Fig. 3: Oscillatory cortico-subthalamic connectivity.

a Spatial contributions of maximised imaginary coherency reveal motor cortex and dorsolateral STN as the strongest contributors to high beta connectivity (red dots). Localisations are shown for individual electrodes and interpolated to surfaces alongside multivariate connectivity spectra. Maximised imaginary coherency reproduces the therapeutic suppression of high beta cortico-subthalamic connectivity, shown in the inset (levodopa, t = 0.556, p = 0.03277; DBS, t = 0.615, p = 0.01883). b Shared therapeutic modulation can be observed in the grand average imaginary coherency spectra, demonstrating suppression of cortico-subthalamic high beta connectivity with medication (t = 0.523, p = 0.04312) and DBS (t = 0.653, p = 0.01752). c Granger causality shows that the motor cortex drives communication with STN across medication and stimulation states, with a stimulation-specific suppression of high beta activity. Frequencies of significant connectivity OFF therapy marked as grey lines on the plots. d Bispectral time delay analysis highlights the contributions of mono- and poly-synaptic pathways to cortico-subthalamic communication, and the shared therapeutic suppression of monosynaptic pathway communication. Upper plots show the strength of grand average time delay estimates for each time bin, with opaque lines representing estimates which are significantly greater than the physiological control of parietal cortex – STN communication. The bottom plots show the number of peaks in each connection of the time delay estimates aggregated over 10 ms windows, with significance again determined against the physiological control of parietal cortex – STN communication. All panels: shaded coloured areas show standard error of the mean; shaded light grey areas indicate a significant difference in the average values of canonical frequency bands between conditions; shaded dark grey areas indicate clusters of significant differences between conditions for the respective frequency bins; * p < 0.05; statistical results obtained from two-sided (one-sided for panel d) permutation tests with cluster correction to control for multiple comparisons where appropriate. Source data are provided as a Source Data file. A anterior, DBS deep brain stimulation, ECoG electrocorticography, I inferior, L left, P posterior, R right, S superior, STN subthalamic nucleus.