Buildup and release from proactive interference in a rhesus monkey

The potential of the buildup and release from proactive interference (PI) technique in the study of animal categorization was demonstrated with a rhesus monkey. A serial probe recognition task was used with a list of 4 consecutive slide pictures (upper screen) followed by a single probe picture (lower screen). The monkey moved a lever to indicate whether or not the probe was contained in the list. PI built over 40 consecutive trials tested with either flowers or primate faces. PI was released on category change and then built during 40 trials with the second category. The first 2 serial positions showed somewhat greater PI buildup and release, supporting conclusions from human studies that the effects occur primarily in secondary memory. A second experiment provided 2 replications of the main effect and showed through color border changes and elimination of color differences that color was not a critical feature.     

How a high working memory capacity can increase proactive interference

Previous findings suggested that a high working memory capacity (WMC) is potentially associated with a higher susceptibility to proactive interference (PI) if the latter is measured under high cognitive load. To explain such a finding, we propose to consider susceptibility to PI as a net effect of individual executive processes and the intrinsic potential for PI. With the latter, we refer to the amount of information that is activated at a given time and that has the potential to exert PI subsequently. In two studies deploying generalized linear mixed models, susceptibility to PI was modeled as the decline of performance over trials of a complex span task. The results revealed that a higher WMC was associated with a higher susceptibility to PI. Moreover, the number of stimuli recalled in one trial as a proxy variable for the intrinsic potential for PI negatively affected memory performance in the subsequent trial.     

Speed-accuracy tradeoff and information processing dynamics

For a long time, it has been known that one can tradeoff accuracy for speed in (presumably) any task. The range over which one can obtain substantial speed-accuracy tradeoff varies from 150 msec in some very simple perceptual tasks to 1,000 msec in some recognition memory tasks and presumably even longer in more complex cognitive tasks. Obtaining an entire speed-accuracy tradeoff function provides much greater knowledge concerning information processing dynamics than is obtained by a reaction- time experiment, which yields the equivalent of a single point on this function. For this and other reasons, speed-accuracy tradeoff studies are often preferable to reaction-time studies of the dynamics of perceptual, memory, and cognitive processes. Methods of obtaining speed-accuracy tradeoff functions include: instructions, payoffs, deadlines, bands, response signals (with blocked and mixed designs), and partitioning of reaction time. A combination of the mixed-design signal method supplemented by partitioning of reaction times appears to be the optimal method.     

Implicit memory is vulnerable to proactive interference

We investigated the possibility that implicit memory, like explicit memory, can be disrupted by proactive interference. Participants first viewed a list of words, with nontargets in the first half of the list and targets in the second. Nontargets were either similar in structure (e.g., "ANALOGY") or unrelated (e.g., "URGENCY") to the targets (e.g., "ALLERGY"). After several filler tasks, participants completed an implicit fragment-completion test (e.g., "A_L__ GY") for the target items. Participants who viewed similar nontargets completed fewer fragments with target items and made more intrusions than did participants who viewed unrelated nontargets. Together with previous findings, these results suggest that similar nontargets can compete with target items to produce interference in implicit memory.     

Item-specific proactive interference in olfactory working memory

We examine item-specific olfactory proactive interference (PI) effects and undertake comparisons with verbal and non-verbal visual stimuli. Using a sequential recent-probes task, we show no evidence for PI with hard-to-name odours (Experiment 1). However, verbalisable odours do exhibit PI effects (Experiment 2). These findings occur despite above chance performance and similar serial position functions across both tasks. Experiments 3 and 4 apply words and faces, respectively, to our modified procedure, and show that methodological differences cannot explain the null finding in Experiment 1. The extent to which odours exhibit analogous PI effects to that of other modalities is, we argue, contingent on the characteristics of the odours employed.     

An examination of orienting task relationships in a proactive interference paradigm

Three experiments investigating release from proactive interference were conducted, in which orienting tasks were employed to bias encoding. Following earlier experiments by Bird (1976, 1977), it was expected that release would be observed when tasks were changed after several trials, but only to the extent that the tasks required different processing. Two obviously related nonsemantic tasks were compared in Experiment 1, and no release was obtained. Experiment 2 was a comparison of part-of-speech classification, considered by some to be a nonsemantic task, and of judgments of word pleasantness. The release obtained was sufficiently low to suggest that part-of-speech decisions involve substantial semantic processing. Finally, Experiment 3 employed four tasks, in order to address various questions about task relationships raised in the earlier experiments. Based on the levels of release observed across experiments and the finding that some tasks led to less proactive interference than others, a tentative categorization of tasks was proposed.     

