Effects of set, setting, and sedatives, on reaction time.

The effects of sessions, individual characteristics, group behavior, sedative medications, and pharmacological anticipation, on simple visual and auditory reaction time were evaluated with a randomized block design. The project involved 4 separate small groups of 5 to 9 healthy young adults who met 4 times for 9 hr. over 4 mo. and received 4 drug regimens under controlled conditions. Attitudes toward the experiment, which were mainly related to an early fear of potent drugs and late feelings of weariness, markedly affected reaction time. This effect decreased the test-retest reliability of the instrument, hence its sensitivity. Group behavior, subjective feelings attributable to the medications, and pharmacological anticipation, on the other hand, did not seem to have affected psychomotor performance. The effects of sedatives were much more marked and consistent with reaction time than with subjective responses, which primarily represented the influence of anticipation. This dissociation between objective and subjective behavior indicates that the subjects acted according to the drugs which they had taken but felt according to what they believed they had received.