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Abstract

ESF-EMBO Symposium on Three Dimensional Sensory and Motor Space: Perceptual Consequences of Motor Action.
For all conditions, the subjects corrected online the hand trajectory to counteract the perturbation. On average, the reaching errors ranged from 0.90 degrees to 4.88 degrees. Concerning the latency of the corrections, on average, they ranged from 63 ms to 87 ms in the different conditions. Online corrections tended to occur faster for kinesthetic-evoked corrections than for vision-evoked corrections but this difference failed to reach significance. Neither the time at which the perturbation occurred nor the presence of visual feedback about the hand position did influence the latency of the corrections. Interestingly however, there was an interaction between the type of
perturbation and the presence of visual feedback about the hand position. For vision-evoked corrections, visual feedback about the hand position systematically reduced the latency of the responses. In contrast, for kinesthetic-evoked corrections, visual feedback about the hand position
did not reduce the latency of the corrections and even increased it for some subjects.
Our results show very fast visual- and kinesthetic-evoked online corrections of arm reaching movements. The latency of these motor responses is longer than stretch reflex latencies but shorter than previously reported vision- and proprioception-evoked motor responses. Our results also show
that although providing visual feedback about the hand position reduces the latency of visualevoked responses, it does not improve and even sometimes impairs the latency of kinestheticevoked responses.