Item-specific proactive interference in olfactory working memory.

PubMed

Moss, Andrew; Miles, Christopher; Elsley, Jane; Johnson, Andrew

2018-04-01

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.

Proactive and Retroactive Effects of Negative Suggestion

ERIC Educational Resources Information Center

Brown, Alan S.; Brown, Christine M.; Mosbacher, Joy L.; Dryden, W. Erich

2006-01-01

The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false…

How does susceptibility to proactive interference relate to speech recognition in aided and unaided conditions?

PubMed

Ellis, Rachel J; Rönnberg, Jerker

2015-01-01

Proactive interference (PI) is the capacity to resist interference to the acquisition of new memories from information stored in the long-term memory. Previous research has shown that PI correlates significantly with the speech-in-noise recognition scores of younger adults with normal hearing. In this study, we report the results of an experiment designed to investigate the extent to which tests of visual PI relate to the speech-in-noise recognition scores of older adults with hearing loss, in aided and unaided conditions. The results suggest that measures of PI correlate significantly with speech-in-noise recognition only in the unaided condition. Furthermore the relation between PI and speech-in-noise recognition differs to that observed in younger listeners without hearing loss. The findings suggest that the relation between PI tests and the speech-in-noise recognition scores of older adults with hearing loss relates to capability of the test to index cognitive flexibility.

How does susceptibility to proactive interference relate to speech recognition in aided and unaided conditions?

PubMed Central

Ellis, Rachel J.; Rönnberg, Jerker

2015-01-01

Proactive interference (PI) is the capacity to resist interference to the acquisition of new memories from information stored in the long-term memory. Previous research has shown that PI correlates significantly with the speech-in-noise recognition scores of younger adults with normal hearing. In this study, we report the results of an experiment designed to investigate the extent to which tests of visual PI relate to the speech-in-noise recognition scores of older adults with hearing loss, in aided and unaided conditions. The results suggest that measures of PI correlate significantly with speech-in-noise recognition only in the unaided condition. Furthermore the relation between PI and speech-in-noise recognition differs to that observed in younger listeners without hearing loss. The findings suggest that the relation between PI tests and the speech-in-noise recognition scores of older adults with hearing loss relates to capability of the test to index cognitive flexibility. PMID:26283981

Proactive Interference and Item Similarity in Working Memory

ERIC Educational Resources Information Center

Bunting, Michael

2006-01-01

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…

Inhibitory Control of Proactive Interference in Adults with ADHD

ERIC Educational Resources Information Center

White, Holly A.

2007-01-01

Objective: Attention deficit hyperactivity disorder (ADHD) is associated with poor inhibition of prepotent responses and deficits in distractor inhibition, but relatively few studies have addressed inhibitory control of proactive interference (PI) in individuals with ADHD. Thus, the goal of the present study was to evaluate resistance to spatial…

Experience with proactive interference diminishes its effects: mechanisms of change.

PubMed

Wahlheim, Christopher N; Jacoby, Larry L

2011-02-01

In three experiments, we examined the mechanisms by which prior experience with proactive interference (PI) diminished its effects. Cued recall tasks conforming to an A-B, A-D paradigm were used to induce PI effects. Experiment 1 showed that reduced PI was not due to a reduction in attention to the source of PI. Experiment 2 revealed that participants' awareness of PI effects on memory performance increased with experience, resulting in a shift in encoding processes. Experiment 3 demonstrated that changes in encoding provided additional support for recollection that further enhanced participants' ability to constrain their retrieval processing to the appropriate source of information at the time of test. These results can be interpreted as showing that experience with PI enhances awareness of its effects and allows individuals to adjust their learning and retrieval strategies to compensate for such effects.

When does a good working memory counteract proactive interference? Surprising evidence from a probe recognition task.

PubMed

Cowan, Nelson; Saults, J Scott

2013-02-01

It is often proposed that individuals with high working memory span overcome proactive interference (PI) from previous trials, saving working memory for task-relevant items. We examined this hypothesis in word-list probe recognition. We found no difference in PI related to span. Instead, ex-gaussian analysis of reaction time showed speed advantages for high spans specific to short lists (3 or 4 items) but absent from longer lists (6 or 8 items). We suggest that high-span advantages in reaction time are based on finesse during easy trials, not on overcoming PI. 2013 APA, all rights reserved

How a high working memory capacity can increase proactive interference.

PubMed

Steinwascher, Merle A; Meiser, Thorsten

2016-08-01

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. Copyright © 2016 Elsevier Inc. All rights reserved.

Preserved Proactive Interference in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Carmo, Joana C.; Duarte, Elsa; Pinho, Sandra; Filipe, Carlos N.; Marques, J. Frederico

2016-01-01

In this study, we aimed to evaluate further the functioning and structuring of the semantic system in autism spectrum disorders (ASD). We analyzed the performance of 19 high-functioning young adults with ASD and a group of 20 age-, verbal IQ- and education-matched individuals with the Proactive Interference (PI) Paradigm to evaluate semantic…

Proactive Interference & Language Change in Hearing Adult Students of American Sign Language.

ERIC Educational Resources Information Center

Hoemann, Harry W.; Kreske, Catherine M.

1995-01-01

Describes a study that found, contrary to previous reports, that a strong, symmetrical release from proactive interference (PI) is the normal outcome for switches between American Sign Language (ASL) signs and English words and with switches between Manual and English alphabet characters. Subjects were college students enrolled in their first ASL…

Increasing contextual demand modulates anterior and lateral prefrontal brain regions associated with proactive interference.

PubMed

Wolf, Robert Christian; Walter, Henrik; Vasic, Nenad

2010-01-01

Using a parametric version of a modified item-recognition paradigm with three different load levels and by means of event-related functional magnetic resonance imaging, this study tested the hypothesis that cerebral activation associated with intratrial proactive interference (PI) during working memory retrieval is influenced by increased context processing. We found activation of left BA 45 during interference trials across all levels of cognitive processing, and left lateralized activation of the dorsolateral prefrontal cortex (DLPFC, BA 9/46) and the frontopolar cortex (FPC, BA 10) with increasing contextual load. Compared with high susceptibility to PI, low susceptibility was associated with activation of the left DLPFC. These results suggest that an intratrial PI effect can be modulated by increasing context processing of a transiently relevant stimulus set. Moreover, PI resolution associated with increasing context load involves multiple prefrontal regions including the ventro- and dorsolateral prefrontal cortex as well as frontopolar brain areas. Furthermore, low susceptibility to PI might be influenced by increased executive control exerted by the DLPFC.

Cognitive control of familiarity: directed forgetting reduces proactive interference in working memory.

PubMed

Festini, Sara B; Reuter-Lorenz, Patricia A

2014-03-01

Proactive interference (PI) occurs when previously learned information interferes with new learning. In a working memory task, PI induces longer response times and more errors to recent negative probes than to new probes, presumably because the recent probe's familiarity invites a "yes" response. Warnings, longer intertrial intervals, and the increased contextual salience of the probes can reduce but not eliminate PI, suggesting that cognitive control over PI is limited. Here we tested whether control exerted in the form of intentional forgetting performed during working memory can reduce the magnitude of PI. In two experiments, participants performed a working memory task with directed-forgetting instructions and the occasional presentation of recent probes. Surprise long-term memory testing indicated better memory for to-be-remembered than for to-be-forgotten items, documenting the classic directed-forgetting effect. Critically, in working memory, PI was virtually eliminated for recent probes from prior to-be-forgotten lists, as compared to recent probes from prior to-be-remembered lists. Thus cognitive control, when executed via directed forgetting, can reduce the adverse and otherwise persistent interference from familiarity, an effect that we attribute to attenuated memory representations of the to-be-forgotten items.

Type-specific proactive interference in patients with semantic and phonological STM deficits.

PubMed

Harris, Lara; Olson, Andrew; Humphreys, Glyn

2014-01-01

Prior neuropsychological evidence suggests that semantic and phonological components of short-term memory (STM) are functionally and neurologically distinct. The current paper examines proactive interference (PI) from semantic and phonological information in two STM-impaired patients, DS (semantic STM deficit) and AK (phonological STM deficit). In Experiment 1 probe recognition tasks with open and closed sets of stimuli were used. Phonological PI was assessed using nonword items, and semantic and phonological PI was assessed using words. In Experiment 2 phonological and semantic PI was elicited by an item recognition probe test with stimuli that bore phonological and semantic relations to the probes. The data suggested heightened phonological PI for the semantic STM patient, and exaggerated effects of semantic PI in the phonological STM case. The findings are consistent with an account of extremely rapid decay of activated type-specific representations in cases of severely impaired phonological and semantic STM.

Storage and Retrieval Changes that Occur in the Development and Release of PI

ERIC Educational Resources Information Center

Chechile, Richard; Butler, Keith

1975-01-01

A Bayesian statistical procedure separating storage from retrieval was used to study development and release of proactive interference in the Brown-Peterson paradigm. A theory of PI is developed stressing response competition at test time and interference in transfer between short- and long-term memory. (CHK)

Age-differences in the temporal properties of proactive interference in working memory.

PubMed

Samrani, George; Bäckman, Lars; Persson, Jonas

2017-12-01

The inability to suppress irrelevant information has been suggested as a primary cause of proactive interference (PI), and this deficit may be enhanced in aging. The current study examines age differences and temporal boundaries of PI, by manipulating lure distances in a verbal 2-back working memory task. Both younger and older adults showed effects of interference for proximal 3- and 4-back lures, and this effect was greater for older adults. Whereas younger adults showed less interference during 4-back compared to 3-back lures, in both reaction times and accuracy, older adults improved only in accuracy. For distant lures, when the time between the 1st presentation of an item to its reappearance as a lure item was longer (e.g., 5- to 10-back lures), younger adults were no longer affected by PI. However, older adults were affected by PI throughout all distant lures, up to the most distant lure (9-/10-back). The results suggest that older adults were less successful in resolving interference from both proximal and distant familiar lures. Further, younger adults were able to overcome the effects of PI completely after a specific lure distance. The age differences in temporal properties of PI may therefore highlight a unique component linked to impaired interference control and aging. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Preserved Proactive Interference in Autism Spectrum Disorder.

PubMed

Carmo, Joana C; Duarte, Elsa; Pinho, Sandra; Filipe, Carlos N; Marques, J Frederico

2016-01-01

In this study, we aimed to evaluate further the functioning and structuring of the semantic system in autism spectrum disorders (ASD). We analyzed the performance of 19 high-functioning young adults with ASD and a group of 20 age-, verbal IQ- and education-matched individuals with the Proactive Interference (PI) Paradigm to evaluate semantic functioning in ASD (Experiment 1). In Experiment 2, we analyzed the performances of both groups in a PI paradigm with manipulation of the level of typicality. In both experiments, we observed significant effects of trial and group but no trial by group interactions, which we interpreted as robust evidence of preserved PI (build up effect) that indicated the preservation of semantic mechanisms of encoding and retrieval.

Epilepsy increases vulnerability of long-term face recognition to proactive interference.

PubMed

Bengner, T; Malina, T; Lindenau, M; Voges, B; Goebell, E; Stodieck, S

2006-02-01

Proactive interference (PI) decreases short- and long-term memory in healthy subjects. Neurological patients exhibit a heightened PI effect on short-term memory. It is, however, not known if PI affects long-term memory in neurological patients. We analyzed whether epilepsy heightens the negative effect of PI on long-term face memory. PI was induced by a list of 20 faces learned 24 hours prior to a target list of 20 faces. We tested immediate and 24-hour recognition for both lists. Twelve healthy controls and 42 patients with generalized epilepsy or temporal lobe epilepsy (TLE) were studied. PI led to a decrease in 24-hour recognition in patients with generalized epilepsy and TLE but not in controls. Thus, PI may cause long-term memory disturbances in epilepsy patients. PI was also associated with decreased short-term memory, but only in right TLE. This confirms the dominant role of the right temporal lobe in short-term face memory.

Release from Proactive Interference with Positive and Negative Words

ERIC Educational Resources Information Center

Ferraro, F. Richaro; King, Brent

2004-01-01

Using the release from proactive interference (RPI) task, college students (n = 40) received 4 trials comprised of 3-word triads of either positive (P) or negative (N) words. Word-triad recall served as the dependent measure, and results revealed typical buildup of PI (i.e., no significant group X trial interaction across Trials 1-3). Significant…

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

PubMed

Hanseeuw, Bernard J; Seron, Xavier; Ivanoiu, Adrian

2012-10-01

Increased sensitivity to proactive (PI) and retroactive (RI) interference has been observed in amnestic mild cognitive impairment (aMCI). PI and RI are often explained as being the result of a response competition mechanism. However, patients with aMCI are supposed to suffer mostly from encoding deficits. We hypothesized that in aMCI interference may occur at encoding and not only at the retrieval stage. We developed an original paradigm enabling PI and RI to be tested with and without response competitors. Eighteen young controls (YC), 16 elderly controls (EC) and 15 aMCI participated in the study. The YC and EC groups presented interference effects only in conditions that included a direct response competitor. In contrast, aMCI had interference effects in all conditions including the one without response competitor. Increased sensitivity to interference in aMCI appears to occur at the encoding/consolidation stage and not only at the retrieval stage, as is the case in healthy subjects. This result is discussed in the context of the associative encoding deficits characterizing aMCI. Copyright © 2012 Elsevier Inc. All rights reserved.

Reduced autobiographical memory specificity relates to weak resistance to proactive interference.

PubMed

Smets, Jorien; Wessel, Ineke; Raes, Filip

2014-06-01

Reduced autobiographical memory specificity (rAMS), experiencing intrusive memories, and rumination appear to be risk factors for depression and depressive relapse. The aim of the current study was to investigate whether a weak resistance to proactive interference (PI) might underlie this trio of cognitive risk factors. Resistance to PI refers to being able to ignore cognitive distracters that were previously relevant but became irrelevant for current task goals. Students (N = 65) and depressed patients (N = 37) completed tasks measuring resistance to PI and AMS, and completed questionnaires on intrusive memories and rumination. In both samples, weaker resistance to PI was associated with rAMS. There was no evidence for a relationship between resistance to PI and intrusive memories or rumination. As we did not assess other measures of executive functioning, we cannot conclude whether the observed relationship between rumination and PI is due to unique qualities of PI. Difficulties to deliberately recall specific, rather than general or categoric autobiographical memories appear to be related to more general problems with the inhibition of interference of mental distracters. The results are in line with the executive control account of rAMS. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

PubMed Central

Emery, Lisa; Hale, Sandra; Myerson, Joel

2008-01-01

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 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. PMID:18808252

Event-based proactive interference in rhesus monkeys.

PubMed

Devkar, Deepna T; Wright, Anthony A

2016-10-01

Three rhesus monkeys (Macaca mulatta) were tested in a same/different memory task for proactive interference (PI) from prior trials. PI occurs when a previous sample stimulus appears as a test stimulus on a later trial, does not match the current sample stimulus, and the wrong response "same" is made. Trial-unique pictures (scenes, objects, animals, etc.) were used on most trials, except on trials where the test stimulus matched potentially interfering sample stimulus from a prior trial (1, 2, 4, 8, or 16 trials prior). Greater interference occurred when fewer trials separated interference and test. PI functions showed a continuum of interference. Delays between sample and test stimuli and intertrial intervals were manipulated to test how PI might vary as a function of elapsed time. Contrary to a similar study with pigeons, these time manipulations had no discernable effect on the monkey's PI, as shown by compete overlap of PI functions with no statistical differences or interactions. These results suggested that interference was strictly based upon the number of intervening events (trials with other pictures) without regard to elapsed time. The monkeys' apparent event-based interference was further supported by retesting with a novel set of 1,024 pictures. PI from novel pictures 1 or 2 trials prior was greater than from familiar pictures, a familiar set of 1,024 pictures. Moreover, when potentially interfering novel stimuli were 16 trials prior, performance accuracy was actually greater than accuracy on baseline trials (no interference), suggesting that remembering stimuli from 16 trials prior was a cue that this stimulus was not the sample stimulus on the current trial-a somewhat surprising conclusion particularly given monkeys.

Individual differences in proactive interference in verbal and visuospatial working memory.

PubMed

Lilienthal, Lindsey

2017-09-01

Proactive interference (PI) has been shown to affect working memory (WM) span as well as the predictive utility of WM span measures. However, most of the research on PI has been conducted using verbal memory items, and much less is known about the role of PI in the visuospatial domain. In order to further explore this issue, the present study used a within-subjects manipulation of PI that alternated clusters of trials with verbal and visuospatial to-be-remembered items. Although PI was shown to build and release across trials similarly in the two domains, important differences also were observed. The ability of verbal WM to predict performance on a measure of fluid intelligence was significantly affected by the amount of PI present, consistent with past research, but this proved not to be the case for visuospatial WM. Further, individuals' susceptibility to PI in one domain was relatively independent of their susceptibility in the other domain, suggesting that, contrary to some theories of executive function, individual differences in PI susceptibility may not be domain-general.

Immunity to proactive interference is not a property of the focus of attention in working memory.

PubMed

Ralph, Alicia; Walters, Jade N; Stevens, Alison; Fitzgerald, Kirra J; Tehan, Gerald; Surprenant, Aimee M; Neath, Ian; Turcotte, Josée

2011-02-01

The Focus of Attention (FOA) is the latest incarnation of a limited capacity store in which a small number of items, in this case four, are deemed to be readily accessible and do not need to be retrieved. Thus a corollary of these ideas is that those items in the FOA are always immune to proactive interference. While there is empirical support for instances of immunity to PI in short-term retention tasks that involve memory for four-item lists, there are also many instances in which PI is observed with four-item lists as well as instances where PI and immunity to PI can be shown in the same experiment. In contrast to the FOA assumptions, an alternative cue-based account predicts both the presence of PI and immunity to PI as a function of the relation between the cues available and the particular test. Three experiments contrasted the FOA assumptions and the cue-based approach in a short-term cued recall task in which PI is manipulated by testing whether the presentation of previous, similar items would interfere with immediate recall of three list items. The results indicated that even with very short lists, both PI and immunity to PI could be observed. The PI effects observed in our experiment are at odds with the FOA approach and are more readily explained using the cueing account.

Proactive interference and practice effects in visuospatial working memory span task performance.

PubMed

Blalock, Lisa Durrance; McCabe, David P

2011-01-01

In the current study the influence of proactive interference (PI) and practice on recall from a visuospatial working memory (WM) task was examined. Participants completed a visuospatial WM span task under either high-PI conditions (a traditional span task) or low-PI conditions (a span task with breaks between trials). Trials of each length (i.e., two to five to-be-remembered items) were equally distributed across three blocks in order to examine practice effects. Recall increased across blocks to a greater extent in the low-PI condition than in the high-PI condition, indicating that reducing PI increased recall from WM. Additionally, in the final block the correlation between fluid intelligence and WM recall was stronger for the high-PI condition than the low-PI condition, indicating that practice reduced the strength of the correlation between span task recall and fluid intelligence, but only in the low-PI condition. These results support current theories that propose that one source of variability in recall from WM span task is the build-up of PI, and that PI build-up is an important contributing factor to the relation between visuospatial WM span task recall and higher-level cognition.

The neural bases of the effects of item-nonspecific proactive interference in working memory

PubMed Central

POSTLE, BRADLEY R.; BRUSH, LAUREN N.

2005-01-01

We reanalyzed the behavioral and fMRI data from seven previously published studies of working memory in order to assess the behavioral and neural effects of item-nonspecific proactive interference (PI; attributable to the accrual of antecedent information independent of the repetition of particular items). We hypothesized that item-nonspecific PI, implicated in age-related declines in working memory performance, is mediated by the same mechanism(s) that mediate item-specific PI (occurring when an invalid memory probe matches a memorandum from the previous trial). Reaction time increased across trials as a function of position within the block, a trend that reversed across the duration of each multiblock experiment. The fMRI analyses revealed sensitivity to item-nonspecific PI during the probe epoch in the left anterior inferior frontal gyrus and the left dorsolateral prefrontal cortex (PFC). They also revealed a negative trend, across trials, in the transient probe-evoked component of the global signal. A common PFC-based mechanism may mediate many forms of PI. PMID:15535173

The neural bases of the effects of item-nonspecific proactive interference in working memory.

PubMed

Postle, Bradley R; Brush, Lauren N

2004-09-01

We reanalyzed the behavioral and fMRI data from seven previously published studies of working memory in order to assess the behavioral and neural effects of item-nonspecific proactive interference (PI; attributable to the accrual of antecedent information independent of the repetition of particular items). We hypothesized that item-nonspecific PI, implicated in age-related declines in working memory performance, is mediated by the same mechanism(s) that mediate item-specific PI (occurring when an invalid memory probe matches a memorandum from the previous trial). Reaction time increased across trials as a function of position within the block, a trend that reversed across the duration of each multiblock experiment. The fMRI analyses revealed sensitivity to item-nonspecific PI during the probe epoch in the left anterior inferior frontal gyrus and the left dorsolateral prefrontal cortex(PFC). They also revealed a negative trend, across trials, in the transient probe-evoked component of the global signal. A common PFC-based mechanism may mediate many forms of PI.

Cognition and speech-in-noise recognition: the role of proactive interference.

PubMed

Ellis, Rachel J; Rönnberg, Jerker

2014-01-01

Complex working memory (WM) span tasks have been shown to predict speech-in-noise (SIN) recognition. Studies of complex WM span tasks suggest that, rather than indexing a single cognitive process, performance on such tasks may be governed by separate cognitive subprocesses embedded within WM. Previous research has suggested that one such subprocess indexed by WM tasks is proactive interference (PI), which refers to difficulties memorizing current information because of interference from previously stored long-term memory representations for similar information. The aim of the present study was to investigate phonological PI and to examine the relationship between PI (semantic and phonological) and SIN perception. A within-subjects experimental design was used. An opportunity sample of 24 young listeners with normal hearing was recruited. Measures of resistance to, and release from, semantic and phonological PI were calculated alongside the signal-to-noise ratio required to identify 50% of keywords correctly in a SIN recognition task. The data were analyzed using t-tests and correlations. Evidence of release from and resistance to semantic interference was observed. These measures correlated significantly with SIN recognition. Limited evidence of phonological PI was observed. The results show that capacity to resist semantic PI can be used to predict SIN recognition scores in young listeners with normal hearing. On the basis of these findings, future research will focus on investigating whether tests of PI can be used in the treatment and/or rehabilitation of hearing loss. American Academy of Audiology.

The Medial Temporal Lobe and the Left Inferior Prefrontal Cortex Jointly Support Interference Resolution in Verbal Working Memory

ERIC Educational Resources Information Center

Oztekin, Ilke; Curtis, Clayton E.; McElree, Brian

2009-01-01

During working memory retrieval, proactive interference (PI) can be induced by semantic similarity and episodic familiarity. Here, we used fMRI to test hypotheses about the role of the left inferior frontal gyrus (LIFG) and the medial temporal lobe (MTL) regions in successful resolution of PI. Participants studied six-word lists and responded to a…

Increased susceptibility to proactive interference in adults with dyslexia?

PubMed

Bogaerts, Louisa; Szmalec, Arnaud; Hachmann, Wibke M; Page, Mike P A; Woumans, Evy; Duyck, Wouter

2015-01-01

Recent findings show that people with dyslexia have an impairment in serial-order memory. Based on these findings, the present study aimed to test the hypothesis that people with dyslexia have difficulties dealing with proactive interference (PI) in recognition memory. A group of 25 adults with dyslexia and a group of matched controls were subjected to a 2-back recognition task, which required participants to indicate whether an item (mis)matched the item that had been presented 2 trials before. PI was elicited using lure trials in which the item matched the item in the 3-back position instead of the targeted 2-back position. Our results demonstrate that the introduction of lure trials affected 2-back recognition performance more severely in the dyslexic group than in the control group, suggesting greater difficulty in resisting PI in dyslexia.

Blocked vs. interleaved presentation and proactive interference in episodic memory.

PubMed

Del Missier, Fabio; Sassano, Alessia; Coni, Valentina; Salomonsson, Martina; Mäntylä, Timo

2018-05-01

Although a number of theoretical accounts of proactive interference (PI) in episodic memory have been proposed, existing empirical evidence does not support conclusively a single view yet. In two experiments we tested the predictions of the temporal discrimination theory of PI against alternative accounts by manipulating the presentation schedule of study materials (lists blocked by category vs. interleaved). In line with the temporal discrimination theory, we observed a clear buildup of (and release from) PI in the blocked condition, in which all the lists of the same category were presented sequentially. In the interleaved condition, with alternating lists of different categories, a more gradual and smoother buildup of PI was observed. When participants were left free to choose their presentation schedule, they spontaneously adopted an interleaved schedule, resulting again in more gradual PI. After longer delays, we observed recency effects at the list level in overall recall and, in the blocked condition, PI-related effects. The overall pattern of findings agrees with the predictions of the temporal discrimination theory of PI, complemented with categorical processing of list items, but not with alternative accounts, shedding light on the dynamics and underpinnings of PI under diverse presentation schedules and over different time scales.

Barriers to repeated assessment of verbal learning and memory: a comparison of international shopping list task and rey auditory verbal learning test on build-up of proactive interference.

PubMed

Rahimi-Golkhandan, S; Maruff, P; Darby, D; Wilson, P

2012-11-01

Proactive interference (PI) that remains unidentified can confound the assessment of verbal learning, particularly when its effects vary from one population to another. The International Shopping List Task (ISLT) is a new measure that provides multiple forms that can be equated for linguistic factors across cultural groups. The aim of this study was to examine the build-up of PI on two measures of verbal learning-a traditional test of list learning (Rey Auditory Verbal Learning Test, RAVLT) and the ISLT. The sample consisted of 61 healthy adults aged 18-40. Each test had three parallel forms, each recalled three times. Results showed that repeated administration of the ISLT did not result in significant PI effects, unlike the RAVLT. Although these PI effects, observed during short retest intervals, may not be as robust under normal clinical administrations of the tests, the results suggest that the choice of the verbal learning test should be guided by the knowledge of PI effects and the susceptibility of particular patient groups to this effect.

Training of resistance to proactive interference and working memory in older adults: a randomized double-blind study.

PubMed

Loosli, Sandra V; Falquez, Rosalux; Unterrainer, Josef M; Weiller, Cornelius; Rahm, Benjamin; Kaller, Christoph P

2016-03-01

Working memory (WM) performance is often decreased in older adults. Despite the growing popularity of WM trainings, underlying mechanisms are still poorly understood. Resistance to proactive interference (PI) constitutes a candidate process that contributes to WM performance and might influence training or transfer effects. Here, we investigated whether PI resistance can be enhanced in older adults using a WM training with specifically increased PI-demands. Further, we investigated whether potential effects of such a training were stable and entailed any transfer on non-trained tasks. Healthy old adults (N = 25, 68.8 ± 5.5 years) trained with a recent-probes and an n-back task daily for two weeks. Two different training regimens (high vs. low PI-amount in the tasks) were applied as between-participants manipulation, to which participants were randomly assigned. Near transfer tasks included interference tasks; far transfer tasks assessed fluid intelligence (gF) or speed. Immediate transfer was assessed directly after training; a follow-up measurement was conducted after two months. Both groups similarly improved in PI resistance in both training tasks. Thus, PI susceptibility was generally reduced in the two training groups and there was no difference between WM training with high versus low PI demands. Further, there was no differential near or far transfer on non-trained tasks, neither immediately after the training nor in the follow-up. PI-demands in WM training tasks do not seem critical for enhancing WM performance or PI resistance in older adults. Instead, improved resistance to PI appears to be an unspecific side-effect of a WM training.

The contribution of encoding and retrieval processes to proactive interference.

PubMed

Kliegl, Oliver; Pastötter, Bernhard; Bäuml, Karl-Heinz T

2015-11-01

Proactive interference (PI) refers to the finding that memory for recently studied (target) material can be impaired by the prior study of other (nontarget) material. Previous accounts of PI differed in whether they attributed PI to impaired retrieval or impaired encoding. Here, we suggest an integrated encoding-retrieval account, which assigns a role for each of the 2 types of processes in buildup of PI. Employing a typical PI task, we examined (a) the role of encoding processes in PI by recording scalp EEG during study of nontarget and target lists, and (b) the role of retrieval processes in PI by measuring recall totals and response latencies in target list recall. In addition, we measured subjects' working memory capacity (WMC). Behaviorally, the PI effect arose in both recall totals and response latencies, indicating PI at the sampling and the recovery stage of recall. Neurally, we found an increase in electrophysiological activities in the theta frequency band (5-8 Hz) from nontarget to target list encoding, indicating an increase in memory load during target list encoding. The results demonstrate that impaired retrieval and impaired encoding can contribute to PI. They also show that WMC affects PI. For both encoding and retrieval processes, PI was reduced in high-WMC subjects, suggesting that these subjects are able to separate target from nontarget information and create stronger focus on the target material. (c) 2015 APA, all rights reserved).

Proactive interference in a semantic short-term memory deficit: role of semantic and phonological relatedness.

PubMed

Hamilton, A Cris; Martin, Randi C

2007-01-01

Previous research has indicated that patients with semantic short-term memory (STM) deficits demonstrate unusual intrusions of previously presented material during serial recall tasks (Martin and Lesch, 1996). These intrusions suggest excessive proactive interference (PI) from previous lists. Here, we explore one such patient's susceptibility to PI. Experiment 1 demonstrated patient M.L.'s extreme susceptibility to PI using a probe recognition task that manipulates the recency of negative probes (the recent negatives task). When stimuli consisted of letters, M.L. showed greatly exaggerated effects of PI, well outside of the range of healthy control participants. Experiment 2 used a variation of the recent negatives task to examine the relative contribution of semantic and phonological relatedness in PI. This task manipulated semantic and phonological relatedness of probes and recently presented list items. Relative to healthy control participants, patient M.L. showed exaggerated interference effects for both phonological and semantically related probes, both for probes related to the current list and for probes related to the previous list. These data have important implications for theories of semantic STM deficits. Specifically, these data suggest that it is not the rapid decay of semantic representations that is responsible for difficulties in short-term recall, but rather the abnormal persistence of previously presented material. We propose that this susceptibility to PI is the result of a deficit in control processes acting on STM.

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

PubMed

Carroll, Lauren M; Jalbert, Annie; Penney, Alexander M; Neath, Ian; Surprenant, Aimée M; Tehan, Gerald

2010-09-01

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. Copyright 2010 APA, all rights reserved.

Release from PI in Running Memory: What Does This Tell Us about Developmental STM?

ERIC Educational Resources Information Center

Cohen, Ronald L.; Griffiths, Karen

1987-01-01

To study age-related improvements in information processing, a release from proactive interference (PI) procedure was used with 144 children in conjunction with a running memory task. For class of item and acoustic similarity, evidence was found for PI release with age, but there was no evidence of a relationship between short-term memory (STM)…

Processing Strategy and PI Effects in Recognition Memory of Word Lists.

ERIC Educational Resources Information Center

Hodge, Milton H.; Britton, Bruce K.

Previous research by A. I. Schulman argued that an observed systematic decline in recognition memory in long word lists was due to the build-up of input and output proactive interference (PI). It also suggested that input PI resulted from process automatization; that is, each list item was processed or encoded in much the same way, producing a set…

Does proactive interference play a significant role in visual working memory tasks?

