Figure 4.

Effects of GPi-DBS on information exchange. Data are presented as differences in directed information transfer (DIT), i.e., values greater or smaller than zero indicate opposite directions of information flow as indicated on the diagrams, and DIT magnitude gives the amount of information exchanged in bits. Shaded areas give the 95% confidence interval of the DIT estimates after time-shuffling one of the two signals (leading to zero coupling), i.e., only DIT values outside the CI can be considered significantly different from zero. (A,B) While no exchange of information is observed between both PPNs during DBS-OFF, DBS of either GPi_L or GPi_R* induces a significant flow of information directed from PPN_L to PPN_R*. Abbreviations: CI: confidence interval, DBS: deep brain stimulation, DIT: directed information transfer, GPi: globus pallidus internus (_L = left, _R = right, *denotes clinically more affected side), PPN: pedunculopontine nucleus region (_L = left, _R = right, *denotes clinically more affected side).