Some Psychopharmacological Effects of Atropine

Introduction On the basis of data in the preceding paper,¹we suspect that the focus of attention is influenced by changes in the brainstem reticular system. Drugs and procedures which produce electroencephalographic arousal also produce narrowing of attention; and this relationship between EEG arousal and narrowed attention holds even for anticholinesterases, although these compounds may produce an aroused EEG without apparent behavioral arousal. According to our theory, any drug that produces the opposite of EEG "arousal" (i. e., EEG "drowsiness") should also produce the opposite of "narrowed attention" (i. e., "broadened attention"). Theoretically, "broadened attention" might be produced by morphine, pentobarbital (Nembutal), or atropine, since all three drugs (1) induce high-amplitude slow-wave activity in the EEG (i. e., a drowsy record); (2) raise the threshold for EEG "arousal" from reticular-formation stimulation, and (3) block pituitary activation in the proestrus rat.²Pentobarbital and morphine produce sedation, and actual drowsiness