The Message Design Logics of Responses to HIV Disclosures

This article uses the theory of message design logics to investigate the relative sophistication of responses to disclosure of HIV status. In Study 1, 548 college students imagined a sibling revealing an HIV-positive diagnosis. Their responses to the HIV disclosures were coded as expressive (n= 174), conventional (n= 298), or rhetorical (n= 66). Type of message produced was associated with gender and HIV aversion. In Study 2, 459 individuals living with HIV rated response messages that were taken verbatim from Study 1. Expressive messages were rated lowest in quality, and rhetorical messages were rated highest. The discussion focuses on the utility of message design logics for understanding responses to HIV disclosures and the implications for message design logics

Practice Makes Imperfect: Restorative Effects of Sleep on Motor Learning

Emerging evidence suggests that sleep plays a key role in procedural learning, particularly in the continued development of motor skill learning following initial acquisition. We argue that a detailed examination of the time course of performance across sleep on the finger-tapping task, established as the paradigm for studying the effect of sleep on motor learning, will help distinguish a restorative role of sleep in motor skill learning from a proactive one. Healthy subjects rehearsed for 12 trials and, following a night of sleep, were tested. Early training rapidly improved speed as well as accuracy on pre-sleep training. Additional rehearsal caused a marked slow-down in further improvement or partial reversal in performance to observed levels below theoretical upper limits derived on the basis of early pre-sleep rehearsal. This decrement in learning efficacy does not occur always, but if and only if it does, overnight sleep has an effect in fully or partly restoring the efficacy and actual performance to the optimal theoretically achieveable level. Our findings re-interpret the sleep-dependent memory enhancement in motor learning reported in the literature as a restoration of fatigued circuitry specialized for the skill. In providing restitution to the fatigued brain, sleep eliminates the rehearsal-induced synaptic fatigue of the circuitry specialized for the task and restores the benefit of early pre-sleep rehearsal. The present findings lend support to the notion that latent sleep-dependent enhancement of performance is a behavioral expression of the brain's restitution in sleep

The Responsiveness of Migration to Labor Market Conditions

This dissertation explores how migration responds to economic conditions, particularly differences in responsiveness for various segments of the population. After a brief introduction and motivation of my work in Chapter One, Chapter Two estimates the responsiveness of households’ interstate migration to origin state labor market conditions and surrounding state labor market conditions. Each percentage point increase in origin state unemployment insurance claims leads to a 3.2 percent increase in household’s propensity to migrate interstate and each percentage point increase in the unemployment insurance claims rate of surrounding states reduces interstate migration propensity by 5.2 percent. I then examine how this responsiveness varies by demographics and how it has changed over time. I determine that the responsiveness of migration to labor market conditions is weaker for several groups at high poverty risk, including less educated, non-employed and rural households and households with children present. I also show that between the early 1980s and mid 1990s labor market conditions became a smaller factor in household migration decisions, but since then labor market conditions have gained in importance. While Chapter Two examines short-run migration responsiveness, Chapter Three explores the size of the long-run outflow (or inflow) of skilled labor occurring in local areas in response to economic conditions, amenities and other area characteristics. I estimate the extent of this brain gain and brain drain within localities in the United States between the early 1990s and late 2000s, describing both absolute changes (percentage growth in the stock of educated individuals) and relative changes (growth in the share of educated individuals). For each of three measures of brain gain estimated, I show substantially more positive flows of educated individuals towards local areas with strong initial economic conditions. I also show that non-metropolitan areas are more likely to experience all three measures of brain drain. I present evidence that nonmetropolitan areas’ inability to attract and retain educated individuals stems primarily from labor market disparities including the urban-rural wage differential

Expressions of Multiple Neuronal Dynamics during Sensorimotor Learning in the Motor Cortex of Behaving Monkeys

Previous studies support the notion that sensorimotor learning involves multiple processes. We investigated the neuronal basis of these processes by recording single-unit activity in motor cortex of non-human primates (Macaca fascicularis), during adaptation to force-field perturbations. Perturbed trials (reaching to one direction) were practiced along with unperturbed trials (to other directions). The number of perturbed trials relative to the unperturbed ones was either low or high, in two separate practice schedules. Unsurprisingly, practice under high-rate resulted in faster learning with more pronounced generalization, as compared to the low-rate practice. However, generalization and retention of behavioral and neuronal effects following practice in high-rate were less stable; namely, the faster learning was forgotten faster. We examined two subgroups of cells and showed that, during learning, the changes in firing-rate in one subgroup depended on the number of practiced trials, but not on time. In contrast, changes in the second subgroup depended on time and practice; the changes in firing-rate, following the same number of perturbed trials, were larger under high-rate than low-rate learning. After learning, the neuronal changes gradually decayed. In the first subgroup, the decay pace did not depend on the practice rate, whereas in the second subgroup, the decay pace was greater following high-rate practice. This group shows neuronal representation that mirrors the behavioral performance, evolving faster but also decaying faster at learning under high-rate, as compared to low-rate. The results suggest that the stability of a new learned skill and its neuronal representation are affected by the acquisition schedule.United States-Israel Binational Science FoundationIsrael Science FoundationIda Baruch FundRosetrees Trus