PubMed

Makovski, Tal

2016-10-01

Visual working memory (VWM) is an online memory buffer that is typically assumed to be immune to source memory confusions. Accordingly, the few studies that have investigated the role of proactive interference (PI) in VWM tasks found only a modest PI effect at best. In contrast, a recent study has found a substantial PI effect in that performance in a VWM task was markedly improved when all memory items were unique compared to the more standard condition in which only a limited set of objects was used. The goal of the present study was to reconcile this discrepancy between the findings, and to scrutinize the extent to which PI is involved in VWM tasks. Experiments 1-2 showed that the robust advantage in using unique memory items can also be found in a within-subject design and is largely independent of set size, encoding duration, or intertrial interval. Importantly, however, PI was found mainly when all items were presented at the same location, and the effect was greatly diminished when the items were presented, either simultaneously (Experiment 3) or sequentially (Experiments 4-5), at distinct locations. These results indicate that PI is spatially specific and that without the assistance of spatial information VWM is not protected from PI. Thus, these findings imply that spatial information plays a key role in VWM, and underscore the notion that VWM is more vulnerable to interference than is typically assumed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Automatic Encoding of Superordinate and Subordinate Taxonomic Categories in Different Populations.

ERIC Educational Resources Information Center

Nakayama, Susan Y.; Kee, Daniel W.

1980-01-01

Proactive interference (PI) build-up and release from PI were used to study automatic conceptual encoding of superordinate and subordinate category lists in low-socioeconomic status (SES) Black children and middle-SES White children (grades 2 and 4). (Results for each population on the three category lists are described). (GDC)

Effects of proactive interference on non-verbal working memory.

PubMed

Cyr, Marilyn; Nee, Derek E; Nelson, Eric; Senger, Thea; Jonides, John; Malapani, Chara

2017-02-01

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.

Event-Based Prospective Memory Is Resistant but Not Immune to Proactive Interference.

PubMed

Oates, Joyce M; Peynircioglu, Zehra F

2016-01-01

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.

The Influence of Semantic and Morphological Complexity of Verbs on Sentence Recall: Implications for the Nature of Conceptual Representation and Category-Specific Deficits

ERIC Educational Resources Information Center

Mobayyen, F.; de Almeida, R.G.

2005-01-01

One hundred and forty normal undergraduate students participated in a Proactive Interference (PI) experiment with sentences containing verbs from four different semantic and morphological classes (lexical causatives, morphological causatives, and morphologically complex and simplex perception verbs). Past research has shown significant PI build-up…

Auditory memory in monkeys: costs and benefits of proactive interference.

PubMed

Bigelow, James; Poremba, Amy

2013-05-01

Proactive interference (PI) has traditionally been understood as an adverse consequence of stimulus repetition during memory tasks. Herein, we present data that emphasize costs as well as benefits of PI for monkeys performing an auditory delayed matching-to-sample (DMTS) task. The animals made same/different judgments for a variety of simple and complex sounds separated by a 5-s memory delay. Each session used a stimulus set that included eight sounds; thus, each sound was repeated multiple times per session for match trials and for nonmatch trials as the sample (Cue 1) or test (Cue 2) stimulus. For nonmatch trials, performance was substantially diminished when the test stimulus had been previously presented on a recent trial. However, when the sample stimulus had been recently presented, performance was significantly improved. We also observed a marginal performance benefit when stimuli for match trials had been recently presented. The costs of PI for nonmatch test stimuli were greater than the combined benefits of PI for nonmatch sample stimuli and match trials, indicating that the net influence of PI is detrimental. For all three manifestations of PI, the effects are shown to extend beyond the immediately subsequent trial. Our data suggest that PI in auditory DMTS is best understood as an enduring influence that can be both detrimental and beneficial to memory-task performance. © 2012 Wiley Periodicals, Inc.

Effects of Proactive Interference on Non-Verbal Working Memory

PubMed Central

Cyr, Marilyn; Nee, Derek E.; Nelson, Eric; Senger, Thea; Jonides, John; Malapani, Chara

2016-01-01

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 working memory 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. PMID:27838866

Developmental change in proactive interference across the life span: evidence from two working memory tasks.

PubMed

Loosli, Sandra V; Rahm, Benjamin; Unterrainer, Josef M; Weiller, Cornelius; Kaller, Christoph P

2014-04-01

Working memory (WM) as the ability to temporarily maintain and manipulate various kinds of information is known to be affected by proactive interference (PI) from previously relevant contents, but studies on developmental changes in the susceptibility to PI are scarce. In the present study, we investigated life span development of item-specific PI. To this end, 92 individuals between the ages of 8 and 74 years completed a recent-probes task and an n-back task that both composed experimental manipulations of PI. Regarding global WM development, young adults had higher WM performance than children and older adults in both tasks. Significant PI × Age interactions revealed that susceptibility to PI changed over the life span in both tasks, whereas the developmental course of PI differed between the tasks: Children committed more PI-related errors than young adults in the recent-probes task but showed marginally less PI in the n-back task. Regarding reaction time costs, children did not differ from adults in the recent-probes task and were less affected than adults in the n-back. Older adults showed more PI-related errors than young adults in both tasks. Therefore, as expected, item-specific PI changed over the life span with the young adults being less susceptible to PI than children and older adults. The diverging developmental effects of PI across both tasks, especially in the children, are supposed to reflect different causes for the difficulties regarding resisting PI in children and older adults. These might concern differently developed underlying cognitive processes such as inhibition or recollection, or different responses to task demands across both tasks. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Differential roles of resistance to proactive interference and suppression of prepotent responses in overgeneral memory.

PubMed

Comas, Michelle; Valentino, Kristin; Johnson, Anne F; Gibson, Bradley S; Taylor, Courtney

2018-06-12

Overgeneral memory (OGM), difficulty in retrieving specific autobiographical memories, is a robust phenomenon related to the onset and course of depressive and posttraumatic stress disorders. Inhibitory mechanisms are theorized to underlie OGM; however, empirical support for this link is equivocal. The current study examines the differential roles of two aspects of inhibitory control in association with OGM: suppression of prepotent responses and resistance to proactive interference (PI). Only resistance to PI was expected to be negatively related to OGM, whereby individuals with greater ability to resist PI would have reduced OGM. Participants (n = 49) completed a self-report measure of depressive symptoms and engaged in two tasks aimed at assessing resistance to PI and suppression of prepotent responses. Participants also completed a task assessing overgeneral autobiographical memory. As hypothesized, resistance to PI, but not suppression of prepotent responses negatively predicted OGM above and beyond the influence of depressive symptoms. Because a double dissociation was not examined, we cannot address the potential independence of the submechanisms of inhibitory control that we assessed. Results exemplify the differential associations of two components of inhibition and OGM, suggesting that resistance to PI, in particular, may contribute to the development and/or maintenance of OGM and associated depressive disorders. Directions for future research are discussed. Copyright © 2018. Published by Elsevier Ltd.

Working memory in schizophrenia: behavioral and neural evidence for reduced susceptibility to item-specific proactive interference.

PubMed

Kaller, Christoph P; Loosli, Sandra V; Rahm, Benjamin; Gössel, Astrid; Schieting, Stephan; Hornig, Tobias; Hennig, Jürgen; Tebartz van Elst, Ludger; Weiller, Cornelius; Katzev, Michael

2014-09-15

Susceptibility to item-specific proactive interference (PI) contributes to interindividual differences in working memory (WM) capacity and complex cognition relying on WM. Although WM deficits are a well-recognized impairment in schizophrenia, the underlying pathophysiological effects on specific WM control functions, such as the ability to resist item-specific PI, remain unknown. Moreover, opposing hypotheses on increased versus reduced PI susceptibility in schizophrenia are both justifiable by the extant literature. To provide first insights into the behavioral and neural correlates of PI-related WM control in schizophrenia, a functional magnetic resonance imaging experiment was conducted in a sample of 20 patients and 20 well-matched control subjects. Demands on item-specific PI were experimentally manipulated in a recent-probes task (three runs, 64 trials each) requiring subjects to encode and maintain a set of four target items per trial. Compared with healthy control subjects, schizophrenia patients showed a significantly reduced PI susceptibility in both accuracy and latency measures. Notably, reduced PI susceptibility in schizophrenia was not associated with overall WM impairments and thus constituted an independent phenomenon. In addition, PI-related activations in inferior frontal gyrus and anterior insula, typically assumed to support PI resistance, were reduced in schizophrenia, thus ruling out increased neural efforts as a potential cause of the patients' reduced PI susceptibility. The present study provides first evidence for a diminished vulnerability of schizophrenia patients to item-specific PI, which is presumably a consequence of the patients' more efficient clearing of previously relevant WM traces and the accordingly reduced likelihood for item-specific PI to occur. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Age differences in behavioral and neural correlates of proactive interference: Disentangling the role of overall working memory performance.

PubMed

Loosli, Sandra V; Rahm, Benjamin; Unterrainer, Josef M; Mader, Irina; Weiller, Cornelius; Kaller, Christoph P

2016-02-15

Reliable performance in working memory (WM) critically depends on the ability to resist proactive interference (PI) from previously relevant WM contents. Both WM performance and PI susceptibility are subject to cognitive decline at older adult age. However, the behavioral and neural processes underlying these co-evolving developmental changes and their potential interdependencies are not yet understood. Here, we investigated PI using a recent-probes WM paradigm and functional MRI in a cross-sectional sample of younger (n=18, 10 female, 23.4 ± 2.7 years) and older adults (n=18, 10 female, 70.2 ± 2.7 years). As expected, older adults showed lower WM performance and higher PI susceptibility than younger adults. Resolution of PI activated a mainly bilateral frontal network across all participants. Significant interactions with age indicated reduced neural activation in older adults for PI resolution. A second analysis in a selection of younger and older adults (n=12 each) with matched WM performance also revealed significant differences in PI between both age groups and - on a descriptive level - again a hypo-activation of the older adults' PI network. But the differential effect of age on the neural PI effects did not reach significance in this smaller sample most likely to the reduced statistical power. However, given the highly similar patterns in both the overall and the WM-matched samples, we propose that the hypo-activation of the PI network in the older adults may not be attributable to age-related differences in overall WM performance, hence suggesting that higher PI susceptibility in older adult age does not directly depend on their lower WM performance. Copyright © 2015 Elsevier Inc. All rights reserved.

Item-nonspecific proactive interference in monkeys' auditory short-term memory.

PubMed

Bigelow, James; Poremba, Amy

2015-09-01

Recent studies using the delayed matching-to-sample (DMS) paradigm indicate that monkeys' auditory short-term memory (STM) is susceptible to proactive interference (PI). During the task, subjects must indicate whether sample and test sounds separated by a retention interval are identical (match) or not (nonmatch). If a nonmatching test stimulus also occurred on a previous trial, monkeys are more likely to incorrectly make a "match" response (item-specific PI). However, it is not known whether PI may be caused by sounds presented on prior trials that are similar, but nonidentical to the current test stimulus (item-nonspecific PI). This possibility was investigated in two experiments. In Experiment 1, memoranda for each trial comprised tones with a wide range of frequencies, thus minimizing item-specific PI and producing a range of frequency differences among nonidentical tones. In Experiment 2, memoranda were drawn from a set of eight artificial sounds that differed from each other by one, two, or three acoustic dimensions (frequency, spectral bandwidth, and temporal dynamics). Results from both experiments indicate that subjects committed more errors when previously-presented sounds were acoustically similar (though not identical) to the test stimulus of the current trial. Significant effects were produced only by stimuli from the immediately previous trial, suggesting that item-nonspecific PI is less perseverant than item-specific PI, which can extend across noncontiguous trials. Our results contribute to existing human and animal STM literature reporting item-nonspecific PI caused by perceptual similarity among memoranda. Together, these observations underscore the significance of both temporal and discriminability factors in monkeys' STM. Copyright © 2015 Elsevier B.V. All rights reserved.

The cost of proactive interference is constant across presentation conditions.

PubMed

Endress, Ansgar D; Siddique, Aneela

2016-10-01

Proactive interference (PI) severely constrains how many items people can remember. For example, Endress and Potter (2014a) presented participants with sequences of everyday objects at 250ms/picture, followed by a yes/no recognition test. They manipulated PI by either using new images on every trial in the unique condition (thus minimizing PI among items), or by re-using images from a limited pool for all trials in the repeated condition (thus maximizing PI among items). In the low-PI unique condition, the probability of remembering an item was essentially independent of the number of memory items, showing no clear memory limitations; more traditional working memory-like memory limitations appeared only in the high-PI repeated condition. Here, we ask whether the effects of PI are modulated by the availability of long-term memory (LTM) and verbal resources. Participants viewed sequences of 21 images, followed by a yes/no recognition test. Items were presented either quickly (250ms/image) or sufficiently slowly (1500ms/image) to produce LTM representations, either with or without verbal suppression. Across conditions, participants performed better in the unique than in the repeated condition, and better for slow than for fast presentations. In contrast, verbal suppression impaired performance only with slow presentations. The relative cost of PI was remarkably constant across conditions: relative to the unique condition, performance in the repeated condition was about 15% lower in all conditions. The cost of PI thus seems to be a function of the relative strength or recency of target items and interfering items, but relatively insensitive to other experimental manipulations. Copyright © 2016 Elsevier B.V. All rights reserved.

Typicality as a Dimension of Encoding

ERIC Educational Resources Information Center

Keller, Dennis; Kellas, George

1978-01-01

The salience of encoding attributes in instances of differing levels of category membership was examined using the release from proactive interference (PI) task with college students. Results are discussed in terms of providing converging evidence for Rosch's (1973,1975) theory of semantic category structure. (Editor/RK)

Prefrontal Control of Familiarity and Recollection in Working Memory

ERIC Educational Resources Information Center

Feredoes, Eva; Postle, Bradley R.

2010-01-01

Left inferior frontal gyrus (IFG) is a critical neural substrate for the resolution of proactive interference (PI) in working memory. We hypothesized that left IFG achieves this by controlling the influence of familiarity- versus recollection-based information about memory probes. Consistent with this idea, we observed evidence for an "early" (200…

Event-related potential (ERP) measures reveal the timing of memory selection processes and proactive interference resolution in working memory.

PubMed

Yi, Yuji; Friedman, David

2011-09-09

Behavioral studies show that no-longer-relevant information, although presumably removed from working memory (WM), still engenders proactive interference (PI). However, the timing of selecting items within WM and resolving PI is relatively unknown. To assess this, we recorded ERPs during WM from 20 young adults. In all conditions, a 4-digit display was followed by a cue indicating which digits to remember. In the selection condition, 2 digits were cued. The reaction time difference between the intrusion probe, a match of a to-be-rejected digit, and the non-intrusion probe, which did not match any of the 4 digits, was reliable, indicating a robust effect of PI. In the neutral-2 (remember 2 digits) and -4 (remember all 4) conditions, participants maintained the digits following the cue. Relative to neutral-4, selection elicited larger positivity at parietal sites (approximately 260ms) and negativity at frontal sites (approximately 420ms). Relative to the non-intrusion probe ERP, that to the intrusion probe was more negative over frontal scalp (approximately 500ms). We conclude that initial selection occurs over parietal cortex and reflects top-down attention to task relevant items, whereas the subsequent negativity may reflect inhibition of no-longer-relevant items over frontal cortex. The probe-locked ERPs suggest that the frontal negativity (approximately 500ms) reflects the final resolution of PI. Copyright © 2011 Elsevier B.V. All rights reserved.

Distributed Patterns of Brain Activity that Lead to Forgetting

PubMed Central

Öztekin, Ilke; Badre, David

2011-01-01

Proactive interference (PI), in which irrelevant information from prior learning disrupts memory performance, is widely viewed as a major cause of forgetting. However, the hypothesized spontaneous recovery (i.e., automatic retrieval) of interfering information presumed to be at the base of PI remains to be demonstrated directly. Moreover, it remains unclear at what point during learning and/or retrieval interference impacts memory performance. In order to resolve these open questions, we employed a machine-learning algorithm to identify distributed patterns of brain activity associated with retrieval of interfering information that engenders PI and causes forgetting. Participants were scanned using functional magnetic resonance imaging during an item recognition task. We induced PI by constructing sets of three consecutive study lists from the same semantic category. The classifier quantified the magnitude of category-related activity at encoding and retrieval. Category-specific activity during retrieval increased across lists, consistent with the category information becoming increasingly available and producing interference. Critically, this increase was correlated with individual differences in forgetting and the deployment of frontal lobe mechanisms that resolve interference. Collectively, these findings suggest that distributed patterns of brain activity pertaining to the interfering information during retrieval contribute to forgetting. The prefrontal cortex mediates the relationship between the spontaneous recovery of interfering information at retrieval and individual differences in memory performance. PMID:21897814

Proactive interference and cuing effects in short-term cued recall: does foil context matter?

PubMed

Goh, Winston D; Tan, Huiqin

2006-07-01

Tehan and Humphreys's (1995, 1996) short-term cued recall paradigm showed that recall in short-term memory is cue driven. In critical trials, the participants studied two blocks of four words each and were required to forget the first block while remembering the second block. A foil in the first block (e.g., orange) was related to a target (e.g., carrot) in the second block. Proactive interference (PI) was evident when a retrieval cue was used that subsumed the foil and the target (e.g., type of juice), but not when a cue was used that subsumed only the target (e.g., type of vegetable). Four experiments were performed to examine the extent to which contextual organization in the foil block would enhance or diminish the foil's efficacy in creating PI. A novel condition was included in which the words in the foil block were studied in a phonologically related context but the target was cued semantically, and vice versa with a semantic context and phonological cue. There were no differences in recall accuracy between conditions with and without contextual organization, but reliable increases in foil intrusions were observed when contextual organization was present. Contextual organization enhanced the foil, rather than diminished it, but the strengthened foil generated PI only when the cue subsumed the foil and the target and had no effect when the cue subsumed only the target. The results are consistent with a cue-driven retrieval interpretation of short-term recall.

The Role of Working Memory Capacity and Interference Resolution Mechanisms in Task Switching

PubMed Central

Pettigrew, Corinne; Martin, Randi C.

2015-01-01

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response-distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response-distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching. PMID:26594895

The role of working memory capacity and interference resolution mechanisms in task switching.

PubMed

Pettigrew, Corinne; Martin, Randi C

2016-12-01

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response-distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. A total of 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response-distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores, which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching.

Dissociation of Short- and Long-Term Face Memory: Evidence from Long-Term Recency Effects in Temporal Lobe Epilepsy

ERIC Educational Resources Information Center

Bengner, T.; Malina, T.

2007-01-01

We tested whether memory deficits in temporal lobe epilepsy (TLE) are better described by a single- or dual-store memory model. To this aim, we analyzed the influence of TLE and proactive interference (PI) on immediate and 24-h long-term recency effects during face recognition in 16 healthy participants and 18 right and 21 left non-surgical TLE…

Long-term effects of interference on short-term memory performance in the rat

PubMed Central

Missaire, Mégane; Fraize, Nicolas; Joseph, Mickaël Antoine; Hamieh, Al Mahdy; Parmentier, Régis; Marighetto, Aline; Salin, Paul Antoine; Malleret, Gaël

2017-01-01

A distinction has always been made between long-term and short-term memory (also now called working memory, WM). The obvious difference between these two kinds of memory concerns the duration of information storage: information is supposedly transiently stored in WM while it is considered durably consolidated into long-term memory. It is well acknowledged that the content of WM is erased and reset after a short time, to prevent irrelevant information from proactively interfering with newly stored information. In the present study, we used typical WM radial maze tasks to question the brief lifespan of spatial WM content in rodents. Groups of rats were submitted to one of two different WM tasks in a radial maze: a WM task involving the repetitive presentation of a same pair of arms expected to induce a high level of proactive interference (PI) (HIWM task), or a task using a different pair in each trial expected to induce a low level of PI (LIWM task). Performance was effectively lower in the HIWM group than in LIWM in the final trial of each training session, indicative of a “within-session/short-term” PI effect. However, we also observed a different “between-session/long-term” PI effect between the two groups: while performance of LIWM trained rats remained stable over days, the performance of HIWM rats dropped after 10 days of training, and this impairment was visible from the very first trial of the day, hence not attributable to within-session PI. We also showed that a 24 hour-gap across training sessions known to allow consolidation processes to unfold, was a necessary and sufficient condition for the long-term PI effect to occur. These findings suggest that in the HIWM task, WM content was not entirely reset between training sessions and that, in specific conditions, WM content can outlast its purpose by being stored more permanently, generating a long-term deleterious effect of PI. The alternative explanation is that WM content could be transferred and stored more permanently in an intermediary form or memory between WM and long-term memory. PMID:28288205

Long-term effects of interference on short-term memory performance in the rat.

PubMed

Missaire, Mégane; Fraize, Nicolas; Joseph, Mickaël Antoine; Hamieh, Al Mahdy; Parmentier, Régis; Marighetto, Aline; Salin, Paul Antoine; Malleret, Gaël

2017-01-01

A distinction has always been made between long-term and short-term memory (also now called working memory, WM). The obvious difference between these two kinds of memory concerns the duration of information storage: information is supposedly transiently stored in WM while it is considered durably consolidated into long-term memory. It is well acknowledged that the content of WM is erased and reset after a short time, to prevent irrelevant information from proactively interfering with newly stored information. In the present study, we used typical WM radial maze tasks to question the brief lifespan of spatial WM content in rodents. Groups of rats were submitted to one of two different WM tasks in a radial maze: a WM task involving the repetitive presentation of a same pair of arms expected to induce a high level of proactive interference (PI) (HIWM task), or a task using a different pair in each trial expected to induce a low level of PI (LIWM task). Performance was effectively lower in the HIWM group than in LIWM in the final trial of each training session, indicative of a "within-session/short-term" PI effect. However, we also observed a different "between-session/long-term" PI effect between the two groups: while performance of LIWM trained rats remained stable over days, the performance of HIWM rats dropped after 10 days of training, and this impairment was visible from the very first trial of the day, hence not attributable to within-session PI. We also showed that a 24 hour-gap across training sessions known to allow consolidation processes to unfold, was a necessary and sufficient condition for the long-term PI effect to occur. These findings suggest that in the HIWM task, WM content was not entirely reset between training sessions and that, in specific conditions, WM content can outlast its purpose by being stored more permanently, generating a long-term deleterious effect of PI. The alternative explanation is that WM content could be transferred and stored more permanently in an intermediary form or memory between WM and long-term memory.

Cognitive declines in healthy aging: evidence from multiple aspects of interference resolution.

PubMed

Pettigrew, Corinne; Martin, Randi C

2014-06-01

The present study tested the hypothesis that older adults show age-related deficits in interference resolution, also referred to as inhibitory control. Although oftentimes considered as a unitary aspect of executive function, various lines of work support the notion that interference resolution may be better understood as multiple constructs, including resistance to proactive interference (PI) and response-distractor inhibition (e.g., Friedman & Miyake, 2004). Using this dichotomy, the present study assessed whether older adults (relative to younger adults) show impaired performance across both, 1, or neither of these interference resolution constructs. To do so, we used multiple tasks to tap each construct and examined age effects at both the single task and latent variable levels. Older adults consistently demonstrated exaggerated interference effects across resistance to PI tasks. Although the results for the response-distractor inhibition tasks were less consistent at the individual task level analyses, age effects were evident on multiple tasks, as well as at the latent variable level. However, results of the latent variable modeling suggested declines in interference resolution are best explained by variance that is common to the 2 interference resolution constructs measured herein. Furthermore, the effect of age on interference resolution was found to be both distinct from declines in working memory, and independent of processing speed. These findings suggest multiple cognitive domains are independently sensitive to age, but that declines in the interference resolution constructs measured herein may originate from a common cause. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Re-examination of "release-from-PI" phenomena: recall accuracy does not recover after a semantic switch.

PubMed

Hubbard, Nicholas A; Weaver, Travis P; Turner, Monroe P; Rypma, Bart

2018-01-29

Recall accuracy decreases over successive memory trials using similar memoranda. This effect reflects proactive interference (PI) - the tendency for previously studied information to reduce recall of new information. However, recall improves if memoranda for a subsequent trial are semantically dissimilar from the previous trials. This improvement is thought to reflect a release from PI. We tested whether PI is reduced or released from the semantic category for which it had been induced by employing paradigms which featured inducement, semantic switch, and then return-to-original category epochs. Two experiments confirmed that PI was not released after various semantic switch trials (effects from d = -0.93 to -1.6). Combined analyses from both studies demonstrated that the number of intervening new category trials did not reduce or release PI. In fact, in all conditions recall accuracy decreased, demonstrating that PI is maintained and can increase after the new category trials. The release-from-PI account cannot accommodate these broader dynamics of PI. This account is also incongruent with evidence and theory from cognitive psychology, linguistics, and neuroscience. We propose a reintroduction-of-PI account which explains these broader PI dynamics and is consistent with the wider psychological and neurosciences.

Cue-dependent interference in comprehension

PubMed Central

Van Dyke, Julie A.

2011-01-01

The role of interference as a primary determinant of forgetting in memory has long been accepted, however its role as a contributor to poor comprehension is just beginning to be understood. The current paper reports two studies, in which speed-accuracy tradeoff and eye-tracking methodologies were used with the same materials to provide converging evidence for the role of syntactic and semantic cues as mediators of both proactive (PI) and retroactive interference (RI) during comprehension. Consistent with previous work (e.g., Van Dyke & Lewis, 2003), we found that syntactic constraints at the retrieval site are among the cues that drive retrieval in comprehension, and that these constraints effectively limit interference from potential distractors with semantic/pragmatic properties in common with the target constituent. The data are discussed in terms of a cue-overload account, in which interference both arises from and is mediated through a direct-access retrieval mechanism that utilizes a linear, weighted cue-combinatoric scheme. PMID:21927535

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

PubMed

Rowe, Gillian; Hasher, Lynn; Turcotte, Josée

2010-11-01

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. 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). 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. 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.

The Role of Shape in Semantic Memory Organization of Objects: An Experimental Study Using PI-Release.

PubMed

van Weelden, Lisanne; Schilperoord, Joost; Swerts, Marc; Pecher, Diane

2015-01-01

Visual information contributes fundamentally to the process of object categorization. The present study investigated whether the degree of activation of visual information in this process is dependent on the contextual relevance of this information. We used the Proactive Interference (PI-release) paradigm. In four experiments, we manipulated the information by which objects could be categorized and subsequently be retrieved from memory. The pattern of PI-release showed that if objects could be stored and retrieved both by (non-perceptual) semantic and (perceptual) shape information, then shape information was overruled by semantic information. If, however, semantic information could not be (satisfactorily) used to store and retrieve objects, then objects were stored in memory in terms of their shape. The latter effect was found to be strongest for objects from identical semantic categories.

Proactive control of proactive interference using the method of loci.

PubMed

Bass, Willa S; Oswald, Karl M

2014-01-01

Proactive interferencebuilds up with exposure to multiple lists of similar items with a resulting reduction in recall. This study examined the effectiveness of using a proactive strategy of the method of loci to reduce proactive interference in a list recall paradigm of categorically similar words. While all participants reported using some form of strategy to recall list words, this study demonstrated that young adults were able to proactively use the method of loci after 25 min of instruction to reduce proactive interference as compared with other personal spontaneous strategies. The implications of this study are that top-down proactive strategies such as the method of loci can significantly reduce proactive interference, and that the use of image and sequence or location are especially useful in this regard.

Proactive control of proactive interference using the method of loci

PubMed Central

Bass, Willa S.; Oswald, Karl M.

2014-01-01

Proactive interferencebuilds up with exposure to multiple lists of similar items with a resulting reduction in recall. This study examined the effectiveness of using a proactive strategy of the method of loci to reduce proactive interference in a list recall paradigm of categorically similar words. While all participants reported using some form of strategy to recall list words, this study demonstrated that young adults were able to proactively use the method of loci after 25 min of instruction to reduce proactive interference as compared with other personal spontaneous strategies. The implications of this study are that top-down proactive strategies such as the method of loci can significantly reduce proactive interference, and that the use of image and sequence or location are especially useful in this regard. PMID:25157300

Practice schedules for surgical skills: the role of task characteristics and proactive interference on psychomotor skills acquisition.

PubMed

Willis, Ross E; Curry, Eileen; Gomez, Pedro Pablo

2013-01-01

Although break periods during training sessions are desirable, it is unclear what learners should do during these breaks. Some educators recommend that learners abstain from all task-related practice; however, it is possible that switching to an alternate exercise during break periods can also be effective. The construct of proactive interference (PI) posits that new learning is disrupted by prior learning. PI can be "released" when the nature of the task is changed after several practice trials. In this study, we examined the existence of PI in motor learning under 5 training conditions that differed in contrast to a target exercise. Preclinical medical students (n = 75) performed 1 trial of peg transfer as a pretest. Participants were then randomly assigned to 1 of 5 training conditions: mass practice, similar exercise (laparoscopic bean transfer), dissimilar exercise (open suturing), observation, or rest. Participants in the mass practice condition practiced peg transfer in 3 training blocks of 15 minutes, each separated by a 5-minute break. Participants in the other conditions performed 3 training blocks consisting of 15 minutes of peg transfer followed by an interspersed alternate exercise. On completion of 3 training blocks, participants performed 1 additional peg transfer trial as a posttest. Despite having trained for the same amount of time on the target task, Analysis of Covariance on posttest scores using pretest scores as the covariate indicated a significant main effect for training condition (p = 0.009). Participants engaging in mass practice performed significantly worse than participants in the dissimilar (p = 0.012), observation (p = 0.022), and rest (p < 0.001) conditions. Additionally, participants in the similar exercise condition performed worse than participants in the rest condition (p = 0.03). When learning a laparoscopic task, a break comprised of dissimilar practice or unrelated activities is effective in releasing PI and improving performance. © 2013 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Pre-stressor cognitive control is related to intrusive cognition of a stressful film.

PubMed

Wessel, Ineke; Overwijk, Sippie; Verwoerd, Johan; de Vrieze, Nienke

2008-04-01

It has been suggested that relatively weak cognitive control existing prior to a stressful event may be associated with intrusive memories of that stressor afterwards. We explored this in two analog studies employing unselected participants who saw an emotional film fragment and completed behavioral (i.e., color-naming interference [CNI]) and self-report indices of intrusions. Prior to film presentation, several cognitive control tests were administered. Study 1 showed that better updating/monitoring was linked to less CNI from negative film-related words. However, better updating/monitoring was associated with more diary reports of intrusive memories. Study 2 showed that a better resistance to pro-active interference (PI) predicted less self-reported film-related intrusive cognition after 24h. However, after this delay, both self-reported intrusions and CNI were not related to updating/monitoring. Taken together, the results suggest that a specific pre-existing cognitive control function (i.e., resistance to PI) may be involved in the regulation of post-stressor intrusive memory phenomena.

Memory Operations That Support Language Comprehension: Evidence From Verb-Phrase Ellipsis

PubMed Central

Martin, Andrea E.; McElree, Brian

2010-01-01

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. PMID:19686017

The influence of semantic and morphological complexity of verbs on sentence recall: Implications for the nature of conceptual representation and category-specific deficits.

PubMed

Mobayyen, Forouzan; de Almeida, Roberto G

2005-03-01

One hundred and forty normal undergraduate students participated in a Proactive Interference (PI) experiment with sentences containing verbs from four different semantic and morphological classes (lexical causatives, morphological causatives, and morphologically complex and simplex perception verbs). Past research has shown significant PI build-up effects for semantically and morphologically complex verbs in isolation (de Almeida & Mobayyen, 2004). The results of the present study show that, when embedded into sentence contexts, semantically and morphologically complex verbs do not produce significant PI build-up effects. Different verb classes, however, yield different recall patterns: sentences with semantically complex verbs (e.g., causatives) were recalled significantly better than sentences with semantically simplex verbs (e.g., perception verbs). The implications for the nature of both verb-conceptual representations and category-specific semantic deficits are discussed.

