Testing Hypotheses About Binding in Context Memory With a Hierarchical Multinomial Modeling Approach

In experiments on multidimensional source memory, a stochastic dependency of source memory for different facets of an episode has been repeatedly demonstrated. This may suggest an integrated representation leading to mutual cuing in context retrieval. However, experiments involving a manipulated reinstatement of one source feature have often failed to affect retrieval of the other feature, suggesting unbound features or rather item-feature binding. The stochastic dependency found in former studies might be a spurious correlation due to aggregation across participants varying in memory strength. We test this artifact explanation by applying a hierarchical multinomial model. Observing stochastic dependency when accounting for interindividual differences would rule out the artifact explanation. A second goal is to elucidate the nature of feature binding: Contrasting encoding conditions with integrated feature judgments versus separate feature judgments are expected to induce different levels of stochastic dependency despite comparable overall source memory if integrated representations include feature-feature binding. The experiment replicated the finding of stochastic dependency and, thus, ruled out an artifact interpretation. However, we did not find different levels of stochastic dependency between conditions. Therefore, the current findings do not reveal decisive evidence to distinguish between the feature-feature binding and the item-context binding account.