title: Additional exposures reverse the latent inhibitory effects of recent and remote exposures.
abstract: We studied the learning produced by simple exposures to a stimulus. Exposures depressed orienting and subsequent conditioned freezing in rats. A remotely preexposed conditioned stimulus (CS) conditioned better and overshadowed a novel CS more than a recently preexposed CS. Additional preexposures reversed these effects: a remotely preexposed CS elicited more orienting, conditioned worse and overshadowed less than a recently preexposed CS. Exposure to a compound composed of a novel CS and a remotely preexposed CS resulted in the novel CS subsequently conditioning better than a novel CS exposed in compound with a recently preexposed CS. The results were interpreted to mean that stimulus-alone exposures produce a loss in associability which recovers across time, that this restoration deepens the loss in associability, and that this deepening is regulated by a common error term.
authors.affiliation: School of Psychology, University of New South Wales, Sydney 2052, New South Wales, Australia.
authors.forename: Orit
authors.initials: O
authors.lastname: Holtzman
authors.forename: Joyce
authors.initials: J
authors.lastname: Siette
authors.forename: Nathan M
authors.initials: NM
authors.lastname: Holmes
authors.forename: R Frederick
authors.initials: RF
authors.lastname: Westbrook
mesh_terms: D000818:Animals; D001245:Association Learning; D003214:Conditioning, Classical / Q000502:physiology*; D003463:Cues; D004192:Discrimination, Psychological; D046352:Freezing Reaction, Cataleptic / Q000502:physiology; D007266:Inhibition, Psychological; D008297:Male; D009949:Orientation / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D021641:Recognition, Psychology / Q000502:physiology*; D013997:Time Factors