Proactive Interference Does Not Meaningfully Distort Visual Working Memory Capacity Estimates in the Canonical Change Detection Task

PubMed Central

Lin, Po-Han; Luck, Steven J.

2012-01-01

The change detection task has become a standard method for estimating the storage capacity of visual working memory. Most researchers assume that this task isolates the properties of an active short-term storage system that can be dissociated from long-term memory systems. However, long-term memory storage may influence performance on this task. In particular, memory traces from previous trials may create proactive interference that sometimes leads to errors, thereby reducing estimated capacity. Consequently, the capacity of visual working memory may be higher than is usually thought, and correlations between capacity and other measures of cognition may reflect individual differences in proactive interference rather than individual differences in the capacity of the short-term storage system. Indeed, previous research has shown that change detection performance can be influenced by proactive interference under some conditions. The purpose of the present study was to determine whether the canonical version of the change detection task – in which the to-be-remembered information consists of simple, briefly presented features – is influenced by proactive interference. Two experiments were conducted using methods that ordinarily produce substantial evidence of proactive interference, but no proactive interference was observed. Thus, the canonical version of the change detection task can be used to assess visual working memory capacity with no meaningful influence of proactive interference. PMID:22403556

Proactive interference does not meaningfully distort visual working memory capacity estimates in the canonical change detection task.

PubMed

Lin, Po-Han; Luck, Steven J

2012-01-01

The change detection task has become a standard method for estimating the storage capacity of visual working memory. Most researchers assume that this task isolates the properties of an active short-term storage system that can be dissociated from long-term memory systems. However, long-term memory storage may influence performance on this task. In particular, memory traces from previous trials may create proactive interference that sometimes leads to errors, thereby reducing estimated capacity. Consequently, the capacity of visual working memory may be higher than is usually thought, and correlations between capacity and other measures of cognition may reflect individual differences in proactive interference rather than individual differences in the capacity of the short-term storage system. Indeed, previous research has shown that change detection performance can be influenced by proactive interference under some conditions. The purpose of the present study was to determine whether the canonical version of the change detection task - in which the to-be-remembered information consists of simple, briefly presented features - is influenced by proactive interference. Two experiments were conducted using methods that ordinarily produce substantial evidence of proactive interference, but no proactive interference was observed. Thus, the canonical version of the change detection task can be used to assess visual working memory capacity with no meaningful influence of proactive interference.

Differential development of retroactive and proactive interference during post-learning wakefulness.

PubMed

Brawn, Timothy P; Nusbaum, Howard C; Margoliash, Daniel

2018-07-01

Newly encoded, labile memories are prone to disruption during post-learning wakefulness. Here we examine the contributions of retroactive and proactive interference to daytime forgetting on an auditory classification task in a songbird. While both types of interference impair performance, they do not develop concurrently. The retroactive interference of task-B on task-A developed during the learning of task-B, whereas the proactive interference of task-A on task-B emerged during subsequent waking retention. These different time courses indicate an asymmetry in the emergence of retroactive and proactive interference and suggest a mechanistic framework for how different types of interference between new memories develop. © 2018 Brawn et al.; Published by Cold Spring Harbor Laboratory Press.

Impact of ageing on problem size and proactive interference in arithmetic facts solving.

PubMed

Archambeau, Kim; De Visscher, Alice; Noël, Marie-Pascale; Gevers, Wim

2018-02-01

Arithmetic facts (AFs) are required when solving problems such as "3 × 4" and refer to calculations for which the correct answer is retrieved from memory. Currently, two important effects that modulate the performance in AFs have been highlighted: the problem size effect and the proactive interference effect. The aim of this study is to investigate possible age-related changes of the problem size effect and the proactive interference effect in AF solving. To this end, the performance of young and older adults was compared in a multiplication production task. Furthermore, an independent measure of proactive interference was assessed to further define the architecture underlying this effect in multiplication solving. The results indicate that both young and older adults were sensitive to the effects of interference and of the problem size. That is, both interference and problem size affected performance negatively: the time needed to solve a multiplication problem increases as the level of interference and the size of the problem increase. Regarding the effect of ageing, the problem size effect remains constant with age, indicating a preserved AF network in older adults. Interestingly, sensitivity to proactive interference in multiplication solving was less pronounced in older than in younger adults suggesting that part of the proactive interference has been overcome with age.

Developmental Change in Proactive Interference.

ERIC Educational Resources Information Center

Kail, Robert

2002-01-01

Two studies examined age-related change in proactive interference from previously learned material. The meta-analysis of 26 studies indicated that proactive interference decreased with age. The cross-sectional study found that third through sixth graders' and college students' recall was accurate on Trial 1, but became less so over Trials 2…

The focus of attention is similar to other memory systems rather than uniquely different

PubMed Central

Beaudry, Olivia; Neath, Ian; Surprenant, Aimée M.; Tehan, Gerald

2014-01-01

According to some current theories, the focus of attention (FOA), part of working memory, represents items in a privileged state that is more accessible than items stored in other memory systems. One line of evidence supporting the distinction between the FOA and other memory systems is the finding that items in the FOA are immune to proactive interference (when something learned earlier impairs the ability to remember something learned more recently). The FOA, then, is held to be unique: it is the only memory system that is not susceptible to proactive interference. We review the literature used to support this claim, and although there are many studies in which proactive interference was not observed, we found more studies in which it was observed. We conclude that the FOA is not immune to proactive interference: items in the FOA are susceptible to proactive interference just like items in every other memory system. And, just as in all other memory systems, it is how the items are represented and processed that plays a critical role in determining whether proactive interference will be observed. PMID:24574996

Traditional test administration and proactive interference undermine visual-spatial working memory performance in schizophrenia-spectrum disorders.

PubMed

Girard, Todd A; Wilkins, Leanne K; Lyons, Kathleen M; Yang, Lixia; Christensen, Bruce K

2018-05-31

Introduction Working-memory (WM) is a core cognitive deficit among individuals with Schizophrenia Spectrum Disorders (SSD). However, the underlying cognitive mechanisms of this deficit are less known. This study applies a modified version of the Corsi Block Test to investigate the role of proactive interference in visuospatial WM (VSWM) impairment in SSD. Methods Healthy and SSD participants completed a modified version of the Corsi Block Test involving both high (typical ascending set size from 4 to 7 items) and low (descending set size from 7 to 4 items) proactive interference conditions. Results The results confirmed that the SSD group performed worse overall relative to a healthy comparison group. More importantly, the SSD group demonstrated greater VSWM scores under low (Descending) versus high (Ascending) proactive interference; this pattern is opposite to that of healthy participants. Conclusions This differential pattern of performance supports that proactive interference associated with the traditional administration format contributes to VSWM impairment in SSD. Further research investigating associated neurocognitive mechanisms and the contribution of proactive interference across other domains of cognition in SSD is warranted.

Sleep can reduce proactive interference.

PubMed

Abel, Magdalena; Bäuml, Karl-Heinz T

2014-01-01

Sleep has repeatedly been connected to processes of memory consolidation. While extensive research indeed documents beneficial effects of sleep on memory, little is yet known about the role of sleep for interference effects in episodic memory. Although two prior studies reported sleep to reduce retroactive interference, no sleep effect has previously been found for proactive interference. Here we applied a study format differing from that employed by the prior studies to induce a high degree of proactive interference, and asked participants to encode a single list or two interfering lists of paired associates via pure study cycles. Testing occurred after 12 hours of diurnal wakefulness or nocturnal sleep. Consistent with the prior work, we found sleep in comparison to wake did not affect memory for the single list, but reduced retroactive interference. In addition we found sleep reduced proactive interference, and reduced retroactive and proactive interference to the same extent. The finding is consistent with the view that arising benefits of sleep are caused by the reactivation of memory contents during sleep, which has been suggested to strengthen and stabilise memories. Such stabilisation may make memories less susceptible to competition from interfering memories at test and thus reduce interference effects.

Proactive Interference in Short-Term Recognition and Recall Memory

ERIC Educational Resources Information Center

Dillon, Richard F.; Petrusic, William M.

1972-01-01

Purpose of study was to (a) compare the rate of increase of proactive interference over the first few trials under recall and recognition memory test conditions, (2) determine the effects of two types of distractors on short-term recognition, and (3) test memory after proactive interference had reached a stable level under each of three test…

Neural mechanisms of proactive interference-resolution.

PubMed

Nee, Derek Evan; Jonides, John; Berman, Marc G

2007-12-01

The ability to mitigate interference from information that was previously relevant, but is no longer relevant, is central to successful cognition. Several studies have implicated left ventrolateral prefrontal cortex (VLPFC) as a region tied to this ability, but it is unclear whether this result generalizes across different tasks. In addition, it has been suggested that left anterior prefrontal cortex (APFC) also plays a role in proactive interference-resolution although support for this claim has been limited. The present study used event-related functional magnetic resonance imaging (fMRI) to investigate the role of these regions in resolving proactive-interference across two different tasks performed on the same subjects. Results indicate that both left VLPFC and left APFC are involved in the resolution of proactive interference across tasks. However, different functional networks related to each region suggest dissociable roles for the two regions. Additionally, regions of the posterior cingulate gyrus demonstrated unique involvement in facilitation when short- and long-term memory converged. This pattern of results serves to further specify models of proactive interference-resolution.

Language Proficiency and Executive Control in Proactive Interference: Evidence from Monolingual and Bilingual Children and Adults

ERIC Educational Resources Information Center

Bialystok, Ellen; Feng, Xiaojia

2009-01-01

Two studies are reported in which monolingual and bilingual children (Study 1) and adults (Study 2) completed a memory task involving proactive interference. In both cases, the bilinguals attained lower scores on a vocabulary test than monolinguals but performed the same on the proactive interference task. For the children, bilinguals made fewer…

Reduced interference in working memory following mindfulness training is associated with increases in hippocampal volume.

PubMed

Greenberg, Jonathan; Romero, Victoria L; Elkin-Frankston, Seth; Bezdek, Matthew A; Schumacher, Eric H; Lazar, Sara W

2018-03-17

Proactive interference occurs when previously relevant information interferes with retaining newer material. Overcoming proactive interference has been linked to the hippocampus and deemed critical for cognitive functioning. However, little is known about whether and how this ability can be improved or about the neural correlates of such improvement. Mindfulness training emphasizes focusing on the present moment and minimizing distraction from competing thoughts and memories. It improves working memory and increases hippocampal density. The current study examined whether mindfulness training reduces proactive interference in working memory and whether such improvements are associated with changes in hippocampal volume. 79 participants were randomized to a 4-week web-based mindfulness training program or a similarly structured creative writing active control program. The mindfulness group exhibited lower proactive interference error rates compared to the active control group following training. No group differences were found in hippocampal volume, yet proactive interference improvements following mindfulness training were significantly associated with volume increases in the left hippocampus. These results provide the first evidence to suggest that (1) mindfulness training can protect against proactive interference, and (2) that these benefits are related to hippocampal volumetric increases. Clinical implications regarding the application of mindfulness training in conditions characterized by impairments to working memory and reduced hippocampal volume such as aging, depression, PTSD, and childhood adversity are discussed.

Proactive effects of memory in young and older adults: The role of change recollection

PubMed Central

Wahlheim, Christopher N.

2015-01-01

Age-related deficits in episodic memory are sometimes attributed to older adults being more susceptible to proactive interference. These deficits have been explained by impaired abilities to inhibit competing information and to recollect target information. In the present article, I propose that a change recollection deficit also contributes to age differences in proactive interference. Change recollection occurs when individuals can remember how information changed across episodes, and this counteracts proactive interference by preserving the temporal order of information. Three experiments were conducted to determine whether older adults are less likely to counteract proactive interference by recollecting change. Paired-associate learning paradigms with two lists of word pairs included pairs that repeated across lists, pairs that only appeared in List 2 (control items), and pairs with cues that repeated and responses that changed across lists. Young and older adults’ abilities to detect changed pairs in List 2 and to later recollect those changes at test were measured, along with cued recall of the List 2 responses and confidence in recall performance. Change recollection produced proactive facilitation in the recall of changed pairs, whereas the failure to recollect change resulted in proactive interference. Confidence judgments were sensitive to these effects. The critical finding was that older adults recollected change less than did young adults, and this partially explained older adults’ greater susceptibility to proactive interference. These findings have theoretical implications, showing that a change recollection deficit contributes to age-related deficits in episodic memory. PMID:24710672

Proactive effects of memory in young and older adults: the role of change recollection.

PubMed

Wahlheim, Christopher N

2014-08-01

Age-related deficits in episodic memory are sometimes attributed to older adults being more susceptible to proactive interference. These deficits have been explained by impaired abilities to inhibit competing information and to recollect target information. In the present article, I propose that a change recollection deficit also contributes to age differences in proactive interference. Change recollection occurs when individuals can remember how information changed across episodes, and this counteracts proactive interference by preserving the temporal order of information. Three experiments were conducted to determine whether older adults are less likely to counteract proactive interference by recollecting change. Paired-associate learning paradigms with two lists of word pairs included pairs that repeated across lists, pairs that only appeared in List 2 (control items), and pairs with cues that repeated and responses that changed across lists. Young and older adults' abilities to detect changed pairs in List 2 and to later recollect those changes at test were measured, along with cued recall of the List 2 responses and confidence in recall performance. Change recollection produced proactive facilitation in the recall of changed pairs, whereas the failure to recollect change resulted in proactive interference. Confidence judgments were sensitive to these effects. The critical finding was that older adults recollected change less than did young adults, and this partially explained older adults' greater susceptibility to proactive interference. These findings have theoretical implications, showing that a change recollection deficit contributes to age-related deficits in episodic memory.

How to Be Proactive About Interference: Lessons From Animal Memory

PubMed Central

Wright, Anthony A.; Katz, Jeffrey S.; Ma, Wei Ji

2015-01-01

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memory (e.g., familiarity vs. recollection) are discussed. PMID:22491142

How to be proactive about interference: lessons from animal memory.

PubMed

Wright, Anthony A; Katz, Jeffrey S; Ma, Wei Ji

2012-05-01

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memory (e.g., familiarity vs. recollection) are discussed.

Neurogenesis-mediated forgetting minimizes proactive interference.

PubMed

Epp, Jonathan R; Silva Mera, Rudy; Köhler, Stefan; Josselyn, Sheena A; Frankland, Paul W

2016-02-26

Established memories may interfere with the encoding of new memories, particularly when existing and new memories overlap in content. By manipulating levels of hippocampal neurogenesis, here we show that neurogenesis regulates this form of proactive interference. Increasing hippocampal neurogenesis weakens existing memories and, in doing so, facilitates the encoding of new, conflicting (but not non-conflicting) information in mice. Conversely, decreasing neurogenesis stabilizes existing memories, and impedes the encoding of new, conflicting information. These results suggest that reduced proactive interference is an adaptive benefit of neurogenesis-induced forgetting.

Release from Proactive Interference: Insufficiency of an Attentional Account

ERIC Educational Resources Information Center

MacLeod, Colin M.

1975-01-01

If an attentional cue affects retroactive interference, perhaps a similar mechanism underlies release from proactive interference. This study tested this hypothesis by inserting an attentional cue before the final trial in Wickens' paradigm. (Author/RK)

Are precues effective in proactively controlling taboo interference during speech production?

PubMed

White, Katherine K; Abrams, Lise; Hsi, Lisa R; Watkins, Emily C

2018-02-07

This research investigated whether precues engage proactive control to reduce emotional interference during speech production. A picture-word interference task required participants to name target pictures accompanied by taboo, negative, or neutral distractors. Proactive control was manipulated by presenting precues that signalled the type of distractor that would appear on the next trial. Experiment 1 included one block of trials with precues and one without, whereas Experiment 2 mixed precued and uncued trials. Consistent with previous research, picture naming was slowed in both experiments when distractors were taboo or negative compared to neutral, with the greatest slowing effect when distractors were taboo. Evidence that precues engaged proactive control to reduce interference from taboo (but not negative) distractors was found in Experiment 1. In contrast, mixing precued trials in Experiment 2 resulted in no taboo cueing benefit. These results suggest that item-level proactive control can be engaged under certain conditions to reduce taboo interference during speech production, findings that help to refine a role for cognitive control of distraction during speech production.

Electrophysiological correlates of proactive interference in the 'Recent Probes' verbal working memory task.

PubMed

Zhang, John X; Wu, Renhua; Kong, Lingyue; Weng, Xuchu; Du, Yingchun

2010-06-01

Using event-related potentials (ERPs), the present study examined the temporal dynamics of proactive interference in working memory using a recent probes task. Participants memorized and retained a target set of four letters over a short retention interval. They then responded to a recognition probe by judging whether it was from the memory set. ERP waveforms elicited by positive probes compared to those from negative probes showed positive shifts in a fronto-central early N2 component and a parietal late positive component (LPC). The LPC was identified as the electrophysiological signature of proactive interference, as it differentiated between two types of negative probes defined based on whether they were recently encountered. These results indicate that the proactive interference we observed arises from a mismatch between familiarity and contextual information during recognition memory. When considered together with related studies in the literature, the results also suggest that there are different forms of proactive interference associated with different neural correlates. Copyright 2010 Elsevier Ltd. All rights reserved.

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

PubMed

Cunningham, Christopher J L; De La Rosa, Gabriel M

2008-07-01

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 (alpha<.05). No other interactions between proactive personality and other forms of work-family interference were observed. The benefits of proactive personality may only emerge when personal control over occupational stressors can be exercised. Copyright (c) 2008 APA, all rights reserved.

Age-related changes in overcoming proactive interference in associative memory: The role of PFC-mediated executive control processes at retrieval.

PubMed

Dulas, Michael R; Duarte, Audrey

2016-05-15

Behavioral evidence has shown age-related impairments in overcoming proactive interference in memory, but it is unclear what underlies this deficit. Imaging studies in the young suggest overcoming interference may require several executive control processes supported by the ventrolateral prefrontal cortex (VLPFC) and dorsolateral PFC (DLPFC). The present functional magnetic resonance imaging (fMRI) study investigated whether age-related changes in dissociable executive control processes underlie deficits in overcoming proactive interference in associative memory during retrieval. Participants were tasked with remembering which associate (face or scene) objects were paired with most recently during study, under conditions of high or low proactive interference. Behavioral results demonstrated that, as interference increased, memory performance decreased similarly across groups, with slight associative memory deficits in older adults. Imaging results demonstrated that, across groups, left mid-VLPFC showed increasing activity with increasing interference, though activity did not distinguish correct from incorrect associative memory responses, suggesting this region may not directly serve in successful resolution of proactive interference, per se. Under conditions of high interference, older adults showed reduced associative memory accuracy effects in the DLPFC and anterior PFC. These results suggest that age-related PFC dysfunction may not be ubiquitous. Executive processes supported by ventral regions that detect mnemonic interference may be less affected than processes supported by dorsal and anterior regions that directly resolve interference. Copyright © 2016 Elsevier Inc. All rights reserved.

An electrophysiological signature for proactive interference resolution in working memory.

PubMed

Du, Yingchun; Xiao, Zhuangwei; Song, Yan; Fan, Silu; Wu, Renhua; Zhang, John X

2008-08-01

We used event-related potentials (ERPs) to study the temporal dynamics of proactive interference in working memory. Participants performed a Sternberg item-recognition task to determine whether a probe was in a target memory set. Familiar negative probes were found to be more difficult to reject than less familiar ones. A fronto-central N2 component peaking around 300 ms post-probe-onset differentiated among target probes, familiar and less familiar non-target probes. The study identifies N2 as the ERP signature for proactive interference resolution. It also indicates that the resolution process occurs in the same time window as target/non-target discrimination and provides the first piece of electrophysiological evidence supporting a recent interference resolution model based on localization data [Jonides, J., Nee, D.E., 2006. Brain mechanisms of proactive interference in working memory. Neuroscience 139, 181-193].

Neurogenesis-mediated forgetting minimizes proactive interference

PubMed Central

Epp, Jonathan R.; Silva Mera, Rudy; Köhler, Stefan; Josselyn, Sheena A.; Frankland, Paul W.

2016-01-01

Established memories may interfere with the encoding of new memories, particularly when existing and new memories overlap in content. By manipulating levels of hippocampal neurogenesis, here we show that neurogenesis regulates this form of proactive interference. Increasing hippocampal neurogenesis weakens existing memories and, in doing so, facilitates the encoding of new, conflicting (but not non-conflicting) information in mice. Conversely, decreasing neurogenesis stabilizes existing memories, and impedes the encoding of new, conflicting information. These results suggest that reduced proactive interference is an adaptive benefit of neurogenesis-induced forgetting. PMID:26917323

The effects of trait impulsivity on proactive and reactive interference control.

PubMed

Xiang, Ling; Chen, Yan; Chen, Antao; Zhang, Fenghua; Xu, Fuming; Wang, Baoxi

2018-02-01

The current study used event-related brain potentials (ERPs) to explore whether self-reported trait impulsivity in healthy individuals might be differentially related to proactive and reactive interference control. Participants with high and low impulsivity (HI and LI, respectively) performed a modified version of the prime-target interference task. Proactive interference control was induced in the mostly incongruent (MI) context and reactive interference control was induced in the mostly congruent (MC) context. Although the behavioral data revealed no difference between HI and LI individuals in terms of the interference effects (incongruent - congruent) under both contexts, the ERP results showed that impulsivity has a different influence on the interference effects under different task contexts. In the MC context, the interference effects on the medial frontal negativity (MFN) and the negative sustained potential (N-SP) were greater, while that on the positive sustained potential (P-SP) were smaller in the HI compared to those in the LI group. This suggests that high levels of impulsivity might be associated with a reduced efficiency of the processes supporting reactive control to resolve interference when interference is not expected. In contrast, the three ERP indices (MFN, P-SP, and N-SP) of interference processing in the MI context were insensitive to variations in impulsivity. This suggests that HI individuals might be as effective as LI individuals in recruiting proactive control for sustained active maintenance of task goals to anticipate and prevent interference throughout the experimental blocks where interference occurs frequently. In conclusion, these results indicate that impulsivity has a more negative influence on reactive interference control than on proactive interference control. Copyright © 2017. Published by Elsevier B.V.

Individual Differences in Digit Span, Susceptibility to Proactive Interference, and Aptitude/Achievement Test Scores.

ERIC Educational Resources Information Center

Dempster, Frank N.; Cooney, John B.

1982-01-01

Individual differences in digit span, susceptibility to proactive interference, and various aptitude/achievement test scores were investigated in two experiments with college students. Results indicated that digit span was strongly correlated with aptitude/achievement scores, but did not indicate that susceptibility to proactive interference…

Proactive interference effects on sentence production

PubMed Central

FERREIRA, VICTOR S.; FIRATO, CARLA E.

2007-01-01

Proactive interference refers to recall difficulties caused by prior similar memory-related processing. Information-processing approaches to sentence production predict that retrievability affects sentence form: Speakers may word sentences so that material that is difficult to retrieve is spoken later. In this experiment, speakers produced sentence structures that could include an optional that, thereby delaying the mention of a subsequent noun phrase. This subsequent noun phrase was either (1) conceptually similar to three previous noun phrases in the same sentence, leading to greater proactive interference, or (2) conceptually dissimilar, leading to less proactive interference. Speakers produced more thats (and were more disfluencies) before conceptually similar noun phrases, suggesting that retrieval difficulties during sentence production affect the syntactic structures of sentences that speakers produce. PMID:12613685

Is the phonological similarity effect in working memory due to proactive interference?

PubMed

Baddeley, Alan D; Hitch, Graham J; Quinlan, Philip T

2018-04-12

Immediate serial recall of verbal material is highly sensitive to impairment attributable to phonological similarity. Although this has traditionally been interpreted as a within-sequence similarity effect, Engle (2007) proposed an interpretation based on interference from prior sequences, a phenomenon analogous to that found in the Peterson short-term memory (STM) task. We use the method of serial reconstruction to test this in an experiment contrasting the standard paradigm in which successive sequences are drawn from the same set of phonologically similar or dissimilar words and one in which the vowel sound on which similarity is based is switched from trial to trial, a manipulation analogous to that producing release from PI in the Peterson task. A substantial similarity effect occurs under both conditions although there is a small advantage from switching across similar sequences. There is, however, no evidence for the suggestion that the similarity effect will be absent from the very first sequence tested. Our results support the within-sequence similarity rather than a between-list PI interpretation. Reasons for the contrast with the classic Peterson short-term forgetting task are briefly discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Enhanced conditioned eyeblink response acquisition and proactive interference in anxiety vulnerable individuals

PubMed Central

Holloway, Jacqueline L.; Trivedi, Payal; Myers, Catherine E.; Servatius, Richard J.

2012-01-01

In classical conditioning, proactive interference may arise from experience with the conditioned stimulus (CS), the unconditional stimulus (US), or both, prior to their paired presentations. Interest in the application of proactive interference has extended to clinical populations as either a risk factor for disorders or as a secondary sign. Although the current literature is dense with comparisons of stimulus pre-exposure effects in animals, such comparisons are lacking in human subjects. As such, interpretation of proactive interference over studies as well as its generalization and utility in clinical research is limited. The present study was designed to assess eyeblink response acquisition after equal numbers of CS, US, and explicitly unpaired CS and US pre-exposures, as well as to evaluate how anxiety vulnerability might modulate proactive interference. In the current study, anxiety vulnerability was assessed using the State/Trait Anxiety Inventories as well as the adult and retrospective measures of behavioral inhibition (AMBI and RMBI, respectively). Participants were exposed to 1 of 4 possible pre-exposure contingencies: 30 CS, 30 US, 30 CS, and 30 US explicitly unpaired pre-exposures, or Context pre-exposure, immediately prior to standard delay training. Robust proactive interference was evident in all pre-exposure groups relative to Context pre-exposure, independent of anxiety classification, with CR acquisition attenuated at similar rates. In addition, trait anxious individuals were found to have enhanced overall acquisition as well as greater proactive interference relative to non-vulnerable individuals. The findings suggest that anxiety vulnerable individuals learn implicit associations faster, an effect which persists after the introduction of new stimulus contingencies. This effect is not due to enhanced sensitivity to the US. Such differences would have implications for the development of anxiety psychopathology within a learning framework. PMID:23162449

Enhanced conditioned eyeblink response acquisition and proactive interference in anxiety vulnerable individuals.

PubMed

Holloway, Jacqueline L; Trivedi, Payal; Myers, Catherine E; Servatius, Richard J

2012-01-01

In classical conditioning, proactive interference may arise from experience with the conditioned stimulus (CS), the unconditional stimulus (US), or both, prior to their paired presentations. Interest in the application of proactive interference has extended to clinical populations as either a risk factor for disorders or as a secondary sign. Although the current literature is dense with comparisons of stimulus pre-exposure effects in animals, such comparisons are lacking in human subjects. As such, interpretation of proactive interference over studies as well as its generalization and utility in clinical research is limited. The present study was designed to assess eyeblink response acquisition after equal numbers of CS, US, and explicitly unpaired CS and US pre-exposures, as well as to evaluate how anxiety vulnerability might modulate proactive interference. In the current study, anxiety vulnerability was assessed using the State/Trait Anxiety Inventories as well as the adult and retrospective measures of behavioral inhibition (AMBI and RMBI, respectively). Participants were exposed to 1 of 4 possible pre-exposure contingencies: 30 CS, 30 US, 30 CS, and 30 US explicitly unpaired pre-exposures, or Context pre-exposure, immediately prior to standard delay training. Robust proactive interference was evident in all pre-exposure groups relative to Context pre-exposure, independent of anxiety classification, with CR acquisition attenuated at similar rates. In addition, trait anxious individuals were found to have enhanced overall acquisition as well as greater proactive interference relative to non-vulnerable individuals. The findings suggest that anxiety vulnerable individuals learn implicit associations faster, an effect which persists after the introduction of new stimulus contingencies. This effect is not due to enhanced sensitivity to the US. Such differences would have implications for the development of anxiety psychopathology within a learning framework.

Sleep and memory consolidation: motor performance and proactive interference effects in sequence learning.

PubMed

Borragán, Guillermo; Urbain, Charline; Schmitz, Rémy; Mary, Alison; Peigneux, Philippe

2015-04-01

That post-training sleep supports the consolidation of sequential motor skills remains debated. Performance improvement and sensitivity to proactive interference are both putative measures of long-term memory consolidation. We tested sleep-dependent memory consolidation for visuo-motor sequence learning using a proactive interference paradigm. Thirty-three young adults were trained on sequence A on Day 1, then had Regular Sleep (RS) or were Sleep Deprived (SD) on the night after learning. After two recovery nights, they were tested on the same sequence A, then had to learn a novel, potentially competing sequence B. We hypothesized that proactive interference effects on sequence B due to the prior learning of sequence A would be higher in the RS condition, considering that proactive interference is an indirect marker of the robustness of sequence A, which should be better consolidated over post-training sleep. Results highlighted sleep-dependent improvement for sequence A, with faster RTs overnight for RS participants only. Moreover, the beneficial impact of sleep was specific to the consolidation of motor but not sequential skills. Proactive interference effects on learning a new material at Day 4 were similar between RS and SD participants. These results suggest that post-training sleep contributes to optimizing motor but not sequential components of performance in visuo-motor sequence learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Mechanisms and neuronal networks involved in reactive and proactive cognitive control of interference in working memory.

PubMed

Irlbacher, Kerstin; Kraft, Antje; Kehrer, Stefanie; Brandt, Stephan A

2014-10-01

Cognitive control can be reactive or proactive in nature. Reactive control mechanisms, which support the resolution of interference, start after its onset. Conversely, proactive control involves the anticipation and prevention of interference prior to its occurrence. The interrelation of both types of cognitive control is currently under debate: Are they mediated by different neuronal networks? Or are there neuronal structures that have the potential to act in a proactive as well as in a reactive manner? This review illustrates the way in which integrating knowledge gathered from behavioral studies, functional imaging, and human electroencephalography proves useful in answering these questions. We focus on studies that investigate interference resolution at the level of working memory representations. In summary, different mechanisms are instrumental in supporting reactive and proactive control. Distinct neuronal networks are involved, though some brain regions, especially pre-SMA, possess functions that are relevant to both control modes. Therefore, activation of these brain areas could be observed in reactive, as well as proactive control, but at different times during information processing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Release From Proactive Interference with Young Children

ERIC Educational Resources Information Center

Cann, Linda F.; And Others

1973-01-01

This demonstration of release from proactive interference with young children confirms the suggestion that the technique is appropriate for the study of developmental changes in the encoding of information. (Authors/CB)

Similarities of Recently Acquired and Reactivated Memories in Interference

ERIC Educational Resources Information Center

Gordon, William C.

1977-01-01

Together, these studies replicate and extend Gordon and Spear's (1973a) findings that proactive interference decreases as the interval between prior and subsequent learning increases and that reactivation of a prior memory just before subsequent learning significantly increases the proactive interference due to the prior learning. (Author/RK)

Individual differences in executive processing predict susceptibility to interference in verbal working memory.

