Temporal and Spatial Accuracy of Reaching Movements do not Improve Off-line

Abstract

Consolidation has been associated with performance gains without additional practice (i.e., off-line learning). However, the movement characteristics improving off-line remain poorly understood. To investigate this question, participants were trained to produce a sequence of planar reaching movements toward four different visual targets. The training session with feedback required them to learn the relative time of the movements, the total movement time and aim accurately at each target. The retention test was performed either 10-min or 24-h after. Results revealed that a 24-h consolidation interval did not result in better temporal or spatial accuracy. This finding suggests that off-line learning may be restricted to sequence production tasks in which the different segments must be regrouped (“chunked”) together to accelerate their execution.

Keywords:

• Learning
• consolidation
• motor skills
• movement sequence
• reaching movement

Acknowledgments

We thank Luc Proteau for allowing us to use his experimental apparatus and Marcel Beaulieu for his assistance with the computer software.

Disclosure Statement

The authors report there are no competing interests to declare.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Notes

1 $\mathit{\text{RMSE}}=\sqrt{\frac{\sum {\left(P{T}_i-y_i\right)}^2}{4}}$ where $P{T}_i$ is the prescribed time of the segment $i$ and $y_i$ is the actual movement time of the segment $i.$

2 $\mathit{\text{AE}}=\sum \frac{|x_i-1800|}{n}$ where $x_i$ is the total movement time on trial $i$ and $n$ is the total number of sequences executed.

3 $\mathit{\text{VE}}=\sqrt{\sum \frac{{\left(x_i-M\right)}^2}{n}}$ where $x_i$ is the total movement time on trial $i,$ $M$ is the mean total movement time, and $n$ is the total number of sequences executed.