Evidence for proactive interference in the focus of attention of working memory.

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 PI. 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 four 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in proactive interference, working memory, and abstract reasoning.

[Correction Notice: An erratum for this article was reported in Vol 23(4) of Psychology and Aging (see record 2008-19072-007). The original article contained an incorrect DOI. The correct DOI is as follows: 10.1037/a0012577.] It has been hypothesized that older adults are especially susceptible to proactive interference (PI) and that this may contribute to age differences in working memory performance. In young adults, individual differences in PI affect both working memory and reasoning ability, but the relations between PI, working memory, and reasoning in older adults have not been examined. In the current study, young, old, and very old adults performed a modified operation span task that induced several cycles of PI buildup and release as well as two tests of abstract reasoning ability. Age differences in working memory scores increased as PI built up, consistent with the hypothesis that older adults are more susceptible to PI, but both young and older adults showed complete release from PI. Young adults' reasoning ability was best predicted by working memory performance under high PI conditions, replicating M. Bunting (2006). In contrast, older adults' reasoning ability was best predicted by their working memory performance under low PI conditions, thereby raising questions regarding the general role of susceptibility to PI in differences in higher cognitive function among older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory span and the role of proactive interference.

The author 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control of interference during working memory updating.

The current study examined the nature of the processes underlying working memory updating. In 4 experiments using the n-back paradigm, the authors demonstrate that continuous updating of items in working memory prevents strong binding of those items to their contexts in working memory, and hence leads to an increased susceptibility to proactive interference. Results of Experiments 1 and 2 show that this interference reflects a competition between a process that reveals the degree of familiarity of an item and a context-sensitive recollection process that depends on the strength of bindings in working memory. Experiment 3 further clarifies the origins of interference during updating by demonstrating that even items that are semantically related to the updated working memory contents but that have not been maintained in working memory before cause proactive interference. Finally, the results of Experiment 4 indicate that the occurrence of interference leads to top-down behavioral adjustments that prioritize recollection over familiarity assessment. The implications of these findings for the construct validity of the n-back task, for the control processes involved in working memory updating, and for the concept of executive control more generally are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contributions of source and inhibitory mechanisms to age-related retroactive interference in verbal working memory.

Determining contributions of source-monitoring and inhibitory function to age-related forgetting has been an elusive goal for cognitive theorists. Five studies used a verbal working memory paradigm to examine mechanisms accounting for disproportionate retroactive interference (RI) experienced with adult aging. Participants distinguished studied target-word pairs from interfering pairs that were read aloud. Source-monitoring and inhibitory task components varied through manipulations of response requirements. RI effects were primarily due to source-monitoring failures rather than to inhibitory failures. Removing both source and inhibitory components eliminated age differences in RI. When source monitoring was emphasized, RI continued to be observed in all age groups but disproportionately for older adults. Process dissociation analyses of memory found recollection decreases and familiarity increases consistent with source failures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion processing effects on interference resolution in working memory.

The interaction between emotion and working memory maintenance, load, and performance has been investigated with mixed results. The effect of emotion on specific executive processes such as interference resolution, however, remains relatively unexplored. In this series of studies, we examine how emotion affects interference resolution processes within working memory by modifying the Recency-probes paradigm (Monsel, 1978) to include emotional and neutral stimuli. Reaction time differences were compared between interference and non-interference trials for neutral and emotional words (Studies 1 & 3) and pictures (Study 2). Our results indicate that trials using emotional stimuli show a relative decrease in interference compared with trials using neutral stimuli, suggesting facilitation of interference resolution in the former. Furthermore, both valence and arousal seem to interact to produce this facilitation effect. These findings suggest that emotion facilitates response selection amid interference in working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proactive interference and item similarity in working memory.

Proactive interference (PI) may influence the predictive utility of working memory span tasks. Participants in one experiment (N=70) completed Ravens Advanced Progressive Matrices (RAPM) and multiple versions of operation span and probed recall, modified for the type of memoranda (digits or words). Changing memoranda within- or across-trials released PI, but not doing so permitted PI buildup. Scores from PI-build trials, but not PI-release trials, correlated with RAPM and accounted for as much variance in RAPM as unmodified tasks. These results are consistent with controlled attention and inhibition accounts of working memory, and they elucidate a fundamental component of working memory span tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age, time of testing, and proactive interference.

