EFFECTS OF CNS ACTIVE-DRUGS ON MANUAL AND COMPUTERIZED PSYCHOMOTOR TESTS AND MEMORY

Six Letter Cancellation Test (SLCT) and Digit Symbol Substitution Test (DSST) are commonly employed for psychomotor evaluation in human subj ects. They suffer from many disadvantages, for the removal of which th is computerisation project was undertaken. The number of correct cance llations/substitutions in the manual SLCT/DSST were compared to the ti me required to complete the computerised Versions of these tests. Ther e was a significant negative correlation between the cancellations in the manual SLCT and the time taken to complete computerised SLCT (r = -0.61; p < 0.05) as well as between the correct substitutions in manua l DSST and the time taken to complete the computerised DSST (r = -0.63 ; p < 0.05) when compared in 12 human volunteers before and two hours after the oral administration of placebo, diazepam (5 mg), promethazin e (25 mg) and amitripthyline (25 mg) in a double blind study. Prometha zine significantly improved the performance in the manual and computer ised SLCT but had no effect on DSST. There was no significant effect o f any other treatment on either manual or computerised SLCT and DSST. In addition, diazepam significantly reduced (p < 0.05) computerised me mory recall 20 min after learning, but not immediate recall. No other treatment had any significant effect on either of the two memory recal l tests. It is concluded that computerised SLCT and DSST are similar t o their manual counterparts, offer all the advantages of computerisati on and may be preferred when these tests have to be administered to si ngle subjects or small groups repeatedly as in pharmacological studies .