Examining Lateralized Aspects of Motor Control Using Non-invasive Neural Stimulation

Motor adaptation and generalization are believed to occur via the integration of various forms of sensory feedback for a congruent representation of the body's position in space along with estimation of inertial properties of the limb segments for accurate specification of movement. Thus, motor adaptation is often studied within curated environments incorporating a "mis-match" between different sensory systems (i.e. a visual field shift via prism googles or a visuomotor rotation via virtual reality environment) and observing how motor plans change based on this mis-match. However, these adaptations are environment-specific and show little generalization outside of their restricted experimental setup. There remains a need for motor adaptation research that demonstrates motor learning that generalizes to other environments and movement types. This work could then inform physical and occupational therapy neurorehabilitation interventions targeted at addressing motor deficits.

Study Overview

• Status: Not yet recruiting
• Conditions: Cerebellum; Motor Adaptation and Generalization; Posterior Parietal Cortex
• Intervention / Treatment: Behavioral: Comparing motor adaptation reaching performance

Detailed Description

Voluntary movement and sensory perception are fundamental aspects of the human experience. Senses such as visual and proprioceptive feedback inform movement by continuously providing the central nervous system with information on limb location, movement error, and task performance. However, the specific mechanisms behind how different forms of sensory information are used to adapt and generalize movement remain poorly understood.

Motor adaptation, or the modification of movement based on error feedback (Martin et al., 1996), is often elicited during rehabilitation but must be generalized to functional performance, such as activities of daily living, in order to successfully rehabilitate motor deficits following stroke. Motor adaptation and generalization are believed to occur via the integration of various forms of sensory feedback for a congruent representation of the body's position in space along with estimation of inertial properties of the limb segments for accurate specification of movement. Thus, motor adaptation is often studied within curated environments incorporating a "mis-match" between different sensory systems (i.e. a visual field shift via prism googles or a visuomotor rotation via virtual reality environment) and observing how motor plans change based on this mis-match. However, these adaptations are environment-specific and show little generalization outside of their restricted experimental setup. There remains a need for motor adaptation research that demonstrates motor learning that generalizes to other environments and movement types. This work could then inform physical and occupational therapy neurorehabilitation interventions targeted at addressing motor deficits.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Brooke Dexheimer, PhD, OTD, OTR/L; Phone Number: 563-547-0125; Email: dexheimerb@vcu.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Right-handed as determined by the short-form Edinburgh Handedness Inventory
• Between the ages of 18 and 40

Exclusion Criteria:

• Mixed- or left-handed as determined by the short-form Edinburgh Handedness Inventory
• Self-reported history of any of the following:

Seizure and/or diagnosis of epilepsy Fainting spells Concussion with loss of consciousness Ringing in the ears (tinnitus) Cochlear implants Migraines Diagnosed psychological or neurological condition Metal in the scalp

• Any previous adverse reaction to a brain stimulation technique
• Any previous adverse reaction to 3D virtual reality environments (i.e. 'cybersickness')
• Possibility of being currently pregnant (for females only)
• Current open head wound or skin condition of the scalp
• Current implanted device(s) (i.e. cardiac pacemaker)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Posterior parietal cortex group; Posterior parietal cortex group, which will receive the stimulation to their left posterior parietal cortex	Behavioral: Comparing motor adaptation reaching performance; By comparing motor adaptation reaching performance between these three groups, the investigators can examine how stimulation to each specific area of the brain modulates different aspects of motor adaptation
Experimental: Cerebellum group; Cerebellum group, which will receive stimulation to their right cerebellum,	Behavioral: Comparing motor adaptation reaching performance; By comparing motor adaptation reaching performance between these three groups, the investigators can examine how stimulation to each specific area of the brain modulates different aspects of motor adaptation
Sham Comparator: Sham group; Sham group, which will have the electrode cap placed on their head but receive no stimulation	Behavioral: Comparing motor adaptation reaching performance; By comparing motor adaptation reaching performance between these three groups, the investigators can examine how stimulation to each specific area of the brain modulates different aspects of motor adaptation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Initial direction error, or difference between participant's fingertip direction	Initial direction error, or difference between participant's fingertip direction at the timepoint of peak velocity relative to a linear path to the target. As for time frame, this is a single-visit study. Initial direction error will be compared during baseline reaching and following 20 minutes of non-invasive neural stimulation.	Completion of the study visit, approx 20 minutes
Initial direction error variance	Initial direction error variance across multiple trials.	Completion of the study visit, approx 20 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Final position error	Secondary outcome: final position error, or distance from participant's fingertip position at the conclusion of the reach to the center of the target. Similar to above, this measure will be compared during baseline and following 20 minutes of stimulation.	Completion of the study visit, approx 20 min
Final position error variance across multiple trials.	Final position error variance across multiple trials.	Completion of the study visit, approx 20 min
Deviation from linearity	Deviation from linearity, or a ratio of minimum and maximum displacement across the parallel and perpendicular planes of the reaching movement.	Completion of the study visit, approx 20 min
Peak tangential velocity	Peak tangential velocity, or highest tangential velocity reached during reach.	Completion of the study visit, approx 20 min

Collaborators and Investigators

• Sponsor: Virginia Commonwealth University

Study record dates

Study Major Dates

• Study Start (Estimated): April 15, 2024
• Primary Completion (Estimated): December 15, 2024
• Study Completion (Estimated): December 15, 2025

Study Registration Dates

• First Submitted: June 30, 2023
• First Submitted That Met QC Criteria: July 7, 2023
• First Posted (Actual): July 17, 2023

Study Record Updates

• Last Update Posted (Actual): March 21, 2024
• Last Update Submitted That Met QC Criteria: March 19, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: HM20025761

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No