Results from standard implicit memory tests suggest that automatic retrieval decreases or remains relatively stable over time, whereas results from the process dissociation procedure (PDP) suggest that automatic retrieval may actually increase over time. Advocates of the PDP view, have suggested that this incongruity results from contamination of the implicit tests by intentional retrieval, whereas the PDP provides a valid index of automatic retrieval. In contrast, new results from a speeded implicit memory test suggest that the standard implicit memory tests provide reasonable estimates of automatic retrieval, but that the PDP underestimates automatic retrieval at a short retention interval when recollection is relatively high. The pattern of underestimation of automatic retrieval found for the PDP condition supports the conclusion that automatic retrieval and recollection are not independent, but rather are positively correlated