Adaptive tuning functions arise from visual observation of past movement

Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality

Using Information to Manage Uncertainty During Organ Transplantation

People living with a chronic illness can experience uncertainty about their physical conditions, identities, and relationships. One way individuals cope with this uncertainty is through managing information related to their illness. We conducted in-depth interviews with 38 pretransplant and posttransplant patients and analyzed the transcripts using grounded theory techniques. Participants reported that they managed their uncertainty related to transplantation by seeking and avoiding specific information and by strategically handling personal and social information. Participants also described a number of challenges associated with their information use. We discuss the theoretical implications of these findings for literature on information management, uncertainty in illness, and organ transplantation. In addition, we highlight practical implications for medical professionals as well as transplant patients and their loved ones, and we suggest that future research might usefully address what role uncertainty appraisal plays for people coping with chronic illness.</jats:p

Attention modulates adaptive motor learning in the ‘broken escalator’ paradigm

The physical stumble caused by stepping onto a stationary (broken) escalator represents a locomotor aftereffect (LAE) that attests to a process of adaptive motor learning. Whether such learning is primarily explicit (requiring attention resources) or implicit (independent of attention) is unknown. To address this question, we diverted attention in the adaptation (MOVING) and aftereffect (AFTER) phases of the LAE by loading these phases with a secondary cognitive task (sequential naming of a vegetable, fruit and a colour). Thirty-six healthy adults were randomly assigned to 3 equally sized groups. They performed 5 trials stepping onto a stationary sled (BEFORE), 5 with the sled moving (MOVING) and 5 with the sled stationary again (AFTER). A 'Dual-Task-MOVING (DTM)' group performed the dual-task in the MOVING phase and the 'Dual-Task-AFTEREFFECT (DTAE)' group in the AFTER phase. The 'control' group performed no dual task. We recorded trunk displacement, gait velocity and gastrocnemius muscle EMG of the left (leading) leg. The DTM, but not the DTAE group, had larger trunk displacement during the MOVING phase, and a smaller trunk displacement aftereffect compared with controls. Gait velocity was unaffected by the secondary cognitive task in either group. Thus, adaptive locomotor learning involves explicit learning, whereas the expression of the aftereffect is automatic (implicit). During rehabilitation, patients should be actively encouraged to maintain maximal attention when learning new or challenging locomotor tasks

Proprioceptive loss and the perception, control and learning of arm movements in humans: evidence from sensory neuronopathy

© 2018 The Author(s) It is uncertain how vision and proprioception contribute to adaptation of voluntary arm movements. In normal participants, adaptation to imposed forces is possible with or without vision, suggesting that proprioception is sufficient; in participants with proprioceptive loss (PL), adaptation is possible with visual feedback, suggesting that proprioception is unnecessary. In experiment 1 adaptation to, and retention of, perturbing forces were evaluated in three chronically deafferented participants. They made rapid reaching movements to move a cursor toward a visual target, and a planar robot arm applied orthogonal velocity-dependent forces. Trial-by-trial error correction was observed in all participants. Such adaptation has been characterized with a dual-rate model: a fast process that learns quickly, but retains poorly and a slow process that learns slowly and retains well. Experiment 2 showed that the PL participants had large individual differences in learning and retention rates compared to normal controls. Experiment 3 tested participants’ perception of applied forces. With visual feedback, the PL participants could report the perturbation’s direction as well as controls; without visual feedback, thresholds were elevated. Experiment 4 showed, in healthy participants, that force direction could be estimated from head motion, at levels close to the no-vision threshold for the PL participants. Our results show that proprioceptive loss influences perception, motor control and adaptation but that proprioception from the moving limb is not essential for adaptation to, or detection of, force fields. The differences in learning and retention seen between the three deafferented participants suggest that they achieve these tasks in idiosyncratic ways after proprioceptive loss, possibly integrating visual and vestibular information with individual cognitive strategies

Interactive acquisition and sharing: Understanding the dynamics of HIV/AIDS information networks

