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Distractor interference is a phenomenon in which irrelevant stimuli (the distractor) within the visual field interfere with the cognitive performance of the target. This study explored the impact of temporal order and relative location between the distractor and target on distractor interference in visual working memory. Experiment 1 (including the target-alone condition) investigated the role of temporal order (distractor preceding target, target and distractor simultaneous, or distractor succeeding target). Distractors interfered with visual working memory in all kinds of temporal order. Particularly, when all conditions were intermixed, distractors presented simultaneously with the target caused the least interference (Experiment 1a). When each condition was presented in a single block, no significant difference in distractor interference was observed across all three kinds of temporal order (Experiment 1b). Experiment 2 examined the impact of relative location on distractor interference in all three kinds of temporal order (excluding the target-alone condition). The relative location did not affect distractor interference when presenting distractors ahead of targets. When targets and distractors were presented simultaneously with or after targets, distractor interference increased as the distance between targets and distractors decreased. Therefore, the temporal order and the relative location between distractors and targets influence distractor interference in visual working memory. To minimize distractor interference, when specifying the relative location of distractors and targets, a simultaneous presentation of distractors and targets would be better, and when specifying the temporal order of distractors and targets, increasing the distance between distractors and targets would be better., Author(s): Tingting Xie [sup.1] , Yiping Wei [sup.2] Author Affiliations: (1) https://ror.org/02rkvz144, grid.27446.33, 0000 0004 1789 9163, School of Psychology, Northeast Normal University, , No. 5268 Renmin Street, 130024, Changchun, [...]

Studies indicate that young individuals with high trait anxiety exhibit attentional biases towards threat due to pre-existing 'danger' cognitive schemata. On the other hand, findings suggest that old individuals avoid the processing of negative information due to the 'positivity effect' that becomes apparent in older age. However, the effect of trait anxiety on attentional biases in older people is unclear. We used the Emotional Stroop task and the Stroop task to elucidate the role of trait anxiety in the performance of four participant groups: 11 low anxiety young; 11 high anxiety young (20-30 years); 11 low anxiety old; 11 high anxiety old (60-87 years). We found that age acted as a moderator to the relationship between trait anxiety and emotional interference in the Emotional Stroop task. We found no effect of trait anxiety in the Stroop task, which indicates that attentional biases related to anxiety are threat-specific. Our findings integrate the two bodies of research and suggest that high trait anxiety results in attentional biases towards threat in young adults only, whereas old adults with high trait anxiety do not exhibit such biases. This finding indicates the moderating role of age in the expression of threat-specific attentional biases in individuals with high trait anxiety., Author(s): Christina Kamboureli [sup.1] , Alexandra Economou [sup.2] Author Affiliations: (1) grid.5216.0, 0000 0001 2155 0800, Medical School, National and Kapodistrian University of Athens, , Athens, Greece (2) grid.5216.0, 0000 [...]

Improving memory is a high priority for many. One strategy that reliably improves long-term memory is spacing of learning. Using a within-subject cued recall task, we compared recall of 50 [...]

Leo J. Postman was an internationally recognized experimental psychologist whose work after World War II helped frame the modern empirical study of perception, memory, and other psychological processes. Postman was [...]

Recent evidence suggests that proactive interference (PI) does not hurt event-based prospective memory (ProM) the way it does retrospective memory (RetroM) (Oates, Peynircioglu, & Bates, 2015). We investigated this apparent resistance further. Introduction of a distractor task to ensure we were testing ProM rather than vigilance in Experiment 1 and tripling the number of lists to provide more opportunity for PI buildup in Experiment 2 still did not produce performance decrements. However, when the ProM task was combined with a RetroM task in Experiment 3, a comparable buildup and release was observed also in the ProM task. It appears that event-based ProM is indeed somewhat resistant to PI, but this resistance can break down when the ProM task comprises the same stimuli as in an embedded RetroM task. We discuss the results using the ideas of cue overload and distinctiveness as well as shared attentional and working memory resources. KEYWORDS: prospective memory, proactive interference, proactive inhibition, buildup and release from proactive interference, distinctiveness, cue overload, cognitive resources, Prospective memory (ProM) is remembering to do a task in the future. A cue triggers what was intended to be remembered, and this cue may be time-based or event-based (McDaniel [...]

Backward blocking (BB) and interference between cues (IbC) are cue competition effects produced by very similar manipulations. In a standard BB design, both effects might occur simultaneously, which implies a potential problem for studying BB. In the present study with humans, the magnitude of both effects was compared using a non-causal scenario and a within-subjects design. Previous studies have made this comparison using learning tasks framed within causal scenarios. This posits a limit to generalizing their findings to non-causal learning situations because there is ample evidence showing that participants engage in causal reasoning when tasks are causally framed. The results obtained showed BB and IbC effects of the same magnitude in a non-causally-framed task. This highlights the methodological need for an IbC control in BB experiments. Key words: Associative learning; Backward blocking; interference between cues; Human learning, Backward Mocking (BB hereafter) and interference between cues (IbC hereafter) are two learning and memory phenomena with many similarities regarding the standard experimental conditions in which they are observed. In [...]