PubMed

Hedden, Trey; Yoon, Carolyn

2006-09-01

Recent theories have suggested that resistance to interference is a unifying principle of executive function and that individual differences in interference may be explained by executive function (M. J. Kane & R. W. Engle, 2002). Measures of executive function, memory, and perceptual speed were obtained from 121 older adults (ages 63-82). We used structural equation modeling to investigate the relationships of these constructs with interference in a working memory task. Executive function was best described as two related subcomponent processes: shifting and updating goal-relevant representations and inhibition of proactive interference. These subcomponents were distinct from verbal and visual memory and speed. Individual differences in interference susceptibility and recollection were best predicted by shifting and updating and by resistance to proactive interference, and variability in familiarity was predicted by resistance to proactive interference and speed. ((c) 2006 APA, all rights reserved).

Neural mechanisms of interference control in working memory: effects of interference expectancy and fluid intelligence.

PubMed

Burgess, Gregory C; Braver, Todd S

2010-09-20

A critical aspect of executive control is the ability to limit the adverse effects of interference. Previous studies have shown activation of left ventrolateral prefrontal cortex after the onset of interference, suggesting that interference may be resolved in a reactive manner. However, we suggest that interference control may also operate in a proactive manner to prevent effects of interference. The current study investigated the temporal dynamics of interference control by varying two factors - interference expectancy and fluid intelligence (gF) - that could influence whether interference control operates proactively versus reactively. A modified version of the recent negatives task was utilized. Interference expectancy was manipulated across task blocks by changing the proportion of recent negative (interference) trials versus recent positive (facilitation) trials. Furthermore, we explored whether gF affected the tendency to utilize specific interference control mechanisms. When interference expectancy was low, activity in lateral prefrontal cortex replicated prior results showing a reactive control pattern (i.e., interference-sensitivity during probe period). In contrast, when interference expectancy was high, bilateral prefrontal cortex activation was more indicative of proactive control mechanisms (interference-related effects prior to the probe period). Additional results suggested that the proactive control pattern was more evident in high gF individuals, whereas the reactive control pattern was more evident in low gF individuals. The results suggest the presence of two neural mechanisms of interference control, with the differential expression of these mechanisms modulated by both experimental (e.g., expectancy effects) and individual difference (e.g., gF) factors.

Ghosts in the machine: memory interference from the previous trial.

PubMed

Papadimitriou, Charalampos; Ferdoash, Afreen; Snyder, Lawrence H

2015-01-15

Previous memoranda can interfere with the memorization or storage of new information, a concept known as proactive interference. Studies of proactive interference typically use categorical memoranda and match-to-sample tasks with categorical measures such as the proportion of correct to incorrect responses. In this study we instead train five macaques in a spatial memory task with continuous memoranda and responses, allowing us to more finely probe working memory circuits. We first ask whether the memoranda from the previous trial result in proactive interference in an oculomotor delayed response task. We then characterize the spatial and temporal profile of this interference and ask whether this profile can be predicted by an attractor network model of working memory. We find that memory in the current trial shows a bias toward the location of the memorandum of the previous trial. The magnitude of this bias increases with the duration of the memory period within which it is measured. Our simulations using standard attractor network models of working memory show that these models easily replicate the spatial profile of the bias. However, unlike the behavioral findings, these attractor models show an increase in bias with the duration of the previous rather than the current memory period. To model a bias that increases with current trial duration we posit two separate memory stores, a rapidly decaying visual store that resists proactive interference effects and a sustained memory store that is susceptible to proactive interference. Copyright © 2015 the American Physiological Society.

Ghosts in the machine: memory interference from the previous trial

PubMed Central

Ferdoash, Afreen; Snyder, Lawrence H.

2014-01-01

Previous memoranda can interfere with the memorization or storage of new information, a concept known as proactive interference. Studies of proactive interference typically use categorical memoranda and match-to-sample tasks with categorical measures such as the proportion of correct to incorrect responses. In this study we instead train five macaques in a spatial memory task with continuous memoranda and responses, allowing us to more finely probe working memory circuits. We first ask whether the memoranda from the previous trial result in proactive interference in an oculomotor delayed response task. We then characterize the spatial and temporal profile of this interference and ask whether this profile can be predicted by an attractor network model of working memory. We find that memory in the current trial shows a bias toward the location of the memorandum of the previous trial. The magnitude of this bias increases with the duration of the memory period within which it is measured. Our simulations using standard attractor network models of working memory show that these models easily replicate the spatial profile of the bias. However, unlike the behavioral findings, these attractor models show an increase in bias with the duration of the previous rather than the current memory period. To model a bias that increases with current trial duration we posit two separate memory stores, a rapidly decaying visual store that resists proactive interference effects and a sustained memory store that is susceptible to proactive interference. PMID:25376781

Randomized Controlled Trial Considering Varied Exercises for Reducing Proactive Memory Interference.

PubMed

Frith, Emily; Sng, Eveleen; Loprinzi, Paul D

2018-06-11

We evaluated the effects of exercise on proactive memory interference. Study 1 ( n = 88) employed a 15-min treadmill walking protocol, while Study 2 ( n = 88) included a 15-min bout of progressive maximal exertion treadmill exercise. Each study included four distinct groups, in which groups of 22 participants each were randomly assigned to: (a) exercise before memory encoding, (b) a control group with no exercise, (c) exercise during memory encoding, and (d) exercise after memory encoding (i.e., during memory consolidation). We used the Rey Auditory Verbal Learning Test (RAVLT) to assess proactive memory interference. In both studies, the group that exercised prior to memory encoding recalled the most words from list B (distractor list) of the RAVLT, though group differences were not statistically significant for Study 1 (walking exercise) ( p = 0.521) or Study 2 (high-intensity exercise) ( p = 0.068). In this sample of young adults, high intensity exercise prior to memory encoding showed a non-significant tendency to attenuate impairments in recall attributable to proactive memory interference. Thus, future work with larger samples is needed to clarify potential beneficial effects of exercise for reducing proactive memory interference.

Negative Transfer and Positive Interference: Some Confusion in Introductory Psychology Textbooks.

ERIC Educational Resources Information Center

Reid, Edward

1981-01-01

Discusses weakness in 11 introductory psychology textbooks in distinguishing between the terms proactive behavior and negative transfer. Negative transfer relates to a detrimental effect of prior experience on the learning of a new task, whereas proactive interference concerns a detrimental affect of prior interference on the recall of a second…

Reactive and Proactive Interference Control in Adults with Autism Spectrum Disorder across the Lifespan

ERIC Educational Resources Information Center

Lever, Anne G.; Ridderinkhof, K. Richard; Marsman, Maarten; Geurts, Hilde M.

2017-01-01

As a large heterogeneity is observed across studies on interference control in autism spectrum disorder (ASD), research may benefit from the use of a cognitive framework that models specific processes underlying reactive and proactive control of interference. Reactive control refers to the expression and suppression of responses and proactive…

Implicit proactive interference, age, and automatic versus controlled retrieval strategies.

PubMed

Ikier, Simay; Yang, Lixia; Hasher, Lynn

2008-05-01

We assessed the extent to which implicit proactive interference results from automatic versus controlled retrieval among younger and older adults. During a study phase, targets (e.g., "ALLERGY") either were or were not preceded by nontarget competitors (e.g., "ANALOGY"). After a filled interval, the participants were asked to complete word fragments, some of which cued studied words (e.g., "A_L_ _GY"). Retrieval strategies were identified by the difference in response speed between a phase containing fragments that cued only new words and a phase that included a mix of fragments cuing old and new words. Previous results were replicated: Proactive interference was found in implicit memory, and the negative effects were greater for older than for younger adults. Novel findings demonstrate two retrieval processes that contribute to interference: an automatic one that is age invariant and a controlled process that can reduce the magnitude of the automatic interference effects. The controlled process, however, is used effectively only by younger adults. This pattern of findings potentially explains age differences in susceptibility to proactive interference.

The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but No Proactive Interference

ERIC Educational Resources Information Center

Oberauer, Klaus; Awh, Edward; Sutterer, David W.

2017-01-01

We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3…

Proactive Interference and Its Release in Short-Term Memory of Mildly Retarded Adolescents

ERIC Educational Resources Information Center

Cody, William J.; Borkowski, John G.

1977-01-01

Release from proactive interference in mildly retarded adolescents due to taxonomic shifts and rest periods prior to the final, critical-word triad was investigated with 40 educable mentally handicapped persons 18 years old. (Author/MH)

Transfer Failure and Proactive Interference in Short-Term Memory

ERIC Educational Resources Information Center

Ellis, John A.

1977-01-01

Two experiments tested the hypothesis that proactive interference over a series of Brown-Peterson trials results from a combination of the subject's failure to transfer information to a permanent memory state and failure to retrieve information from permanent memory. (Editor)

Separating intentional inhibition of prepotent responses and resistance to proactive interference in alcohol-dependent individuals.

PubMed

Noël, Xavier; Van der Linden, Martial; Brevers, Damien; Campanella, Salvatore; Verbanck, Paul; Hanak, Catherine; Kornreich, Charles; Verbruggen, Frederick

2013-03-01

Impulsivity is a hallmark of addictive behaviors. Addicts' weakened inhibition of irrelevant prepotent responses is commonly thought to explain this association. However, inhibition is not a unitary mechanism. This study investigated the efficiency of overcoming competition due to irrelevant responses (i.e., inhibition of a prepotent response) and overcoming competition in memory (i.e., resistance to proactive interference) in sober and recently detoxified alcohol-dependent individuals. Three cognitive tasks assessing the inhibition of a prepotent response (Hayling task, anti-saccade task and Stroop task) and two tasks tapping into the capacity to resist proactive interference (cued recall, Brown-Peterson variant) were administered to 30 non-amnesic recently detoxified alcohol-dependent individuals and 30 matched healthy participants without alcohol dependency. In addition, possible confounds such as verbal updating in working memory was assessed. Alcohol-dependent subjects performed worse than healthy participants on the three cognitive tasks assessing the inhibition of irrelevant prepotent responses but group performance was similar in the tasks assessing overcoming proactive interference in memory, updating of working memory and abstract reasoning. These findings suggest that alcohol-dependence is mainly associated with impaired capacity to intentionally suppress irrelevant prepotent response information. Control of proactive interference from memory is preserved. Theoretical and clinical implications are discussed. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Testing can counteract proactive interference by integrating competing information.

PubMed

Wahlheim, Christopher N

2015-01-01

Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A-B, A-D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A-B, A-B), control pairs appeared in List 2 only (A-B, C-D), and changed pairs appeared with the same cue in both lists but with different responses (A-B, A-D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information.

Information processing and proactive interference in children with and without specific language impairment.

PubMed

Marton, Klara; Campanelli, Luca; Eichorn, Naomi; Scheuer, Jessica; Yoon, Jungmee

2014-02-01

Increasing evidence suggests that children with specific language impairment (SLI) have a deficit in inhibition control, but research isolating specific abilities is scarce. The goal of this study was to examine whether children with SLI differ from their peers in resistance to proactive interference under different conditions. An information processing battery with manipulations in interference was administered to 66 children (SLI, age matched peers, and language-matched controls). In Experiment 1, previously relevant targets were used as distractors to create conflict. Experiment 2 used item repetitions to examine how practice strengthens word representations and how the strength of a response impacts performance on the following item. Children with SLI performed similarly to their peers in the baseline condition but were more susceptible to proactive interference than the controls in both experimental conditions. Children with SLI demonstrated difficulty suppressing irrelevant information, made significantly more interference errors than their peers, and showed a slower rate of implicit learning. Children with SLI show weaker resistance to proactive interference than their peers, and this deficit impacts their information processing abilities. The coordination of activation and inhibition is less efficient in these children, but future research is needed to further examine the interaction between these two processes.

Material-specific retroactive interference effects of the Wechsler Adult Intelligence Scale-Fourth Edition on the Wechsler Memory Scale-Fourth Edition in a nonclinical sample.

PubMed

Ingram, Nicolette S; Diakoumakos, Jessica V; Sinclair, Erin R; Crowe, Simon F

2016-01-01

This study investigated proactive and retroactive interference effects between the Wechsler Memory Scale-Fourth Edition (WMS-IV) using the flexible approach, and the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). One hundred and eighty nonclinical participants were assigned to a four (visual interference, verbal interference, visual and verbal interference, vs. no interference) by two (retroactive vs. proactive) between-subjects design. The administration order of the tests was counterbalanced (i.e., administration of the WAIS-IV prior to the WMS-IV, and the WAIS-IV administered during the delay interval of the WMS-IV). The WAIS-IV produced significant retroactive interference effects on the WMS-IV; however, no proactive interference effect was observed. The retroactive interference effect was dependent on material specificity. The results indicate that material presented within the delay of the WMS-IV can have a significant effect on subsequent delayed recall. Clinicians should carefully consider the effects associated with carry-over effects of these tests when using them in combination.

Girls Not Boys Show Gender-Connotation Encoding from Print.

ERIC Educational Resources Information Center

Perez, Susan M.; Kee, Daniel W.

2000-01-01

Investigated possible gender differences in third grade students' encoding of gender-connotation from words using the release from proactive interference method to measure gender-connotation encoding. Students were presented with stimulus word triads in print. Results showed reliable proactive interference buildup and release for…

Proactive and coactive interference in age-related performance in a recognition-based operation span task.

PubMed

Zeintl, Melanie; Kliegel, Matthias

2010-01-01

Generally, older adults perform worse than younger adults in complex working memory span tasks. So far, it is unclear which processes mainly contribute to age-related differences in working memory span. The aim of the present study was to investigate age effects and the roles of proactive and coactive interference in a recognition-based version of the operation span task. Younger and older adults performed standard versions and distracter versions of the operation span task. At retrieval, participants had to recognize target words in word lists containing targets as well as proactive and/or coactive interference-related lures. Results show that, overall, younger adults outperformed older adults in the recognition of target words. Furthermore, analyses of error types indicate that, while younger adults were only affected by simultaneously presented distracter words, older adults had difficulties with both proactive and coactive interference. Results suggest that age effects in complex span tasks may not be mainly due to retrieval deficits in old age. Copyright 2009 S. Karger AG, Basel.

Visual Working Memory Capacity and Proactive Interference

PubMed Central

Hartshorne, Joshua K.

2008-01-01

Background Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory tasks, like verbal working memory tasks, are subject to proactive interference, coupled with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggests that visual working memory capacity may be systematically under-estimated. Methodology/Principal Findings Working memory capacity was probed behaviorally in adult humans both in laboratory settings and via the Internet. Several experiments show that although the effect of proactive interference on visual working memory is significant and can last over several trials, it only changes the capacity estimate by about 15%. Conclusions/Significance This study further confirms the sharp limitations on visual working memory capacity, both in absolute terms and relative to verbal working memory. It is suggested that future research take these limitations into account in understanding differences across a variety of tasks between human adults, prelinguistic infants and nonlinguistic animals. PMID:18648493

Visual working memory capacity and proactive interference.

PubMed

Hartshorne, Joshua K

2008-07-23

Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory tasks, like verbal working memory tasks, are subject to proactive interference, coupled with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggests that visual working memory capacity may be systematically under-estimated. Working memory capacity was probed behaviorally in adult humans both in laboratory settings and via the Internet. Several experiments show that although the effect of proactive interference on visual working memory is significant and can last over several trials, it only changes the capacity estimate by about 15%. This study further confirms the sharp limitations on visual working memory capacity, both in absolute terms and relative to verbal working memory. It is suggested that future research take these limitations into account in understanding differences across a variety of tasks between human adults, prelinguistic infants and nonlinguistic animals.

Drilling Deeper into tooth brushing skills: Is proactive interference an under-recognized factor in oral hygiene behavior change?

PubMed

Thavarajah, Rooban; Kumar, Madan; Mohandoss, Anusa Arunachalam; Vernon, Lance T

2015-09-01

Proper tooth brushing is a seemingly simple motor activity that can promote oral health. Applying health theories, such as the Information-Motivation-Behavioral Skills (IMB) model, Motivational Interviewing (MI) and Integrated Health Coaching (IHC), may help optimize tooth brushing technique in those with suboptimal skills. Some motor activities, including tooth brushing, may over time become rote and unconscious actions, such that an existing habit can inhibit new learning, i.e., exert proactive interference on learning the new skill. Proactive interference may impede the acquisition of new tooth brushing skills; thus, in this report, we: (1) Review how the habit of tooth brushing is formed; (2) Postulate how proactive interference could impede the establishment of proper tooth brushing retraining; (3) Discuss the merits of this hypothesis; and (4) Provide guidance for future work in this topic within the context of an approach to behavior change that integrates IMB, MI and IHC methodology.

Drilling Deeper into tooth brushing skills: Is proactive interference an under-recognized factor in oral hygiene behavior change?

PubMed Central

Thavarajah, Rooban; Kumar, Madan; Mohandoss, Anusa Arunachalam

2015-01-01

Proper tooth brushing is a seemingly simple motor activity that can promote oral health. Applying health theories, such as the Information-Motivation-Behavioral Skills (IMB) model, Motivational Interviewing (MI) and Integrated Health Coaching (IHC), may help optimize tooth brushing technique in those with suboptimal skills. Some motor activities, including tooth brushing, may over time become rote and unconscious actions, such that an existing habit can inhibit new learning, i.e., exert proactive interference on learning the new skill. Proactive interference may impede the acquisition of new tooth brushing skills; thus, in this report, we: (1) Review how the habit of tooth brushing is formed; (2) Postulate how proactive interference could impede the establishment of proper tooth brushing retraining; (3) Discuss the merits of this hypothesis; and (4) Provide guidance for future work in this topic within the context of an approach to behavior change that integrates IMB, MI and IHC methodology. PMID:26457238

Proactive and reactive control depends on emotional valence: a Stroop study with emotional expressions and words.

PubMed

Kar, Bhoomika Rastogi; Srinivasan, Narayanan; Nehabala, Yagyima; Nigam, Richa

2018-03-01

We examined proactive and reactive control effects in the context of task-relevant happy, sad, and angry facial expressions on a face-word Stroop task. Participants identified the emotion expressed by a face that contained a congruent or incongruent emotional word (happy/sad/angry). Proactive control effects were measured in terms of the reduction in Stroop interference (difference between incongruent and congruent trials) as a function of previous trial emotion and previous trial congruence. Reactive control effects were measured in terms of the reduction in Stroop interference as a function of current trial emotion and previous trial congruence. Previous trial negative emotions exert greater influence on proactive control than the positive emotion. Sad faces in the previous trial resulted in greater reduction in the Stroop interference for happy faces in the current trial. However, current trial angry faces showed stronger adaptation effects compared to happy faces. Thus, both proactive and reactive control mechanisms are dependent on emotional valence of task-relevant stimuli.

Testing can counteract proactive interference by integrating competing information

PubMed Central

Wahlheim, Christopher N.

2015-01-01

Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A–B, A–D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A–B, A–B), control pairs appeared in List 2 only (A–B, C–D), and changed pairs appeared with the same cue in both lists but with different responses (A–B, A–D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information. PMID:25120241

The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but no Proactive Interference

PubMed Central

Oberauer, Klaus; Awh, Edward; Sutterer, David W.

2016-01-01

We report four experiments examining whether associations in visual working memory are subject to proactive interference from long term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of three concrete objects in an array. Each array in the WM test consisted of one old (previously learned) object with a new color (old-mismatch), one old object with its old color (old-match), and one new object. Experiments 1 to 3 showed that WM performance was better in the old-match condition than in the new condition, reflecting a beneficial contribution from long term memory. In the old mismatch condition, participants sometimes reported colors associated with the relevant shape in LTM, but the probability of successful recall was equivalent to that in the new condition. Thus, information from LTM only intruded in the absence of reportable information in WM. Experiment 4 tested for, and failed to find, proactive interference from the preceding trial in the WM test: Performance in the old-mismatch condition, presenting an object from the preceding trial with a new color, was equal to performance with new objects. Experiment 5 showed that long-term memory for object-color associations is subject to proactive interference. We conclude that the exchange of information between LTM and WM appears to be controlled by a gating mechanism that protects the contents of WM from proactive interference but admits LTM information when it is useful. PMID:27685018

Benefits of a hungry mind: When hungry, exposure to food facilitates proactive interference resolution.

PubMed

Maran, Thomas; Sachse, Pierre; Martini, Markus; Furtner, Marco

2017-01-01

Hunger is an everyday motivational state, which biases cognition to detect food. Although evidence exists on how hunger affects basic attentional and mnemonic processes, less is known about how motivational drive for food modulates higher cognition. We aimed to investigate the effects of food deprivation on proactive interference resolution, in the presence and absence of food. Normal-weight participants performed a recency probes paradigm providing an experimental block with food and object stimuli as well as a control block with object stimuli only, in a fasted and a sated state. Results showed that the interaction of shifts in nutritional state with the perception of food cues evoked an altered resolution of proactive interference. Satiety led to impaired performance, whereas a hungry state resulted in strengthened resistance to proactive interference and lying in between, the control block presenting neutral objects remained unaffected by nutritional state manipulation. Additionally, a further increase in proactive interference resolution occurred when the conflicting probe depicted food compared to non-food objects. We conclude that when exposed to food, hunger initiates biased competition of active memory representations in favor of prioritized source information at cost of familiar, but irrelevant information. The implications of these findings are discussed in terms of an arousal-biased competition in working memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

Information Processing and Proactive Interference in Children With and Without Specific Language Impairment

PubMed Central

Marton, Klara; Campanelli, Luca; Eichorn, Naomi; Scheuer, Jessica; Yoon, Jungmee

2014-01-01

Purpose Increasing evidence suggests that children with specific language impairment (SLI) have a deficit in inhibition control, but research isolating specific abilities is scarce. The goal of this study was to examine whether children with SLI differ from their peers in resistance to proactive interference under different conditions. Method An information processing battery with manipulations in interference was administered to 66 children (SLI, age-matched peers, and language-matched controls). In Experiment 1, previously relevant targets were used as distractors to create conflict. Experiment 2 used item repetitions to examine how practice strengthens word representations and how the strength of a response impacts performance on the following item. Results Children with SLI performed similarly to their peers in the baseline condition but were more susceptible to proactive interference than the controls in both experimental conditions. Children with SLI demonstrated difficulty suppressing irrelevant information, made significantly more interference errors than their peers, and showed a slower rate of implicit learning. Conclusion Children with SLI show weaker resistance to proactive interference than their peers, and this deficit impacts their information processing abilities. The coordination of activation and inhibition is less efficient in these children, but future research is needed to further examine the interaction between these two processes. PMID:23900030

Reactive and proactive interference control in adults with autism spectrum disorder across the lifespan.

PubMed

Lever, Anne G; Ridderinkhof, K Richard; Marsman, Maarten; Geurts, Hilde M

2017-02-01

As a large heterogeneity is observed across studies on interference control in autism spectrum disorder (ASD), research may benefit from the use of a cognitive framework that models specific processes underlying reactive and proactive control of interference. Reactive control refers to the expression and suppression of responses and proactive control refers to the adjustment of response to previous situations. We administered a Simon conflict task in 2 independent adult samples (IQ >80) and applied distributional analyses to examine temporal dynamics of interference control in ASD. Along comparable interference effects in both reactive and proactive control, young men (n = 23, 18-36 years) diagnosed with ASD made as many fast errors on conflict trials as neurotypical controls (n = 19) and showed similar suppression on slow responses (Study 1). However, over the adult life span (19-79 years), individuals with ASD (n = 118) made fewer fast errors on conflict trials, and had overall slower and more accurate responses than controls (n = 160; Study 2). These results converge to the idea that individuals with ASD adopt a more cautious response bias over the adult life span, which is not yet observed among young adults. Our findings suggest that it is fruitful to distinguish different processes involved in interference control and contribute to an increased understanding of interference control mechanisms in adults with ASD. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Role of Response Confusion in Proactive Interference

ERIC Educational Resources Information Center

Dillon, Richard F.; Thomas, Heather

1975-01-01

In two experiments using the Brown-Peterson memory paradigm, instructions to guess had small effects on recall, but sizeable effects on incidence of prior list intrustion. However, results indicate that proactive interference is primarily the result of inability to generate correct items, rather than confusion between present and previous items.…

The Ranschburg Effect: Tests of the Guessing-Bias and Proactive Interference Hypotheses

ERIC Educational Resources Information Center

Walsh, Michael F.; Schwartz, Marian

1977-01-01

The guessing-bias and proactive interference hypotheses of the Ranschburg Effect were investigated by giving three groups different instructions as to guessing during recall. Results failed to support the prediction that the effect should be reduced or eliminated on shift trials. Neither hypothesis received significant support. (CHK)

Neural systems and time course of proactive interference in working memory.

PubMed

Du, Yingchun; Zhang, John X; Xiao, Zhuangwei; Wu, Renhua

2007-01-01

The storage of information in working memory suffers as a function of proactive interference. Many works using neuroimaging technique have been done to reveal the brain mechanism of interference resolution. However, less is yet known about the time course of this process. Event-related potential method(ERP) and standardized Low Resolution Brain Electromagnetic Tomography method (sLORETA) were used in this study to discover the time course of interference resolution in working memory. The anterior P2 was thought to reflect interference resolution and if so, this process occurred earlier in working memory than in long-term memory.

Revealing past memories: proactive interference and ketamine-induced memory deficits.

PubMed

Chrobak, James J; Hinman, James R; Sabolek, Helen R

2008-04-23

Memories of events that occur often are sensitive to interference from memories of similar events. Proactive interference plays an important and often unexamined role in memory testing for spatially and temporally unique events ("episodes"). Ketamine (NMDA receptor antagonist) treatment in humans and other mammals induces a constellation of cognitive deficits, including impairments in working and episodic memory. We examined the effects of the ketamine (2.5-100 mg/kg) on the acquisition, retrieval, and retention of memory in a delayed-match-to-place radial water maze task that can be used to assess proactive interference. Ketamine (2.5-25 mg/kg, i.p.) given 20 min before the sample trial, impaired encoding. The first errors made during the test trial were predominantly to arms located spatially adjacent to the goal arm, suggesting an established albeit weakened representation. Ketamine (25-100 mg/kg) given immediately after the sample trial had no effect on retention. Ketamine given before the test trial impaired retrieval. First errors under the influence of ketamine were predominantly to the goal location of the previous session. Thus, ketamine treatment promoted proactive interference. These memory deficits were not state dependent, because ketamine treatment at both encoding and retrieval only increased the number of errors during the test session. These data demonstrate the competing influence of distinct memory representations during the performance of a memory task in the rat. Furthermore, they demonstrate the subtle disruptive effects of the NMDA antagonist ketamine on both encoding and retrieval. Specifically, ketamine treatment disrupted retrieval by promoting proactive interference from previous episodic representations.

Information Processing and Proactive Interference in Children with and without Specific Language Impairment

ERIC Educational Resources Information Center

Marton, Klara; Campanelli, Luca; Eichorn, Naomi; Scheuer, Jessica; Yoon, Jungmee

2014-01-01

Purpose: Increasing evidence suggests that children with specific language impairment (SLI) have a deficit in inhibition control, but research isolating specific abilities is scarce. The goal of this study was to examine whether children with SLI differ from their peers in resistance to proactive interference under different conditions. Method: An…

"Testing during Study Insulates against the Buildup of Proactive Interference": Correction

ERIC Educational Resources Information Center

Szpunar, Karl K.; McDermott, Kathleen B.; Roedigger, Henry L., III

2009-01-01

Reports an error in "Testing during study insulates against the buildup of proactive interference" by Karl K. Szpunar, Kathleen B. McDermott and Henry L. Roediger III ("Journal of Experimental Psychology: Learning, Memory, and Cognition," 2008[Nov], Vol 34[6], 1392-1399). Incorrect figures were printed due to an error in the…

The inhibition of proactive interference among adults with Internet gaming disorder.

PubMed

Ko, Chih-Hung; Wang, Peng-Wei; Liu, Tai-Ling; Yen, Cheng-Fang; Chen, Cheng-Sheng; Yen, Ju-Yu

2015-06-01

Cognitive control plays a pivotal role in the mechanism of addictive behavior. The aim of the study was to evaluate the deficit in inhibition of proactive interference of Internet gaming disorder (IGD) using a directed forgetting task among young adults. A total of 64 participants with IGD and 69 controls were recruited on a university campus. They completed the directed forgetting task for online gaming words and neutral words. The results demonstrated that the IGD group had a poorer performance on the directed forgetting task, and this represented a deficit in inhibition of proactive interference. They also had a higher tendency to remember online gaming words rather than neutral words in comparison with the control group. This demonstrated memory bias toward online gaming words. These results suggested that more attention should be paid to deficits in inhibition of proactive interference and memory bias toward gaming content when treating subjects with IGD. Furthermore, it is essential and practical to prevent exposure to online gaming-related cues when endeavoring to control online gaming behavior. © 2014 Wiley Publishing Asia Pty Ltd.

The role of long-term memory in a test of visual working memory: Proactive facilitation but no proactive interference.

PubMed

Oberauer, Klaus; Awh, Edward; Sutterer, David W

2017-01-01

We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3 concrete objects in an array. Each array in the WM test consisted of 1 old (previously learned) object with a new color (old-mismatch), 1 old object with its old color (old-match), and 1 new object. Experiments 1 to 3 showed that WM performance was better in the old-match condition than in the new condition, reflecting a beneficial contribution from LTM. In the old-mismatch condition, participants sometimes reported colors associated with the relevant shape in LTM, but the probability of successful recall was equivalent to that in the new condition. Thus, information from LTM only intruded in the absence of reportable information in WM. Experiment 4 tested for, and failed to find, proactive interference from the preceding trial in the WM test: Performance in the old-mismatch condition, presenting an object from the preceding trial with a new color, was equal to performance with new objects. Experiment 5 showed that long-term memory for object-color associations is subject to proactive interference. We conclude that the exchange of information between LTM and WM appears to be controlled by a gating mechanism that protects the contents of WM from proactive interference but admits LTM information when it is useful. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Enhanced Eyeblink Conditioning in Behaviorally Inhibited Individuals is Disrupted by Proactive Interference Following US Alone Pre-exposures.

PubMed

Allen, Michael Todd; Miller, Daniel P

2016-01-01

Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from conditioned stimulus (CS) or unconditioned stimulus (US) alone pre-exposures (Holloway et al., 2012). US alone pre-exposures disrupt subsequent conditioned response (CR) acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al. (2012) reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioral Inhibition (AMBI). Sixty-six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI) individuals exhibited enhanced proactive interference as compared to non-inhibited (NI) individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible learned helplessness. Applications of these findings of enhanced proactive interference in BI individuals to pre-exposure therapies to reduce anxiety disorders such as posttraumatic stress disorder (PTSD) will be discussed.

Enhanced Eyeblink Conditioning in Behaviorally Inhibited Individuals is Disrupted by Proactive Interference Following US Alone Pre-exposures

PubMed Central

Allen, Michael Todd; Miller, Daniel P.

2016-01-01

Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from conditioned stimulus (CS) or unconditioned stimulus (US) alone pre-exposures (Holloway et al., 2012). US alone pre-exposures disrupt subsequent conditioned response (CR) acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al. (2012) reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioral Inhibition (AMBI). Sixty-six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI) individuals exhibited enhanced proactive interference as compared to non-inhibited (NI) individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible learned helplessness. Applications of these findings of enhanced proactive interference in BI individuals to pre-exposure therapies to reduce anxiety disorders such as posttraumatic stress disorder (PTSD) will be discussed. PMID:27014001

Testing complex animal cognition: Concept learning, proactive interference, and list memory.

