“…The experimental designs of most of these studies (like the present one) do not provide a crucial test between these alternative interpretations. But since there is abundant clinical evidence that tra.nquilizing drugs do decrease hyperexcitability and anxiety (Berger, Hendley, & Tynes, 1956;Osinski, 1957;Wilder, 1958) and some experimental data showing they also decrease the activation level as measured by the psychogalvanometer (Carran, 1960;Kristofferson & Cormack, 1960), our predictions are based on the assumption that tranquil izing drugs possess drive-altering properties.…”