Hans-Peter Krüger, Ralf Kohnen

• In an experimental analog of verbal examinations, the call-up situation, the effects of two dosages of a tranquillizing agent (lopirazepam) are compared to placebo treatment. 72 male and female, healthy, young volunteers have been randomly assigned to 12 groups of 6 subjects each. Pulse frequency and performance were registered. The results indicated differential drug effects which were interpreted according to the hypotheses of "differential effects of social stressors". If a situation was highly challenging for a subject, the application of aIn an experimental analog of verbal examinations, the call-up situation, the effects of two dosages of a tranquillizing agent (lopirazepam) are compared to placebo treatment. 72 male and female, healthy, young volunteers have been randomly assigned to 12 groups of 6 subjects each. Pulse frequency and performance were registered. The results indicated differential drug effects which were interpreted according to the hypotheses of "differential effects of social stressors". If a situation was highly challenging for a subject, the application of a tranquillizer in an adequately high dosage enabled him to perform well in spite of or because of strong increases in pulse frequency.…