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Postural Hand Synergies for Tool Use
The results suggest that the control of hand posture involves a few postural synergies, regulating the general shape of the hand, coupled with a finer control mechanism providing for small, subtle adjustments. Expand
Moving effortlessly in three dimensions: does Donders' law apply to arm movement?
It was found that, in general, the posture of the arm at a given hand location does depend on the starting location of the movement and that Donders' law is violated in this experimental condition. Expand
Early stages in a sensorimotor transformation
We present a model for several early stages of the sensorimotor transformations involved in targeted arm movement. In psychophysical experiments, human subjects pointed to the remembered locations ofExpand
Sensorimotor representations for pointing to targets in three-dimensional space.
It is concluded that subjects have a reasonably accurate visual representation of target location and are able to effectively use kinesthetically derived information about target location. Expand
Errors in pointing are due to approximations in sensorimotor transformations.
It is proposed that errors in pointing occur because subjects implement a linear approximation to the transformation from extrinsic to intrinsic coordinates and that this transformation is one step in the process of transforming a visually derived representation of target location into an appropriate pattern of muscle activity. Expand
Patterns of Hand Motion during Grasping and the Influence of Sensory Guidance
A principal components analysis was developed to provide a concise description of the spatiotemporal patterns underlying the motion of temporal synergies of hand movement and the influence of sensory cues on the control of these synergies. Expand
Muscular and postural synergies of the human hand.
It appears that the organization of the global pattern of hand muscle activation is highly distributed, which mirrors the highly fractured somatotopy of cortical hand representations and may provide an ideal substrate for motor learning and recovery from injury. Expand
Moving in three-dimensional space: frames of reference, vectors, and coordinate systems.
The question of spatial representation is a theme common to a variety of movements in three-dimensional space, and the neural systems involved in the production of each must deal with aspects that are particular to that task. Expand
Two components of muscle activation: scaling with the speed of arm movement.
Electromyographic (EMG) activity was recorded from several superficial elbow and/or shoulder muscles and the time base of rectified EMG records was normalized for movement time such that records from movements with various speeds were compressed to align the ending times of the movements. Expand
Arm muscle activation for static forces in three-dimensional space.
It is suggested that multimodal directional tuning results from the convergence of multiple sources of descending signals onto motoneurons, and suggests that arm position is an important determinate of EMG patterns. Expand