The human frontal lobes and their role in the organization of activity.

The role of the human frontal lobes (and predominantly their mediobasal parts) in regulation of the two types of unspecific activation was studied. These types were: fast orienting reactions and slow changes in levels of vigilance. 92 normal persons and 202 patients with lesions of the frontal lobes and other regions of the brain were observed. As indicators for the fast kind of activation we used different components of the orienting reflex; as indicators for the slow kind of activation we employed slow changes in the form of the EEG waves. The data show that the mediobasal parts of the frontal lobes are important regulators for both types of activation.