PubMed

Wright, Anthony A

2018-01-01

This article describes an approach for assessing and comparing complex cognition in rhesus monkeys and pigeons by training them in a sequence of synergistic tasks, each yielding a whole function for enhanced comparisons. These species were trained in similar same/different tasks with expanding training sets (8, 16, 32, 64, 128 … 1024 pictures) followed by novel-stimulus transfer eventually resulting in full abstract-concept learning. Concept-learning functions revealed better rhesus transfer throughout and full concept learning at the 128 set, versus pigeons at the 256 set. They were then tested in delayed same/different tasks for proactive interference by inserting occasional tests within trial-unique sessions where the test stimulus matched a previous sample stimulus (1, 2, 4, 8, 16 trials prior). Proactive-interference functions revealed time-based interference for pigeons (1, 10 s delays), but event-based interference for rhesus (no effect of 1, 10, 20 s delays). They were then tested in list-memory tasks by expanding the sample to four samples in trial-unique sessions (minimizing proactive interference). The four-item, list-memory functions revealed strong recency memory at short delays, gradually changing to strong primacy memory at long delays over 30 s for rhesus, and 10 s for pigeons. Other species comparisons and future directions are discussed. © 2018 Society for the Experimental Analysis of Behavior.

Memory Consequences of Looking Back to Notice Change: Retroactive and Proactive Facilitation

ERIC Educational Resources Information Center

Jacoby, Larry L.; Wahlheim, Christopher N.; Kelley, Colleen M.

2015-01-01

Three experiments contrasted recollection of change with differentiation as means of avoiding retroactive interference and proactive interference. We manipulated the extent to which participants looked back to notice change between pairs of cues and targets (A-B, A-D) and measured the effects on later cued recall of either the first or second…

A Release from Proactive Interference Analysis of Gender Schema Encoding for Occupations in Adults and Children

ERIC Educational Resources Information Center

Kee, D.W.; Gregory-Domingue, A.; Rice, K.; Tone, K.

2005-01-01

The present study examined gender schema encoding (activation of gender stereotypes) in the absence deliberate purposes relating to people (stereotype application). A release from proactive interference short-term-memory task was used. College (Experiment 1) and sixth-grade (Experiment 2) participants were asked to retain item identity and…

Presentation Modality and Proactive Interference in Children's Short-Term Memory.

ERIC Educational Resources Information Center

Douglas, Joan Delahanty

This study examined the role of visual and auditory presentation in memory encoding processes of 80 second-grade children, using the release-from-proactive-interference short-term memory (STM) paradigm. Words were presented over three trials within one of the presentation modes and one taxonomic category, followed by a fourth trial in which the…

Individual differences in experiencing intrusive memories: the role of the ability to resist proactive interference.

PubMed

Verwoerd, Johan; Wessel, Ineke; de Jong, Peter J

2009-06-01

This study explored whether a relatively poor ability to resist or inhibit interference from irrelevant information in working memory is associated with experiencing undesirable intrusive memories. Non-selected participants (N=91) completed a self-report measure of intrusive memories, and carried out experimental tasks intended to measure two different types of inhibition: resistance to proactive interference and response inhibition (i.e., the ability to prevent automatically triggered responses). The results showed a significant relationship between inhibition at the cognitive level (i.e., resistance to proactive interference) and the frequency of intrusive memories (especially in the group of female participants) whereas no such relationship with measures of response inhibition emerged. These findings are consistent with the idea that deficient inhibitory control reflects a vulnerability factor for experiencing intrusive memories. Implications for research investigating risk factors for the development of posttraumatic stress disorder (PTSD) are discussed.

The Effect of Aging on the Dynamics of Reactive and Proactive Cognitive Control of Response Interference

PubMed Central

Xiang, Ling; Zhang, Baoqiang; Wang, Baoxi; Jiang, Jun; Zhang, Fenghua; Hu, Zhujing

2016-01-01

A prime-target interference task was used to investigate the effects of cognitive aging on reactive and proactive control after eliminating frequency confounds and feature repetitions from the cognitive control measures. We used distributional analyses to explore the dynamics of the two control functions by distinguishing the strength of incorrect response capture and the efficiency of suppression control. For reactive control, within-trial conflict control and between-trial conflict adaption were analyzed. The statistical analysis showed that there were no reliable between-trial conflict adaption effects for either young or older adults. For within-trial conflict control, the results revealed that older adults showed larger interference effects on mean RT and mean accuracy. Distributional analyses showed that the decline mainly stemmed from inefficient suppression rather than from stronger incorrect responses. For proactive control, older adults showed comparable proactive conflict resolution to young adults on mean RT and mean accuracy. Distributional analyses showed that older adults were as effective as younger adults in adjusting their responses based on congruency proportion information to minimize automatic response capture and actively suppress the direct response activation. The results suggest that older adults were less proficient at suppressing interference after conflict was detected but can anticipate and prevent inference in response to congruency proportion manipulation. These results challenge earlier views that older adults have selective deficits in proactive control but intact reactive control. PMID:27847482

The Effect of Aging on the Dynamics of Reactive and Proactive Cognitive Control of Response Interference.

PubMed

Xiang, Ling; Zhang, Baoqiang; Wang, Baoxi; Jiang, Jun; Zhang, Fenghua; Hu, Zhujing

2016-01-01

A prime-target interference task was used to investigate the effects of cognitive aging on reactive and proactive control after eliminating frequency confounds and feature repetitions from the cognitive control measures. We used distributional analyses to explore the dynamics of the two control functions by distinguishing the strength of incorrect response capture and the efficiency of suppression control. For reactive control, within-trial conflict control and between-trial conflict adaption were analyzed. The statistical analysis showed that there were no reliable between-trial conflict adaption effects for either young or older adults. For within-trial conflict control, the results revealed that older adults showed larger interference effects on mean RT and mean accuracy. Distributional analyses showed that the decline mainly stemmed from inefficient suppression rather than from stronger incorrect responses. For proactive control, older adults showed comparable proactive conflict resolution to young adults on mean RT and mean accuracy. Distributional analyses showed that older adults were as effective as younger adults in adjusting their responses based on congruency proportion information to minimize automatic response capture and actively suppress the direct response activation. The results suggest that older adults were less proficient at suppressing interference after conflict was detected but can anticipate and prevent inference in response to congruency proportion manipulation. These results challenge earlier views that older adults have selective deficits in proactive control but intact reactive control.

Interference Resolution in Emotional Working Memory as a Function of Alexithymia.

PubMed

Colligan, Sean M; Koven, Nancy S

2015-01-01

Although alexithymia is recognized as a set of traitlike deficits in emotion processing, research suggests there are concomitant cognitive issues as well, including what appears to be an unusual pattern of enhanced working memory (WM) despite broader executive dysfunction. It is unknown whether this enhancement includes the executive elements of WM and whether executive control of WM in alexithymia differs for emotional and neutral stimuli. This study examined how alexithymia moderates patterns of interference resolution in WM with valenced and nonvalenced stimuli. Participants (N = 93) completed the Toronto Alexithymia Scale and a recency probes WM task containing positive, negative, and neutral stimuli, with some trials containing proactive interference from previous trials. The reaction time difference between interference and noninterference trials indexed degree of interference resolution. Toronto Alexithymia Scale score moderated a within-subject effect such that, when valenced probes were used, there was less proactive interference in the positive relative to negative valence condition; this valence-based interference discrepancy was significant for a subset of highly alexithymic participants. Alexithymia did not moderate proactive interference to negative or neutral stimuli or accuracy of responses. These results suggest that, although alexithymia does not influence executive control in WM for nonemotional items, alexithymic people demonstrate an idiosyncratic response to positive stimuli that might indicate blunted reactivity.

The Role of Test Expectancy in the Build-Up of Proactive Interference in Long-Term Memory

ERIC Educational Resources Information Center

Weinstein, Yana; Gilmore, Adrian W.; Szpunar, Karl K.; McDermott, Kathleen B.

2014-01-01

We examined the hypothesis that interpolated testing in a multiple list paradigm protects against proactive interference by sustaining test expectancy during encoding. In both experiments, recall on the last of 5 word lists was compared between 4 conditions: a tested group who had taken tests on all previous lists, an untested group who had not…

Focusing the Search: Proactive and Retroactive Interference and the Dynamics of Free Recall

ERIC Educational Resources Information Center

Unsworth, Nash; Brewer, Gene A.; Spillers, Gregory J.

2013-01-01

Targeting information in long-term memory is an important cognitive ability, but one that is not well understood. In this study, 4 experiments were conducted to examine the influence of proactive and retroactive interference on memory targeting. Participants were given either 1 or 2 lists and asked to recall List 1, List 2, or in some cases both…

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

PubMed

Hogge, Michaël; Adam, Stéphane; Collette, Fabienne

2008-07-01

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.

Delayed Release from Proactive Interference with Meaningful Material: How Much Do We Remember After Reading Brief Prose Passages?

ERIC Educational Resources Information Center

Blumenthal, Gary B.; Robbins, Donald

1977-01-01

Three experiments were conducted, investigating the buildup of and the release from proactive interference, in which the stimulus materials were brief prose passages about specific topics. Each passage was followed by a multiple-choice test, and then a final test on all the passages read was given. Implications of the data for standardized tests…

Evidence for decay in verbal short-term memory: a commentary on Berman, Jonides, and Lewis (2009).

PubMed

Campoy, Guillermo

2012-07-01

M. G. Berman, J. Jonides, and R. L. Lewis (2009) adapted the recent-probes task to investigate the causes of forgetting in short-term memory. In 7 experiments, they studied the persistence of memory traces by assessing the level of proactive interference generated by previous-trial items over a range of intertrial intervals. None of the experiments found a reduction in proactive interference over time, which they interpreted as evidence against time-based decay. However, it is possible that decay actually occurred over a shorter time period than was tested in this study, wherein the shortest decay interval was 3,300 ms. By reducing the time scale, the 2 experiments reported in the current commentary revealed a sharp decrease in proactive interference over time, with this reduction reaching a plateau in less than 3 s. This pattern suggests that decay operates in the early stages, whereas subsequent forgetting is likely to be due to interference. 2012 APA, all rights reserved

Understanding the Transfer Deficit: Contextual Mismatch, Proactive Interference, and Working Memory Affect Toddlers' Video-Based Transfer.

PubMed

Choi, Koeun; Kirkorian, Heather L; Pempek, Tiffany A

2017-04-17

Researchers tested the impact of contextual mismatch, proactive interference, and working memory (WM) on toddlers' transfer across contexts. Forty-two toddlers (27-34 months) completed four object-retrieval trials, requiring memory updating on Trials 2-4. Participants watched hiding events on a tablet computer. Search performance was tested using another tablet (match) or a felt board (mismatch). WM was assessed. On earlier search trials, WM predicted transfer in both conditions, and toddlers in the match condition outperformed those in the mismatch condition; however, the benefit of contextual match and WM decreased over trials. Contextual match apparently increased proactive interference on later trials. Findings are interpreted within existing accounts of the transfer deficit, and a combined account is proposed. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

Inhibition, interference, and conflict in task switching.

PubMed

Costa, Russell E; Friedrich, Frances J

2012-12-01

The role of inhibition in the task-switching process has received increased empirical and theoretical attention in the literature on cognitive control. Many accounts have suggested that inhibition occurs when a conflict must be resolved-for example, when a target stimulus contains features of more than one task. In the two experiments reported here, we used variants of backward inhibition, or N - 2 repetition, designs to examine (1) whether inhibition occurs in the absence of conflict at the stimulus or response level, (2) when in the task-switching process such inhibition may occur, and (3) the potential consequences of inhibition. In Experiment 1, we demonstrate that neither stimulus- nor response-level conflict is necessary for inhibition to occur, while the results of Experiment 2 suggest that inhibition may be associated with a reduction of proactive interference (PI) from a previously performed task. Evidence of inhibition and the reduction of PI both occurred at the task-set level. However, inhibition of specific stimulus values can also occur, but this is clearly separable from task-set inhibition. Both experiments also provided evidence that task-set inhibition can be applied at the time of the new task cue, as opposed to at the onset of the target or at the response stage of the trial. Taken together, the results from these experiments provide insight into when and where in the task-switching process inhibition may occur, as well as into the potential functional benefits that inhibition of task sets may provide.

Proactive Time-Rearrangement Scheme for Multi-Radio Collocated Platform

NASA Astrophysics Data System (ADS)

Kim, Chul; Shin, Sang-Heon; Park, Sang Kyu

We present a simple proactive time rearrangement scheme (PATRA) that reduces the interferences from multi-radio devices equipped in one platform and guarantees user-conceived QoS. Simulation results show that the interference among multiple radios in one platform causes severe performance degradation and cannot guarantee the user requested QoS. However, the PATRA can dramatically improve not only the userconceived QoS but also the overall network throughput.

Evidence for selective inhibitory impairment in individuals with autism spectrum disorder.

PubMed

Christ, Shawn E; Kester, Lindsay E; Bodner, Kimberly E; Miles, Judith H

2011-11-01

The social and communicative challenges faced by individuals with autism spectrum disorder (ASD) are often compounded by additional difficulties with executive function. It remains unclear, however, to what the extent individuals with ASD experienced impairment in inhibitory control. The objective of the present study was to assess the three main subtypes of executive inhibitory control within a single ASD sample thus providing new insight into the unique ASD-related pattern of sparing and impairment observed across different aspects of inhibitory control. A sample of 28 children with ASD (mean age = 13.1 years) and a comparison group of 49 neurologically uncompromised children (mean age = 13.3 years) participated. A prepotent response inhibition task, a flanker visual filtering task, and a proactive interference memory task were used to evaluate prepotent response inhibition, resistance to distracter interference, and resistance to proactive interference, respectively. After accounting for individual differences in noninhibition abilities (e.g., processing speed) and overall level of functioning, there was no evidence of group-related differences in inhibitory performance on the prepotent response inhibition test or proactive interference test. ASD-related impairments in inhibitory control were evident, however, on the flanker visual filtering task. Taken together, the present findings indicate that ASD is associated with impairments in some, but not all, aspects of inhibitory control. Individuals with ASD appear to have difficulty ignoring distracting visual information, but prepotent response inhibition and resistance to proactive interference are relatively intact. The current findings also provide support for a multitype model of inhibitory control.

Testing protects against proactive interference in face-name learning.

PubMed

Weinstein, Yana; McDermott, Kathleen B; Szpunar, Karl K

2011-06-01

Learning face-name pairings at a social function becomes increasingly more difficult the more individuals one meets. This phenomenon is attributable to proactive interference--the negative influence of prior learning on subsequent learning. Recent evidence suggests that taking a memory test can alleviate proactive interference in verbal list learning paradigms. We apply this technique to face-name pair learning. Participants studied four lists of 12 face-name pairings and either attempted to name the 12 faces just studied after every list or did not. Recall attempts after every list improved learning of the fourth list by over 100%. Moreover, no reduction in learning of face-name pairings occurred from list 1 to list 4 for participants who attempted to name studied faces between lists. These results suggest that testing oneself on the names of a group of new acquaintances before moving on to the next group is an effective mnemonic technique for social functions.

The specific role of inhibition in reading comprehension in good and poor comprehenders.

PubMed

Borella, Erika; Carretti, Barbara; Pelegrina, Santiago

2010-01-01

Difficulties in inhibitory processes have been shown to characterize the performance of poor comprehenders. However, the inhibitory inefficiency of poor comprehenders is most often assessed by their resistance to proactive interference, that is, the ability to suppress off-goal task information from working memory (WM). In two studies tasks assessing resistance to proactive interference (intrusion errors), response to distracters (Text With Distracters task) and prepotent response inhibition (Stroop and Hayling tests), along with WM measures, were administered to children aged 10 to 11, both good and poor comprehenders. The aim of the study was to specifically determine whether general or specific inhibitory factors affect poor comprehenders' reading difficulties. Results showed that poor comprehenders, compared to good ones, are impaired in WM tasks and in inhibitory tasks that assess resistance to proactive interference. This suggests that reading comprehension difficulties of poor comprehenders are related to specific inhibitory problems.

Escaping the recent past: Which stimulus dimensions influence proactive interference?

PubMed Central

Craig, Kimberly S.; Berman, Marc G.; Jonides, John; Lustig, Cindy

2013-01-01

Proactive interference occurs when information from the past disrupts current processing and is a major source of confusion and errors in short-term memory (Wickens, Born & Allen, 1963). The present investigation examines potential boundary conditions for interference, testing the hypothesis that potential competitors must be similar along task-relevant dimensions to influence proactive interference effects. We manipulated both the type of task being completed (Experiments 1, 2 and 3) and dimensions of similarity irrelevant to the current task (Experiments 4 and 5) to determine how the recent presentation of a probe item would affect the speed with which participants could reject that item. Experiments 1, 2 and 3 contrasted short-term memory judgments, which require temporal information, with semantic and perceptual judgments, for which temporal information is irrelevant. In Experiments 4 and 5, task-irrelevant information (perceptual similarity) was manipulated within the recent probes task. We found that interference from past items affected short-term memory (STM) task performance but did not affect performance in semantic or perceptual judgment tasks. Conversely, similarity along a nominally-irrelevant perceptual dimension did not affect the magnitude of interference in STM tasks. Results are consistent with the view that items in STM are represented by noisy codes consisting of multiple dimensions, and that interference occurs when items are similar to each other and thus compete along the dimensions relevant to target selection. PMID:23297049

Escaping the recent past: which stimulus dimensions influence proactive interference?

PubMed

Craig, Kimberly S; Berman, Marc G; Jonides, John; Lustig, Cindy

2013-07-01

Proactive interference occurs when information from the past disrupts current processing and is a major source of confusion and errors in short-term memory (STM; Wickens, Born, & Allen, Journal of Verbal Learning and Verbal Behavior, 2:440-445, 1963). The present investigation examines potential boundary conditions for interference, testing the hypothesis that potential competitors must be similar along task-relevant dimensions to influence proactive interference effects. We manipulated both the type of task being completed (Experiments 1, 2, and 3) and dimensions of similarity irrelevant to the current task (Experiments 4 and 5) to determine how the recent presentation of a probe item would affect the speed with which participants could reject that item. Experiments 1, 2, and 3 contrasted STM judgments, which require temporal information, with semantic and perceptual judgments, for which temporal information is irrelevant. In Experiments 4 and 5, task-irrelevant information (perceptual similarity) was manipulated within the recent probes task. We found that interference from past items affected STM task performance but did not affect performance in semantic or perceptual judgment tasks. Conversely, similarity along a nominally irrelevant perceptual dimension did not affect the magnitude of interference in STM tasks. Results are consistent with the view that items in STM are represented by noisy codes consisting of multiple dimensions and that interference occurs when items are similar to each other and, thus, compete along the dimensions relevant to target selection.

Failure to Recover from Proactive Semantic Interference and Abnormal Limbic Connectivity in Asymptomatic, Middle-Aged Offspring of Patients with Late-Onset Alzheimer's Disease.

PubMed

Sánchez, Stella M; Abulafia, Carolina; Duarte-Abritta, Barbara; de Guevara, M Soledad Ladrón; Castro, Mariana N; Drucaroff, Lucas; Sevlever, Gustavo; Nemeroff, Charles B; Vigo, Daniel E; Loewenstein, David A; Villarreal, Mirta F; Guinjoan, Salvador M

2017-01-01

We have obtained previous evidence of limbic dysfunction in middle-aged, asymptomatic offspring of late-onset Alzheimer's disease (LOAD) patients, and failure to recover from proactive semantic interference has been shown to be a sensitive cognitive test in other groups at risk for LOAD. To assess the effects of specific proactive semantic interference deficits as they relate to functional magnetic resonance imaging (fMRI) neocortical and limbic functional connectivity in middle aged offspring of individuals with LOAD (O-LOAD) and age-equivalent controls. We examined 21 O-LOAD and 20 controls without family history of neurodegenerative disorders (CS) on traditional measures of cognitive functioning and the LASSI-L, a novel semantic interference test uniquely sensitive to the failure to recover from proactive interference (frPSI). Cognitive tests then were correlated to fMRI connectivity of seeds located in entorhinal cortex and anterodorsal thalamic nuclei among O-LOAD and CS participants. Relative to CS, O-LOAD participants evidenced lower connectivity between entorhinal cortex and orbitofrontal, anterior cingulate, and anterior temporal cortex. In the offspring of LOAD patients, LASSI-L measures of frPSI were inversely associated with connectivity between anterodorsal thalamus and contralateral posterior cingulate. Intrusions on the task related to frPSI were inversely correlated with a widespread connectivity network involving hippocampal, insular, posterior cingulate, and dorsolateral prefrontal cortices, along with precunei and anterior thalamus in this group. Different patterns of connectivity associated with frPSI were observed among controls. The present results suggest that both semantic interference deficits and connectivity abnormalities might reflect limbic circuit dysfunction as a very early clinical signature of LOAD pathology, as previously demonstrated for other limbic phenotypes, such as sleep and circadian alterations.

Schema benefit vs. proactive interference: Contradicting behavioral outcomes and coexisting neural patterns.

PubMed

Oren, Noga; Shapira-Lichter, Irit; Lerner, Yulia; Tarrasch, Ricardo; Hendler, Talma; Giladi, Nir; Ash, Elissa L

2017-09-01

Prior knowledge can either assist or hinder the ability to learn new information. These contradicting behavioral outcomes, referred to as schema benefit and proactive interference respectively, have been studied separately. Here we examined whether the known neural correlates of each process coexist, and how they are influenced by attentional loading and aging. To this end we used an fMRI task that affected both processes simultaneously by presenting pairs of related short movies in succession. The first movie of each pair provided context for the second movie, which could evoke schema benefit and/or proactive interference. Inclusion of an easy or hard secondary task performed during encoding of the movies, as well as testing both younger (22-35y) and older (65-79y) adults, allowed examining the effect of attentional load and older age on the neural patterns associated with context. Analyses focused on three predefined regions and examined how their inter-subject correlation (inter-SC) and functional connectivity (FC) with the hippocampi changed between the first and second movie. The results in the medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC) matched and expanded previous findings: higher inter-SC and lower FC were observed during the second compared to the first movie; yet the differentiation between the first and second movies in these regions was attenuated under high attentional load, pointing to dependency on attentional resources. Instead, at high load there was a significant context effect in the FC of the left ventrolateral prefrontal cortex (vlPFC), and greater FC in the second movie was related to greater proactive interference. Further, older adults showed context effect in the PCC and vlPFC. Intriguingly, older adults with inter-SC mPFC patterns similar to younger adults exhibited schema benefit in our task, while those with inter-SC PCC patterns similar to younger adults showed proactive interference in an independent task. The brain-behavior relationships corroborate the functional significance of these regions and indicate that the mPFC mainly contributes to schema benefit, while the left vlPFC and PCC contribute to proactive interference. Importantly, our findings show that the functions of the regions are retained throughout the lifespan and may predict the predominant behavioral outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

Updating of working memory: lingering bindings.

PubMed

Oberauer, Klaus; Vockenberg, Kerstin

2009-05-01

Three experiments investigated proactive interference and proactive facilitation in a memory-updating paradigm. Participants remembered several letters or spatial patterns, distinguished by their spatial positions, and updated them by new stimuli up to 20 times per trial. Self-paced updating times were shorter when an item previously remembered and then replaced reappeared in the same location than when it reappeared in a different location. This effect demonstrates residual memory for no-longer-relevant bindings of items to locations. The effect increased with the number of items to be remembered. With one exception, updating times did not increase, and recall of final values did not decrease, over successive updating steps, thus providing little evidence for proactive interference building up cumulatively.

Proactive interference from items previously stored in visual working memory.

PubMed

Makovski, Tal; Jiang, Yuhong V

2008-01-01

This study investigates the fate of information that was previously stored in visual working memory but that is no longer needed. Previous research has found inconsistent results, with some showing effective release of irrelevant information and others showing proactive interference. Using change detection tasks of colors or shapes, we show that participants tend to falsely classify a changed item as "no change" if it matches one of the memory items on the preceding trial. The interference is spatially specific: Memory for the preceding trial interferes more if it matches the feature value and the location of a test item than if it does not. Interference results from retaining information in visual working memory, since it is absent when items on the preceding trials are passively viewed, or are attended but not memorized. We conclude that people cannot fully eliminate unwanted visual information from current working memory tasks.

Focusing the search: proactive and retroactive interference and the dynamics of free recall.

PubMed

Unsworth, Nash; Brewer, Gene A; Spillers, Gregory J

2013-11-01

Targeting information in long-term memory is an important cognitive ability, but one that is not well understood. In this study, 4 experiments were conducted to examine the influence of proactive and retroactive interference on memory targeting. Participants were given either 1 or 2 lists and asked to recall List 1, List 2, or in some cases both lists. Multiple dependent measures were explored including the proportion of items recalled, number of intrusions output, and recall latency to arbitrate between 4 extant accounts of memory targeting. In general, recalling either List 1 or List 2 resulted in lower probability of recall, recall of more intrusions, and longer recall latencies compared to when recalling a list alone, suggesting both proactive and retroactive interference. These results suggest that long-term memory targeting is guided by noisy temporal-contextual cues (unless other salient cues are present) that activate both relevant and irrelevant memoranda that are then subjected to a postretrieval monitoring process. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Dissociating interference-control processes between memory and response.

PubMed

Bissett, Patrick G; Nee, Derek Evan; Jonides, John

2009-09-01

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. (c) 2009 APA, all rights reserved.

Individual differences in working memory capacity and search efficiency.

PubMed

Miller, Ashley L; Unsworth, Nash

2018-05-29

In two experiments, we examined how various learning conditions impact the relation between working memory capacity (WMC) and memory search abilities. Experiment 1 employed a delayed free recall task with semantically related words to induce the buildup of proactive interference (PI) and revealed that the buildup of PI differentially impacted recall accuracy and recall latency for low-WMC and high-WMC individuals. Namely, the buildup of PI impaired recall accuracy and slowed recall latency for low-WMC individuals to a greater extent than what was observed for high-WMC individuals. To provide a circumstance in which previously learned information remains relevant over the course of learning, Experiment 2 required participants to complete a multitrial delayed free recall task with unrelated words. Results revealed that with increased practice with the same word list, WMC-related differences were eventually eliminated in interresponse times (IRTs) and recall accuracy, but not recall latency. Thus, despite still accumulating larger search sets, low-WMC individuals searched LTM as efficiently as high-WMC individuals. Collectively, these results are consistent with the notion that under normal free recall conditions, low-WMC individuals search LTM less efficiently than do high-WMC individuals because of their reliance on noisy temporal-contextual cues at retrieval. However, it appears that under conditions in which previously learned items remain relevant at recall, this tendency to rely on vague self-generated retrieval cues can actually facilitate the ability to accurately and quickly recall information.

An Evaluation of Deficits in Semantic Cuing, Proactive and Retroactive Interference as Early Features of Alzheimer’s disease

PubMed Central

Crocco, Elizabeth; Curiel, Rosie E.; Acevedo, Amarilis; Czaja, Sara J.; Loewenstein, David A.

2015-01-01

OBJECTIVE To determine the degree to which susceptibility to different types of semantic interference may reflect the earliest manifestations of early Alzheimer disease (AD) beyond the effects of global memory impairment. METHODS Normal elderly (NE) subjects (n= 47), subjects with amnestic mild cognitive impairment (aMCI: n=34) and 40 subjects with probable AD were evaluated using a unique cued recall paradigm that allowed for an evaluation of both proactive and retroactive interference effects while controlling for global memory impairment (LASSI-L procedure). RESULTS Controlling for overall memory impairment, aMCI subjects had much greater proactive and retroactive interference effects than NE subjects. LASSI-L indices of learning using cued recall evidenced high levels of sensitivity and specificity with an overall correct classification rate of 90%. These provided better discrimination than traditional neuropsychological measures of memory function. CONCLUSION The LASSI-L paradigm is unique and unlike other assessments of memory in that items presented for cued recall are explicitly presented, and semantic interference and cuing effects can be assessed while controlling for initial level of memory impairment. This represents a powerful procedure allowing the participant to serve as his or her own control. The high levels of discrimination between subjects with aMCI and normal cognition that exceeded traditional neuropsychological measures makes the LASSI-L worthy of further research in the detection of early AD. PMID:23768680

The Relations Among Inhibition and Interference Control Functions: A Latent-Variable Analysis

ERIC Educational Resources Information Center

Friedman, Naomi P.; Miyake, Akira

2004-01-01

This study used data from 220 adults to examine the relations among 3 inhibition-related functions. Confirmatory factor analysis suggested that Prepotent Response Inhibition and Resistance to Distractor Interference were closely related, but both were unrelated to Resistance to Proactive Interference. Structural equation modeling, which combined…

The disruptive effects of methamphetamine on delayed-matching-to-sample performance reflect proactive interference and are reduced by SCH23390.

PubMed

Macaskill, Anne C; Harrow, Catherine C; Harper, David N

2015-01-01

Different drugs produce different patterns of impairment on delayed matching-to-sample tasks. For example, (+/-)3,4-methylenedioxymethamphetamine (MDMA) produces an increase in proactive interference. That is, subjects are less accurate when they are required to make a response different to the one they made on the immediately previous trial. The current study assessed whether methamphetamine also produces this particular pattern of disruption in delayed matching-to-sample performance in rats. Methamphetamine primarily reduced accuracy on trials where the correct response differed from the one made on the previous trial. Thus methamphetamine, like MDMA and other stimulant-based drugs of abuse, increased proactive interference. This impairment was reduced by prior administration of the dopamine D1 antagonist SCH23390. These results further extend a general conclusion that a range of stimulant-based drugs may disrupt working memory function indirectly via a tendency to repeat previously made responses and that this disruption is related to D1 receptor activity. Copyright © 2014 Elsevier Inc. All rights reserved.

An evaluation of deficits in semantic cueing and proactive and retroactive interference as early features of Alzheimer's disease.

PubMed

Crocco, Elizabeth; Curiel, Rosie E; Acevedo, Amarilis; Czaja, Sara J; Loewenstein, David A

2014-09-01

To determine the degree to which susceptibility to different types of semantic interference may reflect the initial manifestations of early Alzheimer's disease (AD) beyond the effects of global memory impairment. Normal elderly (NE) subjects (n = 47), subjects with amnestic mild cognitive impairment (aMCI; n = 34), and subjects with probable AD (n = 40) were evaluated by using a unique cued recall paradigm that allowed for evaluation of both proactive and retroactive interference effects while controlling for global memory impairment (i.e., Loewenstein-Acevedo Scales of Semantic Interference and Learning [LASSI-L] procedure). Controlling for overall memory impairment, aMCI subjects had much greater proactive and retroactive interference effects than NE subjects. LASSI-L indices of learning by using cued recall revealed high levels of sensitivity and specificity, with an overall correct classification rate of 90%. These measures provided better discrimination than traditional neuropsychological measures of memory function. The LASSI-L paradigm is unique and unlike other assessments of memory in that items posed for cued recall are explicitly presented, and semantic interference and cueing effects can be assessed while controlling for initial level of memory impairment. This is a powerful procedure that allows the participant to serve as his or her own control. The high levels of discrimination between subjects with aMCI and normal cognition that exceeded traditional neuropsychological measures makes the LASSI-L worthy of further research in the detection of early AD. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Disjunction and conjunction fallacies in episodic memory.

