Figure 7.

Spiking-related changes in spectral power of EEG in the normal and parkinsonian states. The figure shows averaged means of spectral power values of EEG from (A) MC and (B) SMA calculated for the periods before (open columns) and after (gray columns) the onset of the shortest (S), randomly chosen (R), or the longest (L) ISIs in short consecutive epochs of basal ganglia firing. Data were first normalized to the whole-segment background power and then averaged across all available EEG segments, frequencies, and cells from 3 monkeys for the normal state (upper row, labeled Normal) and from 1 monkey for the parkinsonian state (lower row, labeled MPTP). Error bars represent 95% CIs. Cases in which error bars do not cross the baseline (0%) are statistically different from the background (P < 0.05). *P < 0.05, 2-tailed independent t-tests (Bonferroni–Holm adjusted), MPTP versus normal, of the mean of the differences between pre- and postspike power changes; +P < 0.05, 2-tailed paired Dunnett's t-tests for Short or Long versus Rand series, of the mean of the differences between pre- and postspike power changes, calculated separately for each combination of basal ganglia and cortex structure.