Drugs and behaviour
The stable behaviour resulting from schedules of intermittent reinforcement provides a controlled situation in which the important variables are reasonably well identified, and is therefore suitable for investigating the effects of drugs on behaviour. The converse may also apply: careful selection of behavioural baselines can make it possible to conclude with confidence that certain drugs do affect perceptual processes. Experimenters have been much more interested in the chemical nature of the pharmacological substances themselves and their effects on the physiological system. One important determinant of the behavioural effect of a drug seems to be the rate of responding in non-drug condition. The response rate after the drug is expressed as a percentage of the control rates of responding in the various conditions. It will be seen that the dose-effect curves are substantially similar when similar schedules are compared. Operant conditioning techniques are also becoming increasingly important in investigating drug addiction.