Single unit and beta oscillatory activities in subthalamic nucleus are modulated during visual choice preference

Parkinson's disease is a neurodegenerative disease affecting the supply of dopamine to basal ganglia nuclei, leading to pathological beta band (13–35 Hz) oscillations in the subthalamic nucleus (STN). STN and beta activity are recognized in motoric functions but their role in cognitive functions remains elusive. We examined single unit and beta local field potential (LFP) activity in the STN during a visual choice preference task in PD patients (n = 12) undergoing deep brain stimulation surgery. Patients viewed 2 of 5 possible animal picture‐pairs and were instructed to choose their favorite (“fav”) picture by clicking the left or right mouse key. A block of trials consisted of 50–75 picture‐pair presentations. Single unit histograms and LFP spectrograms were aligned to picture presentation and point of decision for pairs that included the fav and non‐fav pictures, respectively. A total of 58 neurons from 26 blocks of trials were analyzed. Thirty of 58 neurons showed a selective change in spiking activity 0.20–0.65 s to fav picture presentation, which preceded the shortest recorded reaction time (=0.7 s), and 17/58 neurons showed no significant response in our task. Beta LFP significantly desynchronized in response to fav but not non‐fav pictures in all trials, and in 14/26 blocks of trials, the desynchronization was followed by a “beta burst” and ramp‐up to baseline activity. Neurons with choice preference responses were found throughout the dorsoventral extent of the STN. STN single units and beta activity are modulated during visual choice preference, and this suggests a role for STN beta activity in cognitive processing. To explore the role of the STN in non‐motor behavior, we recorded single units and beta LFPs during a visual choice preference task in 12 awake PD patients undergoing DBS surgery. Both single unit and beta activity were selectively modulated to the preferred picture. Beta LFP averages aligned to the point of decision were desynchronized during favorite picture trials and often showed beta bursts synchronized to the decision, supporting a role for beta activity and the STN in choice preference.