Conditional (CS) / Unconditional (US) Stimulus

Conditional and unconditional stimulus in classical conditioning is the process that explains how fears and phobias develop—the process of forming learned associations unconditioned stimulus (US) is any stimulus that naturally, automatically, and unconditionally triggers a reaction or response without any prior learning–an innate, physiological reflex. Food makes a hungry dog salivate. Food is the US. Salivation is the unconditioned response (UR). In agoraphobia, the US is often a biologically or psychologically significant aversive event, such as a sudden, unexpected panic attack, a genuine loss of control, or a traumatic experience that naturally and automatically elicits intense fear, terror, and a fight-or-flight response (FFR). A conditioned stimulus (CS) is a previously neutral stimulus that, by itself, produces no significant response. However, after being repeatedly paired with a US, eventually comes to trigger a similar response. This response is now a learned or “conditioned” response, which is learned through association. A ringing bell (initially a neutral stimulus) is repeatedly paired with food (US). Eventually, the dog learns the association, and the bell alone (CS) makes the dog salivate (conditioned response/CR). In agoraphobia, CS is a place, situation, or even internal bodily sensation (elevated heartrate) that was once neutral but has become associated with the panic attack (US). The goal of exposure therapy is to break the learned association between the CS (being in a store) and the US (panic attack).