Psychological performance models as indicators of the effects of hypnotic drugs on sleep.

A theoretical and practical scheme for the measurement of change in psychological performance is presented. An information processing paradigm is used as the basis for the model while personality, memory, motivational and experiential variables are shown to be amenable to control via the application of standard experimental methodologies. The model is realised in practical experimental terms in the use of measures of choice reaction time and critical flicker fusion threshold. The reliability and sensitivity of these parsimonious indices of performance change is illustrated in a brief review of the effects of benzodiazepine hypnotics on early morning performance.