Digitalized spiral drawing in Parkinson’s disease: A tool for evaluating beyond the written trace

One of the current scientific challenges is to propose novel tools and tasks designed to identify new motor biomarkers in Parkinson’s disease (PD). Among these, a focus has placed on drawing tasks. Independently from clinical ratings, this study aimed to evaluate the pen movement and holding in digitalized spiral drawing in individuals with PD without and with medical treatment and in healthy controls. A three-step data-driven analysis was conducted. First, the effects of spatial and temporal constraints on several variables were determined. Second, the relationship between handedness and dominance of PD symptoms was investigated for the most relevant variables. Finally, a third analysis was conducted to assess the occurrence of changes associated with PD. The first analysis revealed that the number of velocity peaks and pen altitude variations were the most relevant variables in spiral drawing for evaluating the effect of the disease and medication. The second analysis revealed that the effect of medication was present for the movement fluency only, when spirals with spatial constraints were produced at a spontaneous speed by the hand on the side of dominant PD signs. Finally, the third analysis showed that the effect of medication was greater at the beginning of drawing than at the end. Digitalized spiral drawing makes it possible to observe precisely when the kinematic changes related to the disease occur during the task. Such a simple and quick task might be of great relevance to contribute to the diagnosis and follow-up of PD.     

Is imagery better than reality? Performance in imagined dart throwing

We investigated whether deviations from optimal performance are predicted in motor imagery. In Experiment 1, novices and experts imagined and executed dart throws. In imagination, they reported the final position of the dart. Experts performed better than novices in execution and imagination. Distance to the target and bias were smaller in imagination than in execution. In Experiment 2, we dissociated the roles of feedback from proximal and distal action elements for predictions. Three groups of novices estimated the dart’s final position in imagination, in execution without visual feedback, or in execution with delayed visual feedback. Estimates did not differ significantly between groups, indicating that (the lack of) feedback did not influence predictions. Deviations from optimal performance were lower in estimated than in actual performance. In conclusion, although predictive mechanisms may be similar in imagination and execution, the full extent of deviation from optimal performance is not predicted.     

An examination of muscle force control in individuals with a functionally unstable ankle

Previous studies suggest that functional ankle instability (FAI) may be associated with deficits in the ability to sense muscle forces. We tested individuals with FAI to determine if they have reduced ability to control ankle muscle forces, which is a function of force sense. Our test was performed isometrically to minimize the involvement of joint position sense and kinesthesia. A FAI group and a control group were recruited to perform an ankle force control task using a platform-based ankle robot. They were asked to move a cursor to hit 24 targets as accurately and as fast as possible in a virtual maze. The cursor movement was based on the direction and magnitude of the forces applied to the robot. Participants underwent three conditions: pre-test (baseline), practice (skill acquisition), and post-test (post skill acquisition). The force control ability was quantified based on the accuracy performance during the task. The accuracy performance was negatively associated with the collision count of the cursor with the maze wall. The FAI group showed reduced ability to control ankle muscle forces compared to the control group in the pre-test condition, but the difference became non-significant in the post-test condition after practice. The change in performance before and after practice may be due to different degrees of reliance on force sense.     

Fractal properties and short-term correlations in motor control in cycling: influence of a cognitive challenge

Fluctuations in cyclic tasks periods is a known characteristic of human motor control. Specifically, long-range fractal fluctuations have been evidenced in the temporal structure of these variations in human locomotion and thought to be the outcome of a multicomponent physiologic system in which control is distributed across intricate cortical, spinal and neuromuscular regulation loops.Combined with long-range correlation analyses, short-range autocorrelations have proven their use to describe control distribution across central and motor components.We used relevant tools to characterize long- and short-range correlations in revolution time series during cycling on an ergometer in 19 healthy young adults. We evaluated the impact of introducing a cognitive task (PASAT) to assess the role of central structures in control organization.Autocorrelation function and detrending fluctuation analysis (DFA) demonstrated the presence of fractal scaling. PSD in the short range revealed a singular behavior which cannot be explained by the usual models of even-based and emergent timing.The main outcomes are that (1) timing in cycling is a fractal process, (2) this long-range fractal behavior increases in persistence with dual-task condition, which has not been previously observed, (3) short-range behavior is highly persistent and unaffected by dual-task.Relying on the inertia of the oscillator may be a way to distribute more control to the periphery, thereby allocating less resources to central process and better managing additional cognitive demands. This original behavior in cycling may explain the high short-range persistence unaffected by dual-task, and the increase in long-range persistence with dual-task.     

