Pranati Modumudi

Pranati Modumudi

MS Student at Columbia Univeristy studying CS and Neuroscience

Exploring Cortical and Muscular Responses to Voluntary and EMS-Evoked Motion

Published:

Overview

This project investigates how the brain’s motor cortex responds during voluntary versus externally-evoked muscle motion. Using a combined EEG + EMG + EMS setup, we study the supinator muscle, which rotates the forearm, to compare cortical and muscular activity across three conditions: voluntary movement, motor imagery, and EMS-triggered motion.

The project is being conducted for COMS:4995 — Computation and the Brain (Fall 2025) at Columbia University.

Motivation

While EEG–EMG studies and electrical stimulation experiments exist independently, few directly compare cortical signatures of voluntary versus externally-evoked activation in the same muscle. Understanding these differences can inform neuroscience, brain-computer interfaces, and applied rehabilitation systems.

Technical Details

Technologies Used

  • OpenBCI Ganglion Board — 4-channel EEG recording (C3/C4/Cz/CP3)
  • Surface EMG electrodes — supinator muscle
  • Backyard Brains Human-to-Human Interface — two-channel EMS stimulation
  • Python / MNE — data processing, event-related potentials, time–frequency analysis

Methodology

  • Record EEG and EMG signals under voluntary movement, motor imagery, and EMS-induced motion
  • Synchronize stimulation with recordings for time-locked analysis
  • Extract mu (8–13 Hz) and beta (13–30 Hz) band features, readiness potentials, and post-stimulation cortical rebound
  • Compare anticipatory vs feedback-driven cortical activity patterns

Current Progress

  • Hardware and signal quality verified separately for EEG, EMG, and EMS
  • Electrode placement and timing synchronization in progress
  • Pilot data collection planned for next steps

What I’m Learning

  • Practical EEG and EMG data acquisition and preprocessing
  • Event-related potential analysis and time–frequency decomposition
  • Synchronization of external stimulation with neurophysiological recordings

Future Work

  • Collect and analyze pilot trials
  • Quantify cortical differences between voluntary, imagined, and EMS-driven motion
  • Explore implications for corticomuscular coherence and motor control research

Project Status: In Progress
Timeline: September 2025 – December 2025