A four-list version of a release from proactive interference paradigm was used to assess the degree to which older (aged 58-78 yrs) and younger adults (aged 18-32 yrs) tested at optimal and nonoptimal times of day are vulnerable to interference effects in memory, effects that may increase at nonoptimal times. Morning type older adults and Evening type younger adults were tested either early in the morning or late in the afternoon. Standard buildup and release effects were shown for all age groups except for older adults tested in the afternoon; they failed to show release. Recall and intrusion data suggested that older adults are more vulnerable to proactive interference than younger adults and that for older adults at least, interference effects are heightened at nonoptimal times of day. The data are discussed in terms of an inhibitory model of control over the contents of working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orienting attention in visual working memory reduces interference from memory probes.

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 1 s 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related deficits in mice performing working memory tasks in a water maze.

This study determined whether mice exhibit spatial working memory deficits with increased age. C57BL/6JNia mice of 3 different ages were tested in the Morris water maze with 2 protocols designed to assess immediate and delayed working memory abilities. Young mice required multiple trials in order to show improvements in the working memory task. Deficits in immediate working memory were detected in both 10- and 24- to 26-month-old mice. Reference memory deficits and declines in performance in the delayed working memory task were only seen in 24- to 26-month-olds. This increased susceptibility of immediate working memory processes to the aging process in mice may be related to their need for more rehearsal in the water maze than other species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and interference in verbal working memory.

According to inhibitory views of working memory, old adults should have particular problems deleting irrelevant information from working memory, leading to greater interference effects compared with young adults. The authors investigated this hypothesis by using variations of an A-B, C-D retroactive interference paradigm in working memory with young and old adults. They used a recognition measure of memory, assessing both accuracy and reaction time. The primary finding was that senior adults consistently exhibited proportionally greater retroactive interference effects compared with young adults when interfering word pairs that had been read aloud had to be rejected. Patterns of recognition and reaction time data suggested that old adults' activation of target material is similar to young adults, but they experience sustained activation of irrelevation material that has entered working memory. Theoretical implications of these findings for inhibitory deficit (R.T. Zacks & L. Hasher, 1998) and source memory deficit accounts of cognitive aging are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task experience and children's working memory performance: A perspective from recall timing.

Working memory is an important theoretical construct among children, and measures of its capacity predict a range of cognitive skills and abilities. Data from 9- and 11-year-old children illustrate how a chronometric analysis of recall can complement and elaborate recall accuracy in advancing our understanding of working memory. A reading span task was completed by 130 children, 75 of whom were tested on 2 occasions, with sequence length either increasing or decreasing during test administration. Substantial pauses occur during participants' recall sequences, and they represent consistent performance traits over time, while also varying with recall circumstances and task history. Recall pauses help to predict reading and number skills, alongside as well as separate from levels of recall accuracy. The task demands of working memory change as a function of task experience, with a combination of accuracy and response timing in novel task situations being the strongest predictor of cognitive attainment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A meta-analysis of performance on simple span and more complex working memory tasks in Parkinson's disease.

The working memory (WM) concept has stimulated substantial research since Baddeley and Hitch advanced their model in 1974. There has also been growing interest in WM in Parkinson's disease (PD) where the brain structures considered important for WM are often compromised. However, it remains unclear how and to what degree WM is affected in PD. The authors used meta-analysis to clarify the research findings on WM in PD. The results confirmed that people with PD are impaired on tests of WM. This impairment is small for verbal span but moderate on complex verbal and both simple and complex visuospatial tasks. These data do not support the belief that WM impairment in PD is solely at the level of the central executive. However, our findings support the notion that impairment is more pronounced for visuospatial than verbal WM. A number of different interpretations of these results are discussed. It remains to be established what these statistically significant differences mean in terms of clinically significant levels of impairment in WM. Another important methodological issue that demands greater consideration in this area is that of sampling and the generalizability of results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The interactive effects of proactive personality and work-family interference on well-being.

Proactive personality was expected to moderate the relationship between controllable work and nonwork stressors (e.g., time-based work-family interference) and job/life satisfaction. Moderated multiple regression analyses of survey data from a sample of professionals (N=133) revealed a significant interaction between time-based family interfering-with work and proactive personality predicting life satisfaction and several main effects offering partial support for the hypothesized relationships (α     

Interference, aging, and visuospatial working memory: The role of similarity.

