Murray J Goddard | PubMed Health

PubMed2004

Serial order learning in associative formation.

Serial order learning was investigated in rats by delivering food to two spatially distinct feeders. All rats received three food pellets in feeder A delivered 10 min into the session. Three additional pellets were then delivered in feeder B after 20s, in Group Short (S), or 150 s, in Group Long (L). The rats in Group S learned the A-B association better than the rats in Group L. Of more interest, however, was that the rats in Group S showed more anticipatory responding to feeder A, suggesting subjects had better learned that feeder A delivered food "first". Implications for classical conditioning and serial order learning are considered.

Animals↗

PubMed2003

Latent inhibition of US signal value.

Three experiments with rats examined the effects of preexposure to an unconditioned stimulus (US; a single food pellet) on the subsequent ability of that US to effectively signal the delivery of three food pellets during a US-US conditioning procedure. In Experiment 1, latent inhibition (LI) rats showed attenuated conditioning, compared to control (C) rats, when a single food pellet, delivered 10 minutes into a session, was followed by three additional pellets. In preexposure, one pellet had been delivered 10 minutes into each session (in group LI), or placed into the magazine at the beginning of each session (in group C). Experiment 2 showed that this effect was evident when the conditions of preexposure matched those of conditioning for group C, and Experiment 3 showed that the difference between groups LI and C was not a product of context conditioning, or latent inhibition to the noise of the feeder in group LI. Implications of these results for theories of latent inhibition are considered.

Animals↗