In order to clarify whether the influence of color knowledge information in object recognition depends on the presence of the appropriate surface color, we designed a name-object verification task. The relationship between color and shape information provided by the name and by the object photo was manipulated in order to assess color interference independently of shape interference. We tested three different versions for each object: typically colored, black and white, and nontypically colored. The response times on the nonmatching trials were used to measure the interference between the name and the photo. We predicted that the more similar the name and the photo are, the longer it would take to respond. Overall, the color similarity effect disappeared in the black-and-white and nontypical color conditions, suggesting that the influence of color knowledge on object recognition depends on the presence of the appropriate surface color information.

To be rational is to be able to reason. Thirty years ago psychologists believed that human reasoning depended on formal rules of inference akin to those of a logical calculus. This hypothesis ran into difficulties, which led to an alternative view: reasoning depends on envisaging the possibilities consistent with the starting point--a perception of the world, a set of assertions, a memory, or some mixture of them. We construct mental models of each distinct possibility and derive a conclusion from them. The theory predicts systematic errors in our reasoning, and the evidence corroborates this prediction. Yet, our ability to use counterexamples to refute invalid inferences provides a foundation for rationality. On this account, reasoning is a simulation of the world fleshed out with our knowledge, not a formal rearrangement of the logical skeletons of sentences. abduction | deduction | induction | logic | rationality doi/ 10.1073/pnas.1012933107

Smaller Simon effects when stimulus locations are repeated on successive trials rather than alternated have been explained by the attention shift hypothesis, suggesting that shifts of attention result in interfering response codes. We investigated whether the attention shift hypothesis can also explain smaller flanker effects for repeated flankers than for alternated flankers, which occur only with directional information. In 3 peripheral letter identification tasks, target locations were cued by partial or complete flanker stimuli. Experiments 1 and 2 showed that directional flankers elicit shifts of attention. However, Experiment 3 revealed that directional flankers induced inverted cuing effects when reacting to the central target arrow was additionally required. These results are difficult to reconcile with the attention shift hypothesis as an explanation for the congruency reduction with repetitions of directional flankers.

Proactive interference (PI) occurs when an earlier item interferes with memory for a newer item. Whereas some researchers (e.g., Surprenant & Neath, 2009a) argue that PI can be observed in all memory systems, some multiple systems theorists (e.g., Cowan, 1999) propose that items in the focus of attention of working memory are immune to Pl. Two experiments tested whether PI occurs when the to-be-remembered items are assumed, by multiple-systems theorists, to be held in the focus of attention. In each experiment, subjects saw tour trials in a row with the same type of to-be-remembered items, followed by four trials in a row with a different type of material. On each trial, only 3 stimuli were shown, which is below the capacity limit of the focus of attention, and subjects were asked if a probe item was one of those 3 items seen. In both experiments, response time increased from Trial 1 to Trial 4, suggesting that items from the earlier trials interfered with memory on the later trials. In addition, release from PI was shown in that response times decreased with a change of materials. The results replicate those first reported by Hanley and Scheirer (1975), and pose a problem for theorists who argue that parts of short-term memory are immune to PI. Keywords: focus of attention, working memory, proactive interference DOI: 10.1037/a0021011

The task-switching paradigm offers enormous possibilities to study cognitive control as well as task interference. The current review provides an overview of recent research on both topics. First, we review different experimental approaches to task switching, such as comparing mixed-task blocks with single-task blocks, predictable task-switching and task-cuing paradigms, intermittent instructions, and voluntary task selection. In the 2nd part, we discuss findings on preparatory control mechanisms in task switching and theoretical accounts of task preparation. We consider preparation processes in two-stage models, consider preparation as an all-or-none process, address the question of whether preparation is switch-specific, reflect on preparation as interaction of cue encoding and memory retrieval, and discuss the impact of verbal mediation on preparation. In the 3rd part, we turn to interference phenomena in task switching. We consider proactive interference of tasks and inhibition of recently performed tasks indicated by asymmetrical switch costs and n-2 task-repetition costs. We discuss stimulus-based interference as a result of stimulus-based response activation and stimulus-based task activation, and response-based interference because of applying bivalent rather than univalent responses, response repetition effects, and carryover of response selection and execution. In the 4th and final part, we mention possible future research fields. Keywords: task switching, cognitive control, interference DOI: 10.1037/a0019842

