The effects of some analeptic and depressant drugs upon tracking behavior.

Sixty-four volunteer male subjects were given extensive training on a multidimensional tracking task, then required to perform the task for 4 hours after having been divided into 8 treatment subgroups, as follows: Placebo, d-amphetamine (5 mgm.), mephentermine (25 mgm.), pipradrol (2 mgm.), promethazine (25 mgm.), meclizine (50 mgm.), cyclizine (50 mgm.), and a mixture of scopolamine (0.65 mgm.) with diphenhydramine hydrochloride (50 mgm.). Drug effects were appraised by an analysis of the variance of postexperimental scores following their adjustment for regression upon preexperimental values. After the lapse of time required for absorption and distribution processes, all three analeptics sustained performance significantly above that exhibited by the neutral group. Performance under cyclizine, promethazine, and meclizine conditions was not distinguishable statistically from that of the control group, but the scopolamine-diphenhydramine mixture hastened and maximized performance decrement. The utility value of such preparations for airborne operating personnel was discussed.