Pavlov and classical conditioning

My 1st post, so thought I lob up an extract from a recent assignment on drug addiction and conditioning.....

Pavlov was a Russian physiologist whose salivation studies in dogs led to what it is now known as classical conditioning. Subkov & Zilov (1937) extended Pavlovs' research by developing what is now termed pharmacological conditioning. Their experiment involved injecting dogs with adrenaline which speeds up the heart rate. The animals exhibited bradycardia (slowing heart rate) but also exhibited bradycardia on presentation of CS cues The dogs also showed bradycardia upon the injection of an inert substance, this also is a CR to a CS.

What researchers have subsequently discovered is the human body develops a drug compensatory response when a drug is administered, and that humans can develop a learned response called conditional compensatory responses (CCR). A CCR is the human body's homeostatic response, i.e. counterbalance, to the effects of a drug, and the strength of the drug's effects will reduce over repeated administration.

It has also been found that a CCR in absence of a UCS is in fact what people recognise as a craving and that if a drug user is presented with a CS but no UCS a craving (or CCR) will start. Drug users can have multiple CS or environmental cues which elicit a CCR. These cues might be a combination of the following: the drug paraphernalia, the physical environment/room, habits/rituals and the self administration cues (SAC).

Narcotic overdoses do not necessarily occur when an individual takes what generally constitutes too much of a drug. It has been established that overdoses are commonplace when users take the drug in a novel environment or there is a distortion in some of the CS though the drug amount or strength is the same as usual. When this occurs, the reduced CCR cannot counteract the UCS and the person can suffer an overdose.

Pavlov found that when he presented the tone several times on its own without the meat powder to the dogs, there was less and less salivation from the animals. This is known as extinction. Drug users could employ extinction techniques and extinguish learned drug using behaviours by repeated exposure to a CS but not seeing/using/feeling the UCS. The user will eventually experience a weakening of the CCR the longer the extinction process used employed.

Unfortunately extinction does not mean that a drug CR is erased and spontaneous recovery (SR) will occur if a user is readmitted to a CS environment. SR is the reappearance of a CR when a CS is presented after extinction but without reconditioning being present.

Therefore, crack users can manage to abstain from the drug when they are taken away from their normal CS cues, environment and the UCS and were able to abstain from crack. However as the crack users returned to their locality, the sight of their local neighbourhood, the environmental cues elicit a re-emergence of cravings (CCR). Similarly, the more they were exposed to the CS cues the greater the potential for strengthening the CCR and a greater chance for the crack user to relapse into drug usage.