We investigated the effects of the duration and type of to-be-articulated distractors during encoding of a verbal list into short-term memory (STM). Distractors and to-be-remembered items alternated during list presentation, as in the complex-span task that underlies much of working-memory research. According to an interference model of STM, known as serial order in a box (SOB; Farrell & Lewandowsky, 2002), additional repeated articulations of the same word between list items should cause minimal further disruption of encoding into STM even though the retention interval for early list items is increased. SOB also predicts that the articulation of several different distractor items should lead to much enhanced disruption if the distractor interval is increased. Those predictions were qualitatively confirmed in 4 experiments that found that it is the type of distractors, not their total duration, that determines the success of encoding a list into STM. The results pose a challenge to temporal models of complex-span performance, such as the time-based resource sharing model (Barrouillet, Bernardin, & Camos, 2004). The results add to a growing body of evidence that memory for the short term is not exclusively governed by purely temporal processes. Keywords: working memory, short-term memory, complex-span task, memory models, interference-based forgetting DOI: 10.1037/a0019764

In 3 experiments, subjects named pictures with low- or high-frequency superimposed distractor words. In a 1st experiment, we replicated the finding that low-frequency words induce more interference in picture naming than high-frequency words (i.e., distractor frequency effect; Miozzo & Caramazza, 2003). According to the response exclusion hypothesis, this effect has its origin at a postlexical stage and is related to a response buffer. The account predicts that the distractor frequency effect should only be present when a response to the word enters the response buffer. This was tested by masking the distractor (Experiment 2) and by presenting it at various time points before stimulus onset (Experiment 3). Results supported the hypothesis by showing that the effect was only present when distractors were visible, and if they were presented in close proximity to the target picture. These results have implications for the models of lexical access and for the tasks that can be used to study this process. Keywords: distractor frequency effect, response exclusion hypothesis, picture-word interference, word production, competition models DOI: 10.1037/a0019128

The task-switching paradigm is being increasingly used as a tool for studying cognitive control and task coordination. Different procedural variations have been developed. They have in common that a comparison is made between transitions in which the previous task is repeated and transitions that involve a change toward another task. In general, a performance switch cost is observed such that switching to a new task results in a slower and more error-prone execution of the task. The present article reviews the theoretical explanations of the switch cost and the findings collected in support of those explanations. Resolution and protection from interference by previous events explain part of the switching cost, but processes related to task setting and task preparation also play a prominent role, as testified by faster execution and lower switch costs when the preparation time is longer. The authors discuss the evidence in favor of each of these sets of accounts and raise a number of questions that situate task switching in a broader context of cognitive control processes. The role of several aspects of the task set, including task variations, task-set overlap, and task-set structure, is addressed, as is the role of knowledge about probability of task changes and about the structure of task sequences. Keywords: task switching, cognitive control, task-set reconfiguration, interference DOI: 10.1037/a0019791

The degree to which phonological codes constrain handwriting is at present controversial. Two experiments used a picture--word interference paradigm in which participants wrote down the names of pictures while attempting to ignore visual distractor words presented at various time intervals (SOAs). Distractors could be orthographically and phonologically related, orthographically related only, or unrelated. We found an exclusive effect of phonology at an early SOA, and orthographic priming at a later SOA. In a second experiment, we showed that the effect of phonology was diminished when writers engaged in concurrent articulatory suppression. The results suggest a role of phonology in the generation of handwritten words that is to some extent dependent on situational circumstances. doi: 10.3758/MC.38.4.519

A large word fragment (e.g., "r--i--rop") is harder to solve when disclosed piecemeal from a smaller fragment (e.g., "r--p") than when shown all at once. This perceptual interference has been found to decrease with the number of solutions to the initial fragments. In the present study, 2 experiments manipulated the number of solutions (1 vs. at least 3) to examine this solution effect using a fragment completion task with Chinese characters. The results revealed a solution effect and showed for the first time no interference in the multiple-solution condition. These findings provide evidence against a competition explanation, which attributes interference to activations of incorrect hypotheses in an early presentation, and in favor of a mismatch explanation, which attributes interference to an enduring inhibition of the correct hypothesis regarding stimulus identity after a mismatch is detected between the hypothesis and the stimulus early in the presentation sequence.

We investigated whether learning effects influencing the Simon effect, such as those found when learning involves the spatial stimulus dimension, might be also found when learning tasks involve other nonspatial stimulus features, such as color, shape, and orientation. Experiment 1 focused on mutual influences between Simon tasks based on color and shape. The Simon task on color is affected by a previously performed Simon task on shape more than the latter is affected by a previously performed Simon task on color. We hypothesized that this difference depends on the difficulty of the tasks. Because orientation discrimination seems more difficult than both color and shape discrimination (Experiment 2), we predicted that a Simon task on orientation would be influenced by a Simon task on color or shape more than tasks on color or shape would be influenced by a task on orientation. Experiments 3 and 4 confirmed our hypothesis.

