Formation of a novel preference and aversion by simultaneous activation of the representations of absent cues.

Pairing the associatively activated representation of almond with the representation of sucrose resulted in greater consumption of almond on test than controls. In addition, pairing the representation of almond with the representation of quinine resulted in lower almond consumption than controls. These results support and extend the novel finding of Dwyer, Mackintosh and Boakes [Dwyer, D.M., Mackintosh, N.J., Boakes, R.A., 1998. Simultaneous activation of the representation of absent cues results in the formation of an excitatory association between them. J. Exp. Psychol. Anim. Behav. Process. 24, 163-171] that a preference could be established to a neutral flavour by pairing the representation of that flavour with the representation of sucrose in the absence of either flavour. Taken together these results question the modification of SOP proposed by Holland [Holland, P.C., 1983. Representation mediated overshadowing and potentiation of conditioned aversions. J. Exp. Psychol. Anim. Behav. Process. 9, 1-13; Holland, P.C., 1990. Event representation in Pavlovian conditioning: image and action. Cognition 37, 105-131] to explain the occurrence of mediated conditioning. An alternative modification of SOP by Dickinson and Burke [Dickinson, A., Burke, J., 1996. Within-compound associations mediate the retrospective revaluation of causality judgments. Q. J. Exp. Psychol. 49B, 60-80] is considered, but while it can account for the current results it does not predict mediated conditioning.