Visual contribution to human standing balance during support surface tilts

Visual position and velocity cues improve human standing balance, reducing sway responses to external disturbances and sway variability. Previous work suggested that human balancing is based on sensory estimates of external disturbances and their compensation using feedback mechanisms (Disturbance Estimation and Compensation, DEC model). This study investigates the visual effects on sway responses to pseudo-random support surface tilts, assuming that improvements result from lowering the velocity threshold in a tilt estimate and the position threshold in an estimate of the gravity disturbance. Center of mass (COM) sway was measured with four different tilt amplitudes, separating the effect of visual cues across the conditions ‘Eyes closed’ (no visual cues), ‘4 Hz stroboscopic illumination’ (visual position cues), and ‘continuous illumination’ (visual position and velocity cues). In a model based approach, parameters of disturbance estimators were identified. The model reproduced experimental results and showed a specific reduction of the position and velocity threshold when adding visual position and velocity cues, respectively. Sway variability was analyzed to explore a hypothesized relation between estimator thresholds and internal noise. Results suggest that adding the visual cues reduces the contribution of vestibular noise, thereby reducing sway variability and allowing for lower thresholds, which improves the disturbance compensation.     

Synthesis of asymmetric movement trajectories in timed rhythmic behaviour by means of frequency modulation

Results from different empirical investigations on gestural aspects of timed rhythmic movements indicate that the production of asymmetric movement trajectories is a feature that seems to be a common characteristic of various performances of repetitive rhythmic patterns. The behavioural or neural origin of these asymmetrical trajectories is, however, not identified. In the present study we outline a theoretical model that is capable of producing syntheses of asymmetric movement trajectories documented in empirical investigations by Balasubramaniam et al. (2004). Characteristic qualities of the extension/flexion profiles in the observed asymmetric trajectories are reproduced, and we conduct an experiment similar to Balasubramaniam et al. (2004) to show that the empirically documented movement trajectories and our modelled approximations share the same spectral components. The model is based on an application of frequency modulated movements, and a theoretical interpretation offered by the model is to view paced rhythmic movements as a result of an unpaced movement being “stretched” and “compressed”, caused by the presence of a metronome. We discuss our model construction within the framework of event-based and emergent timing, and argue that a change between these timing modes might be reflected by the strength of the modulation in our model.     

Opinion Climates in Social Media: Blending Mass and Interpersonal Communication

Social media's capacity for users to generate, comment on, and forward content (including mass media messages) to other users has created new forms of mass interpersonal communication. These systems render observable processes underlying the formation of opinion climates. Five attributes of contemporary electronic opinion environments can alter the way users gauge, form, and express opinions on topics of public interest: the juxtaposition of mass media and user‐generated content, ideological homogeneity and heterogeneity of online networks, technical ease with which to express opinions, the reach of messages, and networked audiences. These attributes facilitate analysis of theoretical and empirical works from different scholarly traditions, suggesting lines of inquiry that can enrich the analysis of (public) opinion formation via current communication technologies.     

Cognition and Emotion,Volume 24, 2010, List of Contents

Effective emotion regulation is important for high-quality social functioning. Recent laboratory-based evidence suggests that mindfulness may enhance emotion regulation in socioemotional contexts; however, little is known about mindful emotion regulation during in vivo social interactions. In a study of romantic couples, we assessed each partner's mindfulness and top-down attentional efficiency (with an Emotional Go/No-Go task) prior to sampling emotions and perceived connection with others during day-to-day social interactions. Analyses revealed that mindfulness-related differences in top-down attentional efficiency on the Emotional Go/No-Go predicted positive emotion during daily social interactions. In turn, positive emotion and two additional indices of social emotion regulation each mediated the relation between actor mindfulness and perceived social connection. In corresponding analyses, neither trait reappraisal nor suppression use predicted the outcomes, and all mindfulness relations held controlling for these strategies. Findings support a framework for investigating mindfulness and higher-quality social functioning, for which mindful emotion regulation may be key.     

Volition in prospective Memory: Evidence against differences between free and fixed target events

Volition is the extent to which actions are generated as a result of internal states in contrast to responses to external conditions or dictated by external events. Delayed intentions about future action are stored in prospective memory until the intended action has to be formed at a later point in time. It is unknown how voluntary choice affects prospective memory. We compared the difference between freely chosen and fixed targets on the reaction times and task performance in the ongoing task and for the target stimuli in a prospective memory task. The task performance and the reaction time was modelled using a Bayesian hierarchical drift–diffusion model. The analysis showed no differences between self-chosen and fixed prospective memory cues on task responses. The result suggests that volition in choosing the cue to act upon or given a fixed cue does not make a difference for prospective memory task performance.     

Occupational Identity,Competence, and Environments Among Adults With and Without Attention Deficit Hyperactivity Disorder

Exploring occupational adaptation among adults with attention deficit hyperactivity disorder (ADHD) is essential due to associated occupational difficulties. Occupational Performance History Interview scales—identity, competence, and environments—were compared between 51 adults with and 50 without ADHD who participated in occupations. Internal and external resources supporting occupational participations were represented by the competence and environment scales, respectively. The group with ADHD reported fewer internal and external occupational resources compared to the group without ADHD, despite occupational identity similarities. Study findings suggest that occupational interventions aimed at increasing internal and external occupational resources may support occupational adaptation among adults with ADHD.