When patterning discriminations are harder than biconditional ones: A cue constellation approach

Recent attempts to distinguish configural from nonconfigural accounts of causal learning have compared the relative ease of learning 2 kinds of complex discriminations, a biconditional discrimination (e.g., AB+, CD+, AC0, and BD0), and a negative patterning discrimination, (e.g., A+, B+, and AB0), but have yielded conflicting results. Some studies have found the biconditional task to be easier than negative patterning and others have found negative patterning to be easier than the biconditional. This article evaluates these complex discriminations in several studies using a method that attempts to correct methodological problems that arise in comparisons of individual stimuli and stimulus compounds. Across several variations in procedure, negative patterning discriminations were significantly more difficult than biconditional discriminations. The research also found evidence in comparisons across studies that the difficulty of the biconditional, relative to a comparable nonconfigural compound discrimination, depended on whether the task emphasized configural or nonconfigural cues. The overall pattern of results appeared to be well accounted for by models that include configural information, suggesting that theories which invoke configural elements as a basis for learning complex discriminations remain viable explanatory frameworks.