title: Conditioned suppression is an inverted-U function of footshock intensity.
abstract: Most theories of associative learning assert that conditioned responding to a target cue is a monotonically increasing function of unconditioned-stimulus (US) intensity. In a lick suppression preparation with rats, a cue was paired with a 0.4-, 0.6-, 0.8-, 1.0-, 1.2-, or 1.4-mA footshock in Experiment 1a, and with a 0.3-, 0.8-, 1.3-, or 1.8-mA footshock in Experiment 1b. Subsequent suppression in response to the cue was an inverted-U function of the US intensity. In Experiment 2, we demonstrated that massive extinction of the training context and compound conditioning can each attenuate the response decrement caused by training with a high-intensity US. The sometimes-competing-retrieval model (Stout & Miller, Psychological Review 114:759-783, 2007) provides a better fit to these data than do several other models of associative learning.
authors.affiliation: State University of New York, Brockport, NY, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Witnauer
authors.forename: Ralph R
authors.initials: RR
authors.lastname: Miller
mesh_terms: D000818:Animals; D001245:Association Learning; D003214:Conditioning, Classical; D003463:Cues; D004597:Electroshock; D005108:Extinction, Psychological; D005121:Extremities; D005260:Female; D007266:Inhibition, Psychological; D008297:Male; D008960:Models, Psychological; D051381:Rats