Letter identification in relation to linguistic context and masking conditions

With a two-choice detection procedure, identifiability of signal letters was determined in backgrounds of words, nonword letter strings, or homogeneous noise characters. Under high performance conditions of exposure duration and pre- and postmasks, there was a substantial advantage in identifiability of letters presented alone over letters embedded in words; under low performance conditions there were generally no differences between the two types of context, but some interactive effects appeared involving particular letters with serial position and type of background. No differences were obtained between word and nonword contexts. The disparities between these findings and those reported by Reicher (1969) and Wheeler (1970) may be related to the more complete elimination under the present procedures of effects of redundancy on response selection.     

Detection and placement of redundant signal elements in tachistoscopic displays of letters

On each trial of a forced-choice detection experiment, S indicated which of two signal elements was represented and also specified the cell of the 5 by 5 matrix display in which he detected the signal. Reaction time on correct choice, Correct placement trials proved virtually invariant with respect to number of redundant signal elements present in the display. These data do not support a serial model for sensory processing, but they could be accommodated by a parallel model for sensory processing together with a serial self-terminating model for processes involving comparison of elements of a display with items in memory. Further analyses of both frequency and reaction time data support the assumption that the distributions of observed detection response measures represent mixtures of true detections, guesses, and misperceptions.     

Retrieval-induced forgetting in an eyewitness-memory paradigm

The potential impact of repeated questioning of a witness was examined. Subjects were shown slides depicting the aftermath of a theft and subsequently were asked several times to recall selected details of what they saw. Previous experiments employing simple verbal materials have demonstrated that information addressed by questioning becomes more recallable in the future than it would have been without such retrieval practice, but other information, especially that bearing a categorical similarity to the practiced items, becomes less recallable. Such positive and negative effects appeared in subjects’ later recall of crime-scene details in the present experiment. These results have an important implication for legal practice: Repeated interrogation of a witness can modify the witness’s memory-enhancing the recall of certain details while inducing the forgetting of other details-even when no misinformation is contained or implied in the questioning.     

Composite models never (well, hardly ever) compromise: reply to Schooler and Tanaka (1991)

With respect to the influence of postevent information, Schooler and Tanaka (1991) made a useful distinction between composite recollections--in which subjects retrieve "items from both the original and the postevent sources" (p.97)--and compromise recollections--in which subjects retrieve" at least one feature that cannot be exclusively associated with either the original or the postevent sources, but which reflects some compromise between [the] two" (p.97). Schooler and Tanaka argued that only the latter constitutes good evidence for blend-memory representations of the CHARM-type. As it turns out, Schooler and Tanaka's intuitions (and Metcalfe & Bjork's, initially) are faulty. Compromise recall--defined as a preference for an intervening alternative over either of the actually presented alternatives--is not normally a prediction of CHARM and may not be a prediction of composite-trace models in general. Only under specialized conditions--a systematic displacement of the test alternatives or a systematic shift attributable to assimilation to prior semantic knowledge--will computer simulations of CHARM produce unimodal compromise recollection. Equally surprising is the fact that separate-trace models, under a different set of conditions, can predict compromise recollection.     

Predicting one's own forgetting: the role of experience-based and theory-based processes

The authors examined the hypothesis that judgments of learning (JOL), if governed by processing fluency during encoding, should be insensitive to the anticipated retention interval. Indeed, neither item-by-item nor aggregate JOLs exhibited "forgetting" unless participants were asked to estimate recall rates for several different retention intervals, in which case their estimates mimicked closely actual recall rates. These results and others reported suggest that participants can access their knowledge about forgetting but only when theory-based predictions are made, and then only when the notion of forgetting is accentuated either by manipulating retention interval within individuals or by framing recall predictions in terms of forgetting rather than remembering. The authors interpret their findings in terms of the distinction between experience-based and theory-based JOLs.     

Inflation of conditional predictions

The authors report 7 experiments indicating that conditional predictions--the assessed probability that a certain outcome will occur given a certain condition--tend to be markedly inflated. The results suggest that this inflation derives in part from backward activation in which the target outcome highlights aspects of the condition that are consistent with that outcome, thus supporting the plausibility of that outcome. One consequence of this process is that alternative outcomes are not conceived to compete as fully as they should. Another consequence is that prediction inflation is resistant to manipulations that induce participants to consider alternative outcomes to the target outcome.     

Exploring a mnemonic debiasing account of the underconfidence-with-practice effect

Judgments of learning (JOLs) underestimate the increase in recall that occurs with repeated study (the underconfidence-with-practice effect; UWP). The authors explore an account in terms of a foresight bias in which JOLs are inflated when the to-be-recalled target highlights aspects of the cue that are not transparent when the cue appears alone and the tendency of practice to alleviate bias by providing learners with cues pertinent to recall. In 3 experiments the UWP effect was strongest for items that induce a foresight bias, but delaying JOLs reduced the debiasing effects of practice, thereby moderating the UWP effect. This occurred when delayed JOLs were prompted by the cue alone (like during testing), not when prompted by the cue-target pair (like during study).     

Is retrieval success a necessary condition for retrieval-induced forgetting?

When information is retrieved from memory, it becomes more recallable than it would have been otherwise. Other information associated with the same cue or configuration of cues, however, becomes less recallable. Such retrieval-induced forgetting (Anderson, Bjork, &; Bjork, 1994) appears to reflect the suppression of competing nontarget information, with this suppression facilitating the selection of target information. But is success at such selection a necessary condition for retrieval-induced forgetting? Using a procedure in which some cues posed an impossible retrieval task for participants, we report evidence that the attempt to retrieve, even if unsuccessful, can produce retrieval-induced forgetting. This finding, we believe, supports and refines a suppression/inhibitory account of retrieval-induced forgetting.