PubMed

Nakamura, K; Brainerd, C J

2017-09-01

It has recently been found that episodic memory displays analogues of the well-known disjunction and conjunction fallacies of probability judgement. The aim of the present research was, for the first time, to study these memory fallacies together under the same conditions, and test theoretical predictions about the reasons for each. The focus was on predictions about the influence of semantic gist, target versus context recollection, and proactive versus retroactive interference. Disjunction and conjunction fallacies increased in conditions in which subjects were able to form semantic connections among list words. In addition, disjunction fallacies were increased by manipulations that minimised proactive interference, whereas conjunction fallacies were increased by manipulations that minimised retroactive interference. That pattern suggests that disjunction fallacies are more dependent on target recollection, whereas conjunction fallacies are more dependent on context recollection.

Stopping the past from intruding the present: Social anxiety disorder and proactive interference.

PubMed

Moore, Harry T A; Gómez-Ariza, Carlos J; Garcia-Lopez, Luis-Joaquín

2016-04-30

It has recently been suggested that social anxiety disorder (SAD) entails a deficit in downregulating unwanted (even non-threatening) memories. In the present study we test this hypothesis by comparing a sample of young adults diagnosed with SAD and healthy controls in their ability to resist proactive interference in a working memory task. Where participants performed similarly in the control condition of the memory task, participants with SAD were more susceptible to interference in the experimental condition than the healthy controls. This finding is in line with previous studies that show anxiety to be associated with impoverished executive control and, specifically, suggests that SAD entails a reduced ability to get rid of interfering memories. Clinical implications are discussed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Consolidation through the looking-glass: sleep-dependent proactive interference on visuomotor adaptation in children.

PubMed

Urbain, Charline; Houyoux, Emeline; Albouy, Geneviève; Peigneux, Philippe

2014-02-01

Although a beneficial role of post-training sleep for declarative memory has been consistently evidenced in children, as in adults, available data suggest that procedural memory consolidation does not benefit from sleep in children. However, besides the absence of performance gains in children, sleep-dependent plasticity processes involved in procedural memory consolidation might be expressed through differential interference effects on the learning of novel but related procedural material. To test this hypothesis, 32 10-12-year-old children were trained on a motor rotation adaptation task. After either a sleep or a wake period, they were first retested on the same rotation applied at learning, thus assessing offline sleep-dependent changes in performance, then on the opposite (unlearned) rotation to assess sleep-dependent modulations in proactive interference coming from the consolidated visuomotor memory trace. Results show that children gradually improve performance over the learning session, showing effective adaptation to the imposed rotation. In line with previous findings, no sleep-dependent changes in performance were observed for the learned rotation. However, presentation of the opposite, unlearned deviation elicited significantly higher interference effects after post-training sleep than wakefulness in children. Considering that a definite feature of procedural motor memory and skill acquisition is the implementation of highly automatized motor behaviour, thus lacking flexibility, our results suggest a better integration and/or automation or motor adaptation skills after post-training sleep, eventually resulting in higher proactive interference effects on untrained material. © 2013 European Sleep Research Society.

Stroop proactive control and task conflict are modulated by concurrent working memory load.

PubMed

Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai; Davelaar, Eddy J; Usher, Marius

2015-06-01

Performance on the Stroop task reflects two types of conflict-informational (between the incongruent word and font color) and task (between the contextually relevant color-naming task and the irrelevant, but automatic, word-reading task). According to the dual mechanisms of control theory (DMC; Braver, 2012), variability in Stroop performance can result from variability in the deployment of a proactive task-demand control mechanism. Previous research has shown that when proactive control (PC) is diminished, both increased Stroop interference and a reversed Stroop facilitation (RF) are observed. Although the current DMC model accounts for the former effect, it does not predict the observed RF, which is considered to be behavioral evidence for task conflict in the Stroop task. Here we expanded the DMC model to account for Stroop RF. Assuming that a concurrent working memory (WM) task reduces PC, we predicted both increased interference and an RF. Nineteen participants performed a standard Stroop task combined with a concurrent n-back task, which was aimed at reducing available WM resources, and thus overloading PC. Although the results indicated common Stroop interference and facilitation in the low-load condition (zero-back), in the high-load condition (two-back), both increased Stroop interference and RF were observed, consistent with the model's prediction. These findings indicate that PC is modulated by concurrent WM load and serves as a common control mechanism for both informational and task Stroop conflicts.

Impaired inhibition of proactive interference in abstinent individuals with alcoholism.

PubMed

Noël, Xavier; Billieux, Joël; Van der Linden, Martial; Dan, Bernard; Hanak, Catherine; de Bournonville, Stéphanie; Baurain, Céline; Verbanck, Paul

2009-01-01

Cognitive impairment has been associated with higher risk of alcoholism and relapse. Recent theoretical refinements have separated inhibition of dominant response and inhibition of proactive interference. We assessed the latter using a directed-forgetting procedure in 38 recently detoxified individuals with alcoholism and in 26 controls. On this task, memory performance of letter trigrams was compared when presented alone, followed by a second trigram to be recalled, then a second trigram to be forgotten (directed-forgetting condition). Individuals with alcoholism recalled more letters to be forgotten and performed worse than controls in the directed-forgetting condition, which significantly correlated with the duration of alcoholism.

The Dynamics and Neural Correlates of Audio-Visual Integration Capacity as Determined by Temporal Unpredictability, Proactive Interference, and SOA.

PubMed

Wilbiks, Jonathan M P; Dyson, Benjamin J

2016-01-01

Over 5 experiments, we challenge the idea that the capacity of audio-visual integration need be fixed at 1 item. We observe that the conditions under which audio-visual integration is most likely to exceed 1 occur when stimulus change operates at a slow rather than fast rate of presentation and when the task is of intermediate difficulty such as when low levels of proactive interference (3 rather than 8 interfering visual presentations) are combined with the temporal unpredictability of the critical frame (Experiment 2), or, high levels of proactive interference are combined with the temporal predictability of the critical frame (Experiment 4). Neural data suggest that capacity might also be determined by the quality of perceptual information entering working memory. Experiment 5 supported the proposition that audio-visual integration was at play during the previous experiments. The data are consistent with the dynamic nature usually associated with cross-modal binding, and while audio-visual integration capacity likely cannot exceed uni-modal capacity estimates, performance may be better than being able to associate only one visual stimulus with one auditory stimulus.

The Dynamics and Neural Correlates of Audio-Visual Integration Capacity as Determined by Temporal Unpredictability, Proactive Interference, and SOA

PubMed Central

Wilbiks, Jonathan M. P.; Dyson, Benjamin J.

2016-01-01

Over 5 experiments, we challenge the idea that the capacity of audio-visual integration need be fixed at 1 item. We observe that the conditions under which audio-visual integration is most likely to exceed 1 occur when stimulus change operates at a slow rather than fast rate of presentation and when the task is of intermediate difficulty such as when low levels of proactive interference (3 rather than 8 interfering visual presentations) are combined with the temporal unpredictability of the critical frame (Experiment 2), or, high levels of proactive interference are combined with the temporal predictability of the critical frame (Experiment 4). Neural data suggest that capacity might also be determined by the quality of perceptual information entering working memory. Experiment 5 supported the proposition that audio-visual integration was at play during the previous experiments. The data are consistent with the dynamic nature usually associated with cross-modal binding, and while audio-visual integration capacity likely cannot exceed uni-modal capacity estimates, performance may be better than being able to associate only one visual stimulus with one auditory stimulus. PMID:27977790

Control of interference during working memory updating.

PubMed

Szmalec, Arnaud; Verbruggen, Frederick; Vandierendonck, André; Kemps, Eva

2011-02-01

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. (c) 2010 APA, all rights reserved.

Comparing cognition by integrating concept learning, proactive interference, and list memory.

PubMed

Wright, Anthony A; Kelly, Debbie M; Katz, Jeffrey S

2018-06-01

This article describes an approach for training a variety of species to learn the abstract concept of same/different, which in turn forms the basis for testing proactive interference and list memory. The stimulus set for concept-learning training was progressively doubled from 8, 16, 32, 64, 128 . . . to 1,024 different pictures with novel-stimulus transfer following learning. All species fully learned the same/different abstract concept: capuchin and rhesus monkeys learned more readily than pigeons; nutcrackers and magpies were at least equivalent to monkeys and transferred somewhat better following initial training sets. A similar task using the 1,024-picture set plus delays was used to test proactive interference on occasional trials. Pigeons revealed greater interference with 10-s than with 1-s delays, whereas delay time had no effect on rhesus monkeys, suggesting that the monkeys' interference was event based. This same single-item same/different task was expanded to a 4-item list memory task to test animal list memory. Humans were tested similarly with lists of kaleidoscope pictures. Delays between the list and test were manipulated, resulting in strong initial recency effects (i.e., strong 4th-item memory) at short delays and changing to a strong primacy effect (i.e., strong 1st-item memory) at long delays (pigeons 0-s to 10-s delays; monkeys 0-s to 30-s delays; humans 0-s to 100-s delays). Results and findings are discussed in terms of these species' cognition and memory comparisons, evolutionary implications, and future directions for testing other species in these synergistically related tasks.

Dynamical coupled-channels study of {pi}N {right arrow} {pi pi}N reactions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamano, H.; Julia-Diaz, B.; Lee, T.-S. H.

As a step toward performing a complete coupled-channels analysis of the world data of {pi}N,{gamma}*N {yields} {pi}N,{eta}N,{pi}{pi}N reactions, the {pi}N {yields} {pi}{pi}N reactions are investigated starting with the dynamical coupled-channels model developed in Phys. Rev. C 76, 065201 (2007). The channels included are {pi}N,{eta}N, and {pi}{pi}N which has {pi}{Delta},{rho}N, and {sigma}N resonant components. The nonresonant amplitudes are generated from solving a set of coupled-channels equations with the meson-baryon potentials defined by effective Lagrangians. The resonant amplitudes are generated from 16 bare excited nucleon (N*) states that are dressed by the nonresonant interactions as constrained by the unitarity condition. The datamore » of total cross sections and {pi}N and {pi}{pi} invariant mass distributions of {pi} + p {yields} {pi} + {pi} + n, {pi} + {pi}0p and {pi} - p {yields} {pi} + {pi} - n, {pi} - {pi}0p,{pi}0{pi}0n reactions from threshold to the invariant mass W = 2 GeV can be described to a very large extent. We show the importance of the coupled-channels effects and the strong interference among the contributions from the {pi}{Delta},{sigma}N, and {rho}N channels. The large interference between the resonant and nonresonant amplitudes is also demonstrated. Possible future developments are discussed.« less

The contribution of disengagement to temporal discriminability.

PubMed

Shipstead, Zach; Nespodzany, Ashley

2018-05-01

The present study examines the idea that time-based forgetting of outdated information can lead to better memory of currently relevant information. This was done using the visual arrays task, along with a between-subjects manipulation of both the retention interval (1 s vs. 4 s) and the time between two trials (1 s vs. 4 s). Consistent with prior work [Shipstead, Z., & Engle, R. W. (2013). Interference within the focus of attention: Working memory tasks reflect more than temporary maintenance. Journal of Experimental Psychology: Learning, Memory, and Cognition, 39, 277-289; Experiment 1], longer retention intervals did not lead to diminished memory of currently relevant information. However, we did find that longer periods of time between two trials improved memory for currently relevant information. This replicates findings that indicate proactive interference affects visual arrays performance and extends previous findings to show that reduction of proactive interference can occur in a time-dependent manner.

Proactive transfer of learning depends on the evolution of prior learned task in memory.

PubMed

Tallet, Jessica; Kostrubiec, Viviane; Zanone, Pier-Giorgio

2010-06-01

The aim of the present study was to investigate the processes underlying the proactive interference effect using bimanual coordination. Our rationale was that interference would only occur when the prior learned A coordination pattern enters in competition with the required subsequent B pattern. We hypothesized that competition would arise only if the A pattern persists in memory before introducing the B pattern. In the experimental group, both A and B patterns were practiced and recalled, whereas in the control group only the B pattern was practiced and recalled. In Experiment 1, which involved initially bistable participants, the persistence of the A pattern led to interference, while, surprisingly, the A pattern forgetting entailed facilitation. In Experiment 2, which involved initially tristable participants, no such transfer effect was found. The apparently contradictory results can be interpreted coherently in the light of dynamical principles of learning. (c) 2010 Elsevier B.V. All rights reserved.

Dynamical coupled-channels study of {pi}N{yields}{pi}{pi}N reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamano, H.; Julia-Diaz, B.; Department d'Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona E-08028 Barcelona

As a step toward performing a complete coupled-channels analysis of the world data of {pi}N,{gamma}*N{yields}{pi}N,{eta}N,{pi}{pi}N reactions, the {pi}N{yields}{pi}{pi}N reactions are investigated starting with the dynamical coupled-channels model developed in Phys. Rev. C 76, 065201 (2007). The channels included are {pi}N,{eta}N, and {pi}{pi}N which has {pi}{delta},{rho}N, and {sigma}N resonant components. The nonresonant amplitudes are generated from solving a set of coupled-channels equations with the meson-baryon potentials defined by effective Lagrangians. The resonant amplitudes are generated from 16 bare excited nucleon (N*) states that are dressed by the nonresonant interactions as constrained by the unitarity condition. The data of total cross sectionsmore » and {pi}N and {pi}{pi} invariant mass distributions of {pi}{sup +}p{yields}{pi}{sup +}{pi}{sup +}n,{pi}{sup +}{pi}{sup 0}p and {pi}{sup -}p{yields}{pi}{sup +}{pi}{sup -}n,{pi}{sup -}{pi}{sup 0}p,{pi}{sup 0}{pi}{sup 0}n reactions from threshold to the invariant mass W=2 GeV can be described to a very large extent. We show the importance of the coupled-channels effects and the strong interference among the contributions from the {pi}{delta},{sigma}N, and {rho}N channels. The large interference between the resonant and nonresonant amplitudes is also demonstrated. Possible future developments are discussed.« less

Playing the computer game Tetris prior to viewing traumatic film material and subsequent intrusive memories: Examining proactive interference.

PubMed

James, Ella L; Lau-Zhu, Alex; Tickle, Hannah; Horsch, Antje; Holmes, Emily A

2016-12-01

Visuospatial working memory (WM) tasks performed concurrently or after an experimental trauma (traumatic film viewing) have been shown to reduce subsequent intrusive memories (concurrent or retroactive interference, respectively). This effect is thought to arise because, during the time window of memory consolidation, the film memory is labile and vulnerable to interference by the WM task. However, it is not known whether tasks before an experimental trauma (i.e. proactive interference) would also be effective. Therefore, we tested if a visuospatial WM task given before a traumatic film reduced intrusions. Findings are relevant to the development of preventative strategies to reduce intrusive memories of trauma for groups who are routinely exposed to trauma (e.g. emergency services personnel) and for whom tasks prior to trauma exposure might be beneficial. Participants were randomly assigned to 1 of 2 conditions. In the Tetris condition (n = 28), participants engaged in the computer game for 11 min immediately before viewing a 12-min traumatic film, whereas those in the Control condition (n = 28) had no task during this period. Intrusive memory frequency was assessed using an intrusion diary over 1-week and an Intrusion Provocation Task at 1-week follow-up. Recognition memory for the film was also assessed at 1-week. Compared to the Control condition, participants in the Tetris condition did not report statistically significant difference in intrusive memories of the trauma film on either measure. There was also no statistically significant difference in recognition memory scores between conditions. The study used an experimental trauma paradigm and findings may not be generalizable to a clinical population. Compared to control, playing Tetris before viewing a trauma film did not lead to a statistically significant reduction in the frequency of later intrusive memories of the film. It is unlikely that proactive interference, at least with this task, effectively influences intrusive memory development. WM tasks administered during or after trauma stimuli, rather than proactively, may be a better focus for intrusive memory amelioration. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The categorical structure of semantic memory for famous people: a new approach using release from proactive interference.

PubMed

Darling, Stephen; Valentine, Tim

2005-05-01

Memory for familiar people is essential to understand their identity and guide social interaction. Nevertheless, we know surprisingly little about the structure of such memory. Previous research has assumed that semantic memory for people has a categorical structure, but recently it was proposed that memory for people consists only of associations and lacks any categorical structure. Four experiments are reported that use a novel approach by adapting the 'release from proactive interference' (RPI) methodology for use with lists of famous names. Proactive interference occurs when items presented on successive trials are drawn from the same category. Recall can improve following a change to a different category. Sets of names were selected relating to aspects previously demonstrated, on the basis of reaction time data, to form a category (occupation) and a property (nationality) of celebrities (Johnston & Bruce, 1990). RPI was observed for a change at both levels of representation but was only present without explicitly cueing the change of set when the stimuli differed at the category level. At the property level, RPI was only evident when change of set was explicitly cued. RPI was absent at the set change in a novel, ad hoc distinction suggesting that the effect reflected the underlying memory structure.

The role of test expectancy in the build-up of proactive interference in long-term memory.

PubMed

Weinstein, Yana; Gilmore, Adrian W; Szpunar, Karl K; McDermott, Kathleen B

2014-07-01

We examined the hypothesis that interpolated testing in a multiple list paradigm protects against proactive interference by sustaining test expectancy during encoding. In both experiments, recall on the last of 5 word lists was compared between 4 conditions: a tested group who had taken tests on all previous lists, an untested group who had not taken any tests on previous lists, and 2 other groups (one tested and the other untested) who were warned about the upcoming test prior to study of the fifth list. In both experiments, the untested/warned group performed significantly better than the untested/unwarned group on both correct recall and prior list intrusions but did not achieve the same recall accuracy as tested groups. In Experiment 2, an instruction manipulation check further narrowed the gap between the untested/warned group and the tested groups. In addition, we verified that a reduction in test expectancy indeed occurred in the untested group compared with the tested group by asking participants to indicate how likely they believed they were to receive a test on each studied list. These findings suggest that testing protects against proactive interference largely via attentional processes and/or more effective encoding. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Rendezvous Protocols and Dynamic Frequency Hopping Interference Design for Anti-Jamming Satellite Communication

DTIC Science & Technology

2013-11-25

previously considered this proactive approach to combat unintentional, persistent (non- reactive) interference . In this project, we plan on extending our...channel” (or code ) by chance, through public knowledge of the underlying protocol semantics , or by compromising one of the network devices. An alternative...AFRL-RV-PS- AFRL-RV-PS- TR-2013-0142 TR-2013-0142 RENDEZVOUS PROTOCOLS AND DYNAMIC FREQUENCY HOPPING INTERFERENCE DESIGN FOR ANTI-JAMMING

Differential item functioning of the patient-reported outcomes information system (PROMIS®) pain interference item bank by language (Spanish versus English).

PubMed

Paz, Sylvia H; Spritzer, Karen L; Reise, Steven P; Hays, Ron D

2017-06-01

About 70% of Latinos, 5 years old or older, in the United States speak Spanish at home. Measurement equivalence of the PROMIS ® pain interference (PI) item bank by language of administration (English versus Spanish) has not been evaluated. A sample of 527 adult Spanish-speaking Latinos completed the Spanish version of the 41-item PROMIS ® pain interference item bank. We evaluate dimensionality, monotonicity and local independence of the Spanish-language items. Then we evaluate differential item functioning (DIF) using ordinal logistic regression with item response theory scores estimated from DIF-free "anchor" items. One of the 41 items in the Spanish version of the PROMIS ® PI item bank was identified as having significant uniform DIF. English- and Spanish-speaking subjects with the same level of pain interference responded differently to 1 of the 41 items in the PROMIS ® PI item bank. This item was not retained due to proprietary issues. The original English language item parameters can be used when estimating PROMIS ® PI scores.

The Auditory Verbal Learning Test (Rey AVLT): An Arabic Version

ERIC Educational Resources Information Center

Sharoni, Varda; Natur, Nazeh

2014-01-01

The goals of this study were to adapt the Rey Auditory Verbal Learning Test (AVLT) into Arabic, to compare recall functioning among age groups (6:0 to 17:11), and to compare gender differences on various memory dimensions (immediate and delayed recall, learning rate, recognition, proactive interferences, and retroactive interferences). This…

An Individual Differences Analysis of Memory Control

ERIC Educational Resources Information Center

Salthouse, Timothy A.; Siedlecki, Karen L.; Krueger, Lacy E.

2006-01-01

Performance on a wide variety of memory tasks can be hypothesized to be influenced by processes associated with controlling the contents of memory. In this project 328 adults ranging from 18 to 93 years of age performed six tasks (e.g., multiple trial recall with an interpolated interference list, directed forgetting, proactive interference, and…

Proactive Semantic Interference is Associated with Total and Regional Abnormal Amyloid Load in Non-Demented Community-Dwelling Elders: A Preliminary Study.

PubMed

Loewenstein, David A; Greig, Maria T; Curiel, Rosie; Rodriguez, Rosemarie; Wicklund, Meredith; Barker, Warren W; Hidalgo, Jacqueline; Rosado, Marian; Duara, Ranjan

2015-12-01

To evaluate the relationship between susceptibility to proactive semantic interference (PSI) and retroactive semantic interference (RSI) and brain amyloid load in non-demented elders. 27 participants (11 cognitively normal [CN] with subjective memory complaints, 8 CN without memory complaints, and 8 with mild cognitive impairment [MCI]) underwent complete neurological and neuropsychological evaluations. Participants also received the Semantic Interference Test (SIT) and AV-45 amyloid PET imaging. High levels of association were present between total amyloid load, regional amyloid levels, and the PSI measure (in the entire sample and a subsample excluding MCI subjects). RSI and other memory measures showed much weaker associations or no associations with total and regional amyloid load. No associations between amyloid levels and non-memory performance were observed. In non-demented individuals, vulnerability to PSI was highly associated with total and regional beta-amyloid load and may be an early cognitive marker of brain pathology. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Development and evaluation of the PI-G: a three-scale measure based on the German translation of the PROMIS ® pain interference item bank.

PubMed

Farin, Erik; Nagl, Michaela; Gramm, Lukas; Heyduck, Katja; Glattacker, Manuela

2014-05-01

Study aim was to translate the PROMIS(®) pain interference (PI) item bank (41 items) into German, test its psychometric properties in patients with chronic low back pain and develop static subforms. We surveyed N = 262 patients undergoing rehabilitation who were asked to fill out questionnaires at the beginning and 2 weeks after the end of rehabilitation, applying the Oswestry Disability Index (ODI) and Pain Disability Index (PDI) in addition to the PROMIS(®) PI items. For psychometric testing, a 1-parameter item response theory (IRT) model was used. Exploratory and confirmatory factor analyses as well as reliability and construct validity analyses were conducted. The assumptions regarding IRT scaling of the translated PROMIS(®) PI item bank as a whole were not confirmed. However, we succeeded in devising three static subforms (PI-G scales: PI mental 13 items, PI functional 11 items, PI physical 4 items), revealing good psychometric properties. The PI-G scales in their static form can be recommended for use in German-speaking countries. Their strengths versus the ODI and PDI are that pain interference is assessed in a differentiated manner and that several psychometric values are somewhat better than those associated with the ODI and PDI (distribution properties, IRT model fit, reliability). To develop an IRT-scaled item bank of the German translations of the PROMIS(®) PI items, it would be useful to have additional studies (e.g., with larger sample sizes and using a 2-parameter IRT model).

Event-related potential evidence for separable automatic and controlled retrieval processes in proactive interference.

PubMed

Bergström, Zara M; O'Connor, Richard J; Li, Martin K-H; Simons, Jon S

2012-05-21

Interference between competing memories is a major source of retrieval failure, yet, surprisingly little is known about how competitive memory activation arises in the brain. One possibility is that interference during episodic retrieval might be produced by relatively automatic conceptual priming mechanisms that are independent of strategic retrieval processes. Such priming-driven interference might occur when the competing memories have strong pre-existing associations to the retrieval cue. We used ERPs to measure the neural dynamics of retrieval competition, and investigated whether the ERP correlates of interference were affected by varying task demands for selective retrieval. Participants encoded cue words that were presented either two or four times, paired either with the same or different strongly associated words across repetitions. In a subsequent test, participants either selectively recalled each cue's most recent associate, or simply judged how many times a cue had been presented, without requiring selective recall. Interference effects on test performance were only seen in the recall task. In contrast, ERPs during test revealed an early posterior positivity for high interference items that was present in both retrieval tasks. This early ERP effect likely reflects a conceptual priming-related N400 reduction when many associations to a cue were pre-activated. A later parietal positivity resembling the ERP correlate of conscious recollection was found only in the recall task. The results suggest that early effects of proactive interference are relatively automatic and independent of intentional retrieval processes, consistent with suggestions that interference can arise through conceptual priming. Copyright © 2012 Elsevier B.V. All rights reserved.

The Effect of Modality Shifts on Practive Interference in Long-Term Memory.

ERIC Educational Resources Information Center

Dean, Raymond S.; And Others

1983-01-01

In experiment one, subjects learned a word list in blocked or random forms of auditory/visual change. In experiment two, high- and low-conceptual rigid subjects read passages in shift conditions or nonshift, exclusively in auditory or visual modes. A shift in modality provided a powerful release from proactive interference. (Author/CM)

An Integrated Model of Cognitive Control in Task Switching

ERIC Educational Resources Information Center

Altmann, Erik M.; Gray, Wayne D.

2008-01-01

A model of cognitive control in task switching is developed in which controlled performance depends on the system maintaining access to a code in episodic memory representing the most recently cued task. The main constraint on access to the current task code is proactive interference from old task codes. This interference and the mechanisms that…

Changing room cues reduces the effects of proactive interference in Clark's Nutcrackers, Nucifraga columbiana.

PubMed

Lewis, Jody L; Kamil, Alan C; Webbink, Kate E

2013-04-01

To determine what factors are important for minimizing interference effects in spatial memory, Clark's Nutcrackers, Nucifraga columbiana were tested for their spatial memory for two serial lists of locations per day. In this experiment two unique landmark sets were either different between List 1 and List 2 or the same. We found that Nutcrackers were most susceptible to interference when the landmark sets were the same. This study suggests that repeatedly testing animal memory in the same room, with the same cues, can hamper recall due to interference.

Paradoxical effects of testing: retrieval enhances both accurate recall and suggestibility in eyewitnesses.

PubMed

Chan, Jason C K; Langley, Moses M

2011-01-01

Although retrieval practice typically enhances memory retention, it can also impair subsequent eyewitness memory accuracy (Chan, Thomas, & Bulevich, 2009). Specifically, participants who had taken an initial test about a witnessed event were more likely than nontested participants to recall subsequently encountered misinformation—an effect we called retrieval-enhanced suggestibility (RES). Here, we sought to test the generality of RES and to further elucidate its underlying mechanisms. To that end, we tested a dual mechanism account, which suggests that RES occurs because initial testing (a) enhances learning of the later misinformation by reducing proactive interference and (b) causes the reactivated memory trace to be more susceptible to later interference (i.e., a reconsolidation account). Three major findings emerged. First, RES was found after a 1-week delay, where a robust testing benefit occurred for event details that were not contradicted by later misinformation. Second, blockage of reconsolidation was unnecessary for RES to occur. Third, initial testing enhanced learning of the misinformation even when proactive interference played a minimal role.

Modeling age differences in effects of pair repetition and proactive interference using a single parameter.

PubMed

Stephens, Joseph D W; Overman, Amy A

2018-02-01

In this article, we apply the REM model (Shiffrin & Steyvers, 1997) to age differences in associative memory. Using Criss and Shiffrin's (2005) associative version of REM, we show that in a task with pairs repeated across 2 study lists, older adults' reduced benefit of pair repetition can be produced by a general reduction in the diagnosticity of information stored in memory. This reduction can be modeled similarly well by reducing the overall distinctiveness of memory features, or by reducing the accuracy of memory encoding. We report a new experiment in which pairs are repeated across 3 study lists and extend the model accordingly. Finally, we extend the model to previously reported data using the same task paradigm, in which the use of a high-association strategy introduced proactive interference effects in young adults but not older adults. Reducing the diagnosticity of information in memory also reduces the proactive interference effect. Taken together, the modeling and empirical results reported here are consistent with the claim that some age differences that appear to be specific to associative information can be produced via general degradation of information stored in memory. The REM model provides a useful framework for examining age differences in memory as well as harmonizing seemingly conflicting prior modeling approaches for the associative deficit. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Beamforming design with proactive interference cancelation in MISO interference channels

NASA Astrophysics Data System (ADS)

Li, Yang; Tian, Yafei; Yang, Chenyang

2015-12-01

In this paper, we design coordinated beamforming at base stations (BSs) to facilitate interference cancelation at users in interference networks, where each BS is equipped with multiple antennas and each user is with a single antenna. By assuming that each user can select the best decoding strategy to mitigate the interference, either canceling the interference after decoding when it is strong or treating it as noise when it is weak, we optimize the beamforming vectors that maximize the sum rate for the networks under different interference scenarios and find the solutions of beamforming with closed-form expressions. The inherent design principles are then analyzed, and the performance gain over passive interference cancelation is demonstrated through simulations in heterogeneous cellular networks.

Identifying cognitive predictors of reactive and proactive aggression.

PubMed

Brugman, Suzanne; Lobbestael, Jill; Arntz, Arnoud; Cima, Maaike; Schuhmann, Teresa; Dambacher, Franziska; Sack, Alexander T

2015-01-01

The aim of this study was to identify implicit cognitive predictors of aggressive behavior. Specifically, the predictive value of an attentional bias for aggressive stimuli and automatic association of the self and aggression was examined for reactive and proactive aggressive behavior in a non-clinical sample (N = 90). An Emotional Stroop Task was used to measure an attentional bias. With an idiographic Single-Target Implicit Association Test, automatic associations were assessed between words referring to the self (e.g., the participants' name) and words referring to aggression (e.g., fighting). The Taylor Aggression Paradigm (TAP) was used to measure reactive and proactive aggressive behavior. Furthermore, self-reported aggressiveness was assessed with the Reactive Proactive Aggression Questionnaire (RPQ). Results showed that heightened attentional interference for aggressive words significantly predicted more reactive aggression, while lower attentional bias towards aggressive words predicted higher levels of proactive aggression. A stronger self-aggression association resulted in more proactive aggression, but not reactive aggression. Self-reports on aggression did not additionally predict behavioral aggression. This implies that the cognitive tests employed in our study have the potential to discriminate between reactive and proactive aggression. Aggr. Behav. 41:51-64 2015. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Effects of Length of Retention Interval on Proactive Interference in Short-Term Visual Memory

ERIC Educational Resources Information Center

Meudell, Peter R.

1977-01-01

These experiments show two things: (a) In visual memory, long-term interference on a current item from items previously stored only seems to occur when the current item's retention interval is relatively long, and (b) the visual code appears to decay rapidly, reaching asymptote within 3 seconds of input in the presence of an interpolated task.…

Depth of Processing and Interference Effects in the Learning and Remembering of Sentences. Technical Report No. 21.

ERIC Educational Resources Information Center

Kane, Janet Hidde; Anderson, Richard C.

In two experiments, college students who supplied the last words of sentences they read learned more than subjects who simply read whole sentences. This facilitation was observed even with a list of sentences which were almost always completed with the wrong words. However, proactive interference attributable to acquisition errors appeared on…

Encoding Dimensions in Memory: Developmental Similarities at Two Grade Levels

ERIC Educational Resources Information Center

Geis, Mary Fulcher

1975-01-01

Second and sixth grade children's relative sensitivity to acoustic, semantic, and physical dimensions was inferred from the amount of release from proactive interference obtained for shifts along each dimension. (ED)

[Serotonin receptor (5-HTR2A) and dysbindin (DTNBP1) genes and component process variables of short-term verbal memory in schizophrenia].

