Value transfer contributes to ambiguous-cue discrimination learning

Abstract

Pigeons learned two concurrent simultaneous discriminations in which the S for one served as the S for the other. When all correct choices were reinforced, accuracy on the former (positive vs. ambiguous-cue or PA) discrimination was lower than on the latter (negative vs. ambiguous-cue or NA) discrimination. When correct choices on the PA discrimination were intermittently reinforced, however, pigeons chose the S more often than the S on those trials. By contrast, intermittently reinforcing correct choices on the NA discrimination did not affect NA-trial accuracy but yielded higher PA-trial accuracy relative to continuous reinforcement. Together with a separate preference assessment, these results indicate that value transfer, in which some of the positive value accrued by an S transfers to its companion S , contributes to ambiguous-cue performances.

European starlings unriddle the ambiguous-cue problem

“…The effect was still present in both PA-Partial groups, but to a smaller degree than expected. These findings are inconsistent with the literature, in particular with the results of Urcuioli and Michalek (2007) with pigeons, and question the aforementioned theoretical accounts as complete explanations of the ambiguous-cue effect. In our view, to achieve such high levels of accuracy on PA trials, starlings must have attended to configural (i.e., contextual) cues, thus differentiating stimulus A when presented on PA trials from stimulus A when presented on NA trials.…”

“…Thompson, 1954; Leary, 1958; Zeaman and House, 1962; Fletcher et al, 1968; Boyer and Polidora, 1972; Fletcher and Garske, 1972), currently it is uncontroversial that, if salient stimuli are used as cues, performance on PA trials is less accurate than on NA trials—the ambiguous-cue effect. This pattern has been observed in a variety of species, including pigeons, monkeys, honeybees, children, and adults with mental retardation (e.g., Fletcher and Garske, 1972; Richards and Marcattilio, 1975; Hall, 1980; Couvillon and Bitterman, 1986; Urcuioli and Michalek, 2007; Nardi, 2009). …”

“…More recently, Urcuioli and Michalek (2007) proposed that value transfer may also contribute to the effect. Value transfer theory (von Fersen et al, 1991) proposes that associative value transfers from one stimulus to the other in a simultaneous discrimination and subsequent research has shown that value transfer (a) does indeed occur (Zentall and Sherburne, 1994), and (b) it occurs only from the S+ to the S- and not in the opposite direction (Clement et al, 1998; for a possible role of the hippocampus in value transfer, see Van Elzakker et al, 2003).…”

“…To test whether or not the value transfer mechanism plays a role in an ambiguous-cue task, Urcuioli and Michalek (2007, Experiment 1) devised a test involving partially reinforcing P on PA trials. With this schedule, both P and A would be reinforced 50% of the time, but A would also acquire some value from P via value transfer.…”

“…Typically, animals’ accuracy is lower on PA trials—the ambiguous-cue effect. We conducted two experiments with European starlings ( Sturnus vulgaris ) using Urcuioli and Michalek’s (2007, Psychon B Rev 14, 658–662) experimental manipulations as a springboard to test the predictions of two of the most important theoretical accounts of the effect: the interfering cue hypothesis and value transfer theory. Both experiments included two groups of birds, one trained with a regular ambiguous-cue problem (Group Continuous) and another trained with partial reinforcement on PA trials (Group PA-Partial).…”