tDCS and Prismatic Adaptation: Roles of the Cerebellum and the Primary Motor Cortex in the Transfer of After-effects

NCT ID: NCT04271449

Last Updated: 2024-01-18

Basic Information

• Recruitment Status: WITHDRAWN
• Clinical Phase: NA
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-01-17
• Study Completion Date: 2024-01-17

Brief Summary

Human beings are able to produce precise and smooth movements despite varying demands thank to the nervous system plasticity. Primastic exposure is a method that allows to easily study these sensorimotor plasticity processes in a laboratory context. In a typical protocol, participants wear prismatic goggles that induce a lateral deviation of the visual field while performing a goal directed motor task (e.g. pointing). During the first trials, participants make errors in the direction of the deviation and correct them trial-by-trial. Finally, participants go back to baseline performances after a few dozen of trials. Upon goggles removal, participants make mistakes toward the direction opposition to the initial prismatic deviation. These after-effects reflect adaptive processes that occurred to counteract the perturbation. The way that these after-effects can be transferred to other situations which have not been exposed to the prismatic perturbation bring crucial information about the nature of the processes involved. Additionally, these transfer properties might be of great interest in the field of neuro rehabilitation. In fact, the purpose of therapeutic strategies is to induce compensations that can be transferred to daily life situations.

In previous studies, the investigator showed that expertise on the exposed had a notable influence on transfer properties. However, these studies did not allow to identify the cerebral regions involved in transfer.

The cerebellum is described as a major area implied during motor adaptation and the occurrence of after-effects, while the primary motor cortex might play a crucial role in the formation of motor memory. As such, these two regions are likely to be involved in transfer properties.

The objective of this project is to identify the roles of the cerebellum and the primary motor cortex in the transfer of visuomotor compensations acquired during prism exposure to task that has not been practiced under the perturbation. To do so, the investigator will use transcranial direct current stimulation (tDCS) which is a non-painful and non-invasive functional brain stimulation method. Several groups will be constituted to test if stimulation (inhibitory and excitatory) of the cerebellum or the primary motor on the transfer of prism acquired compensations to a non-exposed task. More precisely, the investigator aim to study the influence of different stimulation modalities (cerebellum vs MA, inhibitory vs excitatory vs sham) on the error reduction during prism exposure, on the amount of after-effects and on the amount on transfer to the non-exposed task.

On a fundamental level, this project will allow a better understanding of the sensorimotor plasticity processes involved to counteract a perturbation and about mechanisms underlying transfer properties. Future results would allows to shed light on the conditions necessary to give rise to transfer as well as the implied brain regions. On longer-term these results will be used to optimize rehabitation strategies in motor function recovery in order to favour the transfer of acquired compensations to daily life situations.

Conditions

Healthy Volunteers

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: FACTORIAL
• Primary Study Purpose: HEALTH_SERVICES_RESEARCH
• Blinding Strategy: SINGLE

Study Groups

Cerebellum tDCS

Cerebellum tDCS arm will be subdivided into two other arms according to the polarity of the stimulation (inhibitory vs excitatory stimulation). These two subgroups will be divided into two other subgroups according the the task exposed during prism exposure (pointing vs throwing).

Group Type: EXPERIMENTAL

tDCS (transcranial direct current stimulation)

Intervention Type: DEVICE

Non invasive functional brain stimulation that allows to modulate the excitability of a targeted area (inhibitory or excitatory) thanks to a small current that goes beyond two electrodes. For this arm, the targeted are will be the cerebellum.

Prismatic googles will also be used in the same way in all groups during prism exposure.

Primary motor cortex

Primary motor cortex tDCS arm will be subdivided into two other arms according to the polarity of the stimulation (inhibitory vs excitatory stimulation). These two subgroups will be divided into two other subgroups according the the task exposed during prism exposure (pointing vs throwing).

Group Type: EXPERIMENTAL

Virtual reality device

Intervention Type: BEHAVIORAL

Non invasive functional brain stimulation that allows to modulate the excitability of a targeted area (inhibitory or excitatory) thanks to a small current that goes beyond two electrodes. For this arm, the targeted are will be the cerebellum.

Prismatic googles will also be used in the same way in all groups during prism exposure.

Sham tDCS

Sham tDCS arm will serve as a sham comparator for other experimental conditions. This arm will be subdivided into two groups depending on the localisation of the electrodes (cerebellum placement vs primary motor cortex placement).These two subgroups will be divided again in two subgroups depending on the task exposed (pointing vs throwing).

Group Type: SHAM_COMPARATOR

tDCS (transcranial direct current stimulation)

Intervention Type: DEVICE

Non invasive functional brain stimulation that allows to modulate the excitability of a targeted area (inhibitory or excitatory) thanks to a small current that goes beyond two electrodes. For this arm, the targeted are will be either the cerebellum or the primary motor cortex, but the stimulation will be turned off after 15 seconds to insure a sham condition.

Prismatic googles will also be used in the same way in all groups during prism exposure.

Interventions

tDCS (transcranial direct current stimulation)

Non invasive functional brain stimulation that allows to modulate the excitability of a targeted area (inhibitory or excitatory) thanks to a small current that goes beyond two electrodes. For this arm, the targeted are will be the cerebellum.

Prismatic googles will also be used in the same way in all groups during prism exposure.

Intervention Type: DEVICE

Virtual reality device

Non invasive functional brain stimulation that allows to modulate the excitability of a targeted area (inhibitory or excitatory) thanks to a small current that goes beyond two electrodes. For this arm, the targeted are will be the cerebellum.

Prismatic googles will also be used in the same way in all groups during prism exposure.

Intervention Type: BEHAVIORAL

tDCS (transcranial direct current stimulation)

Non invasive functional brain stimulation that allows to modulate the excitability of a targeted area (inhibitory or excitatory) thanks to a small current that goes beyond two electrodes. For this arm, the targeted are will be either the cerebellum or the primary motor cortex, but the stimulation will be turned off after 15 seconds to insure a sham condition.

Prismatic googles will also be used in the same way in all groups during prism exposure.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Male or female
• Right-handed
• Aged 18 to 70
• Normal or corrected vision
• Signed written informed consent
• Affiliated to a health care organism.

Exclusion Criteria

• Neurological or psychiatric disorder
• Pregnancy
• Epilepsy antecedents
• Presence of metallic implant, pace maker, cochlear implant, chirurgical brain clip.
• Cognitive disorders
• presence of corrective eyeglasses
• Right upper limb orthopedic disorders

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Hospices Civils de Lyon

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Yves ROSSETTI

Role: PRINCIPAL_INVESTIGATOR

Centre de Recherche en Neuroscience de Lyon INSERM U1028, Equipe ImpAct

Locations

Centre de Recherche en Neuroscience de Lyon INSERM U1028, Equipe ImpAct

Bron, , France

Countries

France

Other Identifiers

2019-A02373-54

Identifier Type: OTHER

Identifier Source: secondary_id

69HCL19_0485

Identifier Type: -

Identifier Source: org_study_id