What is "equipotentiality"

Equipotentiality refers to a psychological theory in both neuropsychology and behaviorism. Karl Spencer Lashley defined equipotentiality as “The apparent capacity of any intact part of a functional brain to carry out… the [memory] functions which are lost by the destruction of [other parts]”. In other words, the brain can co-opt other areas to take over the role of the damaged part. Equipotentiality is subject to the other term Lashley coined, the law of mass action. The law of mass action says that the efficiency of any complex function of the brain is reduced proportionately to how much damage the brain as a whole has sustained, but not to the damage of any particular area of the brain. In this context when we use brain we are referring to the cortex.