Effects of forced movements on learning: Findings from a choice reaction time task in rats

Hidekazu Kaneko,Shinya S Suzuki,Hiroto Sano,Yasuhisa Hasegawa,Hiroshi Tamura

doi:10.3758/s13420-016-0255-9

Abstract

To investigate how motor sensation facilitates learning, we used a sensory–motor association task to determine whether the sensation induced by forced movements contributes to performance improvements in rats. The rats were trained to respond to a tactile stimulus (an air puff) by releasing a lever pressed by the stimulated (compatible condition) or nonstimulated (incompatible condition) forepaw. When error rates fell below 15%, the compatibility condition was changed (reversal learning). An error trial was followed by a lever activation trial in which a lever on the correct or the incorrect response side was automatically elevated at a preset time of 120, 220, 320, or 420 ms after tactile stimulation. This lever activation induced forepaw movement similar to that in a voluntary lever release response, and also induced body movement that occasionally caused elevation of the other forepaw. The effects of lever activation may have produced a sensation similar to that of voluntary lever release by the forepaw on the nonactivated lever. We found that the performance improvement rate was increased by the lever activation procedure on the incorrect response side (i.e., with the nonactivated lever on the correct response side). Furthermore, the performance improvement rate changed depending on the timing of lever activation: Facilitative effects were largest with lever activation on the incorrect response side at 320 ms after tactile stimulation, whereas hindering effects were largest for lever activation on the correct response side at 220 ms after tactile stimulation. These findings suggest that forced movements, which provide tactile and proprioceptive stimulation, affect sensory–motor associative learning in a time-dependent manner.

Highlights

To investigate how motor sensation facilitates learning, we used a sensory–motor association task to determine whether the sensation induced by forced movements contributes to performance improvements in rats
In a separate preliminary experiment, we measured lever-press force during the lever activations and releases using three other rats (Wistar, weight: 654–764 g). These results indicated that, the rats did not release the forepaw from the lever opposite the lever activation side within 5–55 ms after lever activation in most of the lever activation trials (~98%; the forepaw release rate [~2%] was lower than that in the main experiment [~11%], possibly due to the greater inertia of the body weights of these three rats [654–764 g] relative to those of the rats used for Fig. 9 [323–581 g]), the lever-press force of this forepaw was reduced from the value at lever activation time in a majority (~83%) of lever activation trials
We investigated the effects of forced movements on the acquisition of a choice reaction time (RT) task in a two-lever operant conditioning chamber

Summary

Introduction

To investigate how motor sensation facilitates learning, we used a sensory–motor association task to determine whether the sensation induced by forced movements contributes to performance improvements in rats. Learn Behav (2017) 45:191–204 motor sensation by application of additional tactile signals facilitates cognitive training for detection of cancers by palpation (Gerling & Thomas, 2005) These findings indicate that performance improvement is facilitated by motor sensations or associated sensory information transmitted to the brain In the rehabilitation field, Ethier, Gallego, and Miller (2015) recently suggested that appropriate plasticity in the peripheral and central nervous system can be facilitated by associating motor intent with artificially generated movement and afferent activity These findings indicate that motor sensation plays an important role even in learning tasks that do not require closed-loop control, and that suitable interaction of sensation with motor intent can facilitate learning

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Discussion

Conclusion