ABSTRACT
The time was long past to consider psychological processes as the result of either strictly localized brain activities or the “mass action” of the brain in which all of its parts were “equipotential.” During recent years people have focused on two main problems, each of which illustrates a different path toward specification of the mechanisms underlying complex psychological functions. During the 1940s and 1950s important progress was made in the study of brain organization. In due time neuroanatomists discovered that the structure of the reticular formation included both ascending and descending fibers, some of which were discharged only by specific forms of stimulation, while others were activated in a nondifferentiated way that seemed to affect the brain as a whole. Subjects were first adapted to sitting quietly in a chair in a bare room where nothing special was happening. Sensory aphasia is a condition in which patients can speak but are unable to understand spoken language.
