trial nor learns more trial-to-trial. Thus, adaptive control of visually guided bimanual reaching movements is reversed between hands after the left hemisphere stroke and lost following the right hemisphere stroke. These results indicate that responsibility assignment is not fully flexible but depends on a central mechanism that is lateralized to the right hemisphere.

Reducing the Risk of Healthcare Associated Infections from Legionella and Other Waterborne Pathogens Using a Water Management for Construction (WMC) Infection Control Risk Assessment (ICRA) Tool.

Construction activities in healthcare settings potentially expose building occupants to waterborne pathogens including Legionella and have been associated with morbidity and mortality. A Water Management for Construction-Infection Control Risk Assessment (WMC-ICRA) tool was developed addressing gaps in building water management programs. This enables healthcare organizations to meet the requirements of ANSI/ASHRAE Standard 188 referenced in numerous guidelines and regulations. A WMC-ICRA was modeled after the ICRA required for prevention and control of airborne pathogens to reduce the risk of healthcare associated infections. The tool allows users to evaluate risk from waterborne pathogen exposure by analyzing construction activities by project category and building occupant risk group. The users then select an appropriate level of risk mitigation measures. Technical aspects (e.g., water age/stagnation, flushing, filtration, disinfection, validation testing), are presented to assist with implementation. An exemplar WMC-ICRA tool is presented as ready for implementation by infection prevention and allied professionals, addressing current gaps in water management, morbidity/mortality risk, and regulatory compliance. To reduce exposure to waterborne pathogens in healthcare settings and improve regulatory compliance, organizations should examine the WMC-ICRA tool, customize it for organization-specific needs, while formulating an organizational policy to implement during all construction activities.

Signals from Single-Opponent Cortical Cells in the Human cVEP.

We used the chromatic visual evoked potential (cVEP) to study responses in human visual cortex evoked by equiluminant color stimuli for 6 male and 11 female observers. Large-area, colored squares were used to stimulate Single-Opponent cells preferentially, and fine color-checkerboard stimuli were used to activate Double-Opponent responses preferentially. Stimuli were modulated along the following two directions in color space: (1) the cardinal direction, L-M or M-L of DKL (Derrington, Krauskopf, and Lennie) space; and (2) the line from the white point to the color of the Red LED in the display screen, which was approximately intermediate between the L-M and -S directions in DKL space in cone-contrast coordinates. The amplitudes of cVEPs to large squares were smaller than those to checkerboards, and the latency of the cVEP response to squares was significantly less than the checkerboard latency. The latency of cVEP responses to the squares varied little with cone-contrast unlike the steep reduction of latency with cone-contrast observed in responses to color checkerboard patterns. The dynamic differences between cVEPs to squares and checkerboards support the hypothesis that a distinct neuronal mechanism responded to squares: Single-Opponent cells. Response amplitude, latency, and transientness-and their dependence on cone-contrast-were similar in the responses in the L-M and Red color directions. The similarity supports the hypothesis that the Single-Opponent signals in the cVEP come from a distinct population of cells that receives subtractive inputs from L and M cones, either L-M or M-L.SIGNIFICANCE STATEMENT This article is about characterizing the visual behavior of a distinct population of neurons in the human visual cortex, the Single-Opponent color cells. Based on single-cell results in the visual cortex of macaque monkeys, we used large uniformly colored stimuli to isolate the responses of Single-Opponent cells in the chromatic visual evoked potential (cVEP) recorded on the scalp of human observers. VEP signals recorded under conditions believed to reveal Single-Opponent responses are small and transient. Their time course is relatively unaffected by cone-contrast, and they are relatively insensitive to stimulus modulation of short wavelength-sensitive S cones. Because Single-Opponent cells convey signals that can be used to judge the color of scene illumination, knowing their visual properties is important for understanding color vision.

Discovery of a Novel Class of d-Amino Acid Oxidase Inhibitors Using the Schrödinger Computational Platform.

d-Serine is a coagonist of the N-methyl d-aspartate (NMDA) receptor, a key excitatory neurotransmitter receptor. In the brain, d-serine is synthesized from its l-isomer by serine racemase and is metabolized by the D-amino acid oxidase (DAO, DAAO). Many studies have linked decreased d-serine concentration and/or increased DAO expression and enzyme activity to NMDA dysfunction and schizophrenia. Thus, it is feasible to employ DAO inhibitors for the treatment of schizophrenia and other indications. Powered by the Schrödinger computational modeling platform, we initiated a research program to identify novel DAO inhibitors with the best-in-class properties. The program execution leveraged an hDAO FEP+ model to prospectively predict compound potency. A new class of DAO inhibitors with desirable properties has been discovered from this endeavor. Our modeling technology on this program has not only enhanced the efficiency of structure-activity relationship development but also helped to identify a previously unexplored subpocket for further optimization.

