Fig. 9.

Spatial distribution of upper and lower limb activity within the STN. (A) shows the absolute difference of the expected value of the pdf for upper and lower limbs based on the contacts with the highest modulation and averaged across the 3 axes. The significant cluster between 80 and 83 Hz shows that this activity was relatively spatially separated when comparing upper vs. lower limb movement. (B) shows the example for the localisation of the directional contacts with the strongest 80 Hz modulation for upper (red) and lower (blue) limb movements relative to the STN (grey mesh) in three different planes. The large ellipsoids illustrate the expected values from the pdfs. Their diameter corresponds to the mean distance of the contacts. The biggest shift is that the blue ellipsoid, which represents the spatial centre of lower limb modulation, is more superior and lateral compared to the ellipsoid representing sites showing the maximal modulation during upper limb movements. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)