Reducing negative emotional memories by retroactive interference

Because negative emotional memories are often disruptive, we conducted two experiments to reduce these memories by using a retroactive interference (RI) paradigm. In both experiments, participants were presented with highly negative pictures (List 1) followed by highly negative, moderately negative, or neutral pictures (List 2) or a rest period. Then, following a filler task, participants took a surprise free recall test, recalling pictures from List 1 in Experiment 1 and from both List 1 and List 2 in Experiment 2. In both experiments, recall of List 1 was reduced by List 2, indicating that RI was present. Furthermore, in Experiment 1, RI was similar between moderately negative and highly negative List 2 whereas in Experiment 2, RI was greater for highly negative List 2 than moderately negative List 2. These results showed that RI can be used to reduce negative emotional memories by making these memories inaccessible.     

Multi-trial recognition memory: Proactive versus retroactive interferences within a single list

Both results and interpretations are conflicting concerning proactive or retroactive interferences that may be generated by individual items upon other items within a single recognition list. In an attempt to explore a factor that may assist in reconciling varied findings, each of the three present lists consisting of either CVCs, two-digits, or words, respectively, was presented via half-lists on multi-study and -test cycles. Two half-lists were given in such a way that both sublists experienced the same number of intervening events in the mean retention interval, but differing ones in the composition of mean retroactive study and test events. Sixty male and female undergraduates participated. In contrast to small proactive study event interference, both retroactive study and retroactive test events did control recognition performances in an intriguing manner: Relative interferences generated by retroactive study events were weaker early in acquisition, but gained strength as learning progressed, and at late acquisition stages became quite powerful vis-à-vis retroactive test events. Thus, the acquisition stage seems to be a relevant factor in determining recognition performance.     

Proactive and retroactive transfer of middle age adults in a sequential motor learning task

We assessed the effects of aging in the transfer of motor learning in a sequential manual assembly task that is representative for real working conditions. On two different days, young (18–30 years) and middle-aged adults (50–65 years) practiced to build two products that consisted of the same six components but which had to be assembled in a partly different order. Assembly accuracy and movement time during tests, which were performed before and after the practice sessions, were compared to determine proactive and retroactive transfer.     

Concurrent and retroactive interference effects in memory of movement patterns

Three experiments examined memory for enacted and observed movement patterns. The effect of visuo-spatial tracing tasks requiring overt motor movements, comparable to those required by the to-be-recalled movement pattern task when enacted, were compared with the effects of non-motor interference tasks, such as articulatory suppression and counting backwards. None of the experiments was able to detect indices of motor mechanisms in memory of movement patterns. The results are discussed in terms of theories of action memory and working memory and of a problem-solving account.     

Proactive interference effects on sentence production

Proactive interference refers to recall difficulties caused by prior similar memory-related processing. Information-processing approaches to sentence production predict that retrievability affects sentence form: Speakers may word sentences so that material that is difficult to retrieve is spoken later. In this experiment, speakers produced sentence structures that could include an optionalthat, thereby delaying the mention of a subsequent noun phrase. This subsequent noun phrase was either (1) conceptually similar to three previous noun phrases in the same sentence, leading to greater proactive interference, or (2) conceptually dissimilar, leading to less proactive interference. Speakers produced morethats (and were more disfluencies) before conceptually similar noun phrases, suggesting that retrieval difficulties during sentence production affect the syntactic structures of sentences that speakers produce.     

Proactive and reactive sequential effects on selective attention

Sequences of events can affect selective attention either through proactive mechanisms, through reactive mechanisms, or through a combination of the two. The current study examined electrophysiological responses to both prime and target stimuli in a primed dichotic listening task. Each trial presented a distractor prime syllable followed by two simultaneous syllables, and participants were asked to report one of the simultaneous syllables. Trials where the participant reported the non-primed syllable showed more negative event-related potentials at prime presentation, which may indicate inhibition of the prime representation. Trials where the participant reported the primed syllable showed more negative event-related potentials at target presentation, which may indicate cognitive conflict and effortful response selection. In context of current theories, the data suggest that the interplay of a proactive inhibition bias and a reactive potential for conflict is involved in causing sequential effects on selective attention mechanisms.     

