Blockade of central cholinergic receptors impairs new learning and increases proactive interference in a word paired-associate memory task.
Experimental data and computational models suggest that blockade of muscarinic cholinergic receptors impairs paired-associate learning and increases proactive interference (E. DeRosa & M. E. Hasselmo, 2000; M. E. Hasselmo & J. M. Bower, 1993). The results presented here provide evidence in humans supporting these hypotheses. Young healthy subjects first learned baseline word pairs (A-B) and, after a delay, learned additional overlapping (A-C) and nonoverlapping (D-E) word pairs. As predicted, when compared with subjects who received the active placebo glycopyrrolate (4 microg/kg) and subjects who were not injected, those who received scopolamine (8 microg/kg) showed (a) overall impairment in new word paired-associate learning, but no impairment in cued recall of previously learned associates; and (b) greater impairment in learning overlapping (A-C) compared with nonoverlapping (D-E) paired associates.
Atri
Alireza
A
Boston University, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts 02215, USA.
Sherman
Seth
S
Norman
Kenneth A
KA
Kirchhoff
Brenda A
BA
Nicolas
Marlene M
MM
Greicius
Michael D
MD
Cramer
Steven C
SC
Breiter
Hans C
HC
Hasselmo
Michael E
ME
Stern
Chantal E
CE
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D018680:Cholinergic Antagonists / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007858:Learning / Q000187:drug effects / Q000502:physiology; D008297:Male; D011334:Proactive Inhibition; D011950:Receptors, Cholinergic / Q000502:physiology*; D014936:Word Association Tests / Q000706:statistics & numerical data*
D018680:Cholinergic Antagonists; D011950:Receptors, Cholinergic