The Common Sensorium: An Essay on the Cerebral Cortex

Abstract

There is a curious ambiguity in the neuroanatomist’s attitude toward the cerebral cortex, the most respected and at the same time the most neglected piece of the human brain. We have learned from the localizationists that the cerebral cortex is responsible for the highest psychic functions, but we do not know what to make of this in view of the stupendous cerebral cortex of a cow, which most nonspecialists can hardly distinguish from that of man. We have also learned that on the surface of the cerebral cortex innumerable “areas ” can be distinguished, each devoted to a very special function, but generations of experimental psychologists have piled up evidence to the effect that it does not matter which part of the cortex of a rat is ablated, — the behavior of the animal in their hands is reduced to a degree that depends on the amount, not on the localization of, the tissue destroyed. Some say that the structure of the cerebral cortex is complex beyond description, too complex ever to be understood by the human mind, which, after all, possesses no more complex instrument that the cortex itself to perform the analysis. Others approach the physiology of the cerebral cortex with the same strategy that has been useful in the study of the frog’s eye, only to discover that the cortex of the monkey is somewhat simpler than the retina of the frog.

Truth is of two kinds, consisting either in the discovery of the proportions of ideas, considered as such, or in the conformity of our ideas of objects to their real existence.

David Hume [8.13]

For the same things can be thought as can be.

Parmenides [8.17]

To Larry, with thanks.