RETARDATION OF FEAR ACQUISITION BY A PREVIOUSLY INHIBITORY CS

Used a reversal conditioning technique to measure inhibitory properties of CS in differential conditioned emotional response. 2 groups of 10 albino rats received tone-shock conditioning and light presentations during Stage 1. For Group I (inhibitory) light presentations were explicitly unpaired with tone-shock presentations. For Group R (random) light presentations occurred randomly in relation to tone-shock presentations. In Stage 2 both groups of 10 albino rats each received light-shock presentations and tone-no-shock presentations. During Stage 2, Group I showed significantly less suppression to light than Group R after short and medium lengths of acquisition, however, not after long acquisition in Stage 1. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1968 American Psychological Association.