Dual-task interference in evaluative conditioning: Similarity matters!

Evaluative conditioning (EC) refers to changes in liking that are due to the pairing of stimuli. Although the question of whether a secondary task can interfere with the occurrence of EC is of great theoretical relevance, previous research has not obtained a consistent pattern of results. Whereas in some studies EC remains intact under dual-task conditions, in others a secondary task resulted in reduced or diminished EC. In order to reconcile these inconsistent findings, we hypothesized that dual-task interference in EC depends on the similarity of demands incurred by processing the stimuli used in the conditioning procedure and the secondary task. Specifically, we assumed that interference only occurs when similar verbal or visuospatial demands are imposed. In order to test this hypothesis, we investigated the occurrence of EC under conditions of a demanding 3-back working memory task while using either orthographic or pictorial stimuli to manipulate verbal and visuospatial processing demands, respectively. Relative to conditions using dissimilar types of stimuli, we found that the 3-back task interfered with the occurrence of EC only when the same types of stimuli were used. The implications for the underlying processes of EC are discussed.