Glossary / Lexicon

Mass action is the theory that the cortex works as a whole, and the more cortex the better. Mass action also refers to the extent to which behavioral impairments are directly proportional to the mass of the removed brain tissue. Mass action is Lashley's observation that if cortical tissue is destroyed following the learning of a complex task, deterioration of performance on the task is determined more by the amount of tissue destroyed than by its location.