Original Research ARTICLE
Anodal Transcranial Direct Current Stimulation Over S1 Differentially Modulates Proprioceptive Accuracy in Young and Old Adults
- 1Max Planck Institute for Human Cognitive and Brain Sciences, Germany
- 2Day Clinic for Cognitive Neurology, University Hospital Leipzig, Germany
- 3Mind Brain Body Institute, Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Germany
- 4Charité Medical University of Berlin, Germany
- 5International Max Planck Research School on the Life Course, Max Planck Institute for Human Development, Germany
- 6Department of Cognitive Neurology, University Hospital Leipzig, Germany
- 7Leipzig University of Applied Sciences, Germany
- 8Berlin School of Mind and Brain, Humboldt University of Berlin, Germany
- 9International Max Planck Research School on the Life Course, Max Planck Institute for Human Development, Germany
Background: Proprioception is a prerequisite for successful motor control but declines throughout the lifespan. Brain stimulation techniques such as anodal transcranial direct current stimulation (a-tDCS) are capable of enhancing sensorimotor performance across different tasks and age groups. Despite such growing evidence for a restorative potential of tDCS, its impact on proprioceptive accuracy has not been studied in detail yet.
Objective: This study investigated online effects of a-tDCS over S1 on proprioceptive accuracy in young (YA) and old healthy adults (OA).
Methods: The effect of 15 min of a-tDCS vs. sham on proprioceptive accuracy was assessed in a cross-over, double blind experiment in both age groups. Performance changes were tested using an arm position matching task in a robotic environment. Electrical field (EF) strengths in the target area S1 and control areas were assessed based on individualized simulations.
Results: a-tDCS elicited differential changes in proprioceptive accuracy and EF strengths in the two groups: while YA showed a slight improvement, OA exhibited a decrease in performance during a-tDCS. Stronger EF were induced in target S1 and control areas in the YA group. However, no relationship between EF strength and performance change was found.
Conclusion: a-tDCS over S1 elicits opposing effects on proprioceptive accuracy as a function of age, a result that is important for future studies investigating the restorative potential of a-tDCS in healthy aging and in the rehabilitation of neurological diseases that occur at advanced age. Modelling approaches could help elucidate the relationship between tDCS protocols, brain structure and performance modulation.
Keywords: tDCS, Aging, Proprioception, position sense, Robotics, Electrical field simulation, Anodal tDCS, kinematics
Received: 10 Jul 2019;
Accepted: 06 Sep 2019.
Copyright: © 2019 Muffel, Kirsch, Shih, Kalloch, Schaumberg, Villringer and Sehm. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mr. Toni Muffel, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, 04103, Lower Saxony, Germany, email@example.com