processdissociation

The processdissociation procedure (PDP) is a methodological approach in cognitive psychology used to separate automatic and controlled contributions to performance on memory and related tasks. Developed by James M. Jacoby and colleagues, PDP aims to quantify how much of a response is driven by fast, automatic processes such as familiarity versus slower, deliberate recollection.

The method relies on two test instructions: inclusion and exclusion. In inclusion tasks, participants are told to endorse or report items as having been studied if either automatic familiarity or conscious recollection supports the judgment. In exclusion tasks, participants are instructed to withhold endorsement for studied items unless a controlled, conscious process provides a basis to respond, effectively requiring deliberate recall to overcome an automatic tendency. By comparing performance across these two conditions, researchers infer the relative contributions of automatic and controlled processes.

PDP rests on a two-process model, typically described as automatic influences (A) and controlled influences (C). The inclusion condition allows both processes to drive responses, while the exclusion condition constrains responses to rely more on controlled processes to reject certain items. The difference in performance between inclusion and exclusion provides estimates of the strengths of A and C. These estimates are used to interpret phenomena such as familiarity-based judgments, recollection, and dissociations between implicit and explicit memory.

Applications of PDP include studies of aging, amnesia, and other clinical conditions, as well as basic research on memory, perception, and language. Criticisms center on the independence of the two processes, potential violations of assumptions, and the availability of alternative models (e.g., signal-detection theory) that may explain the data without invoking two distinct processes.