Figure 6.

Evoked response visualization—each figure contains the evoked response from the first stimulation epoch occurring on Days 3, 15, 30 and 50 to show the temporal evolution (Electrode-R only). Data shown are from Experimental S1; similar results were present in all Experimental animals. (A) The average of 100 evoked responses from a single 5 min train of pulses. Note that on this long time scale the largest difference is the amplitude after stimulation. After normalization, the largest difference occurred in the first 0.01 s after stimulation (star, small bar), which are expanded in ‘B’. (B) Stimulation artefact is removed from the analysis. The average waveform is normalized between 0 and 1 (subtracting the minimum and dividing by the new maximum for each averaged tracing). This is done to minimize amplitude changes due to electrode variability over time. (C) The power spectrum density is computed for each averaged waveform. Temporal changes in the power spectrum density were highly consistent across time in the epileptic animals. Each Control was processed in the same way and there were some measurable differences over time, but they were not consistent with each other nor with the epileptic animals (see Fig. 8).