Visual reaction times may be improved by certain beta-blockers.

The effects of the beta-blocker atenolol on vigilance, concentration, and psychophysiological condition were determined by measuring visual reaction time and choice reaction time in volunteers subjected to combined physical and mental stress. Atenolol 50 mg or placebo were administered for three days in a double-blind crossover design. Forty male subjects aged 26 +/- 6 years with a mean blood pressure of 126/79 mmHg and increased activity of the sympatheticus nerve were admitted to the first study. Physical workload was imposed using a training ergometer for ten minutes and mental workload was introduced by asking the subjects to calculate additions and subtractions on mechanical equipment. Electrooculography was used to measure visual reaction time. Fifty subjects aged 32 +/- 9 years with a mean blood pressure of 141/90 mmHg were admitted to a second study. The same crossover design was followed, but a different mental workload was imposed; subjects were required to respond to coloured light signals which were presented at intervals of 0.8 seconds, by pressing the appropriate buttons. In this second study visual reaction time was also assessed by electrooculography whereas choice reaction time was defined as the time between the lighting of a signal (in one of five colours on 1-25 different places on a screen) and its extinction by pressing an appropriate coloured button. As expected, blood pressure and heart rate decreased with atenolol. In the first study, in both periods, visual reaction time was higher with placebo than with atenolol. The effect of treatment was small but highly significant (p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)