The Effects of Meprobamate on the Performance of a Five-Choice Serial Reaction Time Task

Abstract

The theoretical framework developed by Eysenck (1955) to account for individual differences in motor and other types of performance has, as its main postulate, the statement that extraverts are characterized by high rates and introverts by low rates of inhibitory growth. An extension of this framework (1957) has allowed a link to be made between personality theory and the theory of drug action, since it has been proposed that depressant drugs increase cortical inhibition and so produce extraverted behaviour patterns, while the opposite is true of stimulant drugs. A test of this postulate by Eysenck, Casey and Trouton (1957) suggested that it was essentially confirmed when applied to motor performance. Dextro-amphetamine sulphate was found to improve and sodium amylobarbitone to depress pursuit rotor performance at all stages of practice. It was concluded that the effect of sodium amylobarbitone was to increase the two inhibitory factors recognized by Hullian learning theory, viz. conditioned inhibition (SIR) and reactive inhibition (IR).