Mariscal, Dulce M
(2023)
Effect of Intrinsic and Extrinsic Factors on the Generalization of Locomotor
Adaptation.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
Humans can adapt their gait to compensate for changes in environmental demands (e.g., locomotor adaptation) and carry over learned movements across contexts (generalization). While locomotor adaptation is robust across participant populations, generating these adapted movements between environmental conditions is limited. My work focuses on understanding how intrinsic factors, such as the state of participants' nervous system and extrinsic factors, through experimental manipulation, modulate the generalization of locomotor adaptation. To study this, I used a split-belt treadmill, which forces one leg to move faster than the other, to induce a locomotor adaptation and research how the motor system generalizes movement between the treadmill to overground walking. I determined how children's developmental stage, an intrinsic factor, affects generalization (Aim 1). I found that younger children generalize locomotor patterns much more than older children and adults, suggesting that the ability to form context-specific locomotor memories develops during childhood. I also investigated how levels of attention to the task, an extrinsic factor, affect the generalization of movements (Aim 2). Altering participants' attention to the split-belt environment resulted in a greater generalization of movements. This suggests that altering awareness of one's movements during sensorimotor adaptation facilitates the generalization of recalibrated movements. Next, I studied the interaction between intrinsic and extrinsic factors on the generalization of movement (Aim 3). For this, I studied how healthy aging (intrinsic) and treadmill speed (extrinsic) modulated the generalization of movement. Young adults generalize more when walking faster, while older adults generalize more when walking slower. These results suggest that training at a self-selected walking speed leads to more generalization of movements beyond the training context. Lastly, I studied the process that underlays locomotor adaptation and generalization (Aim 4). For this, I characterized the dynamics underlying the adaptation and generalization of muscle activity (Aim 4). I found that two processes underlay locomotor adaptation but not the generalization of movements. These results suggest that other processes might be at play upon transitioning to overground walking. Together these findings advanced our understanding of how to modulate the generalization of movement, which can guide gait rehabilitation strategies.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
13 June 2023 |
| Date Type: |
Publication |
| Defense Date: |
24 March 2023 |
| Approval Date: |
13 June 2023 |
| Submission Date: |
20 January 2023 |
| Access Restriction: |
2 year -- Restrict access to University of Pittsburgh for a period of 2 years. |
| Number of Pages: |
142 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Bioengineering |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Split-belt, learning |
| Date Deposited: |
13 Jun 2023 14:19 |
| Last Modified: |
13 Jun 2023 14:19 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/44334 |
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Effect of Intrinsic and Extrinsic Factors on the Generalization of Locomotor
Adaptation. (deposited 13 Jun 2023 14:19)
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