Doctor of Philosophy in Applied Physiology

In the

School of Biological Sciences

Chase G. Rock

Will defend his dissertation

LEARNING AND TRANSFER OF HYPOGRAVITY ADAPTATION

ACROSS MOTOR AND COGNITIVE SYSTEMS

Tuesday, November 5, 2024

2:00 PM

Applied Physiology Building (555 14th St.), Room 1257

https://gatech.zoom.us/j/93650250168

Thesis Advisor:

Young-Hui Chang, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Committee Members:

T. Richard Nichols, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Gregory Sawicki, Ph.D.

School of Mechanical Engineering

Georgia Institute of Technology

Lewis Wheaton, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Lena Ting, Ph.D.

School of Biomedical Engineering

Georgia Institute of Technology and Emory University

ABSTRACT: The motor and cognitive systems are easy to think of as inhabiting different domains, but they overlap in many of their functions. Generally, motor learning has important cognitive components, and cognition makes use of motor areas of the nervous system. However, the specifics of the overlap between the motor and cognitive systems remain elusive. The goal of this set of experiments was to determine if different motor and cognitive systems share a single representation of gravity, or if gravity is accommodated separately by each system. Gravity was chosen due to its ubiquitous influence on motor action and cognitive predictions of movement. I hypothesized that gravity is represented in the nervous system in a generalizable way, such that adaptation in one gravity-dependent motor task will affect other, gravity-dependent motor actions, or even cognitive actions. To test this, three experiments were conducted, aimed at 1) characterizing the adaptation to simulated hypogravity jumping, 2) determining if gravity adaptation in jumping transfers to gravity-dependent arm movement, and 3) if the same gravity adaptation transfers to a gravity-dependent cognitive task. In support of my hypothesis, after participants successfully adapted to simulated hypogravity jumping, this adaptation then affected gravity-dependent arm movements as well as the cognitive task. The results support a shared representation of gravity between motor and cognitive systems that is adaptable and relies on accurate predictions of gravity-related sensory feedback, contributing to our understanding of transfer of learning and how abstract phenomena (like gravity) are managed by the neuromuscular system.