What happens if a conditioned reflex is not reinforced with an unconditioned one? - briefly
If a conditioned reflex is not reinforced with an unconditioned stimulus, it will gradually weaken and eventually disappear, a process known as extinction. This occurs because the association between the conditioned and unconditioned stimuli fades over time without reinforcement.
What happens if a conditioned reflex is not reinforced with an unconditioned one? - in detail
When a conditioned reflex is not reinforced by an unconditioned stimulus, several key processes occur that ultimately lead to the extinction of the conditioned response.
Firstly, it's crucial to understand that conditioned reflexes are learned responses where a neutral stimulus (conditioned stimulus or CS) comes to elicit a particular response after being paired with an unconditioned stimulus (US). The US is a stimulus that naturally evokes the unconditioned response (UR), such as food causing salivation.
If the CS is presented repeatedly without the accompanying US, the conditioned response (CR) gradually weakens and eventually disappears. This process is known as extinction. During extinction, the organism learns that the CS no longer predicts the US, leading to a decrease in the CR over time. The rate of extinction depends on various factors, including the strength of the initial conditioning, the number of extinction trials, and the interval between the CS and US during the original conditioning.
Neurobiologically, extinction involves changes in the brain's synaptic connections. During conditioning, synapses between neurons involved in processing the CS and those involved in generating the CR are strengthened. Extinction reverses this process by weakening these synapses, effectively "unlearning" the association between the CS and US.
It's important to note that extinction is not a permanent erasure of the memory trace but rather a suppression or inhibition of the response. In some cases, the extinguished CR can return, a phenomenon known as spontaneous recovery. This occurs when the organism is exposed to the CS after a period of time has passed since extinction. Additionally, if the US is reintroduced with the CS (renewal), or if the context changes significantly (reinstatement), the extinguished response can also return.
In summary, when a conditioned reflex is not reinforced by an unconditioned stimulus, extinction occurs, gradually weakening and eventually eliminating the conditioned response. This process involves both behavioral and neurobiological changes and is essential for adaptive learning in dynamic environments.