A number of recent studies have questioned the idea that lexical selection during speech production is a competitive process. One type of evidence against selection by competition is the observation that in the picture--word interference task semantically related distractors may facilitate the naming of a picture, whereas the selection by competition account predicts them to interfere. In the experiments reported in this article, the authors systematically varied, for a given type of semantic relation--that is, basic-level distractors (e.g., fish) during subordinate-level naming (e.g., carp)--the modality in which distractor words were presented (auditory vs. visual) and the proportion of response-congruent trials (i.e., trials allowing for the correct naming response to be derived from both the distractor and the target). With auditory distractors, semantic interference was obtained irrespective of the proportion of response-congruent trials (low in Experiment 1, high in Experiment 2). With visual distractors, no semantic effect was obtained with a low proportion of response-congruent trials (Experiment 3), whereas a semantic facilitation effect was obtained with a high proportion of response-congruent trials (Experiment 4). The authors propose that two processes contribute to semantic effects observed in the picture--word interference paradigm, namely selection by competition (leading to interference) and response congruency (leading to facilitation). Whether facilitation due to response congruency overrules the interference effect because of competition depends on the relative strength of these two processes. Keywords: speech production, lexical competition, lexical access, picture naming, picture--word interference paradigm DOI: 10.1037/a0017020

Memory suppression is investigated with the no-think paradigm, which produces forgetting following repeated practice of not thinking about a memory [Anderson MC, Green C (2001) Nature 410:366-369]. Because the forgotten item is not retrieved even when tested with an independent, semantically related cue, it has been assumed that this forgetting is due to an inhibition process. However, this conclusion is based on a single stage to recall, whereas global memory models, which produce forgetting through a process of interference, include both a sampling and a recovery stage to recall. By assuming that interference exists during recovery, these models can explain cue-independent forgetting. We tested several predictions of this interference explanation of cue-independent forgetting by modifying the think/no-think paradigm. We added a condition where participants quickly pressed enter rather than not thinking. We also manipulated initial memory strength and tested recognition memory. Most importantly, learning to quickly press enter produced as much cue-independent forgetting as no-think instructions. Demonstrating the adequacy of two-stage recall, a simple computational model (SAM-RI) simultaneously captured the original cue, independent cue, and recognition results. cued recall | inhibition | recall | recognition | computational model

Do spatial directions, such as 'to the right,' influence the integration and segregation of information into situation models? According to a single-framework hypothesis, spatial location serves as an event framework, and spatial directions serve as relational information within that framework but do not establish separate sublocation frameworks. Alternatively, according to a fragmented-framework hypothesis, spatial directions lead the larger framework to be broken down such that each direction is treated as a separate sublocation, thereby producing retrieval interference. In three experiments, people memorized sentences about objects in locations. The results support the fragmented-framework hypothesis. Control conditions ruled out explanations based on the ease of memorization, retrieval demands, or sentence complexity.

The ability to mitigate interference is of central importance to cognition. Previous research has provided conflicting accounts about whether operations that resolve interference are singular in character or form a family of functions. Here, the authors examined the relationship between interference-resolution processes acting on working memory representations versus responses. The authors combined multiple forms of interference into a single paradigm by merging a directed-forgetting task, which induces proactive interference, with a stop-signal task, which taps response inhibition processes. The results demonstrated that proactive interference and response inhibition produced distinct behavioral signatures that did not interact. By contrast, combining two different measures of response inhibition by merging a go/no-go task variant and a stop signal produced overadditive behavioral interference, demonstrating that different forms of response inhibition tap the same processes. However, not all forms of response conflict interacted, suggesting that inhibition-related functions acting on response selection are dissociable from those acting on response inhibition. These results suggest that inhibition-related functions for memory and responses are dissociable. Keywords: inhibition, proactive interference, response selection, stop-signal paradigm, working memory

Comprehension of verb-phrase ellipsis (VPE) requires reevaluation of recently processed constituents, which often necessitates retrieval of information about the elided constituent from memory. A. E. Martin and B. McElree (2008) argued that representations formed during comprehension are content addressable and that VPE antecedents are retrieved from memory via a cue-dependent direct-access pointer rather than via a search process. This hypothesis was further tested by manipulating the location of interfering material--either before the onset of the antecedent (proactive interference; PI) or intervening between antecedent and ellipsis site (retroactive interference; RI). The speed-accuracy tradeoff procedure was used to measure the time course of VPE processing. The location of the interfering material affected VPE comprehension accuracy: RI conditions engendered lower accuracy than PI conditions. Crucially, location did not affect the speed of processing VPE, which is inconsistent with both forward and backward search mechanisms. The observed time-course profiles are consistent with the hypothesis that VPE antecedents are retrieved via a cue-dependent direct-access operation. Keywords: sentence processing, verb-phrase ellipsis, retrieval interference, speed-accuracy tradeoff, proactive interference

