Stimulus intensity and modulation of brain output.

In accordance with the implications of a previously proposed mathematical model of modulation of bioelectric response in the brain, it is found that a single free coefficient predicts the observed modulation periods over a range of stimulus intensities. This coefficient is shown to be a computable function of stimulus intensity. Change in the mean modulation period of evoked bioelectric output at the visual cortex of the rat can be described as a power function of the intensity of photic stimulation.