Assessing a retrieval account of the generation and perceptual-interference effects

A number of memory phenomena are modulated by experimental design, with the effect (e.g., of bizarreness, generation, or perceptual interference) occurring in recall for mixed-list, but not pure-list designs. These effects have other similarities and have been treated in common theoretical frameworks, some focusing on encoding and others on retrieval. The typical paradigm for examining design effects confounds encoding and retrieval contexts, making it difficult to compare these accounts. Using a new paradigm, McDaniel, Dornburg, and Guynn (2005) concluded that retrieval processes contribute to the bizarreness effect. We applied this paradigm to the related perceptual-interference and generation effects. Participants were presented with two pure study lists and later recalled the lists separately (inducing pure retrieval sets) or together (inducing a combined or mixed retrieval set) in a single test. In four experiments, the combined recall condition consistently failed to enhance the size of the generation or perceptual-interference effect. Two additional experiments verified that perceptual interference and generation enhanced recognition memory, as predicted by the standard encoding accounts. The results provide no support for the retrieval account of these two variables but generally are consistent with an encoding locus.