Perceptual learning in flavor-aversion learning: Alternating and blocked exposure to a compound of flavors and to an element of that compound

Within-subjects assessment of the within-compound associations resulting from intermixed and blocked preexposure schedules

“…We tested our hypothesis in a series of between-subjects experiments in which we first confirmed our previous demonstration (Rodríguez & Alonso, 2004, 2008Rodríguez, Lombas, & Alonso, 2009) that intermixed preexposure to a flavor compound and to an element of that compound (AX, X, AX, X, . .…”

“…This perceptuallearning effect has been demonstrated in experiments using either between-subjects (e.g., Rodríguez & Alonso, 2004;Symonds & Hall, 1995) or within-subjects (e.g., Blair & Hall, 2003;Hall et al, 2006) comparisons. Recently, we have demonstrated that conditions able to generate a betweensubjects demonstration of the effect also differentially affect the strength of the within-compound associations (Rodríguez & Alonso, 2014, Exps.…”

“…In this case, detecting the common and the unique features would be easy, thus facilitating the formation of the withincompound associations between them. This may be the case in experiments of the sort presented here, in which rats are used as subjects and flavors as the stimuli (e.g., Bennett & Mackintosh, 1999;Rodríguez & Alonso, 2004;Symonds & Hall, 1995). Following the same logic, it also seems quite plausible that the formation of within-compound associations would not have played a major role in other experiments involving much more complex and dissimilar stimuli.…”

“…It was found that the rats given intermixed preexposure showed less generalization (i.e., better discrimination) between AX and BX than did those that received blocked preexposure. This outcome is referred to as the intermixed-blocked effect and has been demonstrated in a wide variety of conditions with both nonhuman animals (e.g., Bennett & Mackintosh, 1999;Blair & Hall, 2003;Honey, Bateson, & Horn, 1994;Rodríguez & Alonso, 2004) and humans (e.g., Dwyer, Hodder, & Honey, 2004;Lavis & Mitchell, 2006;Mundy, Honey, & Dwyer, 2007;Nelson & Sanjuan, 2009). …”

The role of comparison in perceptual learning: Effects of concurrent exposure to similar stimuli on the perceptual effectiveness of their unique features

“…All animals then received aversion conditioning trials, with X as the CS. Subsequent testing revealed that generalization of this aversion to AX was less in animals that were given alternating exposure than in those given blocked exposure (thus confirming that the presence of a unique feature-e.g., B-in one of the tobe-discriminated stimuli is not essential to produce the alternating versus blocked effect; see also Hall, Blair, & Artigas, 2006;Rodríguez & Alonso, 2004). But the test also showed that even with sensory preconditioning neutralized, conditioned responding to AX was still more profound in animals given concurrent exposure than in those given either alternating or blocked exposure.…”