Coordination in Prehension: information-based coupling of reaching and grasping

Prehension involves the coordination of a reaching and a grasping movement, such that the hand opens and closes in tune with the transport of the hand to the object to be grasped. To investigate this coordination, we focused on the transition from hand opening to hand closing in the grasping component of prehension. Earlier research has suggested that the time taken to close the hand remains constant over varying reaching amplitudes. In the present experiment, in which subjects reached for objects at six different distances and for objects that moved away from them at three different, constant speeds, hand-closure time was found to vary as a function of experimental conditions. Moreover, initiation of hand closure did not occur at a constant value of the (perceptually available) first-order time remaining until contact with the object. However, the variations observed, occurring as a function of initial hand-object distance and object speed, could be accounted for by an abstract dynamical model of perceptually driven postural changes

The genetic basis of apparently idiopathic ventricular fibrillation: a retrospective overview

AimsDuring the diagnostic work-up of patients with idiopathic ventricular fibrillation (VF), next-generation sequencing panels can be considered to identify genotypes associated with arrhythmias. However, consensus for gene panel testing is still lacking, and variants of uncertain significance (VUS) are often identified. The aim of this study was to evaluate genetic testing and its results in idiopathic VF patients.Methods and resultsWe investigated 419 patients with available medical records from the Dutch Idiopathic VF Registry. Genetic testing was performed in 379 (91%) patients [median age at event 39 years (27–51), 60% male]. Single-gene testing was performed in 87 patients (23%) and was initiated more often in patients with idiopathic VF before 2010. Panel testing was performed in 292 patients (77%). The majority of causal (likely) pathogenic variants (LP/P, n = 56, 15%) entailed the DPP6 risk haplotype (n = 39, 70%). Moreover, 10 LP/P variants were found in cardiomyopathy genes (FLNC, MYL2, MYH7, PLN (two), TTN (four), RBM20), and 7 LP/P variants were identified in genes associated with cardiac arrhythmias (KCNQ1, SCN5A (2), RYR2 (four)). For eight patients (2%), identification of an LP/P variant resulted in a change of diagnosis. In 113 patients (30%), a VUS was identified. Broad panel testing resulted in a higher incidence of VUS in comparison to single-gene testing (38% vs. 3%, P ConclusionAlmost all patients from the registry underwent, albeit not broad, genetic testing. The genetic yield of causal LP/P variants in idiopathic VF patients is 5%, increasing to 15% when including DPP6. In specific cases, the LP/P variant is the underlying diagnosis. A gene panel specifically for idiopathic VF patients is proposed.Genetics of disease, diagnosis and treatmen