Retrieval Blocks in Episodic and Semantic Memory*

A retrieval block refers to impaired accessibility in retrieving target information when semantically related information is presented (or retrieved) prior to target retrieval. Research concerning retrieval blocks is reviewed in this paper. Evidence for such blocks occurs in a variety of situations, including both episodic and semantic memory tasks. Retrieval blocks have been most thoroughly studied in the part-list cuing paradigm in episodic recall, but similar principles seem to operate in other situations including the A-B, A-D interference paradigm, episodic recognition, the tipof-the tongue situation, and other semantic memory tasks. The evidence for such retrieval blocks is problematic for theories postulating automatic spreading activation among associated nodes in memory. We review theories accounting for such retrieval blocks and discuss difficulties with the various approaches. Further research on the nature of retrieval blocks may help illuminate similar phenomena, such as the effects of Einstellung in thinking and problem solving. R£SUME Revue de documentation sur les bloquages du processus de recouvrement. II y a bloquage du recouvrement lorsque I'acces a une information cible est diminue par la presentation (ou le recouvrement), avant le recouvrement de la cible, d'une information qui lui est semantiquement reliee. De tels bloquages existent dans une variete de situations reliees aux memoires episodique et semantique. Bien que ces bloquages aient ete etudies de maniere plus approfondie par I'intermediaire du paradigme des indices de liste partielle dans le rappel episodique, des principes analogues semblent etre a I'oeuvre dans d'autres situations telles que I'interference A-B, A-D, la recognition episodique, les situations de 'motssur-le-bout-de-la-langue et d'autres taches de memoire semantique. L'existence de tels blocages fait probleme aux theories qui postulent une propagation automatique de I'activation a travers les differents noeuds associatifs de la memoire. La revue porte sur les theories qui rendent compte de tels bloquages du recouvrement et la discussion touche aux difficultes soulevees par diverses perspectives. De plus amples recherches sur la nature de ces bloquages pourront aider a la comprehension de phenomenes analogues tei I'effet d'Einstellung dans les situations de resolution de problemes. Retrieval blocks refer to experiences in which target information available in the memory store is temporarily blocked from retrieval by the retrieval of *The writing of this paper and some of the research reported here was supported by Grant ROI HD15054 from the National Institute of Child Health and Human Development. Address reprint requests to Henry L Roediger, III, Department of Psychology, Purdue University, West Lafayette, IN 47907, U.S.A.