Mind-body skills groups for treatment of war-traumatized veterans: A randomized controlled study.

OBJECTIVE: This study evaluated the effects of a mind-body skills group (MBSG) intervention on posttraumatic stress disorder (PTSD) symptoms. METHOD: Veterans (n = 108; mean age = 55.97 [SD = 11.72]; 96% male) at a PTSD specialty clinic in the Veterans Affairs Health Care System were randomized to a 10-week MBSG program or standard treatment. PTSD was the primary outcome measure. Secondary outcomes included anger, sleep, depression, anxiety, posttraumatic growth, and health-related quality of life. RESULTS: MBSG participants had significantly greater improvement in the total PTSD score after 10 weeks compared to the standard treatment group. Hyperarousal and avoidance scores significantly improved at 10 weeks and improvements in the hyperarousal symptoms were maintained at 2-month follow-up. MBSG participants also had significant decreases in anger and sleep disturbance. There were no significant differences in the other secondary outcomes. CONCLUSIONS: This MBSG intervention offers promise in helping Veterans with PTSD and its related symptoms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Visual Evoked Potential Abnormalities in Phelan-McDermid Syndrome.

OBJECTIVE: The current study used visual evoked potentials (VEPs) to examine excitatory and inhibitory postsynaptic activity in children with Phelan-McDermid syndrome (PMS) and the association with genetic factors. PMS is caused by haploinsufficiency of SHANK3 on chromosome 22 and represents a common single-gene cause of autism spectrum disorder (ASD) and intellectual disability. METHOD: Transient VEPs were obtained from 175 children, including 31 with PMS, 79 with idiopathic ASD, 45 typically developing controls, and 20 unaffected siblings of children with PMS. Stimuli included standard and short-duration contrast-reversing checkerboard conditions, and the reliability between these 2 conditions was assessed. Test-retest reliability and correlations with deletion size were explored in the group with PMS. RESULTS: Children with PMS and, to a lesser extent, those with idiopathic ASD displayed significantly smaller amplitudes and decreased beta and gamma band activity relative to TD controls and PMS siblings. Across groups, high intraclass correlation coefficients were obtained between standard and short-duration conditions. In children with PMS, test-retest reliability was strong. Deletion size was significantly correlated with P60-N75 amplitude for both conditions. CONCLUSION: Children with PMS displayed distinct transient VEP waveform abnormalities in both time and frequency domains that might reflect underlying glutamatergic deficits that were associated with deletion size. A similar response pattern was observed in a subset of children with idiopathic ASD. VEPs offer a noninvasive measure of excitatory and inhibitory neurotransmission that holds promise for stratification and surrogate endpoints in ongoing clinical trials in PMS and ASD.

Association of Simulation Participation With Diagnostic Reasoning Scores in Preclinical Students.

PURPOSE: The aim of the study was to evaluate for an association between the number of voluntary mannequin simulation sessions completed during the school year with scores on a year-end diagnostic reasoning assessment among second-year medical students. METHOD: This is retrospective analysis of participation in 0 to 8 extracurricular mannequin simulation sessions on diagnostic reasoning assessed among 129 second-year medical students in an end-of-year evaluation. For the final skills assessment, 2 physicians measured students' ability to reason through a standardized case encounter using the Diagnostic Justification (DXJ) instrument (4 categories each scored 0-3 by raters reviewing students' postencounter written summaries). Rater scores were averaged for a total DXJ score (0-12). To provide additional baseline comparison, zero participation students were divided into 2 groups based on intent to participate: those who signed up for extracurricular sessions but never attended versus those who never expressed interest. Scores across the attendance groups were compared with an analysis of variance and trend analysis. RESULTS: The class DXJ mean equaled 7.56, with a standard deviation of 2.78 and range of 0 to 12. Post hoc analysis after a significant analysis of variance (F = 4.91, df = 8, 128, P < 0.001) showed those participating in 1 or more extracurricular sessions had significantly higher DXJ scores than those not participating. Students doing 7 extracurricular sessions had significantly higher DXJ scores than those doing 0 and 2 (P < 0.05). Zero attendance groups were not different. A significant linear trend (R = 0.48, F = 38.0, df = 1, 127, P < 0.001) was found with 9 groups. A significant quadratic effect, like a dose-response pattern, was found (F = 18.1, df = 2, 125, P < 0.001) in an analysis including both zero attendance groups, a low (1-4 extracurricular sessions) group and a high (5-8) group. CONCLUSIONS: Higher year-end diagnostic reasoning scores were associated with increased voluntary participation in extracurricular mannequin-based simulation exercises in an approximate dose-response pattern.