HIV/AIDS information is an important resource for people affected by the disease, particularly information that they obtain from other people. Although existing studies reveal that people with HIV/AIDS (PHAs) rely extensively on personal relationships for HIV/AIDS information, they explain little about how this happens as a social process. To investigate how PHAs and their friends/family members acquire and share network-mediated HIV/AIDS information, semistructured, in-depth interviews were conducted in three rural regions of Canada. Interviews were carried out with 114 PHAs, their friends/family members, and health care and service providers. A network solicitation and chain-referral recruitment procedure was used to delineate HIV/AIDS information networks for participants. Interview data were analyzed qualitatively and compared to Haythornthwaite's ( 1996 ) concepts of network-mediated information processes and Talja and Hansen's ( 2006 ) collaborative information behavior framework. Findings revealed that participants obtained HIV/AIDS information from their networks through five interactive processes: joint seeking, tag-team seeking, exposure, opportunity, and legitimation. The results of this study advance information behavior theory by pointing to the interactive character of information behavior and introducing new concepts to describe everyday life collaborative information behavior. This research also demonstrates the extensive interplay between health information exchange and the sharing of emotional support. The insights emanating from this study suggest that health information practice might benefit from a focus on program strategies such as building information network capacity, developing collaborative information retrieval systems and relationship-building, in addition to the more traditional library-related concerns of reference encounters, collections, and institutional Web sites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64304/1/21151_ftp.pd

Effect of Deutetrabenazine on Chorea Among Patients With Huntington Disease A Randomized Clinical Trial

Importance Deutetrabenazine is a novel molecule containing deuterium, which attenuates CYP2D6 metabolism and increases active metabolite half-lives and may therefore lead to stable systemic exposure while preserving key pharmacological activity. Objective To evaluate efficacy and safety of deutetrabenazine treatment to control chorea associated with Huntington disease. Design, Setting, and Participants Ninety ambulatory adults diagnosed with manifest Huntington disease and a baseline total maximal chorea score of 8 or higher (range, 0-28; lower score indicates less chorea) were enrolled from August 2013 to August 2014 and randomized to receive deutetrabenazine (n = 45) or placebo (n = 45) in a double-blind fashion at 34 Huntington Study Group sites. Interventions Deutetrabenazine or placebo was titrated to optimal dose level over 8 weeks and maintained for 4 weeks, followed by a 1-week washout. Main Outcomes and Measures Primary end point was the total maximal chorea score change from baseline (the average of values from the screening and day-0 visits) to maintenance therapy (the average of values from the week 9 and 12 visits) obtained by in-person visits. This study was designed to detect a 2.7-unit treatment difference in scores. The secondary end points, assessed hierarchically, were the proportion of patients who achieved treatment success on the Patient Global Impression of Change (PGIC) and on the Clinical Global Impression of Change (CGIC), the change in 36-Item Short Form– physical functioning subscale score (SF-36), and the change in the Berg Balance Test. Results Ninety patients with Huntington disease (mean age, 53.7 years; 40 women [44.4%]) were enrolled. In the deutetrabenazine group, the mean total maximal chorea scores improved from 12.1 (95% CI, 11.2-12.9) to 7.7 (95% CI, 6.5-8.9), whereas in the placebo group, scores improved from 13.2 (95% CI, 12.2-14.3) to 11.3 (95% CI, 10.0-12.5); the mean between-group difference was –2.5 units (95% CI, –3.7 to –1.3) (P < .001). Treatment success, as measured by the PGIC, occurred in 23 patients (51%) in the deutetrabenazine group vs 9 (20%) in the placebo group (P = .002). As measured by the CGIC, treatment success occurred in 19 patients (42%) in the deutetrabenazine group vs 6 (13%) in the placebo group (P = .002). In the deutetrabenazine group, the mean SF-36 physical functioning subscale scores decreased from 47.5 (95% CI, 44.3-50.8) to 47.4 (44.3-50.5), whereas in the placebo group, scores decreased from 43.2 (95% CI, 40.2-46.3) to 39.9 (95% CI, 36.2-43.6), for a treatment benefit of 4.3 (95% CI, 0.4 to 8.3) (P = .03). There was no difference between groups (mean difference of 1.0 unit; 95% CI, –0.3 to 2.3; P = .14), for improvement in the Berg Balance Test, which improved by 2.2 units (95% CI, 1.3-3.1) in the deutetrabenazine group and by 1.3 units (95% CI, 0.4-2.2) in the placebo group. Adverse event rates were similar for deutetrabenazine and placebo, including depression, anxiety, and akathisia. Conclusions and Relevance Among patients with chorea associated with Huntington disease, the use of deutetrabenazine compared with placebo resulted in improved motor signs at 12 weeks. Further research is needed to assess the clinical importance of the effect size and to determine longer-term efficacy and safety