Effects of the instructional sets to remember and to forget on short-term retention: Studies of rehearsal control and retrieval inhibition (repression).

Abstract

Five short-term memory experiments are reported which examined whether the instructional set to forget affects trace formation or trace retrieval. The experimental paradigms included a manipulation of covert rehearsal efforts, variation in the temporal point in the memory sequence at which a remember or forget instructional cue is introduced, a "latent memory" design in which 5s perceived identical stimuli under shifting instructional sets, and a procedure in which identical stimuli were repeatedly perceived under constant instructional sets. The results strongly suggest that the motivational set to forget hinders trace utilization, rather than original learning. In addition, the retrieval deficit caused by the instruction was not necessarily mediated by conscious cognitive processes. The relevance of this work to the clinical conception of repression was emphasized.Recent investigations (Bjork, LaBerge, & Legrand, 1968;Weiner, 1968) have demonstrated that instructions to forget perceived stimuli greatly reduce the retention of those stimuli, and lessen the interfering effects of that material on the retention of other stimuli. Why a direction to forget influences retention remains unclear. It may be that the instruction minimizes covert rehearsal, hence retarding the degree of original learning of the stimuli. On the other hand, perhaps the addition of the set to forget results in the distinct storage or differential retrieval of the information. The following five experiments investigated which process in the memory sequence is affected by the instructional set to forget. In addition, the relationship between forgetting instructions and the clinical conception of repression is discussed. EXPERIMENT I MethodExperiment I consisted of two collateral studies; one investigation employed a within-5s design, the

Repetition effects in directed forgetting: evidence for retrieval inhibition

“…The present experiments were designed to replicate and extend the work of Weiner and Reed (1969). In particular, their finding of equivalent recall for Rand F items following repetition could be explained as enhanced encoding of the F items at repetition, thus compensating for the initial encoding deficit resulting from the F cues.…”

“…The work of Weiner and Reed (1969) suggests that, even when subjects are awake, intent to forget enhances forgetting more than nonrehearsal. Yet recent data from our laboratory have shown that subjects describe their forgetting strategies simply as nonrehearsal.…”

“…These include erasure (Bjork, 1972), response suppression (Weiner, 1968), output interference (Geiselman, Bjork, & Fishman, 1983), and disrupted memory trace consolidation (Bjork & Geiselman, 1978). However, Weiner and Reed (1969) found that commands to forget led to greater forgetting of target items…”

Directed forgetting of autobiographical events

“…Moreover, there is a long history of empirical evidence for deliberate forgetting of some kinds of memories (for reviews, see Bjork, 1998;Golding & Long, 1998;Golding & MacLeod, 1998;Johnson, 1994;MacLeod, 1998). Directed forgetting (DF), or intentional forgetting, has been found with a wide range of stimuli, including trigrams (Weiner, 1968;Weiner & Reed, 1969), digits (Brown, 1954), word pairs (Reitman, Malin, Bjork, & Higman, 1973), categorized words (MacLeod, 1975), pictures (Basden & Basden, 1996), sentences (Geiselman, 1974), and even navigation instructions (Golding & Keenan, 1985). However, whether it is reasonable to generalize from such stimuli to autobiographical events is debatable.…”

Failures to find suppression of episodic memories in the think/no-think paradigm

“…For example, Weiner and Reed (1969) used a variant of this procedure to investigate repression by giving subjects a series of letter trigrams to learn with instructions either to remember and rehearse the trigrams, to remember but not rehearse them, or to forget them. They were given a secondary task of number shadowing during the retention interval after each trigram.…”