A briefly presented target can be rendered invisible by a lingering sparse mask that does not even touch it. This form of visual backward masking, called object substitution masking, is thought to occur at the object level of processing. However, it remains unclear whether object-level interference alone produces substitution masking because previous studies manipulated only the presence or absence of a physical masking stimulus after the removal of the target, leaving the possibility of some image-level interference contributing to the total masking. To assess object-level interference in the present study, we used an illusory-contour figure as an object mask, adjacent to the possible target locations, which was created by rotating 4 previewed inducers shaped like Pac-Man to face inward to form a subjective square region. The illusory object persisting beyond the target offset reduced the visibility of the target only when presented in its immediate vicinity. This masking effect could not be attributed to the local directional changes, symmetry, or perceptual closure of the inducers near the target. These results provide strong evidence for a high-level locus of interference in object substitution masking. Keywords: competition for attentional selection, illusory contour, object substitution masking, object updating, subjective figure

The independent cue technique has been developed to test traditional interference theories against inhibition theories of forgetting. In the present study, the authors tested the critical criterion for the independence of independent cues: Studied cues not presented during test (and unrelated to test cues) should not contribute to the retrieval process. Participants first studied a subset of cues (e.g., rope) that were subsequently studied together with a target in a 2nd study phase (e.g., rope--sailing, sunflower--yellow). In the test phase, an extralist category cue (e.g., sports, color) was presented, and participants were instructed to recall an item from the study list that was a member of the category (e.g., sailing, yellow). The experiments showed that previous study of the paired-associate word (e.g., rope) enhanced category cued recall even though this word was not presented at test. This experimental demonstration of covert cuing has important implications for the effectiveness of the independent cue technique. Keywords: independent probe technique, retrieval-induced forgetting, inhibition, interference, memory retrieval

Examinations of interference between visual and spatial materials in working memory have suggested domain- and process-based fractionations of visuo-spatial working memory. The present study examined the role of central time-based resource sharing in visuo-spatial working memory and assessed its role in obtained interference patterns. Visual and spatial storage were combined with both visual and spatial on-line processing components in computer-paced working memory span tasks (Experiment 1) and in a selective interference paradigm (Experiment 2). The cognitive load of the processing components was manipulated to investigate its impact on concurrent maintenance for both within-domain and between-domain combinations of processing and storage components. In contrast to both domain- and process-based fractionations of visuo-spatial working memory, the results revealed that recall performance was determined by the cognitive load induced by the processing of items, rather than by the domain to which those items pertained. These findings are interpreted as evidence for a time-based resource-sharing mechanism in visuo-spatial working memory. Keywords: working memory, attention, between-domain interference, visuo-spatial cognition

In 3 experiments, the role of item strength in the retrieval-induced forgetting paradigm was tested. According to the inhibition theory of forgetting proposed by M. C. Anderson, R. A. Bjork, and E. L. Bjork (1994), retrieval-induced forgetting should be larger for items that are more strongly associated with the category cue. In the present experiments, the authors varied item strength on the study list by manipulating the position of an item within its category (Experiments 1 and 2) and by the number of presentations in the study phase (Experiment 3). Contrary to the predictions from inhibition theory, in all 3 experiments, stronger items did not show more retrieval-induced forgetting than weaker items. Keywords: retrieval-induced forgetting, strength, serial position, interference dependence

Eight experiments with the complex span paradigm are presented to investigate why concurrent processing disrupts short-term retention. Increasing the pace of the processing task led to worse recall, supporting the hypothesis that the processing task distracts attention from maintenance operations. Neither phonological nor semantic similarity between memory items and processing-task material impaired memory. In contrast, the degree of phonological overlap between memory items and processing-task material affected recall negatively, supporting feature overwriting as one source of interference in the complex span paradigm. When compared directly, phonological overlap impaired memory, but similarity had a beneficial effect. These findings rule out response competition or confusion as a mechanism of interference between storage and processing.

The authors examined recognition memory for words or visuospatial patterns under full (FA) or divided attention (DA) conditions with a distracting task requiring either phonological (rhyme) or visuospatial (curved-line) processing of letters, in 72 young adults. The authors found an interaction such that the curved-line distracting task had a more detrimental effect on corrected recognition, and discriminability measured by d', for spatial patterns than did the rhyme distracting task, whereas the reverse was true for memory of words. There was also a general effect of DA on response bias such that C increased under DA relative to FA conditions, regardless of the distracting task, and type of information being remembered. Results suggest memory interference from DA at retrieval is process-specific, and that DA at retrieval leads to a more conservative response strategy. Keywords: memory, spatial, verbal, divided attention, retrieval

To pursue goal directed behavior, the cognitive system must be shielded against interference from irrelevant information. Aside from the online adjustment of cognitive control widely discussed in the literature, an additional mechanism of preventive goal shielding is suggested that circumvents irrelevant information from being processed in the first place. Participants had to react to 8 different words depicting clothing items that were presented in front of line drawings that could be either semantically related (clothes) or unrelated (animals with spatial orientation) to the target words. Participants either learned the stimulus-response (S-R) mappings by heart or used 1 task set (TS). In the S-R group, semantically related and unrelated distractors interfered with performance, whereas in the TS group, only semantically related distractors interfered, and unrelated distractors had no effect. It follows that task representations based on a general TS help to focus attention on relevant information, thereby preventing the processing of irrelevant information. Keywords: goal shielding, distractor interference, conflict, task set, selective attention

