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. [ABSTRACT FROM AUTHOR]