1987, Elbert, Thomas, Rockstroh, Brigitte

Neural networks with mutual excitatory connections, forming the substrate of information processing in the cerebral cortex, might activate each other beyond control. It is suggested that this possibility is avoided by a threshold control of cortical excitability. The tuning of cortical excitability is realized via control of the depolarisation in the apical dendrities, which gives rise to surface negative potentials in the EEG. We suggest that the information about the amount of ongoing cortical activity is projected via the basal ganglia to the thalamus. This in turn projects bach to the apical dendrities. The thalamocortical afferent system is controlled by the mediothalamic-frontocortical system. This paper illustrates how such a threshold regulation could provide a key to the understanding of the EEG and event-related potentials.