Is forgetting in the short term due to decay with the mere passage of time, interference from other memoranda, or both? Past research on short-term memory has revealed some evidence for decay and a plethora of evidence showing that short-term memory is worsened by interference. However, none of these studies has directly contrasted decay and interference in short-term memory in a task that rules out the use of rehearsal processes. In this article the authors present a series of studies using a novel paradigm to address this problem directly, by interrogating the operation of decay and interference in short-term memory without rehearsal confounds. The results of these studies indicate that short-term memories are subject to very small decay effects with the mere passage of time but that interference plays a much larger role in their degradation. The authors discuss the implications of these results for existing models of memory decay and interference. Keywords: short-term memory, decay, interference, recognition, verbal working memory

This investigation examined the contribution of memory awareness to interference, conceptualized as response competition that arises from the encoding of materials similar in appearance. Subjects performed incidental encoding tasks (counting vowels, counting syllables, and word association) on targets and non-targets that were orthographically similar (experimental condition) or dissimilar (control condition). The tasks were intended to make the memories of the studied words at test more or less accessible to subjects' awareness. During the test, fragments of the targets were intermixed with fragments of nonstudied words, and the task was to complete fragments with studied words or, in the absence of such memories, with the first words that came to mind. Response competition was expected to produce a blocking effect, consisting of fewer correct completions and more intrusions (or null responses) in the experimental condition than in the control condition. When the overall accessibility of the studied, orthographically similar words was optimized by the semantic association task, responses recognized as studied exhibited both more intrusions and fewer correct completions than in the control condition. When the accessibility of these words was curtailed by the vowel counting task, only unrecognized correct completions after the proactive interference treatment tended to be lower than in the control condition. These results suggest that memory awareness can modulate interference conceptualized as response competition.

Multiple levels of control may be used in service of reducing Stroop interference. One is list-wide, whereby interference is reduced strategically in lists that include disproportionately more incongruent trials. A second, item- specific control is observed when proportion congruence is manipulated at the level of items. Item-specific control reduces interference for mostly incongruent relative to mostly congruent items. First, we show that item-specific control may drive both list-wide and item-specific proportion congruence effects (Experiment 1). We then show that item-specific control affects Stroop interference similarly when a single feature (a word) as opposed to a feature combination (a word + font type) signals proportion congruence (Experiment 2). Although this suggests that font type offers little advantage for controlling Stroop interference beyond the word, a novel, font-specific proportion congruence effect is observed in Experiment 3, indicating that font type can be used to control interference. These findings support the idea that multiple levels of control are used in reducing Stroop interference.

Although prior research has examined predictions of memory performance under conditions of interference at encoding, predictions of memory performance have not been examined for interference introduced via cues at retrieval. This was investigated in the present study by exposing participants to a random subset of to-be-recalled items just prior to retrieval (part-set cuing) and then eliciting an overall prediction of memory performance. Across three experiments, participants in part-set cuing conditions recalled proportionally fewer items than did participants who were not exposed to any cues. However, participants were unable to predict the detrimental effect of part-set cues on memory performance in either a semantic (Experiment 1) or an episodic (Experiment 2) memory task. Predictions were better calibrated after practice with part-set cuing, and there was evidence that prior experience with part-set cuing transferred to predictions made for a different part-set cuing task (Experiment 3). This suggests that only under some conditions are participants sensitive to the diminished accessibility of memories wrought by part-set cues and illustrates situations in which participants are or are not aware of variables at retrieval that influence memory performance.

Six experiments examined human performance on a modified temporal generalization task when either 1 or 2 standard durations were encoded. In most conditions, participants were presented with a 1st standard duration (A), then judged whether a number of comparison stimuli had the same duration as A. They were then presented with a 2nd standard (B) and again judged whether other comparison stimuli had the same duration as B. Then, after a delay period of 0-45 s, further comparison stimuli were presented, and participants judged whether those stimuli had the same duration as A, without A being represented. A was either the same length as B or shorter or longer than it, so potential retroactive interference effects of B on A could be examined. After a short delay before retesting of A comparisons, the peak of the temporal generalization gradient shifted toward the shortest of the comparisons when A < B and the longest when A > B. The results suggest that certain combinations of delay and interference might render the memory of A unusable, so that a new standard is constructed on the basis of the remembered relationship between A and B, a kind of 'false memory' for duration. Keywords: reference memory, reference, timing, interference, temporal generalization

