Another difference was apparent in the temporal evolution of the spatial distributions for gamma-50 and gamma-80 power. Gamma-50 power was lowest, and without spatial structure, at the start of the session, developing discernible modulation within about 5 laps, and then relatively stable within 10 laps. In contrast, gamma-80 power was highest during early laps, dropping to a relatively stable level within 10 laps. Thus, gamma-50 and gamma-80 oscillations not only showed a differential expression over the spatial extent of the track, but also evolved differently during the initial phase of learning.