Extraversion modulates functional connectivity hubs of resting‐state brain networks

Personality dimension extraversion describes individual differences in social behaviour and socio‐emotional functioning. The intrinsic functional connectivity patterns of the brain are reportedly associated with extraversion. However, whether or not extraversion is associated with functional hubs warrants clarification. Functional hubs are involved in the rapid integration of neural processing, and their dysfunction contributes to the development of neuropsychiatric disorders. In this study, we employed the functional connectivity density (FCD) method for the first time to distinguish the energy‐efficient hubs associated with extraversion. The resting‐state functional magnetic resonance imaging data of 71 healthy subjects were used in the analysis. Short‐range FCD was positively correlated with extraversion in the left cuneus, revealing a link between the local functional activity of this region and extraversion in risk‐taking. Long‐range FCD was negatively correlated with extraversion in the right superior frontal gyrus and the inferior frontal gyrus. Seed‐based resting‐state functional connectivity (RSFC) analyses revealed that a decreased long‐range FCD in individuals with high extraversion scores showed a low long‐range functional connectivity pattern between the medial and dorsolateral prefrontal cortex, middle temporal gyrus, and anterior cingulate cortex. This result suggests that decreased RSFC patterns are responsible for self‐esteem, self‐evaluation, and inhibitory behaviour system that account for the modulation and shaping of extraversion. Overall, our results emphasize specific brain hubs, and reveal long‐range functional connections in relation to extraversion, thereby providing a neurobiological basis of extraversion.     

A common ground in clinical discussion groups: Intersubjective resonance and implicit operational theories

Clinical discussion groups based on the Three‐Level Model for Observing Patient Transformations (3‐LM) enable us to reflect on the clinical common ground shared by psychoanalysts who have different theoretical frameworks. The very existence of this common ground is controversial. While analysts such as Wallerstein support it, others, like Green, think it is just a myth. In their 2005 controversy Wallerstein and Green proposed an observation procedure that might clarify this matter. This procedure bears great similarity to the one used by clinical discussion groups that apply the 3‐LM. The study of numerous theoretically heterogeneous groups that use this model shows that communication is possible in crucial areas. We may thus conclude that a partial and dynamic common ground exists. At a phenomenological level, certain fragments of material produce a shared resonance that enriches clinical understanding for the whole group. Communication is also possible with regard to the conceptualization of patient changes, although some controversial issues persist at this level. Finally, at the level of theoretical explanations, divergences concerning abstract theories do not prevent a fertile interaction among ‘in vivo’ personal implicit theories. The latter give rise to the actual operational frameworks underlying participants' approach to clinical problems.     

Neuroimaging and Occupational Therapy: Bridging the Gap to Advance Rehabilitation in Developmental Coordination Disorder

Developmental coordination disorder (DCD) is a neurodevelopmental disorder characterized by poor motor skills that interfere with a child's ability to perform everyday activities. Little is known about the neural mechanisms that implicate DCD, making it difficult to understand why children with DCD struggle to learn motor skills and selecting the best intervention to optimize function. Neuroimaging studies that utilize magnetic resonance imaging techniques have the capacity to play a critical role in helping to guide clinicians to optimize functional outcomes of children with DCD using evidence-based rehabilitation interventions. The authors' goal is to describe how neuroimaging research can be applied to occupational therapy and rehabilitation sciences by highlighting projects that are at the forefront of the field and elucidate future directions.     

Breastfeeding and motor development: A longitudinal cohort study

BackgroundWhile there is a large body of work supporting the importance of early feeding practices on cognitive, immunity, behavioural and mental outcomes, few longitudinal studies have focused on motor development. The relationship between duration of breast feeding and motor development outcomes at 10, 14, and 17 years were examined.MethodsData were obtained from the Western Australian Pregnancy (Raine) Study. There were 2868 live births recorded and children were examined for motor proficiency at 10 (M = 10.54, SD = 2.27), 14 (M = 14.02, SD = 2.33) and 17 (M = 16.99, SD = 2.97) years using the McCarron Assessment of Neuromuscular Development (MAND). Using linear mixed models, adjusted for covariates known to affect motor development, the influence of predominant breast feeding for <6 months and ⩾6 months on motor development outcomes was examined.ResultsBreast feeding for ⩾6 months was positively associated with improved motor development outcomes at 10, 14 and 17 years of age (p = 0.019, β 1.38) when adjusted for child’s sex, maternal age, alcohol intake, family income, hypertensive status, gestational stress and mode of delivery.ConclusionEarly life feeding practices have an influence on motor development outcomes into late childhood and adolescence independent of sociodemographic factors.     

Motor expertise and performance in spatial tasks: A meta-analysis

The present study aimed to provide a summary of findings relevant to the influence of motor expertise on performance in spatial tasks and to examine potential moderators of this effect. Studies of relevance were those in which individuals involved in activities presumed to require motor expertise were compared to non-experts in such activities. A final set of 62 effect sizes from 33 samples was included in a multilevel meta-analysis. The results showed an overall advantage in favor of motor experts in spatial tasks (d = 0.38). However, the magnitude of that effect was moderated by expert type (athlete, open skills/ball sports, runner/cyclist, gymnast/dancers, musicians), stimulus type (2D, blocks, bodies, others), test category (mental rotation, spatial perception, spatial visualization), specific test (Mental Rotations Test, generic mental rotation, disembedding, rod-and-frame test, other), and publication status. These findings are discussed in the context of embodied cognition and the potential role of activities requiring motor expertise in promoting good spatial performance.