The time-based resource-sharing model of working memory assumes that memory traces suffer from a time-related decay when attention is occupied by concurrent activities. Using complex continuous span tasks in which temporal parameters are carefully controlled, P. Barrouillet, S. Bernardin, S. Portrat, E. Vergauwe, & V. Camos (2007) recently provided evidence that any increase in time of the processing component of these tasks results in lower recall performance. However, K. Oberauer and R. Kliegl (2006) pointed out that, in this paradigm, increased processing times are accompanied by a corollary decrease of the remaining time during which attention is available to refresh memory traces. As a consequence, the main determinant of recall performance in complex span tasks would not be the duration of attentional capture inducing time-related decay, as Barrouillet et al. (2007) claimed, but the time available to repair memory traces, and thus would be compatible with an interference account of forgetting. The authors demonstrate here that even when the time available to refresh memory traces is kept constant, increasing the processing time still results in poorer recall, confirming that time-related decay is the source of forgetting within working memory. Keywords: working memory, forgetting, memory decay, interference

Recent interest in the benefits of retrieval practice on long-term retention--the testing effect--has spawned a considerable amount of research toward understanding the underlying nature of this ubiquitous memory phenomenon. Taking a test may benefit retention through both direct means (engaging appropriate retrieval processes) and indirect means (fostering directed study). Here the authors report 4 experiments demonstrating a novel benefit of testing. Extended study sessions cause a buildup of proactive interference, but interpolating tests during the study sequence insulates against this negative influence. These findings highlight a unique benefit of testing and have important implications for study strategies. Keywords: testing effect, proactive interference, list discrimination, cue overload, source monitoring

Learners (n=48) practiced three multisegment movements with distinct target movement times. Four practice groups were compared: blocked, random, and two groups who had a win-shift/lose-stay schedule (WSLS1 and WSLS2). For these latter groups switching between practice tasks was performance-contingent: within 5% of target time for 1 or 2 consecutive trials, respectively. During acquisition, blocked performance was more accurate than for both random and WSLS2 groups. The WSLS1 group performed between blocked and random groups, but did not differ from either. In a next-day retention test, the random group scored better than the blocked group. The WSLS1 group performed similarly to the random practice while the WSLS2 group's scores were similar to those of the blocked group. Results encourage further study of similar practice schedules.

This article presents a model of long term forgetting based on 3 ideas: (a) Memory for a stimulus can be described by a population of accessible traces; (b) probability of retrieval after a delay is predicted by the proportion of traces in this population that will be defined as correct if sampled; and (c) this population is diluted over time by null traces that, if accessed, block retrieval. Dilution is modeled as a linear function of time and outcome of accessing memories by their temporal organization. The model is applied to 5 published experiments studying forgetting in cued recall, 4 recognition experiments, and 1 using savings methods. The model specifies the different form of the retention function in each case well and provides a principled explanation for some puzzling characteristics of forgetting without recourse to mechanisms such as decay or consolidation. Keywords: multiple traces, dilution, forgetting, temporal discrimination, interference

Previous research suggests that tendencies to misattribute one's own thoughts to an external source, as assessed by an immediate source-monitoring test, are associated with auditory verbal hallucinations (AVHs). However, recent research suggests that such tendencies are associated instead with symptoms of thought interference. The main aim of the present study was to examine whether such tendencies are differentially associated with different types of thought interference, with AVHs, or with both. It has also been suggested that external misattributions are especially likely to occur with emotionally salient material and if the individual's focus is on the self. These suggestions were also tested. The positive psychotic symptoms of 57 individuals with a diagnosis of schizophrenia were assessed and they then completed the Self-Focus Sentence Completion blank. Immediately after completing each sentence they were asked to indicate to what extent the sentence was their own. The number of sentences that were not rated as completely their own served as their externalisation score. Externalisation scores correlated significantly with the severity of three symptoms: voices commenting, delusions of being controlled, and thought insertion. In a logistic regression analysis, all three of these symptoms were significantly and independently related to externalisation. Externalisation was not associated with either a negative or a neutral self-focus. Thus tendencies to misattribute one's own thoughts to an external source are associated with AVHs and some, but not all, symptoms of thought interference. The importance for externalisation of self-focused attention and of the emotional salience of the elicited thoughts was not supported. Keywords: Cognitive intrusions Thought interference Auditory hallucinations Positive symptoms of schizophrenia Self-focused attention

Conflicting evidence has been obtained whether or not patients diagnosed with obsessive-compulsive disorder (OCD) share an attentional bias towards disorder-related stimuli. Some of these inconsistencies can be accounted for by suboptimal stimuli selection. In consideration of the heterogeneity of OCD, we investigated Stroop interference effects for two classes of OCD items (i.e., washing and checking) in 23 OCD patients and 23 healthy controls. In order to cover prevalent OCD concerns, item compilation was based on experts' appraisals. Patients neither displayed greater immediate as well as delayed Stroop interference nor any bias for OCD and subtype-congruent stimuli. On the contrary, for washing-related items, OCD patients, and here especially washers, displayed facilitation relative to healthy controls. Although the present study at first sight refutes the notion of an attentional bias in OCD in contrast to other anxiety disorders, several potential moderators need to be considered before this account is ultimately dismissed. In particular, an attentional bias may only be elicited using visual material that is more attention-grabbing than verbal stimuli. Finally, blockwise instead of random item administration and greater consideration of individual relevance may be crucial prerequisites for the effect to emerge. Keywords: Obsessive compulsive disorder Stroop Washer Checker Attentional bias Interference

