Daily update of motor predictions by physical activity.

Nicolas Gueugneau,Charalambos Papaxanthis,Nicolas Schweighofer

doi:10.1038/srep17933

Abstract

Motor prediction, i.e., the ability to predict the sensory consequences of motor commands, is critical for adapted motor behavior. Like speed or force, the accuracy of motor prediction varies in a 24-hour basis. Although the prevailing view is that basic biological markers regulate this circadian modulation, behavioral factors such as physical activity, itself modulated by the alternation of night and day, can also regulate motor prediction. Here, we propose that physical activity updates motor prediction on a daily basis. We tested our hypothesis by up- and down-regulating physical activity via arm-immobilization and high-intensity training, respectively. Motor prediction was assessed by measuring the timing differences between actual and mental arm movements. Results show that although mental movement time was modulated during the day when the arm was unconstrained, it remained constant when the arm was immobilized. Additionally, increase of physical activity, via release from immobilization or intense bout of training, significantly reduced mental movement time. Finally, mental and actual times were similar in the afternoon in the unconstrained condition, indicating that predicted and actual movements match after sufficient amount of physical activity. Our study supports the view that physical activity calibrates motor predictions on a daily basis.

Highlights

A key point here is the fact that the temporal features of mental movements emerge from sensorimotor predictions of the forward models[1,19,20]
The cosinor analysis failed to detect any variation of mental movement time during the day (P > 0.1; Fig. 2B) showing that physical activity influences motor prediction daily. repeated-measures analysis of variance (rANOVA) showed that mental movement time was stable during the day (F5,45 = 0.44, P = 0.81; 95% of Interval Confidence: 6.2 s–7.1 s at 8 a.m., 6.3 s–7.2 s at 11 a.m., 6.3 s–7.2 s at 2 p.m.; 6.2 s–7.1 s at 5 p.m., 6.2 s–7.1 s at 8 p.m., and 6.4 s–7.1 s at 11 p.m.)
We examined how physical activity during the day influences the modulation of motor prediction

Summary

Introduction

A key point here is the fact that the temporal features of mental movements emerge from sensorimotor predictions of the forward models[1,19,20]. A copy of these motor commands, the efference copy, is still available to the forward model, which predicts the future sensorimotor states of the arm and provides temporal information that are very similar to that of actual movements. When asked to mentally imagine to reach to targets to the right of the left of the workspace, the modulation of mental movement times with respect to target location show an excellent correspondence to actual movement times, which have been explained on the basis of the arm’s dynamics[25,26]. In this paper, the accuracy of motor prediction is estimated by the difference between actual movement time and mental movement time[16,17,19]

Methods

Results

Conclusion