We investigated the issue of whether or not CNS makes use an internal model motor apparatus in planning and controlling arm movements. In particular, we tested ability subjects to predict different hand-held loads by examining grip force adjustments used stabilize load hand during Subjects grasped a manipulandum using precision with tips thumb index finger on either side. The (normal contact surfaces) (tangential were measured, along trajectory hand. was attached two servo-controlled linear...

In reaching for an object in the environment, it has been suggested that movement components concerned with transport of hand toward and those related to grasping are organized executed independently. An experiment is reported demonstrates people adjust grasp aperture compensate factors affecting error. Grasp was found be greater movements performed faster than normal, also wider when eyes closed. both cases, spatially less accurate. It argued that, advance movement, formation planned take...

We report an investigation of postural stability in two groups volunteers (mean ages 57 and 77). Participants were required to stand on a force platform while performing five cognitive tasks: (1) random digit generation, (2) Brooks' spatial memory, (3) backward recall, (4) silently counting from 1-100, (5) threes (aloud). There was also control condition which there no task. Postural adversely affected by age all conditions. Moreover, the difference between significantly greater when tasks 2...

The Hand in Action J.R. Flanagan, P. Haggard, and A.M. Wing, Task at Hand. M.A. Goodale, L.S. Jakobson, Servos, Visual Pathways Mediating Perception Prehension. Motor M.-C. Hepp-Reymond, E.J. Huesler, Maier, Precision Grip Humans: Temporal Spatial Synergies. J. Fridin R.L. Lieber, Muscle Architecture Basis for Neuromuscular Control of the Forearm M.H. Schieber, Individuated Finger Movements: Rejecting Labeled-Line Hypothesis. E.M. Rouiller, Multiple Representations Cortical Areas. Armand, E....

Active sensing systems are purposive and information-seeking sensory systems. usually entails sensor movement, but more fundamentally, it involves control of the apparatus, in whatever manner best suits task, so as to maximize information gain. In animals, active is perhaps most evident modality touch. this theme issue, we look at touch across a broad range species from insects, terrestrial marine mammals, through humans. addition analysing natural touch, also consider how engineering...

Is postural stability controlled automatically, or is it affected by concurrent cognitive activity? Are the effects influenced nature of activity required, and do they increase in old age? To address these questions, 70 participants aged 20‐79 years were asked to stand as still possible on a force platform (postural control task) while performing (a) no task, (b) spatial memory (c) nonspatial task. The tasks also performed seated comparison condition. Both recall declined with increasing age...

Transport of the hand towards an object and formation grasp are logically separable components reaching. It has been suggested that, although two must be temporally co-ordinated, their spatial parameters under control independent visuo-motor channels. A case study reaching by a proficient user manually-operated artificial is presented. pattern natural usage was observed in which index finger rather than thumb responsible for reduction aperture as approached object. The same also even though...

Control of relative timing is critical in ensemble music performance. We hypothesize that players respond to and correct asynchronies tone onsets arise from fluctuations their individual tempos. propose a first-order linear phase correction model demonstrate optimal performance minimizes asynchrony variance predicts specific value for the gain. In two separate case studies, internationally recognized string quartets repeatedly performed short excerpt fourth movement Haydn's quartet Op. 74...

Unconstrained hand movements typically display a decrease in speed around highly curved sections of trajectory. It has been suggested that this relation between tangential velocity and radius curvature conforms to one-third power law. We demonstrate law can be explained by models taking account trajectory costs such as minimum-jerk model. Data were analyzed from 6 subjects performing elliptical drawing varying eccentricities. Conformity the average was obtained but is shown artifactual....

The effects of one night's total sleep deprivation were examined using the Wilkinson vigilance task and four 10 min duration performance tests. A repeated measures design was used in which eight male subjects experienced night loss, order loss being balanced across subjects. short tests consisted choice reaction time, simple short-term memory, a motor task, handwriting. results confirm on also show that two time significantly impaired by sleep, but not at such high level as for vigilance....

Abstract Synchronising movements with events in the surrounding environment is an ubiquitous aspect of everyday behaviour. Often, information about a stream available across sensory modalities. While it clear that we synchronise more accurately to auditory cues than other modalities, little known how brain combines multisensory signals produce timed actions. Here, investigate integration for sensorimotor synchronisation. We extend prevailing linear phase correction model movement...