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3. BIOBEHAVIOURAL PROCESSES UNDERLYING DEPENDENCE

Habituation
A decrease in the ability of a stimulus to elicit a response.

Incentive-motivation
Motivation due to stimuli that elicit responses on the basis of their contingency
with other stimuli (Pavlovian principle).

Learning
A process that results in a relatively permanent change in behaviour or behavioural
potential based on experience.
Memory

The mental capacity to store and later recognize or recall events that were
previously experienced.
Reinforcement
The increase in the probability that a behaviour will occur because of the
consequences of that behaviour.
Reinforcer
A stimulus that strengthens responses upon which it is contingent (i.e. which it
reliably follows).
Reward
A primary, unconditioned stimulus that utilizes sensory modalities (e.g. gustatory,
tactile, thermic), and provides feelings of pleasure or well-being.
Sensitization
An increase in the effect of a drug following repeated use. It may be expressed
as behavioural sensitization, and is presumably the result of neural sensitization.
(An increase in the ability of a stimulus to elicit a response).
Stimulus
Any event in the environment that is detected by the sense organs could be a
stimulus.
Tolerance
A decrease in the effect of the same dose of a drug following repeated use.

Withdrawal
A maladaptive behavioural change, with physiological and cognitive concomitants,
that occurs when blood or tissue concentrations of a substance decline in an
individual who had maintained prolonged heavy use of the substance.

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