Fig. 3.

ALFF, a general measure of brain activity, was increased for participants on the ketogenic diet compared to their standard (std) diets (n = 12). This remained true for resting state, as well as during motor and spatial navigation tasks. Resting state and motor tasks were of 10 min duration. Spatial navigation shows the first 10 min (for comparison with other tasks) and then an additional 30 min, for 40 min total. This was done to assess fatigue effects over longer periods of time. Comparing symmetry over time between shifts from lower- to higher-activity states versus shifts from higher- to lower-activity states, both the ketogenic and fasting conditions showed a mean of zero bias (one-sample t test ketogenic diet: t = –0.22, P = 0.83; overnight fast: t = 0.26, P = 0.80), whereas the standard diet condition showed the brain switching from high- to lower-activity states (standard diet: t = –3.29, P = 0.007).