How does postural control in patients with functional motor disorders adapt to multitasking-based immersive virtual reality?

Background: Motor symptoms in functional motor disorders (FMDs) refer to involuntary, but learned, altered movement patterns associated with aberrant self-focus, sense of agency, and belief/expectations. These conditions commonly lead to impaired posture control, raising the likelihood of falls and disability. Utilizing visual and cognitive tasks to manipulate attentional focus, virtual reality (VR) integrated with posturography is a promising tool for exploring postural control disorders. Objectives: To investigate whether postural control can be adapted by manipulating attentional focus in a 3D immersive VR environment. Methods: We compared postural parameters in 17 FMDs patients and 19 age-matched healthy controls over a single session under four increasingly more complex and attention-demanding conditions: simple fixation task (1) in the real room and (2) in 3D VR room-like condition; complex fixation task in a 3D VR city-like condition (3) avoiding distractors and (4) counting them. Dual-task effect (DTE) measured the relative change in performance induced by the different attention-demanding conditions on postural parameters. Results: Patients reduced sway area and mediolateral center of pressure displacement velocity DTE compared to controls (all, P < 0.049), but only under condition 4. They also showed a significant reduction in the sway area DTE under condition 4 compared to condition 3 (P = 0.025). Conclusions: This study provides novel preliminary evidence for the value of a 3D immersive VR environment combined with different attention-demanding conditions in adapting postural control in patients with FMDs. As supported by quantitative and objective posturographic measures, our findings may inform interventions to explore FMDs pathophysiology

Ground surface temperature scenarios in complex high-mountain topography based on regional climate model results

Climate change can have severe impacts on the high-mountain cryosphere, such as instabilities in rock walls induced by thawing permafrost. Relating climate change scenarios produced from global climate models (GCMs) and regional climate models (RCMs) to complex high-mountain environments is a challenging task. The qualitative and quantitative impact of changes in climatic conditions on local to microscale ground surface temperature (GST) and the ground thermal regime is not readily apparent. This study assesses a possible range of changes in the GST (DGST) in complex mountain topography. To account for uncertainties associated with RCM output, a set of 12 different scenario climate time series (including 10 RCM-based and 2 incremental scenarios) was applied to the topography and energy balance (TEBAL) model to simulate average DGST for 36 different topographic situations. Variability of the simulated DGST is related primarily to the emission scenarios, the RCM, and the approach used to apply RCM results to the impact model. In terms of topography, significant influence on GST simulation was shown by aspect because it modifies the received amount of solar radiation at the surface. North faces showed higher sensitivity to the applied climate scenarios, while uncertainties are higher for south faces. On the basis of the results of this study, use of RCM-based scenarios is recommended for mountain permafrost impact studies, as opposed to incremental scenarios