Concurrent development of excitatory and inhibitory associations during backward conditioning

Dissociation of the blocking of conditioned eyeblink and conditioned fear following a shift in US locus

“…Thus, when a tone or light CS is paired with a paraorbital-shock US, as in the present experiments, one can observe a conditioned eyeblink and a conditioned potentiation of the startle response and can reasonably assume that these two measures are but among many other indices of conditioning that might have been employed. In this context, the results of Experiments I and 2 are significant in supporting those studies (e.g., Tait & Saladin, 1986;Vandercar & Schneiderman, 1967) that indicate that there are important systematic dissociations among distinguishable classes of these measures.…”

“…These differences could be interpreted sim-ply as reflecting a greater sensitivity ofthe former, as compared with the latter, measures, and not necessarily as challenging their monotonic relationship. That the differences between the measures involve a theoretically more interesting divergence is perhaps most forcefully indicated by the findings of Tait and Saladin (1986), which have been replicated and extended in our laboratory (McNish, Betts, Brandon, & Wagner, in press). They show that a backward conditioning protocol, where the CS follows the US, can produce a CER and a conditioned eyeblink tendency that are concurrently of opposite associative valence, with the former being excitatory when the latter is inhibitory.…”

Modulatory mechanisms in Pavlovian conditioning

“…In situations where the inhibitor's excitatory CR interacts with that evoked by the target used for inhibitory assessment, the magnitude of underlying inhibition can be underestimated (Cunningham, 1981;DeVito & Fowler, 1987;Holland, 1984;Rescorla, 1982b, Williams & Overmier, 1988. Under some conditions, the expression of coexisting excitation or inhibition may depend on the method used to assess these properties (e.g., Matzel, Gladstein, & Miller, 1988;Tait & Saladin, 1986). Williams, Overmier, and LoLordo (1992) present an excellent summary and elaboration of these issues.…”

Backward conditioning: Mediation by the context.

“…LoLordo and Fairless (1985) and Williams, Dyck, and Tait (1988) proposed a cue-competition account, according to which the shift from excitation to inhibition presumably reflects the effectiveness of the context with increasing numbers of trials to compete with the backward-trained CS for controlling excitatory conditioned responding. The present experiments explored the role of context in excitatory and inhibitory 1 Notably, the point of transition from excitation to inhibition with increasing numbers of trials appears to differ as a function of the response being monitored, presumably because different responses reflect associations to somewhat different US attributes (McNish, Betts, Brandon, & Wagner, 1997;Tait & Saladin, 1986). stimulus control produced by backward conditioning. In three conditioned lick-suppression experiments, we explored the mediating role of the training context with respect to the excitatory and inhibitory potentials of a backward-trained CS.…”