# Motor cortical signaling of impedance during manipulation

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2021 · $588,024

## Abstract

Project Summary
A large body of research has led to statistical models showing how movement velocity is encoded in the motor
cortex. However, forces also need to be controlled in harmony with motion when interacting with objects and
research has rarely focused on how the motor system coordinates both together. The simultaneous variation
of force and motion is incorporated in the definition of impedance. Our current neural models do not describe
impedance encoding, which limits our understanding of object interaction, an important aspect of human
behavior. The proposed research will develop new models of motor cortical impedance encoding during object
interaction. Using these new models to decode ongoing impedance signaling, we will substantiate an
advanced theory of impedance control used by the motor system to produce accurate object displacement in
response to the forces applied by the hand. This research bridges the expertise of Dr. Schwartz in
neurophysiology and of Dr. Hogan in robot control. Monkey subjects will perform tasks with real and virtual
tools that naturally encourage the use of impedance control. We will record the activity of motor cortical
neurons during these tasks and develop new mathematical models to describe the relation between neural
activity and force, motion and impedance. Results from electromyography recordings, joint angle
measurements and torque calculations, together with the neural models, will be used to better understand how
impedance is regulated at the level of muscles and joints. Contributions of stretch reflexes to impedance will be
studied and compared to the predictive impedance signaling decoded from motor cortex. This work promises
to extend our understanding of the neural control principles governing the way we use our arms and hands to
interact with our surroundings. These principles can be used to build new theories of the cognitive processes
used to predict and effect changes in the world around us. At the same time, elucidation of the neural and
mechanical details of forceful interaction will lead to new rehabilitative and neural prosthetic approaches to
paralysis.

## Key facts

- **NIH application ID:** 10113686
- **Project number:** 5R01NS111148-02
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** ANDREW B. SCHWARTZ
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $588,024
- **Award type:** 5
- **Project period:** 2020-03-01 → 2025-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10113686

## Citation

> US National Institutes of Health, RePORTER application 10113686, Motor cortical signaling of impedance during manipulation (5R01NS111148-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10113686. Licensed CC0.

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