Objective frequency analysis of transient visual evoked potentials in autistic children.

Visual evoked potentials (VEPs) provide a means to examine neural mechanisms in autism with high temporal resolution. Conventional VEP analysis relies on subjective inspection of a few points (peaks and troughs) in the time-domain waveform. The current study applied power spectral analysis and magnitude-squared coherence (MSC) statistics (frequency-domain measures) to VEPs recorded during 1-minute runs and with a recently developed short-duration technique that allow for objective examination of the responses (Zemon & Gordon, European Journal of Neuroscience, 2018, 48, 1765-1788) from nonautistic and autistic children. Results indicate that, for both groups, early time-domain measures (P60 , N75 , P100 ) are highly correlated with middle- and high-frequency (14-28 and 30-48 Hz, respectively) mechanisms, and late measures are highly correlated with a low-frequency (6-12 Hz) mechanism. One frequency-domain measure (power in the middle-frequency band) is capable of predicting the key amplitude measure (N75 -P100 ) with high accuracy. MSC and power measures were combined to yield separate measures of signal and noise strength to evaluate alternate hypotheses in autism. Linear mixed-effects modeling demonstrated selective differences in early time-domain and middle-to-high frequency-domain measures in autistic children as compared to nonautistic children given both recording techniques, implicating weaker excitatory input to the cortex. Receiver-operating-characteristic curve analysis showed predictive diagnostic accuracy for middle- and high-frequency bands based on MSC. These findings support the value of frequency analysis measures (power spectral analysis and MSC) in the objective examination of neural differences in autism. LAY SUMMARY: Visual evoked potentials (VEPs) are used to assess neural mechanisms. Typically, VEPs are analyzed by subjective examination of time-series waveforms; but here objective techniques were applied to quantify VEP frequency components to investigate neural differences between autistic and nonautistic children. The objective measures demonstrate group differences in brain function that point to weaker excitatory input to the cortex in autism.

Updates in Motor Learning: Implications for Physical Therapist Practice and Education.

Over the past 3 decades, the volume of human motor learning research has grown enormously. As such, the understanding of motor learning (ie, sustained change in motor behavior) has evolved. It has been learned that there are multiple mechanisms through which motor learning occurs, each with distinctive features. These mechanisms include use-dependent, instructive, reinforcement, and sensorimotor adaptation-based motor learning. It is now understood that these different motor learning mechanisms contribute in parallel or in isolation to drive desired changes in movement, and each mechanism is thought to be governed by distinct neural substrates. This expanded understanding of motor learning mechanisms has important implications for physical therapy. It has the potential to facilitate the development of new, more precise treatment approaches that physical therapists can leverage to improve human movement. This Perspective describes scientific advancements related to human motor learning mechanisms and discusses the practical implications of this work for physical therapist practice and education.

A randomized controlled study of convalescent plasma for individuals hospitalized with COVID-19 pneumonia.

BackgroundAntibody-based strategies for COVID-19 have shown promise in prevention and treatment of early disease. COVID-19 convalescent plasma (CCP) has been widely used but results from randomized trials supporting its benefit in hospitalized patients with pneumonia are limited. Here, we assess the efficacy of CCP in severely ill, hospitalized adults with COVID-19 pneumonia.MethodsWe performed a randomized control trial (PennCCP2), with 80 adults hospitalized with COVID-19 pneumonia, comparing up to 2 units of locally sourced CCP plus standard care versus standard care alone. The primary efficacy endpoint was comparison of a clinical severity score. Key secondary outcomes include 14- and 28-day mortality, 14- and 28-day maximum 8-point WHO ordinal score (WHO8) score, duration of supplemental oxygenation or mechanical ventilation, respiratory SARS-CoV-2 RNA, and anti-SARS-CoV-2 antibodies.ResultsEighty hospitalized adults with confirmed COVID-19 pneumonia were enrolled at median day 6 of symptoms and day 1 of hospitalization; 60% were anti-SARS-CoV-2 antibody seronegative. Participants had a median of 3 comorbidities, including risk factors for severe COVID-19 and immunosuppression. CCP treatment was safe and conferred significant benefit by clinical severity score (median [MED] and interquartile range [IQR] 10 [5.5-30] vs. 7 [2.75-12.25], P = 0.037) and 28-day mortality (n = 10, 26% vs. n = 2, 5%; P = 0.013). All other prespecified outcome measures showed weak evidence toward benefit of CCP.ConclusionTwo units of locally sourced CCP administered early in hospitalization to majority seronegative participants conferred a significant benefit in clinical severity score and 28-day mortality. Results suggest CCP may benefit select populations, especially those with comorbidities who are treated early.Trial RegistrationClinicalTrials.gov NCT04397757.FundingUniversity of Pennsylvania.