Objective: Older adults' performance on working memory (WM) span tasks is known to be negatively affected by the buildup of proactive interference (PI) across trials. PI has been reduced in verbal tasks and performance increased by presenting distinctive items across trials. In addition, reversing the order of trial presentation (i.e., starting with the longest sets first) has been shown to reduce PI in both verbal and visuospatial WM span tasks. We considered whether making each trial visually distinct would improve older adults' visuospatial WM performance, and whether combining the 2 PI-reducing manipulations, distinct trials and reversed order of presentation, would prove additive, thus providing even greater benefit. Method: Forty-eight healthy older adults (age range = 60–77 years) completed 1 of 3 versions of a computerized Corsi block test. For 2 versions of the task, trials were either all visually similar or all visually distinct, and were presented in the standard ascending format (shortest set size first). In the third version, visually distinct trials were presented in a reverse order of presentation (longest set size first). Results: Span scores were reliably higher in the ascending version for visually distinct compared with visually similar trials, F(1, 30) = 4.96, p = .03, η2 = .14. However, combining distinct trials and a descending format proved no more beneficial than administering the descending format alone. Conclusions: Our findings suggest that a more accurate measurement of the visuospatial WM span scores of older adults (and possibly neuropsychological patients) might be obtained by reducing within-test interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Manipulation of working memory information is impaired in Parkinson's disease and related to working memory capacity.

It has been suggested that in patients with Parkinson's disease (PD), difficulties in the manipulation of information, which result in problems in executive tasks, are related to a reduction of working memory capacity (J. D. E. Gabrieli, J. Singh, G. T. Stebbins, & C. G. Goetz, 1996). The present study selectively varied the manipulation demand irrespective of the maintenance requirement. In a group of 14 PD patients, performance declined overproportionally with the increasing task demand and was significantly correlated with a measure of working memory capacity. These results suggest that the complexity of working memory processing may decisively contribute to the exhaustion of resources in PD patients. Increasing complexity may either affect their manipulation ability directly or impede the management of inhibitory control requirements inherent to the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of schizophrenia and bipolar patients on verbal and figural working memory tasks.

Working memory (WM) was studied in 82 healthy volunteers, 43 schizophrenia patients, and 81 bipolar patients. Schizophrenia patients were impaired on verbal and figural WM tasks that possessed similar test discriminating power. Bipolar patients performed similarly to healthy volunteers. A mathematical model of WM performance revealed a primary role for reduced WM span in accounting for the impaired verbal WM of schizophrenia patients and a primary role for diminished attention in accounting for impaired figural WM. Although WM impairment in schizophrenia is due neither to the general effects of severe mental illness nor to the specific type of material studied, the microarchitecture of abnormal WM in schizophrenia may depend on the stimulus material presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of working memory abilities across the adult life span.

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20–89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Neural mechanisms of interference control underlie the relationship between fluid intelligence and working memory span.

Fluid intelligence (gF) and working memory (WM) span predict success in demanding cognitive situations. Recent studies show that much of the variance in gF and WM span is shared, suggesting common neural mechanisms. This study provides a direct investigation of the degree to which shared variance in gF and WM span can be explained by neural mechanisms of interference control. The authors measured performance and functional magnetic resonance imaging activity in 102 participants during the n-back WM task, focusing on the selective activation effects associated with high-interference lure trials. Brain activity on these trials was correlated with gF, WM span, and task performance in core brain regions linked to WM and executive control, including bilateral dorsolateral prefrontal cortex (middle frontal gyrus; BA9) and parietal cortex (inferior parietal cortex; BA 40/7). Interference-related performance and interference-related activity accounted for a significant proportion of the shared variance in gF and WM span. Path analyses indicate that interference control activity may affect gF through a common set of processes that also influence WM span. These results suggest that individual differences in interference-control mechanisms are important for understanding the relationship between gF and WM span. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relationship between measures of working memory capacity and the time course of short-term memory retrieval and interference resolution.

The response-signal speed–accuracy trade-off (SAT) procedure was used to investigate the relationship between measures of working memory capacity and the time course of short-term item recognition. High- and low-span participants studied sequentially presented 6-item lists, immediately followed by a recognition probe. Analyses of composite list and serial position SAT functions found no differences in retrieval speed between the 2 span groups. Overall accuracy was higher for high spans than low spans, with more pronounced differences for earlier serial positions. Analysis of false alarms to recent negatives (lures from the previous study list) revealed no differences in the timing or magnitude of early false alarms, thought to reflect familiarity-based judgments. However, analyses of false alarms later in retrieval indicated that recollective information accrues more slowly for low spans, which suggests that recollective information may also contribute less to judgments concerning studied items for low-span participants. These findings can provide an explanation for the greater susceptibility of low spans to interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)