Mental Practice (MP) Combined With Transcranial Direct Current Stimulation (tDCS) on Motor Learning in the Elderly

Summary

Scientific background and rationale: Motor sequence learning (MSL) is composed of three phases: initial acquisition or rapid learning occurs during the first practice session, characterized by a rapid increase in motor performance; consolidation comes next, in the following hours, with a stabilization or even an increase in performance without additional practice; finally, slow learning allows long-term memorization of the skills acquired after several practice sessions. Motor sequence learning is an essential ability at any age but is altered with aging. Furthermore, the repetition of movements required for MSL may be tiring for the most vulnerable individuals. There is thus a need to develop the use of alternative and effective methods of MSL in the elderly. Mental practice (MP) based on motor imagery (MI) and anodal transcranial direct current stimulation (a-tDCS) are such innovative methods that have shown a positive impact on MSL in older adults. On the one hand, motor imagery training relates to mentally practicing movements without actual execution. This method has been shown to advantageously complement or even replace physical practice. Nevertheless, for fine and gross motor skills, the association MP/physical practice (PP) has been little studied in healthy elderly subjects. On the other hand, tDCS is a safe and noninvasive brain stimulation method used to modulate cortical excitability and enhance neuroplasticity. It has been shown that an anodal stimulation of the primary motor cortex (M1) immediately after the acquisition of a sequence of finger movements (manual task) enhanced consolidation in healthy elderly people. These effects have, however, never been tested for more ecological sequential tasks involving the whole body (body task).

Aim: The main aim of this study is to investigate the effects of a-tDCS on the consolidation of complex manual and body tasks, after MP alone, PP alone, and MP + PP in older adults.

A secondary aim is to test the effects of MP alone, PP alone and MP + PP in the acquisition of these complex manual and body tasks, in older adults.

A third aim is to test the evolution of electroencephalographic (EEG) activity between rest and motor imagery of these tasks, and, for motor imagery, before and after training.

Conditions

• Neuron Degeneration

Interventions

DEVICE

Transcranial stimulation

For both tasks, the training modalities are the same. After the pre-test, this group will physically repeat the correct sequence as many times as possible, during 12 blocks of 30s. After this training, they will perform the post-test. And immediately after the post-test, they will receive the real anodal stimulation. The intensity of the current will gradually increase for 30s until it reaches 1mA, will remain constant for 15min, then will gradually decrease for 30s until 0mA is reached. The current density during stimulation will be 0.04 mA/cm². For the manual task the anode will be centered above C4 (according to the international 10-20 EEG system) that is located near the hand area of M1. The cathode will be placed on the supraorbital region ipsilateral to the trained hand (Fp1). For the body task, the anode will be placed in the center of the cortex (Cz) and the cathode will be placed at the medial supraorbital region (Fpz).

Sponsors & Collaborators

• Hospices Civils de Lyon

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

65 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2020-11-01

Primary Completion

2022-04-01

Completion

2022-04-01