Learning of similar complex movement sequences: proactive and retroactive effects on learning

The authors used an interference paradigm to determine the extent to which the learning of 2 similar movement sequences influences the learning of each other. Participants (N=30) produced the sequences by moving a lever with their right arm and hand to sequentially presented target locations. They practiced 2 similar 16-element movement sequences (S1 and S2), 1 sequence on each of 2 consecutive days of practice. Control groups received only 1 day of practice on 1 of the sequences. Early in S2 practice, the experimental group demonstrated a relatively strong level of proactive facilitation arising from previous practice with S1. The advantage was not evident at the end of S2 practice or on the S2 retention test. No advantage of practicing the 1st sequence on the learning of the 2nd sequence (proactive effect) was found in the analysis of element duration in the retention and transfer tests, even though 14 of the 16 elements were common to both sequences. A strong retroactive interference on the switched elements was detected, however. Thus, the memories underpinning S1 seemed to be "overwritten" or adapted in response to the learning of S2.     

Proactive control and episodic binding in context processing effects

Decision making often involves using prior contextual information to evaluate relevant events. A laboratory equivalent of context processing situations, the AX-Continuous Performance Task (AX-CPT), yields errors when a target probe appears in a nontarget context, or when a nontarget probe appears in a target context. According to goal-driven accounts, context information is used for top-down preparation towards processing of context-appropriate information. Performance costs in nontarget trials are attributed to inefficient cognitive control. In contrast, the episodic binding account predicts that prior experiences with combinations of a context, probe, and response are bound in episodic memory and thus bias future actions. Performance costs in this view are caused by the need to overrule prepotent associations. The current experiments tested the relative importance of proactive cognitive control versus episodic learning of appropriate stimulus-response relations for CPT performance. Support was obtained for both contributions.     

Probabilistic retroactive interference: the role of accessibility bias in interference effects

Probabilistic retroactive interference (RI) refers to the interfering effects of intermixing presentations of an earlier studied response (A-B) with presentations of a competing response (A-D). As an example, for a 2/3 condition, a cue word was presented with its earlier studied response twice and its competing response once during the interference phase. Performance on direct and indirect tests of memory for earlier studied responses was combined to reveal dissociations between effects on recollection and accessibility bias. Manipulating probabilistic RI influenced accessibility bias but left recollection unchanged. Effects of probabilistic RI were compared with effects of traditional, nonprobabilistic RI. The authors contrast their dual-process model with traditional accounts of RI and discuss the importance of distinguishing between recollection and accessibility bias for understanding interference effects.     

Similarity neighborhoods of spoken two-syllable words: retroactive effects on multiple activation

This research examines the recognition of two-syllable spoken words and the means by which the auditory word recognition process deals with ambiguous stimulus information. The experiments reported here investigate the influence of individual syllables within two-syllable words on the recognition of each other. Specifically, perceptual identification of two-syllable words comprised of two monosyllabic words (spondees) was examined. Individual syllables within a spondee were characterized as either "easy" or "hard" depending on the syllable's neighborhood characteristics; an easy syllable was defined as a high-frequency word in a sparse neighborhood of low-frequency words, and a hard syllable as a low-frequency word in a high-density, high-frequency neighborhood. In Experiment 1, stimuli were created by splicing together recordings of the component syllables of the spondee, thus equating for syllable stress. Additional experiments tested the perceptual identification of naturally produced spondees, spliced nonwords, and monosyllables alone. Neighborhood structure had a strong effect on identification in all experiments. In addition, identification performance for spondees with a hard-easy syllable pattern was higher than for spondees with an easy-hard syllable pattern, indicating a primarily retroactive pattern of influence in spoken word recognition. Results strongly suggest that word recognition involves multiple activation and delayed commitment, thus ensuring accurate and efficient recognition.