PubMed

Alfimova, M V; Monakhov, M V; Abramova, L I; Golubev, S A; Golimbet, V E

2009-01-01

An association study of variations in the DTNBP1 (P1763 and P1578) and 5-HTR2A (T102C and A-1438G) genes with short-term verbal memory efficiency and its component process variables was carried out in 405 patients with schizophrenia and 290 healthy controls. All subjects were asked to recall immediately two sets of 10 words. Total recall, List 1 recall, immediate recall or attention span, proactive interference and a number of intrusions were measured. Patients significantly differed from controls by all memory variables. The efficiency of test performance, efficiency of immediate memory, effect of proactive interference as well as number of intrusions were decreased in the group of patients. Both 5-HTR2A polymorphisms were associated with short-term verbal memory efficiency in the combined sample, with the worst performance observed in carriers of homozygous CC (T102C) and GG (A-1438G) genotypes. The significant effect of the P1763 (DTNBP1) marker on the component process variables (proactive interference and intrusions) was found while its effect on the total recall was non-significant. The homozygotes for GG (P1763) had the worst scores. Overall, the data obtained are in line with the conception of DTNBP1 and 5-HTR2A involvement in different component process variables of memory in healthy subjects and patients with schizophrenia.

A Multipath Mitigation Algorithm for vehicle with Smart Antenna

NASA Astrophysics Data System (ADS)

Ji, Jing; Zhang, Jiantong; Chen, Wei; Su, Deliang

2018-01-01

In this paper, the antenna array adaptive method is used to eliminate the multipath interference in the environment of GPS L1 frequency. Combined with the power inversion (PI) algorithm and the minimum variance no distortion response (MVDR) algorithm, the anti-Simulation and verification of the antenna array, and the program into the FPGA, the actual test on the CBD road, the theoretical analysis of the LCMV criteria and PI and MVDR algorithm principles and characteristics of MVDR algorithm to verify anti-multipath interference performance is better than PI algorithm, The satellite navigation in the field of vehicle engineering practice has some guidance and reference.

Task switching in video game players: Benefits of selective attention but not resistance to proactive interference.

PubMed

Karle, James W; Watter, Scott; Shedden, Judith M

2010-05-01

Research into the perceptual and cognitive effects of playing video games is an area of increasing interest for many investigators. Over the past decade, expert video game players (VGPs) have been shown to display superior performance compared to non-video game players (nVGPs) on a range of visuospatial and attentional tasks. A benefit of video game expertise has recently been shown for task switching, suggesting that VGPs also have superior cognitive control abilities compared to nVGPs. In two experiments, we examined which aspects of task switching performance this VGP benefit may be localized to. With minimal trial-to-trial interference from minimally overlapping task set rules, VGPs demonstrated a task switching benefit compared to nVGPs. However, this benefit disappeared when proactive interference between tasks was increased, with substantial stimulus and response overlap in task set rules. We suggest that VGPs have no generalized benefit in task switching-related cognitive control processes compared to nVGPs, with switch cost reductions due instead to a specific benefit in controlling selective attention. Copyright 2009 Elsevier B.V. All rights reserved.

Phosphite, an analog of phosphate, suppresses the coordinated expression of genes under phosphate starvation.

PubMed

Varadarajan, Deepa K; Karthikeyan, Athikkattuvalasu S; Matilda, Paino Durzo; Raghothama, Kashchandra G

2002-07-01

Phosphate (Pi) and its analog phosphite (Phi) are acquired by plants via Pi transporters. Although the uptake and mobility of Phi and Pi are similar, there is no evidence suggesting that plants can utilize Phi as a sole source of phosphorus. Phi is also known to interfere with many of the Pi starvation responses in plants and yeast (Saccharomyces cerevisiae). In this study, effects of Phi on plant growth and coordinated expression of genes induced by Pi starvation were analyzed. Phi suppressed many of the Pi starvation responses that are commonly observed in plants. Enhanced root growth and root to shoot ratio, a hallmark of Pi stress response, was strongly inhibited by Phi. The negative effects of Phi were not obvious in plants supplemented with Pi. The expression of Pi starvation-induced genes such as LePT1, LePT2, AtPT1, and AtPT2 (high-affinity Pi transporters); LePS2 (a novel acid phosphatase); LePS3 and TPSI1 (novel genes); and PAP1 (purple acid phosphatase) was suppressed by Phi in plants and cell cultures. Expression of luciferase reporter gene driven by the Pi starvation-induced AtPT2 promoter was also suppressed by Phi. These analyses showed that suppression of Pi starvation-induced genes is an early response to addition of Phi. These data also provide evidence that Phi interferes with gene expression at the level of transcription. Synchronized suppression of multiple Pi starvation-induced genes by Phi points to its action on the early molecular events, probably signal transduction, in Pi starvation response.

Protecting Ideas: Ethical and Legal Considerations When a Grant's Principal Investigator Changes.

PubMed

Koniaris, Leonidas G; Coombs, Mary I; Meslin, Eric M; Zimmers, Teresa A

2016-08-01

Ethical issues related the responsible conduct of research involve questions concerning the rights and obligations of investigators to propose, design, implement, and publish research. When a principal investigator (PI) transfers institutions during a grant cycle, financial and recognition issues need to be addressed to preserve all parties' obligations and best interests in a mutually beneficial way. Although grants often transfer with the PI, sometimes they do not. Maintaining a grant at an institution after the PI leaves does not negate the grantee institution's obligation to recognize the PI's original ideas, contributions, and potential rights to some forms of expression and compensation. Issues include maintaining a role for the PI in determining how to take credit for, share and publish results that involve his or her original ideas. Ascribing proper credit can become a thorny issue. This paper provides a framework for addressing situations and disagreements that may occur when a new PI continues the work after the original PI transfers. Included are suggestions for proactively developing institutional mechanisms that address such issues. Considerations include how to develop solutions that comply with the responsible conduct of research, equitably resolve claims regarding reporting of results, and avoid the possibility of plagiarism.

The Cost of Learning: Interference Effects in Memory Development

PubMed Central

Darby, Kevin P.; Sloutsky, Vladimir M.

2015-01-01

Learning often affects future learning and memory for previously learned information by exerting either facilitation or interference effects. Several theoretical accounts of interference effects have been proposed, each making different developmental predictions. This research examines interference effects across development, with the goal of better understanding mechanisms of interference and of memory development. Preschool-aged children and adults participated in a three-phased associative learning paradigm containing stimuli that were either unique or repeated across phases. Both age groups demonstrated interference effects, but only for repeated items. Whereas proactive interference effects were comparable across age groups, retroactive interference reached catastrophic-like levels in children. Additionally, retroactive interference increased in adults when contextual differences between phases were minimized (Experiment 2), and decreased in adults who were more successful at encoding repeated pairs of stimuli during a training phase (Experiment 3). These results are discussed with respect to theories of memory and memory development. PMID:25688907

Locus of Proactive Interference Effects in Short-Term Memory

ERIC Educational Resources Information Center

Dillon, Richard F.

1973-01-01

This article describes one experiment which tests a prediction from their explanation and another experiment which attempts to measure directly the amount of unlearning and spontaneous recovery-more generally, the availability-of competing responses. (Author)

Novel Cognitive Paradigms for the Detection of Memory Impairment in Preclinical Alzheimer’s Disease

PubMed Central

Loewenstein, David A.; Curiel, Rosie E.; Duara, Ranjan; Buschke, Herman

2017-01-01

In spite of advances in neuroimaging and other brain biomarkers to assess preclinical Alzheimer’s disease (AD), cognitive assessment has relied on traditional memory paradigms developed well over six decades ago. This has led to a growing concern about their effectiveness in the early diagnosis of AD which is essential to develop preventive and early targeted interventions before the occurrence of multisystem brain degeneration. We describe the development of novel tests that are more cognitively challenging, minimize variability in learning strategies, enhance initial acquisition and retrieval using cues, and exploit vulnerabilities in persons with incipient AD such as the susceptibility to proactive semantic interference, and failure to recover from proactive semantic interference. The advantages of various novel memory assessment paradigms are examined as well as how they compare with traditional neuropsychological assessments of memory. Finally, future directions for the development of more effective assessment paradigms are suggested. PMID:29214859

Relations among Personal Initiative and the Development of Reading Strategy Knowledge and Reading Comprehension

ERIC Educational Resources Information Center

Warner, Greta J.; Fay, Doris; Spörer, Nadine

2017-01-01

Reading comprehension is a self-regulated activity that depends on the proactive effort of the reader. Therefore, the authors studied the effects of personal initiative (PI) on the development of reading comprehension, mediated by reading strategy knowledge. Structural equation modelling was applied to a longitudinal study with two data waves…

Damage of GABAergic neurons in the medial septum impairs spatial working memory and extinction of active avoidance: effects on proactive interference.

PubMed

Pang, Kevin C H; Jiao, Xilu; Sinha, Swamini; Beck, Kevin D; Servatius, Richard J

2011-08-01

The medial septum and diagonal band (MSDB) are important in spatial learning and memory. On the basis of the excitotoxic damage of GABAergic MSDB neurons, we have recently suggested a role for these neurons in controlling proactive interference. Our study sought to test this hypothesis in different behavioral procedures using a new GABAergic immunotoxin. GABA-transporter-saporin (GAT1-SAP) was administered into the MSDB of male Sprague-Dawley rats. Following surgery, rats were trained in a reference memory water maze procedure for 5 days, followed by a working memory (delayed match to position) water maze procedure. Other rats were trained in a lever-press avoidance procedure after intraseptal GAT1-SAP or sham surgery. Intraseptal GAT1-SAP extensively damaged GABAergic neurons while sparing most cholinergic MSDB neurons. Rats treated with GAT1-SAP were not impaired in acquiring a spatial reference memory, learning the location of the escape platform as rapidly as sham rats. In contrast, GAT1-SAP rats were slower than sham rats to learn the platform location in a delayed match to position procedure, in which the platform location was changed every day. Moreover, GAT1-SAP rats returned to previous platform locations more often than sham rats. In the active avoidance procedure, intraseptal GAT1-SAP impaired extinction but not acquisition of the avoidance response. Using a different neurotoxin and behavioral procedures than previous studies, the results of this study paint a similar picture that GABAergic MSDB neurons are important for controlling proactive interference. Copyright © 2010 Wiley-Liss, Inc.

Large capacity temporary visual memory.

PubMed

Endress, Ansgar D; Potter, Mary C

2014-04-01

Visual working memory (WM) capacity is thought to be limited to 3 or 4 items. However, many cognitive activities seem to require larger temporary memory stores. Here, we provide evidence for a temporary memory store with much larger capacity than past WM capacity estimates. Further, based on previous WM research, we show that a single factor--proactive interference--is sufficient to bring capacity estimates down to the range of previous WM capacity estimates. Participants saw a rapid serial visual presentation of 5-21 pictures of familiar objects or words presented at rates of 4/s or 8/s, respectively, and thus too fast for strategies such as rehearsal. Recognition memory was tested with a single probe item. When new items were used on all trials, no fixed memory capacities were observed, with estimates of up to 9.1 retained pictures for 21-item lists, and up to 30.0 retained pictures for 100-item lists, and no clear upper bound to how many items could be retained. Further, memory items were not stored in a temporally stable form of memory but decayed almost completely after a few minutes. In contrast, when, as in most WM experiments, a small set of items was reused across all trials, thus creating proactive interference among items, capacity remained in the range reported in previous WM experiments. These results show that humans have a large-capacity temporary memory store in the absence of proactive interference, and raise the question of whether temporary memory in everyday cognitive processing is severely limited, as in WM experiments, or has the much larger capacity found in the present experiments.

Neonatal Perirhinal Lesions in Rhesus Macaques Alter Performance on Working Memory Tasks with High Proactive Interference.

PubMed

Weiss, Alison R; Nadji, Ryhan; Bachevalier, Jocelyne

2015-01-01

The lateral prefrontal cortex is known for its contribution to working memory (WM) processes in both humans and animals. Yet, recent studies indicate that the prefrontal cortex is part of a broader network of interconnected brain areas involved in WM. Within the medial temporal lobe (MTL) structures, the perirhinal cortex, which has extensive direct interactions with the lateral and orbital prefrontal cortex, is required to form active/flexible representations of familiar objects. However, its participation in WM processes has not be fully explored. The goal of this study was to assess the effects of neonatal perirhinal lesions on maintenance and monitoring WM processes. As adults, animals with neonatal perirhinal lesions and their matched controls were tested in three object-based (non-spatial) WM tasks that tapped different WM processing domains, e.g., maintenance only (Session-unique Delayed-nonmatching-to Sample, SU-DNMS), and maintenance and monitoring (Object-Self-Order, OBJ-SO; Serial Order Memory Task, SOMT). Neonatal perirhinal lesions transiently impaired the acquisition of SU-DNMS at a short (5 s) delay, but not when re-tested with a longer delay (30 s). The same neonatal lesions severely impacted acquisition of OBJ-SO task, and the impairment was characterized by a sharp increase in perseverative errors. By contrast, neonatal perirhinal lesion spared the ability to monitor the temporal order of items in WM as measured by the SOMT. Contrary to the SU-DNMS and OBJ-SO, which re-use the same stimuli across trials and thus produce proactive interference, the SOMT uses novel objects on each trial and is devoid of interference. Therefore, the impairment of monkeys with neonatal perirhinal lesions on SU-DNMS and OBJ-SO tasks is likely to be caused by an inability to solve working memory tasks with high proactive interference. The sparing of performance on the SOMT demonstrates that neonatal perirhinal lesions do not alter working memory processes per se but rather impact processes modulating impulse control and/or behavioral flexibility.

Memory for Serial Order.

ERIC Educational Resources Information Center

Lewandowsky, Stephan; Murdock, Bennet B., Jr.

1989-01-01

An extension to Murdock's Theory of Distributed Associative Memory, based on associative chaining between items, is presented. The extended theory is applied to several serial order phenomena, including serial list learning, delayed recall effects, partial report effects, and buildup and release from proactive interference. (TJH)

Proactive interference and concurrent inhibitory processes do not differentially affect item and associative recognition: Implication for the age-related associative memory deficit.

PubMed

Guez, Jonathan; Naveh-Benjamin, Moshe

2016-09-01

Previous studies have suggested an associative deficit hypothesis [Naveh-Benjamin, M. ( 2000 ). Adult age differences in memory performance: Tests of an associative deficit hypothesis. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1170-1187] to explain age-related episodic memory declines. The hypothesis attributes part of the deficient episodic memory performance in older adults to a difficulty in creating and retrieving cohesive episodes. In this article, we further evaluate this hypothesis by testing two alternative processes that potentially mediate associative memory deficits in older adults. Four experiments are presented that assess whether failure of inhibitory processes (proactive interference in Experiments 1 and 2), and concurrent inhibition (in Experiments 3 and 4) are mediating factors in age-related associative deficits. The results suggest that creating conditions that require the operation of inhibitory processes, or that interfere with such processes, cannot simulate associative memory deficit in older adults. Instead, such results support the idea that associative memory deficits reflect a unique binding failure in older adults. This failure seems to be independent of other cognitive processes, including inhibitory and other resource-demanding processes.

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

PubMed

Blank, Hartmut

2005-02-01

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

Interference and problem size effect in multiplication fact solving: Individual differences in brain activations and arithmetic performance.

PubMed

De Visscher, Alice; Vogel, Stephan E; Reishofer, Gernot; Hassler, Eva; Koschutnig, Karl; De Smedt, Bert; Grabner, Roland H

2018-05-15

In the development of math ability, a large variability of performance in solving simple arithmetic problems is observed and has not found a compelling explanation yet. One robust effect in simple multiplication facts is the problem size effect, indicating better performance for small problems compared to large ones. Recently, behavioral studies brought to light another effect in multiplication facts, the interference effect. That is, high interfering problems (receiving more proactive interference from previously learned problems) are more difficult to retrieve than low interfering problems (in terms of physical feature overlap, namely the digits, De Visscher and Noël, 2014). At the behavioral level, the sensitivity to the interference effect is shown to explain individual differences in the performance of solving multiplications in children as well as in adults. The aim of the present study was to investigate the individual differences in multiplication ability in relation to the neural interference effect and the neural problem size effect. To that end, we used a paradigm developed by De Visscher, Berens, et al. (2015) that contrasts the interference effect and the problem size effect in a multiplication verification task, during functional magnetic resonance imaging (fMRI) acquisition. Forty-two healthy adults, who showed high variability in an arithmetic fluency test, participated in our fMRI study. In order to control for the general reasoning level, the IQ was taken into account in the individual differences analyses. Our findings revealed a neural interference effect linked to individual differences in multiplication in the left inferior frontal gyrus, while controlling for the IQ. This interference effect in the left inferior frontal gyrus showed a negative relation with individual differences in arithmetic fluency, indicating a higher interference effect for low performers compared to high performers. This region is suggested in the literature to be involved in resolution of proactive interference. Besides, no correlation between the neural problem size effect and multiplication performance was found. This study supports the idea that the interference due to similarities/overlap of physical traits (the digits) is crucial in memorizing arithmetic facts and in determining individual differences in arithmetic. Copyright © 2018 Elsevier Inc. All rights reserved.

Word Associated Arousal as an Encoding Dimension in Short Term Memory.

ERIC Educational Resources Information Center

Hayduk, Allan W.; Osborne, John W.

1981-01-01

The fact that a significant amount of release from proactive interference was obtained with subjects in this study by shifting between differentially arousing categories of words suggested that rated word arousal is an encoding dimension in short-term memory. (CM)

Large capacity temporary visual memory

PubMed Central

Endress, Ansgar D.; Potter, Mary C.

2014-01-01

Visual working memory (WM) capacity is thought to be limited to three or four items. However, many cognitive activities seem to require larger temporary memory stores. Here, we provide evidence for a temporary memory store with much larger capacity than past WM capacity estimates. Further, based on previous WM research, we show that a single factor — proactive interference — is sufficient to bring capacity estimates down to the range of previous WM capacity estimates. Participants saw a rapid serial visual presentation (RSVP) of 5 to 21 pictures of familiar objects or words presented at rates of 4/s or 8/s, respectively, and thus too fast for strategies such as rehearsal. Recognition memory was tested with a single probe item. When new items were used on all trials, no fixed memory capacities were observed, with estimates of up to 9.1 retained pictures for 21-item lists, and up to 30.0 retained pictures for 100-item lists, and no clear upper bound to how many items could be retained. Further, memory items were not stored in a temporally stable form of memory, but decayed almost completely after a few minutes. In contrast, when, as in most WM experiments, a small set of items was reused across all trials, thus creating proactive interference among items, capacity remained in the range reported in previous WM experiments. These results show that humans have a large-capacity temporary memory store in the absence of proactive interference, and raise the question of whether temporary memory in everyday cognitive processing is severely limited as in WM experiments, or has the much larger capacity found in the present experiments. PMID:23937181

Short-Term Memory; An Annotated Bibliography.

ERIC Educational Resources Information Center

Reynolds, Donald; Rosenblatt, Richard D.

This annotated bibliography on memory is divided into 12 areas: information theory; proactive and retroactive interference and interpolated activities; set, subject strategies, and coding techniques; paired associate studies; simultaneous listening and memory span studies; rate and mode of stimulus presentation; rate and order of recall, and…

Separating math from anxiety: The role of inhibitory mechanisms.

PubMed

Mammarella, Irene C; Caviola, Sara; Giofrè, David; Borella, Erika

2017-07-06

Deficits in executive functions have been hypothesized and documented for children with severe mathematics anxiety (MA) or developmental dyscalculia, but the role of inhibition-related processes has not been specifically explored. The main aim of the present study was to shed further light on the specificity of these profiles in children in terms of working memory (WM) and the inhibitory functions involved. Four groups of children between 8 and 10 years old were selected: one group with developmental dyscalculia (DD) and no MA, one with severe MA and developmental dyscalculia (MA-DD), one with severe MA and no DD (MA), and one with typical development (TD). All children were presented with tasks measuring two inhibition-related functions, that is, proactive interference and prepotent response, and a WM task. The results showed that children with severe MA (but no DD) were specifically impaired in the proactive interference task, while children with DD (with or without MA) failed in the WM task. Our findings point to the importance of distinguishing the cognitive processes underlying these profiles.

Interference effects on commonly used memory tasks.

PubMed

Brophy, Linda M; Jackson, Martin; Crowe, Simon F

2009-02-01

This paper reports two studies which investigated the effect of interference on delayed recall scores of the WMS-III and other commonly used memory measures. In Study 1, participants completed the immediate and delayed components of the WMS-III, with or without the introduction of conceptually similar memory tasks between the recall trials. In Study 2, this order of administration was reversed, with the WMS-III subtests used as the interference items. The results indicated that the introduction of interference items during the delay negatively affected delayed recall performance on almost all sub-tests. In addition, equal effects of proactive and retroactive interference were demonstrated. These findings raise concerns regarding the standardization process for memory tasks and highlight the need to consider interference effects in clinical practice, and stand as a caution in the use of memory-related materials during the delay interval in memory testing.

Active versus passive maintenance of visual nonverbal memory.

PubMed

McKeown, Denis; Holt, Jessica; Delvenne, Jean-Francois; Smith, Amy; Griffiths, Benjamin

2014-08-01

Forgetting over the short term has challenged researchers for more than a century, largely because of the difficulty of controlling what goes on within the memory retention interval. But the "recent-negative-probe" procedure offers a valuable paradigm, by examining the influences of (presumably) unattended memoranda from prior trials. Here we used a recent-probe task to investigate forgetting for visual nonverbal short-term memory. The target stimuli (two visually presented abstract shapes) on a trial were followed after a retention interval by a probe, and participants indicated whether the probe matched one of the target items. Proactive interference, and hence memory for old trial probes, was observed, whereby participants were slowed in rejecting a nonmatching probe on the current trial that nevertheless matched a target item on the previous trial (a recent-negative probe). The attraction of the paradigm is that, by uncovering proactive influences of past-trial probe stimuli, it can be argued that active maintenance in memory of those probes is unlikely. In two experiments, we recorded such proactive interference of prior-trial items over a range of interstimulus (ISI) and intertrial (ITI) intervals (between 1 and 6 s, respectively). Consistent with a proposed two-process memory conception (the active-passive memory model, or APM), actively maintained memories on current trials decayed, but passively "maintained," or unattended, visual memories of stimuli on past trials did not.

Age-related decline in cognitive control: the role of fluid intelligence and processing speed

PubMed Central

2014-01-01

Background Research on cognitive control suggests an age-related decline in proactive control abilities whereas reactive control seems to remain intact. However, the reason of the differential age effect on cognitive control efficiency is still unclear. This study investigated the potential influence of fluid intelligence and processing speed on the selective age-related decline in proactive control. Eighty young and 80 healthy older adults were included in this study. The participants were submitted to a working memory recognition paradigm, assessing proactive and reactive cognitive control by manipulating the interference level across items. Results Repeated measures ANOVAs and hierarchical linear regressions indicated that the ability to appropriately use cognitive control processes during aging seems to be at least partially affected by the amount of available cognitive resources (assessed by fluid intelligence and processing speed abilities). Conclusions This study highlights the potential role of cognitive resources on the selective age-related decline in proactive control, suggesting the importance of a more exhaustive approach considering the confounding variables during cognitive control assessment. PMID:24401034

Electromagnetic interference shielding effectiveness of microcellular polyimide/in situ thermally reduced graphene oxide/carbon nanotubes nanocomposites

NASA Astrophysics Data System (ADS)

Yang, Hongli; Yu, Zhi; Wu, Peng; Zou, Huawei; Liu, Pengbo

2018-03-01

A simple and effective method was adopted to fabricate microcellular polyimide (PI)/reduced graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) nanocomposites. Firstly, microcellular poly (amic acid) (PAA)/GO/MWCNTs nanocomposites were prepared through solvent evaporation induced phase separation. In this process, PAA and dibutyl phthalate (DBP) co-dissolved in N,N-dimethylacetamide (DMAc) underwent phase separation with DMAc evaporating, and DBP microdomains were formed in continuous PAA phase. Subsequently, PAA was thermally imidized and simultaneously GO was in situ reduced. After DBP was removed, the microcellular PI/reduced GO (RGO)/MWCNTs nanocomposites were finally obtained. When the initial filler loading was 8 wt%, the electrical conductivity of microcellular PI/RGO, PI/MWCNTs and PI/RGO/MWCNTs nanocomposites were 0.05, 0.02 and 1.87 S·m-1, respectively, and the electromagnetic interference (EMI) shielding efficiency (SE) of microcellular PI/RGO, PI/MWCNTs and PI/RGO/MWCNTs nanocomposites were 13.7-15.1, 13.0-14.3 and 16.6-18.2 dB, respectively. The synergistic effect between RGO and MWCNTs enhanced both the electrical conductivity and EMI shielding performance of the microcellular PI/RGO/MWCNTs nanocomposites. The dominating EMI shielding mechanism for these materials was microwave absorption. While the initial loading of GO and MWCNT was 8 wt%, the microcellular PI/RGO/MWCNTs nanocomposite (500 μm thickness) had extremely high specific EMI SE value of 755-823 dB·cm2·g-1. Its thermal stability was also obviously improved, the 5% weight loss temperature in nitrogen was 548 °C. In addition, it also possessed a high Young's modulus of 789 MPa.

Interference thinking in constructing students’ knowledge to solve mathematical problems

NASA Astrophysics Data System (ADS)

Jayanti, W. E.; Usodo, B.; Subanti, S.

2018-04-01

This research aims to describe interference thinking in constructing students’ knowledge to solve mathematical problems. Interference thinking in solving problems occurs when students have two concepts that interfere with each other’s concept. Construction of problem-solving can be traced using Piaget’s assimilation and accommodation framework, helping to know the students’ thinking structures in solving the problems. The method of this research was a qualitative method with case research strategy. The data in this research involving problem-solving result and transcripts of interviews about students’ errors in solving the problem. The results of this research focus only on the student who experience proactive interference, where student in solving a problem using old information to interfere with the ability to recall new information. The student who experience interference thinking in constructing their knowledge occurs when the students’ thinking structures in the assimilation and accommodation process are incomplete. However, after being given reflection to the student, then the students’ thinking process has reached equilibrium condition even though the result obtained remains wrong.

From Ξb→Λbπ to Ξc→Λcπ

DOE PAGES

Gronau, Michael; Rosner, Jonathan L.

2016-04-11

Using a successful framework for describing S-wave hadronic decays of light hyperons induced by a subprocess s -> u((u) over bard), we presented recently a model-independent calculation of the amplitude and branching ratio for Xi(-)(b) -> Lambda(b)pi(-) in agreement with a LHCb measurement. The same quark process contributes to Xi(0)(c) -> Lambda(c)pi(-), while a second term from the subprocess cs -> cd has been related by Voloshin to differences among total decay rates of charmed baryons. We calculate this term and find it to have a magnitude approximately equal to the s -> u((u) over bard) term. We argue formore » a negligible relative phase between these two contributions, potentially due to final state interactions. However, we do not know whether they interfere destructively or constructively. For constructive interference one predicts B(Xi(0)(c) -> Lambda(c)pi(-)) = (1.94 +/- 0.70) x 10(-3) and B(Xi(+)(c) -> Lambda(c)pi(0)) = (3.86 +/- 1.35) x 10(-3). For destructive interference, the respective branching fractions are expected to be less than about 10(-4) and 2 x 10(-4). (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

From Ξb→Λbπ to Ξc→Λcπ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gronau, Michael; Rosner, Jonathan L.

Using a successful framework for describing S-wave hadronic decays of light hyperons induced by a subprocess s -> u((u) over bard), we presented recently a model-independent calculation of the amplitude and branching ratio for Xi(-)(b) -> Lambda(b)pi(-) in agreement with a LHCb measurement. The same quark process contributes to Xi(0)(c) -> Lambda(c)pi(-), while a second term from the subprocess cs -> cd has been related by Voloshin to differences among total decay rates of charmed baryons. We calculate this term and find it to have a magnitude approximately equal to the s -> u((u) over bard) term. We argue formore » a negligible relative phase between these two contributions, potentially due to final state interactions. However, we do not know whether they interfere destructively or constructively. For constructive interference one predicts B(Xi(0)(c) -> Lambda(c)pi(-)) = (1.94 +/- 0.70) x 10(-3) and B(Xi(+)(c) -> Lambda(c)pi(0)) = (3.86 +/- 1.35) x 10(-3). For destructive interference, the respective branching fractions are expected to be less than about 10(-4) and 2 x 10(-4). (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

Automatic Conceptual Encoding of Printed Verbal Material: Assessment of Population Differences.

ERIC Educational Resources Information Center

Kee, Daniel W.; And Others

1984-01-01

The release from proactive interference task as used to investigate categorical encoding of items. Low socioeconomic status Black and middle socioeconomic status White children were compared. Conceptual encoding differences between these populations were not detected in automatic conceptual encoding but were detected when the free recall method…

Testing during Study Insulates against the Buildup of Proactive Interference

ERIC Educational Resources Information Center

Szpunar, Karl K.; McDermott, Kathleen B.; Roediger, Henry L., III

2008-01-01

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…

Categorical Coding of Manual & English Alphabet Characters by Beginning Students of American Sign Language.

ERIC Educational Resources Information Center

Hoemann, Harry W.; Koenig, Teresa J.

1990-01-01

Analysis of the performance of beginning American Sign Language students, who had only recently learned the manual alphabet, on a task in which proactive interference would build up rapidly on successive trials, supported the view that different languages have separate memory stores. (Author/CB)

When Bad Things Happen to Good Superintendents: What Comes between Well-Meaning School Boards and Their Superintendents?

ERIC Educational Resources Information Center

Marlowe, John

2001-01-01

Major causes of "sudden-death syndrome" for superintendents include mismatched priorities, unseen problems, interference from special-interest groups, and misdirected disagreements. Beleaguered superintendents should be positive and proactive, act and speak as one person, understand agreements, seek help, listen, rewrite personnel…

Performance improvement CME for quality: challenges inherent to the process.

PubMed

Vakani, Farhan Saeed; O'Beirne, Ronan

2015-01-01

The purpose of this paper is to discuss the perspective debates upon the real-time challenges for a three-staged Performance Improvement Continuing Medical Education (PI-CME) model, an innovative and potential approach for future CME, to inform providers to think, prepare and to act proactively. In this discussion, the challenges associated for adopting the American Medical Association's three-staged PI-CME model are reported. Not many institutions in USA are using a three-staged performance improvement model and then customizing it to their own healthcare context for the specific targeted audience. They integrate traditional CME methods with performance and quality initiatives, and linking with CME credits. Overall the US health system is interested in a structured PI-CME model with the potential to improve physicians practicing behaviors. Knowing the dearth of evidence for applying this structured performance improvement methodology into the design of CME activities, and the lack of clarity on challenges inherent to the process that learners and providers encounter. This paper establishes all-important first step to render the set of challenges for a three-staged PI-CME model.

Modulating effect of COMT Val(158)Met polymorphism on interference resolution during a working memory task.

