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

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.

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)