Strychnine and Memory Process

feedback training can lead to large and significant changes in alpha densities when conditions have lowered alpha density below the levels seen spontaneously under optimal conditions. Subjects can acquire volitional control over alpha activity only under conditions which normally lead to decreased densities. Thus, during the initial orientation in the dark, when subjects experiment, but are not especially set to increase alpha density, they achieve a level approximating the level reached with additional training. In the light condition, however, there are marked volitional increases. In spite of these increases, however, in the three procedures reported here, as well as during a number of other procedures run in our laboratory, we have not seen alpha densities beyond an individual's initially demonstrated normal physiological range. While ambient light is sufficient in the present studies to act as a suppressing stimulus, it is likely that other stimuli such as anxiety or physical stress may, in some circumstances, also lead to suppression which persists. Although no increases in alpha density are seen when the situation presents few suppressing stimuli, alpha feedback training may enable a subject to overcome suppressing effects when they are present. The subjective experiences reported to be associated with alpha feedback training (3, 4) may be understood as a consequence of acquiring skill in disregarding stimuli in the external and, perhaps, internal environment which would ordinarily inhibit alpha activity. Increased alpha densities, then, may best be viewed not as an end in themselves, but as one convenient index of a subject's ability to acquire this skill. DAVID A. PASKEWITZ MARTIN T. ORNE Unit for Experimental Psychiatry, Institutte of thle Pennsylvania Hospital. and University of Peinnsylvania, 111 North 49 Street. Philadelphia 19139