Probability of shock in the presence and absence of cs in fear conditioning.

Abstract

2 EXPERIMENTS WITH MALE SPRAGUE-DAWLEY RATS INDICATE THAT CS-UCS CONTINGENCY IS AN IMPORTANT DETERMINANT OF FEAR CONDITIONING AND THAT PRESENTATION OF UCS IN THE ABSENCE OF CS INTERFERES WITH FEAR CONDITIONING. IN EXP. I, EQUAL PROBABILITY OF A SHOCK UCS IN THE PRESENCE AND ABSENCE OF A TONE CS PRODUCED NO CONDITIONED EMOTIONAL RESPONSE SUPPRESSION TO CS; THE SAME PROBABILITY OF UCS GIVEN ONLY DURING CS PRODUCED SUBSTANTIAL CONDITIONING. IN EXP. II, WHICH EXPLORED 4 DIFFERENT PROBABILITIES OF UCS IN THE PRESENCE AND ABSENCE OF CS, AMOUNT OF CONDITIONING WAS HIGHER THE GREATER THE PROBABILITY OF UCS DURING CS AND WAS LOWER THE GREATER THE PROBABILITY OF UCS IN THE ABSENCE OF CS; WHEN THE 2 PROBABILITIES WERE EQUAL, NO CONDITIONING RESULTED. (PsycINFO Database Record (c) 2006 APA, all rights reserved)