4.4 Article

The contribution of vision, proprioception, and efference copy in storing a neural representation for guiding trail leg trajectory over an obstacle

Journal

JOURNAL OF NEUROPHYSIOLOGY
Volume 107, Issue 8, Pages 2283-2293

Publisher

AMER PHYSIOLOGICAL SOC
DOI: 10.1152/jn.00756.2011

Keywords

obstacle avoidance; locomotion; memory; corollary discharge; sensory feedback

Funding

  1. Natural Science and Engineering Research Council of Canada

Ask authors/readers for more resources

Lajoie K, Bloomfield LW, Nelson FJ, Suh JJ, Marigold DS. The contribution of vision, proprioception, and efference copy in storing a neural representation for guiding trail leg trajectory over an obstacle. J Neurophysiol 107: 2283-2293, 2012. First published February 1, 2012; doi:10.1152/jn.00756.2011.-Stepping over obstacles requires vision to guide the leading leg, but direct visual information is not available to guide the trailing leg. The neural mechanisms for establishing a stored obstacle representation and thus facilitating the trail leg trajectory in humans are unknown. Twenty-four subjects participated in one of three experiments, which were designed to investigate the contribution of visual, proprioceptive, and efference copy signals. Subjects stepped over an obstacle with their lead leg, stopped, and straddled the obstacle for a delay period before stepping over it with their trail leg while toe elevation was recorded. Subsequently, we calculated maximum toe elevation and toe clearance. First, we found that subjects could accurately scale trail leg toe elevation and clearance, despite straddling an obstacle for up to 2 min, similar to quadrupeds. Second, we found that when the lead leg was passively moved over an obstacle (eliminating an efference copy signal and altering proprioception) without vision, trail leg toe elevation and clearance were reduced, and variability increased compared with when subjects actively moved their lead leg. Trail leg toe measures returned to normal when vision was provided during the passive manipulation. Finally, we found that altering lead leg proprioceptive feedback by adding mass to the ankle had no effect on trail leg toe measures. Taken together, our results suggest that humans can store a neural representation of obstacle properties for extended periods of time and that vision appears to be sufficient in this process to guide trail leg trajectory.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.4
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available