A genetic study of brain differentiation by the action current method.

Abstract

Action currents were recorded from the brain of a crayfish, a frog, a snake, a pigeon and a rat. The brain activity as a whole for all animals was characterized by gradients which were noticeably irregular and unpredictable. The lower the animal form, the wider the area involved and the more homogeneous the disturbance. In the higher forms a lateral gradient sometimes resulted from auditory stimulation and a posterior gradient from light stimulation. The magnitude of the response tended to become less in the higher forms, with the exception of the action currents attributed to spontaneous activity. Pain stimuli gave rise to the largest amplitudes. In the higher forms the activity of the brain increased under conditions of dark illumination. The author claims the. results support a dynamic field theory of brain activity as opposed to a specific localization theory.