Motor estimation of short time intervals under the effect of some psychotropic drugs.

A study is made of the human ability to estimate short time intervals (up to 1 s) by a simple motor response under the effect of stimulants (Amphetamine, Caffeine) and depressants (Chlorazin, Diazepam, Phenobarbital). Of all psychotropic drugs used only Chlorazin causes a statistically significant increase in the mean values of the reaction time of all subjects compared with the controls. The psychotropic drugs in the doses used have no influence on the ability of the subjects to produce a light interval of a given duration. In the task requiring reproduction of a 900 ms interval, Amphetamine schortens significantly the response times, which is explained by earlier organization of their motor responce and lack of feedback.