The role of proactive interference in mnemonic techniques

The success of many mnemonic techniques, such as the method of loci, is based on the use of specific well-known anchors, which are mentally combined with to-be-learned items and subsequently facilitate their retrieval. In our studies we intended to answer the question of whether the repeated application of the method of loci may result in proactive interference effects, as might be expected due to the applied association of items with the same loci each time the method is used. To this end, we manipulated list similarity in a typical proactive interference design and compared the method of loci with the link method and the rehearsal method, which do not involve the use of a specified set of anchors. Our results replicate those from other studies, which have shown that the use of a mnemonic technique leads to superior recall of list items compared to a simple rehearsal strategy. We were further able to show that the repeated learning of items from different categories results in moderate practice effects over three list-learning trials, whereas this effect is superimposed by an effect of proactive interference if different lists are composed of items from the same category. However, this effect of proactive interference was not increased for the method of loci, and we discuss this finding with regard to its practical implications.     

Effects of proactive interference on non-verbal working memory

Working memory (WM) is a cognitive system responsible for actively maintaining and processing relevant information and is central to successful cognition. A process critical to WM is the resolution of proactive interference (PI), which involves suppressing memory intrusions from prior memories that are no longer relevant. Most studies that have examined resistance to PI in a process-pure fashion used verbal material. By contrast, studies using non-verbal material are scarce, and it remains unclear whether the effect of PI is domain-general or whether it applies solely to the verbal domain. The aim of the present study was to examine the effect of PI in visual WM using both objects with high and low nameability. Using a Directed-Forgetting paradigm, we varied discriminability between WM items on two dimensions, one verbal (high-nameability vs. low-nameability objects) and one perceptual (colored vs. gray objects). As in previous studies using verbal material, effects of PI were found with object stimuli, even after controlling for verbal labels being used (i.e., low-nameability condition). We also found that the addition of distinctive features (color, verbal label) increased performance in rejecting intrusion probes, most likely through an increase in discriminability between content–context bindings in WM.     

Directed forgetting and aging: the role of retrieval processes, processing speed, and proactive interference

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.     

Transient phonemic codes and immunity to proactive interference

Empirical data indicate that when memory for subspan lists of taxonomically related material is tested immediately after study, prior experience with lists involving the same material has no effect upon recall or recognition. In six experiments, we explored the possibility that immunity to proactive interference (PI) is related to discriminative information that is provided by transient phonemic codes. In these experiments, we manipulated the strength of phonemic codes as well as their presence or absence. Immunity to PI was found only when it was presumed that a phonemic representation of the target items existed and that information provided discriminative information. In all other cases, PI was observed. The finding that PI effects correspond with the manipulation of phonemic information in a principled fashion provides strong evidence for the role of phonemic codes in producing short-term PI effects.     

Short term forgetting in the absence of proactive interference

It has been claimed that the short-term forgetting shown by the Peterson technique is entirely due to proactive interference from prior experimental items. Two experiments investigated this by studying forgetting when prior items were avoided by testing subjects only once. Both experiments showed significant forgetting, although the degree of forgetting was less than with a multitrial procedure. On the basis of this and other results it is suggested that the Peterson technique comprises two components, a primary memory component which decays within 6 sec, and a more stable secondary memory component. Forgetting with the multitrial procedure is attributed principally to the need to use temporal retrieval cues to avoid confusion between successive items; longer retention intervals are associated with reduced temporal discriminability and hence poorer recall.     

The course of proactive interference in immediate probed recall

Measurement of RT in positionally probed immediate recall was used to study the effect of interlist proactive interference (PI) on short-term retention in near- and subspan lists. The first experiment showed a pronounced effect of PI in the sense of a constant increase of RT, but only to the first three serial positions. This was confirmed in a second study that further showed that the size of PI was independent of the size of the preceding list. These results argue against a general acid-bath view of PI but are consistent with the hypothesis of degraded access to the first item. The minimal length of a list susceptible to PI was five items which suggests that PI develops as soon as the list grows beyond the span of direct access to all individual items.     

