[P1] Poster: Day 1

[P1-08] Comparing Neural Oscillations During Cued and Uncued Rhythmic Movement Using Simultaneous Intracranial Basal Ganglia and Cortical Recordings: An Ongoing Study

*Bar Yosef¹, Jingtong Lin¹, Ausaf Bari¹, Kathryn Cross¹ (1. University of California, Los Angeles (United States of America))

Keywords:

rhythmic movement,Parkinson's disease,intracranial electrophysiology,auditory cueing,basal ganglia

Rhythmic auditory stimulation (RAS) is a promising therapy for improving gait in Parkinson’s Disease (PD) patients. By providing external rhythmic cues, such as metronomes or music, RAS may compensate for impaired internal timing and improve motor coordination. However, the electrophysiological mechanisms underlying RAS remain unclear. Rhythmic cues may facilitate the impaired basal ganglia-cortical loop in PD or engage alternative compensatory circuits. Beta-band activity (13–30 Hz), which is linked to movement and might be modulated by rhythmic auditory stimuli, particularly in motor cortical areas, may play a key role. We hypothesize that auditory cues facilitate movement-related beta modulation in the basal ganglia-cortical loop. In the current study, we simultaneously recorded local field potentials from the globus pallidus internus (GPi) and cortex using subdural electrodes (ECoG) in 10 PD patients undergoing deep brain stimulation surgery. Patients performed a rhythmic tapping task with auditory tones presented at isochronous subsecond intervals under three conditions: passive listening (tones only), cued tapping (tones with tapping), and uncued tapping (tapping without ongoing auditory cues). Preliminary analyses show canonical movement-related beta suppression in the motor cortex during tapping compared to passive listening, confirming prior evidence that these signals are movement driven. However, auditory cues during tapping did not affect trial-averaged beta power in the GPi or motor cortex at the group level. Interestingly, auditory cues did affect average beta power in patients with ECoG over prefrontal and auditory cortices, suggesting that these regions may differentially engage in processing rhythmic cues versus internally generated timing. We are conducting ongoing analyses to assess finer temporal dynamics by examining tap-locked beta changes over time and evaluating whether auditory cueing is associated with changes in GPi-cortical connectivity. Understanding how rhythmic cues modulate brain dynamics in PD may reveal compensatory mechanisms beyond the motor system and inform the development of more personalized, neurophysiologically-targeted RAS therapies.