Another look at retroactive and proactive interference: A quantitative analysis of conversion processes

Traditionally, the causes of interference phenomena were sought in “real” or “hard” memory processes such as unlearning, response competition, or inhibition, which serve to reduce the accessibility of target items. I propose an alternative approach which does not deny the influence of such processes but highlights a second, equally important, source of interference—the conversion (Tulving, 1983) of accessible memory information into memory performance. Conversion is conceived as a problem-solving-like activity in which the rememberer tries to find solutions to a memory task. Conversion-based interference effects are traced to different conversion processes in the experimental and control conditions of interference designs. I present a simple theoretical model that quantitatively predicts the resulting amount of interference. In two paired-associate learning experiments using two different types of memory tests, these predictions were corroborated. Relations of the present approach to traditional accounts of interference phenomena and implications for eyewitness testimony are discussed.     

The role of horizontal categorization in retroactive and proactive interference

Four paired-associate experiments with a total N of 291 participants investigated the effects of horizontal categorization on retroactive and proactive interference. (Exclusively) horizontal categorization means that unique categorical relationships hold across the A-B and A-C stimulus-response pairs of successive word lists (e.g., fruit--pear, river--Thames, in list 1; and fruit--plum, river--Wolga, in list 2). Experiment 1 found no significant amounts of interference with this type of list organization. However, strong interference arose with the same materials when the categorical structure was destroyed in Experiment 2. A third experiment contrasted two alternative explanations for these results, and Experiment 4 replicated the effect of horizontal categorization (vs. no categorical relationship) in a within-participants design. The results of the four experiments largely fit with a response competition explanation proposed by Bower, Thompson-Schill, and Tulving (1994), adapted to the within-participants designs used here. Overall, the present findings add to a body of evidence demonstrating limits to retroactive and proactive interference.     

Increased sensitivity to proactive and retroactive interference in amnestic mild cognitive impairment: new insights

Background

Increased sensitivity to proactive (PI) and retroactive (RI) interference has been observed in amnestic mild cognitive impairment (aMCI). PI and RI are often explained as being the result of a response competition mechanism. However, patients with aMCI are supposed to suffer mostly from encoding deficits. We hypothesized that in aMCI interference may occur at encoding and not only at the retrieval stage.

Material and methods

We developed an original paradigm enabling PI and RI to be tested with and without response competitors. Eighteen young controls (YC), 16 elderly controls (EC) and 15 aMCI participated in the study.

Results

The YC and EC groups presented interference effects only in conditions that included a direct response competitor. In contrast, aMCI had interference effects in all conditions including the one without response competitor.

Conclusion

Increased sensitivity to interference in aMCI appears to occur at the encoding/consolidation stage and not only at the retrieval stage, as is the case in healthy subjects. This result is discussed in the context of the associative encoding deficits characterizing aMCI.     

Another look at confirmatory strategies during a real interview

In two experiments, it is shown that interviewers bias to a larger extent their questions towards their hypothesis when they interact with an interviewee than when they only prepare questions for a future interview. Also more biased questions are asked at the beginning of the interview than at the end. This does not seem to be due to the certainty entertained by the interviewers about their hypothesis. More likely, it appears that biased questions have an adaptative value and that they smooth the interview. All in all, our subjects were not especially concerned with diagnosticity.     

An analysis of item gains and losses in retroactive interference.

The repeated-testing paradigm is used to study both retroactive interference and hypermnesia (the improvement in memory across repeated tests). Considerable theoretical progress has been made by separately analyzing the 2 components of hypermnesia: the recovery of previously unrecalled items on later tests (item gains) and the forgetting of previously recalled items on later tests (item losses). Item gains increase with increases in item-specific processing, whereas item losses decrease with increases in relational processing. The authors suggest that separate analysis of item gains and losses in retroactive interference research may also prove fruitful. Three experiments showed that an interpolated list affects item gains but not losses, whereas processing similarity between the target and interpolated lists affects losses but not gains. These results are interpreted within the relational-item-specific processing framework.     

Another look at baseball player initials and longevity

Abel and Kruger (2007) reported that Major League Baseball players whose names have positive initials (such as ACE or GOD) live an average of 13 years longer than do players with negative initials (such as ASS or BAD) or players with neutral initials (such as GHR or TSW). However, this conclusion is based on a very small sample, selective initials, and a flawed statistical test. There is no statistically significant relationship between initials and longevity for Major League Baseball players when a correct test is applied to independently selected initials.     

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.     

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.