Memory interference is a common cause of forgetting. Interference is a byproduct of the need to balance the formation of well-differentiated representations against the ability to retrieve memories from cues that are not identical to the original experience. How the brain accomplishes this has remained elusive. Here we review how insights can be gained from studies of an apparently unrelated phenomenon in the rodent brain--remapping in hippocampal place cells. Remapping refers to the formation of distinct representations in populations of place cells after minor changes in inputs to the hippocampus. Remapping might reflect processes involved generally in decorrelation of overlapping signals. These processes might be crucial for storing large numbers of similar experiences with only minimal interference.

According to the extended bottleneck model, dual-task interference does not arise only from a central bottleneck but also from processing limitations at the motor stage. Evidence for this assumption has previously been found only for same-effector tasks but not for different-effector tasks. In order to examine the existence of motor interference with different effectors, we used the psychological refractory period paradigm and employed response sequences of different length in Task 1 (R1 sequence length). Experiment 1 incorporated vocal response sequences in Task 1 and a manual response in Task 2. In Experiment 2, the assignment of the effectors to the two tasks was reversed. In both experiments, the long R1 sequence prolonged reaction time for Task 2 (RT2), and this effect was reduced with decreasing temporal overlap of the two tasks. Thus, the present experiments demonstrate motor interference between different-effector tasks. This interference may be due to on-line programming or to central response monitoring.

Three lever-press suppression studies were conducted with water-deprived rats to investigate the role of similarity in proactive interference within first-order Pavlovian conditioning. Experiments la and lb assessed the influence of stimulus complexity in proactive interference. Both experiments found greater interference when the interfering cue and target cue were composed of the same number of elements. Experiment 2 assessed the influence of context similarity in proactive interference and demonstrated that stronger proactive interference occurred when the interfering cue and the target cue were trained in the same context. The results in conjunction with other reports indicate that various types of cue interaction (e.g., interference and competition) are influenced by similarity of the interacting training events.

The acoustic confusion effect is the finding that lists of to-be-remembered items that sound similar to one another are recalled worse than otherwise comparable lists of items that sound different. Previous work has shown that concurrent irrelevant speech and concurrent irrelevant tapping both reduce the size of this effect, suggesting similarities between the two manipulations. The authors assessed the relation between irrelevant speech and irrelevant tapping by correlating the disruption each causes to recall of similar- and dissimilar-sounding items. A significant correlation was obtained, indicating a relation between the two. The results indicate that researchers should be sensitive to changes in the magnitude of the effects rather than focusing exclusively on the presence or absence of particular effects. Implications for the 3 major explanations of the irrelevant speech effect are discussed. Keywords: immediate memory, serial recall, tapping task, interference L'effet de confusion acoustique refere au fait que les listes d'items retenir dont la sonorite entre les items est semblable sont plus difficilement rappelees que des listes equivalentes dont la sonorite entre les items est differente. Des travaux anterieurs ont demontre que le discours concurrent non pertinent et le tapage concurrent non pertinent reduisent la taille de cet effet, suggerant des similitudes entre les deux manipulations. Nous avons evalue la relation entre le discours non pertinent et le tapage non pertinent en correlant l'intefference que chacune des manipulations cause au rappel d'items a sonorite similaire et non similaire. Une correlation significative a ete obtenue, indiquant une relation entre les deux. Les resultats indiquent que les chercheurs devraient etre attentifs la magnitude des effets plutot que de s'interesser exclusivement la presence ou a l'absence d'effets. Une discussion quant aux implications de cette recherche pour les trois explications principales de l'effet du discours non pertinent est presentee. Mots-cles : memoire immediate, rappel seriel, tache de tapping, intefference

Given a changing visual environment, and the limited capacity of visual working memory (VWM), the contents of VWM must be in constant flux. Using a change detection task, the authors show that VWM is subject to obligatory updating in the face of new information. Change detection performance is enhanced when the item that may change is retrospectively cued 1s after memory encoding and 0.5 s before testing. The retro-cue benefit cannot be explained by memory decay or by a reduction in interference from other items held in VWM. Rather, orienting attention to a single memory item makes VWM more resistant to interference from the test probe. The authors conclude that the content of VWM is volatile unless it receives focused attention, and that the standard change detection task underestimates VWM capacity. Keywords: visual working memory, visual attention, memory decay, memory interference, change detection