Modulation of attention in discrimination learning: the roles of stimulus relevance and stimulus-outcome correlation

The advantage in learning after an intradimensional shift rather than an extradimensional shift has been widely used as a behavioural marker of attentional changes during discrimination learning in different fields of neuroscientific study. However, some of the factors assumed to guide these attentional changes have not been completely disentangled by previous research. In two predictive-learning experiments, we investigated the importance of stimulus relevance and of stimulus-outcome correlation for the modulation of attention. In each experiment, participants were trained on two discrimination problems given in successive order. Each problem required participants to differentiate stimuli varying on two dimensions. We found that acquisition of the second discrimination was influenced by whether its relevant dimension (Exp. 1) or its irrelevant dimension (Exp. 2) had previously been trained as relevant and uncorrelated or as irrelevant and uncorrelated. We also observed that acquisition of the second discrimination was independent of whether its relevant dimension (Exp. 1) or its irrelevant dimension (Exp. 2) had previously been trained as relevant and uncorrelated or as relevant and correlated. Our results indicated that the modulation of attention is guided by stimulus relevance and not by stimulus-outcome correlation.