Transforming Trauma With Lifestyle Medicine.

A common misconception is that trauma-"injury" to the mind, body, and spirit-comes only to those individuals who have experienced threats of death, sexual violence, or serious injury. The SARS-CoV-2 (COVID-19) and the widespread disruption, anxiety, and stress it has left in its wake have shown us that this is not the case; trauma is universal. Left unaddressed, trauma can have long-term physical and psychological consequences. It appears that the consequences of trauma can also be transmitted from generation to generation through modifications in the DNA of the exposed individual that alter the function of one or more genes. Meditation and other practical, evidence-based mind-body skills can reverse what has been damaged by traumatic events and long-term stress. The Center for Mind-Body Medicine (CMBM), established in 1991, has developed a comprehensive, innovative, and evidence-based model that has been used by diverse populations to heal psychological trauma and promote resilience. Comprehensive, easily available programs of self-care and group support, such as The CMBM's Mind-Body Skills Group Model, can ensure that children and adults everywhere have the psychological skills they need to address the trauma of the COVID-19 pandemic.

Cognitive function mediates the relationship between visual contrast sensitivity and functional outcome in schizophrenia.

BACKGROUND: Individuals with schizophrenia exhibit deficits in visual contrast processing, though less is known about how these deficits impact neurocognition and functional outcomes. This study investigated effects of contrast sensitivity (CS) on cognition and capacity for independent living in schizophrenia. METHODS: Participants were 58 patients with schizophrenia (n = 49) and schizoaffective disorder (n = 9). Patients completed a psychophysical paradigm to obtain CS with stimuli consisting of grating patterns of low (0.5 and 1 cycles/degree) and high spatial frequencies (4, 7, 21 cycles/degree). Patients completed the MATRICS Consensus Cognitive Battery and Wechsler Adult Intelligence Scales, Third Edition to assess cognition, and the problem-solving factor of the Independent Living Scales to assess functional capacity. We computed bivariate correlation coefficients for all pairs of variables and tested mediation models with CS to low (CS-LSF) and high spatial frequencies (CS-HSF) as predictors, cognitive measures as mediators, and capacity for independent living as an outcome. RESULTS: Cognition mediated the relationship between CS and independent living with CS-LSF a stronger predictor than CS-HSF. Mediation effects were strongest for perceptual organization and memory-related domains. In an expanded moderated mediation model, CS-HSF was found to be a significant predictor of independent living through perceptual organization as a mediator and CS-LSF as a moderator of this relationship. CONCLUSION: CS relates to functional capacity in schizophrenia through neurocognition. These relationships may inform novel visual remediation interventions.

Do adolescents consider mind-body skills groups an acceptable treatment for depression: results from a pilot study.

BACKGROUND: Mind-Body Skills Groups (MBSGs) have shown promise in reducing adolescent depression symptoms; however, little is known about adolescents' perspectives on this treatment. The objective of this study was to understand the acceptability of a new treatment for depressed adolescents in primary care settings. METHODS: Adolescents participating in a 10-week MBSG treatment were interviewed to understand their perspectives on the acceptability and effectiveness of the treatment. Interviews were collected at post-intervention and at a 3-month follow-up visit. RESULTS: A total of 39 adolescents completed both the post-intervention and 3-month follow-up interview. At post-intervention and follow-up, 84% of adolescents stated the MBSGs helped them. When asked how the MBSGs helped them, 3 areas were identified: learning new MBSG activities and skills, social connection with others within the group, and outcomes related to the group. Many adolescents reported no concerns with the MBSGs (49% at post- intervention; 62% at follow-up). Those with concerns identified certain activities as not being useful, wanting the group to be longer, and the time of group (after school) being inconvenient. Most adolescents reported that their life had changed because of the group (72% at post-intervention; 61% at follow-up), and when asked how, common responses included feeling less isolated and more hopeful. CONCLUSIONS: Adolescents found the MBSGs to be helpful and acceptable as a treatment option for depression in primary care. Given the strong emphasis on treatment preference autonomy and the social activities within the group, MBSGs appear well-suited for this age group. TRIAL REGISTRATION: NCT03363750 ; December 6th, 2017.