Interpersonal Musical Synchronization and Prosocial Behavior in Children: No Effects in a Controlled Field Experiment

Prosocial effects of music have recently attracted increased attention in research and media. An often-cited experiment, carried out by Kirschner and Tomasello in 2010 under laboratory conditions, found that children at the age of four years were more willing to help each other after they had engaged in synchronous musical activities. The aim of the current study was to replicate this research under controlled field conditions in the children's social environment, and to disentangle the musical synchronization effect by introducing a verbal interaction (singing together) and a motor interaction (tapping together) task, contrasted by an asynchronous control condition. In a between-participants design, no effects of musical synchronization nor the children's gender were found. Furthermore, age was not related to prosocial behavior. Explanations are systematically discussed, yet it remains possible that the original effect found in 2010 might be overestimated and less consistently reproducible as previously assumed.

Hypothesis awareness confounds asynchronous control conditions in indirect measures of the rubber hand illusion

Reports of changes in experiences of body location and ownership following synchronous tactile and visual stimulation of fake and real hands (rubber hand (RH) effects) are widely attributed to multisensory integration mechanisms. However, existing control methods for subjective report measures (asynchronous stroking and control statements) are confounded by participant hypothesis awareness; the report may reflect response to demand characteristics. Subjective report is often accompanied by indirect (also called ‘objective’ or ‘implicit’) measures. Here, we report tests of expectancies for synchronous ‘illusion’ and asynchronous ‘control’ conditions across two pre-registered studies ( n = 140 and n = 45) for two indirect measures: proprioceptive drift (a change in perceived hand location) and skin conductance response (a measure of physiological arousal). Expectancies for synchronous condition measures were greater than for asynchronous conditions in both studies. Differences between synchronous and asynchronous control condition measures are therefore confounded by hypothesis awareness. This means indirect measures of RH effects may reflect compliance, bias and phenomenological control in response to demand characteristics, just as for subjective measures. Valid control measures are required to support claims of a role of multisensory integration for both direct and indirect measures of RH effects.

Virtual reality exercise to help COVID patients with refractory breathlessness

Background: Immersive virtual reality (iVR)-based digital therapeutics (DTx) are gaining clinical attention in the field of pain management. Based on known analogy between chronic pain and dyspnea, we investigated the effects of visual respiratory feedback in iVR, on refractory breathlessness in patients recovering from severe COVID-19 pneumonia. Methods: We performed a controlled, randomized, single-blind, cross-over clinical study to evaluate an iVR-based intervention to alleviate refractory breathlessness in patients recovering from COVID-19 pneumonia. The single-site study was conducted at the university hospital of Geneva, Switzerland. Patients reported refractory breathlessness (≥5 on a 10-point dyspnea scale) and had a MoCA score of ≥24. Cross-over groups were randomly assigned, concealed from the referring clinician. Participants received synchronous (intervention) or asynchronous (control) feedback of their breathing, embodied via a gender-matched avatar in iVR. Prior to the first exposure and following both experimental conditions, patients completed questionnaires. Breathing patterns were captured continuously. The COVVR clinical study is registered with ClinicalTrials.gov (NCT04844567) and is now closed. Findings: Study enrollment was open between November 2020 and April 2021. A total of 26 patients (27% women; age: mean=57, SD±12) were enrolled; 14 patients were randomly assigned to the ″synchronous/asynchronous″ sequence, 12 to the ″asynchronous/synchronous″ sequence. Data was available for all except two (7.7%) of 26 patients. The mean rating of breathing comfort was 0.1 at baseline, 0.8±1.8 for asynchronous, and 1.3±1.4 synchronous feedback (estimated difference of 0.5 (95%CI 0.05 to 1.04; p<0.05) between iVR conditions). Of all patients, 91.2% were satisfied with the intervention (1.8±1.6, t=5.201, p<0.0001, 95%CI 1.173 to inf) and 66.7% perceived it as beneficial for their breathing (0.7±1.9, t=1.806, p<0.05, 95%CI 0.036 to inf). No adverse events were reported. Interpretation: Based on these findings, we propose that our iVR-based DTx is a feasible and safe neuro-rehabilitation tool that improves breathing comfort in patients recovering from severe COVID-19 infection. More research is needed to generalize this tool in other groups of patients suffering from refractory breathlessness.

A multiple convex Lyapunov function for asynchronous control of discrete-time switched systems

In this paper, the problem of asynchronous control for a class of discrete-time switched systems is investigated under mode-dependent integrated dwell time (MDIDT) switching. By constructing a time-dependent convex function, a multiple convex Lyapunov function (MCLF) is firstly proposed for the asynchronous control of the switched systems. Under the MDIDT switching strategy, the matching interval is divided reasonably, and the convex function combination is constructed on the partitioned interval. Under asynchronous switching, the Lyapunov function is continuous when the subsystem mode is switched, but discrete when the controller mode is changed. Then, the increase of the Lyapunov function in the mismatched interval will be offset by the attenuation in the matched interval. In light of these merits, the stability results of the system are deduced, and the asynchronous controller is devised to guarantee the globally uniformly exponentially stability of the closed-loop system. Comparing with the traditional asynchronous control methods, the proposed method has less conservative results and larger stability regions. Finally, a numerical example and an application example are demonstrated to verify the validity and superiority of the asynchronous control scheme.