THE THALAMUS IN THE PHYSIOLOGY AND PATHOLOGY OF THE MIND

Abstract

The role of the thalamus is one of the most interesting and most important problems. The thalamus is essentially the receptive or sensory portion of the primitive or segmental brain, the paleoencephalon. The relation it bears to the impacts which the organism receives from the outside world and to the transmission of these impacts to the neoencephalon, the cortex, gives it a significance and value altogether peculiar. Too often its importance is overlooked or, it may be, underestimated. When we turn our attention to the cephalic end of the nervous axis of a simple vertebrate form, such as a fish, we note the presence of certain aggregations of neurons which stand in definite relation to certain receptors. The first aggregation is that constituting the olfactory lobe; this is in close relation with the olfactory mucous membrane. Back of the olfactory lobe we note a lobe related to the receptors in