EFFECTS OF PRETRIAL AND POSTTRIAL ADMINISTRATION OF CHOLINERGIC AND ANTICHOLINERGIC DRUGS ON SPONTANEOUS ALTERNATION

Studied spontaneous alternation as a 1-trial learning paradigm. The anticholinesterase, physostigmine, or the anticholinergic agent, scopolamine, was administered to 635 male albino rats 15-35 min. before Trial 1 or 15-35 min. before Trial 2. The 2 trials were separated by intervals of 15-150 min., which sampled the range over which spontaneous alternation occurs. When treatment preceded or immediately followed Trial 1, physostigmine increased the rate of alternation and scopolamine lowered it. When these drugs followed Trial 1 by more than 15 min., the alternation rate was not affected. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.