Effects of 2D and 3D image views on hand movement trajectories in the surgeon’s peri-personal space in a computer controlled simulator environment

Recent studies of upper limb movements have provided insights into the computations, mechanisms, and taxonomy of human sensorimotor learning. Motor tasks differ with respect to how they weight different learning processes. These include adaptation, an internal-model based process that reduces sensory-prediction errors in order to return performance to pre-perturbation levels, use-dependent plasticity, and operant reinforcement. Visuomotor rotation and force-field tasks impose systematic errors and thereby emphasize adaptation. In skill learning tasks, which for the most part do not involve a perturbation, improved performance is manifest as reduced motor variability and probably depends less on adaptation and more on success-based exploration. Explicit awareness and declarative memory contribute, to varying degrees, to motor learning. The modularity of motor learning processes maps, at least to some extent, onto distinct brain structures. Copyright © 2011. Published by Elsevier Ltd. Show more

Many researchers have proposed that the near space immediately surrounding the body is represented differently than more distant space. Indeed, it has often been suggested that near space encompasses that within arm's reach. The present study used a line bisection task in healthy adults to investigate the effects of tool use on space perception, and the nature of the transition between near and far space. Subjects bisected lines at four distances controlled for both veridical and angular size using a laser pointer and a set of sticks. When the laser pointer was used, a left to right shift in bias was observed as stimuli were moved from near to far space. When a tool was used, however, a leftward bias was observed at all distances, similar to that observed with the laser pointer in near space. These results suggest that the tool expanded the range of near space. Additionally, the transition from near to far space was gradual, with no abrupt shift at arm's length (or at any other distance). In contrast to theories describing near space as that within arm's reach, these findings suggest that the representation of near space is less rigid, extending with tool use and gradually transitioning into far space. Show more