Explaining Dissociations Between Implicit and Explicit Measures of Retention: A Processing Account
Henry L. Roediger III Rice University
Mary Susan Weldon University of California, Santa Cruz
Bradford H. Challis Purdue University
Explicit measures of memory refer to tasks in which people are directly tested on episodes from their recent experience; in performing the tasks people are instructed to remember events and presumably are aware that they are recollecting recent experiences. Implicit measures of retention are those on which subjects are not told to remember events, but simply to perform some task; retention is measured by transfer from prior experience (relative to an appropriate baseline), and presumably conscious recollection is not necessarily involved ( Graf & Schacter, 1985). Explicit memory tasks are the standard warhorses of the experimental psychologist's armamentarium for investigating memory: free recall, cued recall, recognition, and various judgments (frequency, modality, feeling- of-knowing, etc.). Implicit measures of retention are transfer tasks in which performance on the critical task is influenced by prior experience, without the prior experience necessarily being reflected on explicit measures. Examples of implicit tasks are reading inverted text, naming fragmented words or pictures, or naming words or pictures from brief displays. Great interest has recently been displayed in the relation between explicit and implicit measures of retention, because they are shown to behave differently as a function of many independent variables ( Schacter, 1987). The purpose of the present chapter is to consider functional dissociations between these two classes of tasks and to sketch a theory rationalizing their interrelation.
The first section of the chapter reviews an approach to explaining dissociations developed within the domain of laboratory memory tasks. This approach is based on. Tulving ( 1983) ideas of the encoding/retrieval paradigm and the