Supreeth S Karan, supervised by Dr. Kavita Vemuri received his Master of Science – Dual Degree in Electronics and Communication Engineering (ECE). Here’s a summary of his research work on Exploring EEG microstates during motor movements: A study on tip pinch and wrist flexion-extension:
Spontaneous EEG Microstates are a series of quasi-stable (60-120ms) scalp potential field maps indicating coherent activity in global functional brain networks. Changes in microstates as a function of task are of interest as markers or identifying task-specific activations. This exploratory work investigates EEG microstates of functional hand/finger motor-tasks in 29 healthy male participants (24 right-handed and 5 left-handed; age=18-30; mean=24.25; SD=3.96). Four microstates parameters—occurrence, duration, coverage, and number of microstates (NOM)— across 2 movements (tip-pinch and wrist-flexion/extension) in the pre-event, event, and post-event conditions are analysed. Using 17 electrodes (of a 32 channel EEG system), the extracted microstates are compared to Koenig’s four rs-microstates classes. For the left wrist-flexion/extension motor movement, the event condition has higher values for all parameters (Occurrence, Duration, Coverage, and NOM) than the pre and post conditions. For the right wrist-flexion/extension, only the occurrence parameter is higher. Also, the pre- and post-event duration is significant. The pre-event—event and event—post-event NOM differ significantly for wrist-flexion/extension while event—post-event NOM for tip-pinch. Comparing canonical maps (Koenig et al., 1999) to our motor-task topographies revealed task-specific and common maps, indicating the presence of task-specific states and a few resting state topographies that persisted during motor tasks. Based on the lower disruption in microstates for event condition NOM, tip-pinch affects the resting-state brain spontaneous dynamic activity less than wrist flexion/extension. The identification of disruptions or new task specific topologies is important to apply microstate as a neurophysiological marker. The findings can be used as a reference model to compare with a stroke-patient dataset.
July 2023