Discounting and conditionalization

When people are asked to judge the strengths of two potential causes of an effect, they often demonstrate discounting--devaluing the strength of a target cause when it is judged in the presence of a strong (relative to a weak) alternative cause. Devaluing the target cause sometimes results from conditionalization--holding alternative causes constant while evaluating the target cause. Yet discounting not attributable to conditionalization also occurs. We sought to dissociate conditionalization and discounting (beyond that accounted for by conditionalization) by having subjects perform either a spatial or a verbal working memory task while learning a causal relation. Conditionalization was disrupted by the verbal task but not the spatial task; however, discounting was disrupted by the spatial task but not the verbal task. Conditionalization and discounting are therefore cognitively dissociable processes in human causal inference.