Karl Lashley was a behaviorist well known for his study of functional specialization of cortical areas and their importance in learning and memory. He contributed to two major principles: the law of mass action and the law of equipotentiality. The mass action principle states that the amount of cortical tissue removed is proportional to deficits in memory. Therefore, memory is not localized to one area but distributed across the cortex. The law of equipotentiality states that if a part of the brain is damaged, an intact part within that functional area can take over its function.