Examining genetic and environmental effects on reactive versus proactive aggression

This study compared the contribution of genes and environment to teacher-rated reactive and proactive aggression in 6-year-old twin pairs (172 pairs: 55 monozygotic girls, 48 monozygotic boys, 33 dizygotic girls, 36 dizygotic boys). Genetic effects accounted for 39% of the variance of reactive aggression and for 41% of the variance of proactive aggression. The remainder of the variance was explained by unique environmental effects. Genetic as well as unique environmental effects were significantly correlated across reactive and proactive aggression (genetic correlation = .87, environmental correlation = .34), but this overlap was largely due to a common underlying form of aggression (i.e., teacher-rated physical aggression). Once common etiological factors due to physical aggression were accounted for, reactive and proactive aggression shared no other genes and only a few environmental influences, although additional specific genetic and environmental effects were observed for both reactive and proactive aggression. These specific effects indicate that both reactive and proactive aggression may be influenced mostly by socialization experiences that are specific to each type of aggression and only to a very small degree by specific genes.     

Word length effects are not due to proactive interference

In immediate serial recall short words are better recalled than long words. The word length effect has become pivotal in the development of short-term memory models. The current research tests one explanation of the word length effect; that it is related to proactive interference (PI). We report two experiments in which the relationship is directly tested. In the first experiment we show that word length effects can be observed over the first few trials in an experiment and that the effect shows itself primarily in the number of omissions made. In the second experiment we simultaneously test for PI and word length effects. Strong word length effects were present but there was little evidence for PI influencing either overall levels of recall or the word length effect. In short, no empirical support was found for PI as an explanation of the word length effect.     

Perceptual distinctiveness and proactive interference in the primacy effect

When subjects monitor a list of verbal items for one item which is to be selected and remembered, they are more likely to recall the critical item if it is the first member of the list than if it is presented towards the centre of the list. The present experiment examined the possibility that this primacy results from an accumulation of proactive interference from incidentally processed early members of the list which would cause a decrement in the recall of later members. By changing the semantic category of the list members before presentation of the critical item any accumulated interference would have been released, but this procedure produced no weakening of the primacy effect and so the interference theory of primacy was not supported. An alternative explanation of the effect was discussed in which it is assumed that the first member of a series is perceptually distinct from central members.     

Working memory interference during processing texts and pictures: Implications for the explanation of the modality effect

Auditory text presentation improves learning with pictures and texts. With sequential text–picture presentation, cognitive models of multimedia learning explain this modality effect in terms of greater visuo‐spatial working memory load with visual as compared to auditory texts. Visual texts are assumed to demand the same working memory subsystem as pictures, while auditory texts make use of an additional cognitive resource. We provide two alternative assumptions that relate to more basic processes: First, acoustic‐sensory information causes a retention advantage for auditory over visual texts which occurs no matter if a picture is presented or not. Second, eye movements during reading hamper visuo‐spatial rehearsal. Two experiments applying elementary procedures provide first evidence for these assumptions. Experiment 1 demonstrates that, regarding text recall, the auditory advantage is independent of visuo‐spatial working memory load. Experiment 2 reveals worse matrix recognition performance after reading text requiring eye movements than after listening or reading without eye movements. Copyright © 2008 John Wiley & Sons, Ltd.     

Working memory span and the role of proactive interference.

The authors investigated the possibility that working memory span tasks are influenced by interference and that interference contributes to the correlation between span and other measures. Younger and older adults received the span task either in the standard format or one designed to reduce the impact of interference with no impact on capacity demands. Participants then read and recalled a short prose passage. Reducing the amount of interference in the span task raised span scores, replicating previous results (C. P. May, L. Hasher, & M. J. Kane, 1999). The same interference-reducing manipulations that raised span substantially altered the relation between span and prose recall. These results suggest that span is influenced by interference, that age differences in span may be due to differences in the ability to overcome interference rather than to differences in capacity, and that interference plays an important role in the relation between span and other tasks.