Figure 2.

Localization of electrodes and evoked responses. (A) Renderings from patient 1's MR images with co-localized recording sites. On the left are two coronal sections showing the location of hippocampal depth macroelectrodes, with the most eccentric 1–2 contacts localized to the hippocampus, indicated by the blue dashes. On the right is a rendering of the whole brain, with the anterior tip oriented up and to the right, revealing the locations of subdural surface electrodes. This was the most common arrangement for the patients in this study. (B) Average evoked responses from several electrode locations, aligned to fixation onset. Time is on the x-axis, relative to fixation onset and magnitude in microvolts is on the Y axis. Time points of significant deviations are indicated by the lines at the bottom of the plot, color coded for the corresponding site (p < 0.001 cutoff of the fixation-time shuffled distribution). Note that the post-fixation response is qualitatively strongest in the hippocampus, and shows a polarity reversal across RHD sites; other locations such as the anterior temporal lobe show transient, broad-band modulation around the saccade event. For more information of the electrode locations sampled across subjects, see Table 1.