Figure 3. schematic explanation illustrating how alpha oscillations can emerge from a pulsed inhibition mechanism and there by explain the inverse relationship between firing rate and magnitude of the alpha oscillations.

A) Consider a group of neurons firing as represented by the raster plot. Each line reflect one neuron. The neurons initially discharge at a high rate, but the firing is asynchronous (left). Eventually, the firing is inhibited in a pulsed manner every ∼100 ms, resulting in a population activity at ∼10 Hz (right). B). The population activity is measured as the local field potential, the EEG or MEG. Initially, no modulation is observed in the EEG as the firing is asynchronous (left). However, oscillations in the EEG are emerging due to the pulsed inhibition silencing the neurons periodically (right). This mechanism can explain the somewhat paradoxical finding of why alpha power in the EEG is inversely correlated with the firing rate. Adapted from (86). This scheme can also account for how alpha oscillations impact perception in an inhibitory and phasic manner (87).