Mediated configural learning in rats

ABSTRACT

Three experiments investigated mediated configural learning in male rats. In Experiment 1, after exposure to audio-visual compounds AX and BY, rats received trials where X was paired with shock, and Y was not. The idea that conditioning with X enables the evoked configural representation of AX to be linked to shock received support from the facts that while AX provoked more fear than BX, there was no difference between BY and AY. Similarly, Experiment 2 showed that after exposure to AX and BY, separate pairings of X and Y with shock resulted in more fear to AX and BY than AY and BX. In Experiment 3, rats in group consistent received separate exposures to A and X in Context C, and B and Y in D, while those in group inconsistent received A and X (and B and Y) in both C and D. After rats had received shocks in both C and D, rats in group consistent showed more fear to AX and BY than to BX and AY, but this was not the case in group inconsistent. These results indicate that configural representations, formed either by presenting auditory and visual stimuli as parts of a compound or in a shared context, are subject to a process of mediated learning.

KEYWORDS:

• Associative learning
• configuration

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. It is worth noting in passing that should AX and BY evoke more fear than AY and BX during the test in Experiment 2 then this would undermine another potential explanation for the test results of Experiment 1. This alternative is based on the idea that BX might evoke less fear at test than AX because B evokes the memory of a stimulus (Y) that was paired with no shock during conditioning in Experiment 1. This analysis does not apply to Experiment 2 because both X and Y were paired with shock.

2. An independent-samples t test revealed that the difference between the test ratios for groups consistent (M = .47, SEM = .02) and inconsistent (M = .52, SEM = .02) that was derived from the activity across the three beams approached conventional levels of statistical significance, t(30) = −2.05, p = .05, d = 0.72, 95% CI = [0.36, 1.09].

Additional information

Funding

This work was supported by the Biotechnology and Biological Sciences Research Council UK (BBSRC UK) [grant number BB/I014098/1].