Is Reasoning in Rats Really Unreasonable? Revisiting Recent Associative Accounts

IntroductIon Beckers et al. (2006) published intriguing results, obtained in the rat fear conditioning paradigm, challenging classical associativist theories of learning. One of the main findings of Beckers et al. (2006) is that what they called subadditive pretraining abolished the expression of blocking (see Table 1; Figure 1), an effect that Beckers et al. (2005) had previously demonstrated in Human subjects. Beckers et al. (2006) contended that it was difficult to see how an associative account of this interesting phenomenon could be put forward. Recently, Haselgrove (2010) has put forward an associative account of this phenomenon based on the Rescorla-Wagner model (Rescorla and Wagner, 1972). This associative account is based on the idea of a common element (p) shared by the cues A, B, C, D, E, and X resulting in the presentation of compound trials for each elemental cue presentation i.e., ap, bp, cp, dp, ep, xp, and cdp for the compound CD (where a, b, c, d, e, and x represent the element that distinguished the cues used). This assumption was based on the fact that five of the six cues used were drawn from the same auditory modality, and the purported failure by Beckers et al. (2006) to demonstrate that “the cues used in pretraining and those used for blocking were represented by the rats as entirely different stimuli.” The rationale for Beckers et al. (2006) experiments is based on an “inferential” explanation of blocking. Beckers et al. (2006) put it this way: