Reach to grasp: the natural response to perturbation of object size

摘要: This study assessed the reach to grasp movement and its adaptive response a perturbation of object size. In blocked trials, subjects (n = 12) were instructed 35 cm lift small- (0.7 cm) or large-diameter (8 cylinder. Under an unconstrained condition (condition 1), no instructions as type adopt given. Subjects thus naturally used precision grip (PG) for small cylinder whole hand prehension (WHP) large 2, utilize PG grasps both cylinders. For 3, instruction was use WHP irrespective Kinematic organization determined with analysis recordings active markers placed on wrist, thumb, three fingers. 1 results showed temporal arrangement components (transport manipulation) which differed from that conditions 2 3. perturbed illumination shifted vice versa. With 1, automatically switched one another little increase duration. generally achieved by earlier setting peak wrist deceleration. where change aperture required, duration prolonged without adaptation transport component parameters. It is concluded responses distal patterning also affect proximal component. Assessment constrained may lead interpretations central control differ those obtained assessing more natural prehensile patterns.