The Neural Foundations of Handedness: Insights from a Rare Case of Deafferentation

Authors

S.A.L. Jayasinghe, Pennsylvania State University College of MedicineFollow
F. R. Sarlegna, Aix Marseille Université
Robert A. Scheidt, Marquette UniversityFollow
R. L. Sainburg, Pennsylvania State University College of MedicineFollow

Document Type

Article

Language

eng

Publication Date

7-2020

Publisher

American Physiological Society

Source Publication

Journal of Neurophysiology

Source ISSN

0022-3077

Abstract

The role of proprioceptive feedback on motor lateralization remains unclear. We asked whether motor lateralization is dependent on proprioceptive feedback by examining a rare case of proprioceptive deafferentation (GL). Motor lateralization is thought to arise from asymmetries in neural organization, particularly at the cortical level. For example, we have previously provided evidence that the left hemisphere mediates optimal motor control that allows execution of smooth and efficient arm trajectories, while the right hemisphere mediates impedance control that can achieve stable and accurate final arm postures. The role of proprioception in both of these processes has previously been demonstrated empirically, bringing into question whether loss of proprioception will disrupt lateralization of motor performance. In this study, we assessed whether the loss of online sensory information produces deficits in integrating specific control contributions from each hemisphere by using a reaching task to examine upper limb kinematics in GL and five age-matched controls. Behavioral findings revealed differential deficits in the control of the left and right hands in GL and performance deficits in each of GL’s hands compared with controls. Computational simulations can explain the behavioral results as a disruption in the integration of postural and trajectory control mechanisms when no somatosensory information is available. This rare case of proprioceptive deafferentation provides insights into developing a more accurate understanding of handedness that emphasizes the role of proprioception in both predictive and feedback control mechanisms.

Comments

Accepted version. Journal of Neurophysiology, Vol. 124, No. 1 (July 2020): 259-267. DOI. © 2020 American Physiological Society. Used with permission.

Recommended Citation

Jayasinghe, S.A.L.; Sarlegna, F. R.; Scheidt, Robert A.; and Sainburg, R. L., "The Neural Foundations of Handedness: Insights from a Rare Case of Deafferentation" (2020). Biomedical Engineering Faculty Research and Publications. 626.
https://epublications.marquette.edu/bioengin_fac/626