FIGURE 2.

Multiscale interaction. The macro-, meso-, and microscopic processes are braided together by co-occurring multifrequency oscillations, giving rise to upward and downward causation. Activity at micro-scale (cellular assemblies) sums up to local activities at meso-scale, which in turn gives rise to large-scale dynamics and result in a conscious event. In opposite way, cognitive effort influences global brain oscillations in the low- frequency range, which constrain local oscillations in the high-frequency range by variations of the underlying neuronal excitability. These high-frequency oscillations determine the probability of occurrence of spikes and their temporal coincidences on the millisecond scale.