Reinforcers in infancy: classical conditioning using stroking or intra-oral infusions of milk as UCS.

Journal Article (Journal Article)

Six-day-old rats received 20 forward pairings of an odor-conditioned stimulus (CS) with one of two unconditioned stimuli (UCS); 1) intra-oral milk infusions or 2) stroking with a sable-hair brush. These UCS's produce a common general response of increased behavioral activity, but different specific behaviors. For each UCS, additional pups received backward pairings of the CS and UCS, random pairings of the CS and UCS, CS only, UCS only, or no stimuli. Four hours later, pups received a two-odor choice test to assess the development of an odor preference and a CS-only test to assess the acquisition of conditioned responding (CR). The results of the two-odor choice test indicated that for both UCS's only forward pairings of the CS and UCS resulted in an odor preference. Similarly, the CS-only test showed that only forward pairings of the CS and either UCS were effective in producing CR's; pups that received forward pairings exhibited increased behavioral activity during presentations of the CS, which is an unconditioned response (UCR) to both UCS's. Only the forward paired CS-milk UCS group exhibited increased mouthing and probing during the CS only test; these are UCR's that occur to milk infusions but infrequently to the stroking UCS. These results demonstrate the development of similar conditioned odor preferences using behaviorally activating UCS's, but CR's which are specific to the form of the UCR.

Full Text

Duke Authors

Cited Authors

  • Sullivan, RM; Hall, WG

Published Date

  • April 1, 1988

Published In

Volume / Issue

  • 21 / 3

Start / End Page

  • 215 - 223

PubMed ID

  • 3371554

Electronic International Standard Serial Number (EISSN)

  • 1098-2302

International Standard Serial Number (ISSN)

  • 0012-1630

Digital Object Identifier (DOI)

  • 10.1002/dev.420210303


  • eng