Disinhibition Account of the Conditioned Response (DACR)

Pavlovian conditioning is widely used to study the substrates of learning and memory in the mammalian brain. In a standard protocol, subjects are exposed to pairings of a conditioned stimulus (CS; e.g., a tone) with an unconditioned stimulus (US; e.g., an electric shock). Subsequent presentations of the CS elicit a range of behaviors that relate to the US (e.g., freezing) showing that animals learned the CS-US relation. However, it is still unclear how neuronal activity pertaining to the CS comes to excite a representation of the US, and thereby, conditioned responses. The current analysis of this problem, based on neurophysiological evidence, views Pavlovian conditioning as a process of facilitating the disinhibition, rather than the excitation, of neuronal responses representing the US. Conversely, Pavlovian extinction is viewed as a process of relearning to inhibit neuronal responses representing the US. We propose a mathematical equation that confirms the predictions made by this novel perspective on Pavlovian conditioning when applied to conditioning phenomena that fall beyond classic associative learning theories.