Previous experiences are obviously of great importance for the qualitative and quantitative emotional response. The visceral brain as well as the neocortex is known to contribute to memory, but this topic is beyond the scope of this paper.

After this brief discussion of neo --, paleocortical, and cortico-hypothalamic relations, let us return once more to the problem of hypothalamic balance and its physiological and pathological significance. Facilitatory processes take place between neocortex and hypothalamus via ascending and descending pathways. Thus cortico-fugal discharges induced by topical application of strychnine to a minute area in the neocortex summate with spikes present in the hypothalamus and cause increased convulsive discharges. On the other hand, the temporary reduction in hypothalamic excitability through the injection of a barbiturate into the posterior hypothalamus causes a lessening in frequency and amplitude of cortical strychnine spikes until the hypothalamic excitability is restored. Apparently, a positive feedback exists between the posterior hypothalamus and the cerebral cortex. Consequently, if for any reason the hypothalamic excitability falls below the physiological level, the lessened hypothalamic cortical discharges lead to a diminished state of activity in the cortex with consequent reduction in the cortico-fugal discharges. Obviously, a vicious cycle develops. This tendency can be broken either by restoring hypothalamic excitability directly or via cortico-hypothalamic pathways. It is believed that drug therapy and electroshock involve the former and psychotherapy the latter mechanism.