Herrera, Angelica Janina
(2023)
Effect of Contextual Task Changes on Motor Cortical Activity and Brain-Computer Interface Performance.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
The restoration of arm and hand function is a top rehabilitation priority for people with tetraplegia. To address this need, intracortical brain-computer interfaces (BCIs), which decode neural activity to predict desired movement commands, enable people with severe motor impairments to achieve high performance control of assistive devices in laboratory environments. A key challenge limiting the clinical translation of BCIs is their ability to provide reliable control in more naturalistic settings.
Here, we evaluate the impact of contextual changes on neural activity in human motor cortex to provide a framework for the development of more robust decoding schemes. We began this work by first determining if task-related neural activity is stable over time. We found that there exists a stable representation of latent neural activity patterns that can be aligned over time to provide a stable input to BCI decoders for computer access. Our findings demonstrate that users can obtain reliable, accurate BCI control of their assistive devices for months at a time without the need for technician intervention.
Focusing on the restoration of arm and hand function, we next studied how contextual changes during object interaction affect high degree of freedom control of a robotic arm. When participants were instructed to attempt identical reach and grasp movements with and without an object in the workspace, we found that object presence significantly modulates population neural activity from planning to movement completion. We also found that grasp intention coincided with neural activity modulation in response to object presence. Small modulation of neural activity in primary somatosensory cortex was identified in response to both the presence of an object and grasp intention. Here, we found evidence for movement-related and broader task-context variables in both the motor and somatosensory cortex during attempted movements.
Our results aim to provide researchers a better understanding of the impact of contextual changes on motor cortical activity and provide a framework for developing more contextually invariant BCIs. We hope to advance the clinical translation of BCIs for day-to-day use by providing stable and reliable BCI performance in the face of contextual changes.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
19 January 2023 |
| Date Type: |
Publication |
| Defense Date: |
29 June 2022 |
| Approval Date: |
19 January 2023 |
| Submission Date: |
10 August 2022 |
| Access Restriction: |
2 year -- Restrict access to University of Pittsburgh for a period of 2 years. |
| Number of Pages: |
144 |
| 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: |
Brain-computer interfaces, motor control, neuroprosthetics, neurorehabilitation, spinal cord injury, assistive technology |
| Date Deposited: |
19 Jan 2023 19:05 |
| Last Modified: |
19 Jan 2023 19:05 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/43574 |
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