PubMed

Jaspar, Mathieu; Dideberg, Vinciane; Bours, Vincent; Maquet, Pierre; Collette, Fabienne

2015-04-01

Genetic variability related to the catechol-O-methyltransferase (COMT) gene has received increasing attention in the last 15years, in particular as a potential modulator of the neural substrates underlying inhibitory processes and updating in working memory (WM). In an event-related functional magnetic resonance imaging (fMRI) study, we administered a modified version of the Sternberg probe recency task (Sternberg, 1966) to 43 young healthy volunteers, varying the level of interference across successive items. The task was divided into two parts (high vs. low interference) to induce either proactive or reactive control processes. The participants were separated into three groups according to their COMT Val(158)Met genotype [Val/Val (VV); Val/Met (VM); Met/Met (MM)]. The general aim of the study was to determine whether COMT polymorphism has a modulating effect on the neural substrates of interference resolution during WM processing. Results indicate that interfering trials were associated with greater involvement of frontal cortices (bilateral medial frontal gyrus, left precentral and superior frontal gyri, right inferior frontal gyrus) in VV homozygous subjects (by comparison to Met allele carriers) only in the proactive condition of the task. In addition, analysis of peristimulus haemodynamic responses (PSTH) revealed that the genotype-related difference observed in the left SFG was specifically driven by a larger increase in activity from the storage to the recognition phase of the interfering trials in VV homozygous subjects. These results confirm the impact of COMT genotype on inhibitory processes during a WM task, with an advantage for Met allele carriers. Interestingly, this impact on frontal areas is present only when the level of interference is high, and especially during the transition from storage to recognition in the left superior frontal gyrus. Copyright © 2015 Elsevier Inc. All rights reserved.

Pain interference and physical function demonstrate poor longitudinal association in people living with pain: a PROMIS investigation.

PubMed

Karayannis, Nicholas V; Sturgeon, John A; Chih-Kao, Ming; Cooley, Corinne; Mackey, Sean C

2017-06-01

A primary goal in managing pain is to reduce pain and increase physical function (PF). This goal is also tied to continuing payment for treatment services in many practice guidelines. Pain interference (PI) is often used as a proxy for measurement and reporting of PF in these guidelines. A common assumption is that reductions in PI will translate into improvement in PF over time. This assumption needs to be tested in a clinical environment. Consequently, we used the patient-reported outcomes measurement information system (PROMIS) to describe the topology of the longitudinal relationship between PI in relation to PF. Longitudinal data of 389 people with chronic pain seeking health care demonstrated that PI partially explained the variance in PF at baseline (r = -0.50) and over 90 days of care (r = -0.65). The relationship between pain intensity and PF was not significant when PI was included as a mediator. A parallel process latent growth curve model analysis showed a weak, unidirectional relationship (β = 0.18) between average PF scores and changes in PI over the course of 90 days of care, and no relationship between average PI scores and changes in PF across time. Although PI and PF seem moderately related when measured concurrently, they do not cluster closely together across time. The differential pathways between these 2 domains suggest that therapies that target both the consequences of pain on relevant aspects of persons' lives, and capability to perform physical activities are likely required for restoration of a vital life.

Arabidopsis WRKY45 transcription factor activates PHOSPHATE TRANSPORTER1;1 expression in response to phosphate starvation.

PubMed

Wang, Hui; Xu, Qian; Kong, You-Han; Chen, Yun; Duan, Jun-Ye; Wu, Wei-Hua; Chen, Yi-Fang

2014-04-01

The WRKY transcription factor family has more than 70 members in the Arabidopsis (Arabidopsis thaliana) genome, and some of them are involved in plant responses to biotic and abiotic stresses. This study evaluated the role of WRKY45 in regulating phosphate (Pi) uptake in Arabidopsis. WRKY45 was localized in the nucleus and mainly expressed in roots. During Pi starvation, WRKY45 expression was markedly induced, typically in roots. WRKY45 overexpression in Arabidopsis increased Pi content and uptake, while RNA interference suppression of WRKY45 decreased Pi content and uptake. Furthermore, the WRKY45-overexpressing lines were more sensitive to arsenate, the analog of Pi, compared with wild-type seedlings. These results indicate that WRKY45 positively regulates Arabidopsis Pi uptake. Quantitative real-time polymerase chain reaction and β-glucuronidase staining assays showed that PHOSPHATE TRANSPORTER1;1 (PHT1;1) expression was enhanced in the WRKY45-overexpressing lines and slightly repressed in the WRKY45 RNA interference line. Chromatin immunoprecipitation and electrophoretic mobility shift assay results indicated that WRKY45 can bind to two W-boxes within the PHT1;1 promoter, confirming the role of WRKY45 in directly up-regulating PHT1;1 expression. The pht1;1 mutant showed decreased Pi content and uptake, and overexpression of PHT1;1 resulted in enhanced Pi content and uptake. Furthermore, the PHT1;1-overexpressing line was much more sensitive to arsenate than WRKY45-overexpressing and wild-type seedlings, indicating that PHT1;1 overexpression can enhance Arabidopsis Pi uptake. Moreover, the enhanced Pi uptake and the increased arsenate sensitivity of the WRKY45-overexpressing line was impaired by pht1;1 (35S:WRKY45-18::pht1;1), demonstrating an epistatic genetic regulation between WRKY45 and PHT1;1. Together, our results demonstrate that WRKY45 is involved in Arabidopsis response to Pi starvation by direct up-regulation of PHT1;1 expression.

Mapping interference resolution across task domains: A shared control process in left inferior frontal gyrus

PubMed Central

Nelson, James K.; Reuter-Lorenz, Patricia A.; Persson, Jonas; Sylvester, Ching-Yune C.; Jonides, John

2009-01-01

Work in functional neuroimaging has mapped interference resolution processing onto left inferior frontal regions for both verbal working memory and a variety of semantic processing tasks. The proximity of the identified regions from these different tasks suggests the existence of a common, domain-general interference resolution mechanism. The current research specifically tests this idea in a within-subject design using fMRI to assess the activation associated with variable selection requirements in a semantic retrieval task (verb generation) and a verbal working memory task with a trial-specific proactive interference manipulation (recent-probes). High interference trials on both tasks were associated with activity in the midventrolateral region of the left inferior frontal gyrus, and the regions activated in each task strongly overlapped. The results indicate that an elemental component of executive control associated with interference resolution during retrieval from working memory and from semantic memory can be mapped to a common portion of the left inferior frontal gyrus. PMID:19111526

BE PROACTIVE: "Including Students With Challenging Behavior in Your Classroom"

ERIC Educational Resources Information Center

Mitchem, Katherine J.

2005-01-01

Many teachers feel unprepared to deal with disruptive behavior and believe this substantially interferes with their teaching and their ability to successfully include children with disabilities (Schumm & Vaughn, 1995). In addition to the stress of dealing with never-ending piles of paperwork, working with challenging students may be one of the…

The Specific Role of Inhibition in Reading Comprehension in Good and Poor Comprehenders

ERIC Educational Resources Information Center

Borella, Erika; Carretti, Barbara; Pelegrina, Santiago

2010-01-01

Difficulties in inhibitory processes have been shown to characterize the performance of poor comprehenders. However, the inhibitory inefficiency of poor comprehenders is most often assessed by their resistance to proactive interference, that is, the ability to suppress off-goal task information from working memory (WM). In two studies tasks…

The Effects of Within-Sequence Acoustic Similarity on the Short-Term Retention of Consonants and Words

ERIC Educational Resources Information Center

Marcer, D.; And Others

1977-01-01

Compares the rates of forgetting of five-item sequences of acoustically similar and dissimilar consonants and words in the absence of proactive and retroactive interference in order to test whether within sequence similarity rather than stimulus length would have a greater influence on retention. (Author/RK)

Competition Processes and Proactive Interference in Short-Term Memory

ERIC Educational Resources Information Center

Bennett, Raymond W.; Kurzeja, Paul L.

1976-01-01

In an experiment using single-word items, subjects are run under three different speed-accuracy trade-off conditions. A competition model would predict that when subjects are forced to respond quickly, there will be an increase in errors, and these will be from recent past items. The prediction was confirmed. (CHK)

Context-dependent switching between proactive and reactive working memory control mechanisms in the right inferior frontal gyrus.

PubMed

Marklund, Petter; Persson, Jonas

2012-11-15

A critical feature of higher cognitive functioning is the capacity to flexibly tailor information processing and behaviors to current situational demands. Recent neurocognitive models have been postulated to account for the dynamic nature of human executive processing by invoking two dissociable cognitive control modes, proactive and reactive control. These may involve partially overlapping, but temporally distinct neural implementation in the prefrontal cortex. Prior brain imaging studies exploring proactive control have mainly used tasks requiring only information about single-items to be retained over unfilled delays. Whether proactive control can also be utilized to facilitate performance in more complex working memory tasks, in which concurrent processing of intervening items and updating is mandatory during contextual cue maintenance remains an open question. To examine this issue and to elucidate the extent to which overlapping neural substrates underlie proactive and reactive control we used fMRI and a modified verbal 3-back paradigm with embedded cues predictive of high-interference trials. This task requires context information to be retained over multiple intervening trials. We found that performance improved with item-specific cues predicting forthcoming lures despite increased working memory load. Temporal dynamics of activation in the right inferior frontal gyrus suggest flexible switching between proactive and reactive control in a context-dependent fashion, with greater sustained responses elicited in the 3-back task involving context maintenance of cue information and greater transient responses elicited in the 3-back task absent of cues. Copyright © 2012 Elsevier Inc. All rights reserved.

Attention and Modality Effects in STM: A Second Look. Occasional Paper No. 14.

ERIC Educational Resources Information Center

Evans, Thomas; Byers, Joe

The auditory/verbal short-term memory of 64 college students was examined across a wide range of retention intervals (5 seconds to 60 seconds). High attention during interpolated processing was ensured by monitoring rehearsal with a combination of methods, and errors were analyzed for evidence of proactive and intra-unit interference. Recall of…

Does Active Memory Capacity Change with Age?

ERIC Educational Resources Information Center

Halford, Graeme S.; And Others

A series of experiments, which used the primary memory paradigm of Wickens et al. (1981, 1985) with university students, adults, and 8- and 9-year-old children, found an increase in primary memory capacity with age. Primary memory differs from secondary memory in that the latter is susceptible to proactive interference, whereas the former is not.…

REM sleep rescues learning from interference

PubMed Central

McDevitt, Elizabeth A.; Duggan, Katherine A.; Mednick, Sara C.

2015-01-01

Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost. PMID:25498222

No evidence for memory interference across sessions in food hoarding marsh tits Poecile palustris under laboratory conditions.

PubMed

Urhan, A Utku; Brodin, Anders

2015-05-01

Scatter hoarding birds are known for their accurate spatial memory. In a previous experiment, we tested the retrieval accuracy in marsh tits in a typical laboratory set-up for this species. We also tested the performance of humans in this experimental set-up. Somewhat unexpectedly, humans performed much better than marsh tits. In the first five attempts, humans relocated almost 90 % of the caches they had hidden 5 h earlier. Marsh tits only relocated 25 % in the first five attempts and just above 40 % in the first ten attempts. Typically, in this type of experiment, the birds will be caching and retrieving many times in the same sites in the same experimental room. This is very different from the conditions in nature where hoarding parids only cache once in a caching site. Hence, it is possible that memories from previous sessions will disturb the formation of new memories. If there is such proactive interference, the prediction is that success should decay over sessions. Here, we have designed an experiment to investigate whether there is such memory interference in this type of experiment. We allowed marsh tits and humans to cache and retrieve in three repeated sessions without prior experience of the arena. The performance did not change over sessions, and on average, marsh tits correctly visited around 25 % of the caches in the first five attempts. The corresponding success in humans was constant across sessions, and it was around 90 % on average. We conclude that the somewhat poor performance of the marsh tits did not depend on proactive memory interference. We also discuss other possible reasons for why marsh tits in general do not perform better in laboratory experiments.

Targeting PI3K in cancer: impact on tumor cells, their protective stroma, angiogenesis and immunotherapy

PubMed Central

Okkenhaug, Klaus; Graupera, Mariona; Vanhaesebroeck, Bart

2017-01-01

The PI3K pathway is hyperactivated in most cancers, yet the capacity of PI3K inhibitors to induce tumor cell death is limited. The efficacy of PI3K inhibition can also derive from interference with the cancer cells’ ability to respond to stromal signals, as illustrated by the approved PI3Kδ inhibitor Idelalisib in B-cell malignancies. Inhibition of the leukocyte-enriched PI3Kδ or PI3Kγ may unleash more potent anti-tumor T-cell responses, by inhibiting regulatory T-cells and immune-suppressive myeloid cells. Moreover, tumor angiogenesis may be targeted by PI3K inhibitors to enhance cancer therapy. Future work should therefore focus on the effects of PI3K inhibitors on the stroma, in addition to their direct effects on tumors. Significance The PI3K pathway extends beyond the direct regulation of cancer cell proliferation and survival. In B-cell malignancies, targeting PI3K purges the tumor cells from their protective microenvironment. Moreover, we propose that PI3K isoform-selective inhibitors may be exploited in the context of cancer immunotherapy and by targeting angiogenesis to improve drug and immune cell delivery. PMID:27655435

Reward favours the prepared: incentive and task-informative cues interact to enhance attentional control

PubMed Central

Chiew, Kimberly S.; Braver, Todd S.

2015-01-01

The dual mechanisms of control account suggests that cognitive control may be implemented through relatively proactive mechanisms in anticipation of stimulus onset, or through reactive mechanisms, triggered in response to changing stimulus demands. Reward incentives and task-informative cues (signaling the presence/absence of upcoming cognitive demand) have both been found to influence cognitive control in a proactive or preparatory fashion; yet, it is currently unclear whether and how such cue effects interact. We investigated this in two experiments using an adapted flanker paradigm, where task-informative and reward incentive cues were orthogonally manipulated on a trial-by-trial basis. In Experiment 1, results indicated that incentives not only speed RTs, but specifically reduce both interference and facilitation effects when combined with task-informative cues, suggesting enhanced proactive attentional control. Experiment 2 manipulated the timing of incentive cue information, demonstrating that such proactive control effects were only replicated with sufficient time to process the incentive cue (Early Incentive); when incentive signals were presented close to target onset (Late Incentive) the primary effect was a speed-accuracy tradeoff. Together, results suggest that advance cueing may trigger differing control strategies, and that these strategies may critically depend on both the timing – and the motivational incentive – to use such cues. PMID:26322689

Serial Dependence across Perception, Attention, and Memory.

PubMed

Kiyonaga, Anastasia; Scimeca, Jason M; Bliss, Daniel P; Whitney, David

2017-07-01

Information that has been recently perceived or remembered can bias current processing. This has been viewed as both a corrupting (e.g., proactive interference in short-term memory) and stabilizing (e.g., serial dependence in perception) phenomenon. We hypothesize that this bias is a generally adaptive aspect of brain function that leads to occasionally maladaptive outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Categorical Structure of Semantic Memory for Famous People: A New Approach Using Release from Proactive Interference

ERIC Educational Resources Information Center

Darling, S.; Valentine, T.

2005-01-01

Memory for familiar people is essential to understand their identity and guide social interaction. Nevertheless, we know surprisingly little about the structure of such memory. Previous research has assumed that semantic memory for people has a categorical structure, but recently it was proposed that memory for people consists only of associations…

Dissociation Between Working Memory Performance and Proactive Interference Control in Post-Traumatic Stress Disorder

PubMed Central

Swick, Diane; Cayton, Julien; Ashley, Victoria; Turken, And U.

2017-01-01

Deficits in working memory (WM) and cognitive control processes have been reported in post-traumatic stress disorder (PTSD), in addition to clinical symptoms such as hypervigilance, re-experiencing, and avoidance of trauma reminders. Given the uncontrollable nature of intrusive memories, an important question is whether PTSD is associated with altered control of interference in WM. Some studies also suggest that episodic memory shows a material-specific dissociation in PTSD, with greater impairments in verbal memory and relative sparing of nonverbal memory. It is unclear whether this dissociation applies to WM, as no studies have used identical task parameters across material. Here we tested 29 combat Veterans with PTSD and 29 age-matched control Veterans on a recent probes WM task with words and visual patterns in separate blocks. Participants studied four-item sets, followed by a probe stimulus that had been presented in the previous set (recent probe) or not (nonrecent probe). Participants with PTSD made more errors than controls, and this decrement was similar for verbal and visual stimuli. Proactive interference from items recently presented, but no longer relevant, was not significantly different in the PTSD group and showed no relationship to re-experiencing symptom severity. These results demonstrate that PTSD is not reliably associated with increased intrusions of irrelevant representations into WM when non-emotional stimuli are used. Future studies that use trauma-related material may provide insight into the flashbacks and intrusive thoughts that plague those with PTSD. PMID:28077328

Polymorphism of serotonin receptor genes (5-HTR2A) and Dysbindin (DTNBP1) and individual components of short-term verbal memory processes in Schizophrenia.

PubMed

Alfimova, M V; Monakhov, M V; Abramova, L I; Golubev, S A; Golimbet, V E

2010-10-01

Associations between polymorphisms in the T102C and A-1438G loci of the 5-HTR2A and the P1763 and P1578 markers of the DTNBP1 gene with the overall productivity and individual subprocesses of shortterm verbal memory were studied in 4-5 patients with schizophrenia and 290 healthy subjects. Subjects were asked to reproduce immediately two lists of 10 words. The overall productivity of reproduction was assessed, along with the reproduction productivity of the first list (immediate memory or general attention), the effect of proactive interference, and the number of intrusions. Patients were significantly different from controls on all measures. Patients showed decreases in overall task performance productivity, in immediate memory productivity, and in the effect of proactive interference; fewer intrusions were seen. Both markers of the 5-HTR2A gene were associated with short-term memory productivity in the combined cohort: assessments were worse in T102C CC and A-1438G GG homozygotes. The P1763 marker of the DTNBP1 gene, conversely, had significant influences on the memory subprocesses reflected in the levels of interference and intrusions but had insignificant influence on overall productivity. Homozygotes for P1763G GG had the worst parameters. Overall, these data are consistent with the concept that these polymorphic genes are involved in different subprocesses of short-term memory both in normal subjects and in patients with schizophrenia.

Dissociation between working memory performance and proactive interference control in post-traumatic stress disorder.

PubMed

Swick, Diane; Cayton, Julien; Ashley, Victoria; Turken, And U

2017-02-01

Deficits in working memory (WM) and cognitive control processes have been reported in post-traumatic stress disorder (PTSD), in addition to clinical symptoms such as hypervigilance, re-experiencing, and avoidance of trauma reminders. Given the uncontrollable nature of intrusive memories, an important question is whether PTSD is associated with altered control of interference in WM. Some studies also suggest that episodic memory shows a material-specific dissociation in PTSD, with greater impairments in verbal memory and relative sparing of nonverbal memory. It is unclear whether this dissociation applies to WM, as no studies have used identical task parameters across material. Here we tested 29 combat Veterans with PTSD and 29 age-matched control Veterans on a recent probes WM task with words and visual patterns in separate blocks. Participants studied four-item sets, followed by a probe stimulus that had been presented in the previous set (recent probe) or not (nonrecent probe). Participants with PTSD made more errors than controls, and this decrement was similar for verbal and visual stimuli. Proactive interference from items recently presented, but no longer relevant, was not significantly different in the PTSD group and showed no relationship to re-experiencing symptom severity. These results demonstrate that PTSD is not reliably associated with increased intrusions of irrelevant representations into WM when non-emotional stimuli are used. Future studies that use trauma-related material may provide insight into the flashbacks and intrusive thoughts that plague those with PTSD. Published by Elsevier Ltd.

Proactive AP Selection Method Considering the Radio Interference Environment

NASA Astrophysics Data System (ADS)

Taenaka, Yuzo; Kashihara, Shigeru; Tsukamoto, Kazuya; Yamaguchi, Suguru; Oie, Yuji

In the near future, wireless local area networks (WLANs) will overlap to provide continuous coverage over a wide area. In such ubiquitous WLANs, a mobile node (MN) moving freely between multiple access points (APs) requires not only permanent access to the Internet but also continuous communication quality during handover. In order to satisfy these requirements, an MN needs to (1) select an AP with better performance and (2) execute a handover seamlessly. To satisfy requirement (2), we proposed a seamless handover method in a previous study. Moreover, in order to achieve (1), the Received Signal Strength Indicator (RSSI) is usually employed to measure wireless link quality in a WLAN system. However, in a real environment, especially if APs are densely situated, it is difficult to always select an AP with better performance based on only the RSSI. This is because the RSSI alone cannot detect the degradation of communication quality due to radio interference. Moreover, it is important that AP selection is completed only on an MN, because we can assume that, in ubiquitous WLANs, various organizations or operators will manage APs. Hence, we cannot modify the APs for AP selection. To overcome these difficulties, in the present paper, we propose and implement a proactive AP selection method considering wireless link condition based on the number of frame retransmissions in addition to the RSSI. In the evaluation, we show that the proposed AP selection method can appropriately select an AP with good wireless link quality, i.e., high RSSI and low radio interference.

Defense Small Business Innovation Research Program (SBIR). Defense Agencies Abstracts of Phase 2 Awards 1993

DTIC Science & Technology

1993-01-01

to seven transmitters operating in the 1.71-1.85 and 2.2-2.3 GHz telemetry bands can simultaneously be connected to this antenna without interference ...HUNTINGTON BEACH, CA 92649 Contract#N: DAAA21-91-C-0034 Phone: (714) 373-5509 PI: Dr. Timothy M. Rynne Tide: Electromagnetic Interference (EMI)/Electro...y position data. The system is designed to counteract the severe multipath interference environment resulting from operation within a metal building

PI(4)P Promotes Phosphorylation and Conformational Change of Smoothened through Interaction with Its C-terminal Tail

PubMed Central

Zhang, Jie; Li, Xiang-An; Evers, B. Mark; Zhu, Haining; Jia, Jianhang

2016-01-01

In Hedgehog (Hh) signaling, binding of Hh to the Patched-Interference Hh (Ptc-Ihog) receptor complex relieves Ptc inhibition on Smoothened (Smo). A longstanding question is how Ptc inhibits Smo and how such inhibition is relieved by Hh stimulation. In this study, we found that Hh elevates production of phosphatidylinositol 4-phosphate (PI(4)P). Increased levels of PI(4)P promote, whereas decreased levels of PI(4)P inhibit, Hh signaling activity. We further found that PI(4)P directly binds Smo through an arginine motif, which then triggers Smo phosphorylation and activation. Moreover, we identified the pleckstrin homology (PH) domain of G protein-coupled receptor kinase 2 (Gprk2) as an essential component for enriching PI(4)P and facilitating Smo activation. PI(4)P also binds mouse Smo (mSmo) and promotes its phosphorylation and ciliary accumulation. Finally, Hh treatment increases the interaction between Smo and PI(4)P but decreases the interaction between Ptc and PI(4)P, indicating that, in addition to promoting PI(4)P production, Hh regulates the pool of PI(4)P associated with Ptc and Smo. PMID:26863604

Measurement of {pi}{sup -}p{yields}{eta}n from threshold to p{sub {pi}}{sub {sup -}}=747 MeV/c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prakhov, S.; Nefkens, B.M.K.; Clajus, M.

2005-07-01

The differential cross section for {eta} production in reaction {pi}{sup -}p{yields}{eta}n has been measured over the full angular range at seven incident {pi}{sup -} beam momenta from threshold to p{sub {pi}}{sub {sup -}}=747 MeV/c using the Crystal Ball multiphoton spectrometer. The angular distributions are S wave dominated. At 10 MeV/c above threshold, a small D-wave contribution appears that interferes with the main S wave. The total {eta} production cross section {sigma}{sup tot} is obtained by integration of d{sigma}/d{omega}. Starting at threshold, {sigma}{sup tot} rises rapidly, as expected for S-wave-dominated production. The features of the {pi}{sup -}p{yields}{eta}n cross section are strikinglymore » similar to those of the SU(3) flavor-related process K{sup -}p{yields}{eta}{lambda}. Comparison of the {pi}{sup -}p{yields}{eta}n reaction is made with {eta} photoproduction.« less

Dipion invariant mass distribution of the anomalous {Upsilon}(1S){pi}{sup +}{pi}{sup -} and {Upsilon}(2S){pi}{sup +}{pi}{sup -} production near the peak of {Upsilon}(10860)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Dianyong; He Jun; Nuclear Theory Group, Institute of Modern Physics of CAS, Lanzhou 730000

2011-10-01

Considering the defects of the previous work for estimating the anomalous production rates of e{sup +}e{sup -}{yields}{Upsilon}(1S){pi}{sup +}{pi}{sup -}, {Upsilon}(2S){pi}{sup +}{pi}{sup -} near the peak of the {Upsilon}(5S) resonance at {radical}(s)=10.87 GeV [K. F. Chen et al. (Belle Collaboration), Phys. Rev. Lett. 100, 112001 (2008)], we suggest a new scenario where the contributions from the direct dipion transition and the final-state interactions interfere to result in not only the anomalously large production rates, but also line shapes of the differential widths consistent with experimental measurement when assuming the reactions are due to the dipion emission of {Upsilon}(5S). At the end,more » we raise a new puzzle that the predicted differential width d{Gamma}({Upsilon}(5S){yields}{Upsilon}(2S){pi}{sup +}{pi}{sup -})/dcos{theta} has a discrepant trend from the data while other predictions are well in accord with the data. It should be further clarified by more accurate measurements carried by future experiments.« less

Appetitive Context Conditioning Proactively, but Transiently, Interferes with Expression of Counterconditioned Context Fear

ERIC Educational Resources Information Center

Holmes, Nathan M.; Westbrook, R. Frederick

2014-01-01

Four experiments used rats to study appetitive-aversive transfer. Rats trained to eat a palatable food in a distinctive context and shocked in that context ate and did not freeze when tested 1 d later but froze and did not eat when tested 14 d later. These results were associatively mediated (Experiments 1 and 2), observed when rats were or were…

Evidence for Decay in Verbal Short-Term Memory: A Commentary on Berman, Jonides, and Lewis (2009)

ERIC Educational Resources Information Center

Campoy, Guillermo

2012-01-01

M. G. Berman, J. Jonides, and R. L. Lewis (2009) adapted the recent-probes task to investigate the causes of forgetting in short-term memory. In 7 experiments, they studied the persistence of memory traces by assessing the level of proactive interference generated by previous-trial items over a range of intertrial intervals. None of the…

Medial Prefrontal Cortex Reduces Memory Interference by Modifying Hippocampal Encoding

PubMed Central

Guise, Kevin G.; Shapiro, Matthew L.

2017-01-01

Summary The prefrontal cortex (PFC) is crucial for accurate memory performance when prior knowledge interferes with new learning, but the mechanisms that minimize proactive interference are unknown. To investigate these, we assessed the influence of medial PFC (mPFC) activity on spatial learning and hippocampal coding in a plus maze task that requires both structures. mPFC inactivation did not impair spatial learning or retrieval per se, but impaired the ability to follow changing spatial rules. mPFC and CA1 ensembles recorded simultaneously predicted goal choices and tracked changing rules; inactivating mPFC attenuated CA1 prospective coding. mPFC activity modified CA1 codes during learning, which in turn predicted how quickly rats adapted to subsequent rule changes. The results suggest that task rules signaled by the mPFC become incorporated into hippocampal representations and support prospective coding. By this mechanism, mPFC activity prevents interference by “teaching” the hippocampus to retrieve distinct representations of similar circumstances. PMID:28343868

Temporal Dynamics of Motivation-Cognitive Control Interactions Revealed by High-Resolution Pupillometry

PubMed Central

Chiew, Kimberly S.; Braver, Todd S.

2013-01-01

Motivational manipulations, such as the presence of performance-contingent reward incentives, can have substantial influences on cognitive control. Previous evidence suggests that reward incentives may enhance cognitive performance specifically through increased preparatory, or proactive, control processes. The present study examined reward influences on cognitive control dynamics in the AX-Continuous Performance Task (AX-CPT), using high-resolution pupillometry. In the AX-CPT, contextual cues must be actively maintained over a delay in order to appropriately respond to ambiguous target probes. A key feature of the task is that it permits dissociable characterization of preparatory, proactive control processes (i.e., utilization of context) and reactive control processes (i.e., target-evoked interference resolution). Task performance profiles suggested that reward incentives enhanced proactive control (context utilization). Critically, pupil dilation was also increased on reward incentive trials during context maintenance periods, suggesting trial-specific shifts in proactive control, particularly when context cues indicated the need to overcome the dominant target response bias. Reward incentives had both transient (i.e., trial-by-trial) and sustained (i.e., block-based) effects on pupil dilation, which may reflect distinct underlying processes. The transient pupillary effects were present even when comparing against trials matched in task performance, suggesting a unique motivational influence of reward incentives. These results suggest that pupillometry may be a useful technique for investigating reward motivational signals and their dynamic influence on cognitive control. PMID:23372557

Event models and the fan effect.

PubMed

Radvansky, G A; O'Rear, Andrea E; Fisher, Jerry S

2017-08-01

The current study explored the persistence of event model organizations and how this influences the experience of interference during retrieval. People in this study memorized lists of sentences about objects in locations, such as "The potted palm is in the hotel." Previous work has shown that such information can either be stored in separate event models, thereby producing retrieval interference, or integrated into common event models, thereby eliminating retrieval interference. Unlike prior studies, the current work explored the impact of forgetting up to 2 weeks later on this pattern of performance. We explored three possible outcomes across the various retention intervals. First, consistent with research showing that longer delays reduce proactive and retroactive interference, any retrieval interference effects of competing event models could be reduced over time. Second, the binding of information into events models may weaken over time, causing interference effects to emerge when they had previously been absent. Third, and finally, the organization of information into event models could remain stable over long periods of time. The results reported here are most consistent with the last outcome. While there were some minor variations across the various retention intervals, the basic pattern of event model organization remained preserved over the two-week retention period.

Development of the updating executive function: From 7-year-olds to young adults.

PubMed

Carriedo, Nuria; Corral, Antonio; Montoro, Pedro R; Herrero, Laura; Rucián, Mercedes

2016-04-01

Updating information in working memory (WM) is a critical executive function responsible both for continuously replacing outdated information with new relevant data and to suppress or inhibit content that is no longer relevant according to task demands. The goal of the present research is twofold: First, we aimed to study updating development in 548 participants of 4 different age ranges--7-, 11-, and 15-year-olds and young adults--using the updating task devised by R. De Beni and P. Palladino (2004), which allows differentiating maintenance and inhibition processes. Second, we attempted to determine the relation between these processes across development as well as the differentiation among different types of inhibition processes tapped by this task. Results showed that there was an improvement of memory performance with age along with an upgrading of inhibitory efficiency. However, whereas in memory performance, a progressive increase was observed until the age of 15 years followed by stabilization, in inhibition, a continuous progressive increase was observed until young adulthood. Importantly, results showed that development of the different inhibitory mechanisms does not progress equally. All the groups committed more errors related to inefficient suppression mechanisms in WM than errors related to control of long-term memory interference. Principal component analysis showed that updating implies different subprocesses: active maintenance/suppression of information in WM and control of proactive interference. Developmental trajectories showed that the maintenance/suppression of information in the WM component continues to develop far beyond adolescence but that proactive interference control is responsible for variations in updating across development. (c) 2016 APA, all rights reserved).

Perirhinal Cortex Lesions in Rats: Novelty Detection and Sensitivity to Interference

PubMed Central

2015-01-01

Rats with perirhinal cortex lesions received multiple object recognition trials within a continuous session to examine whether they show false memories. Experiment 1 focused on exploration patterns during the first object recognition test postsurgery, in which each trial contained 1 novel and 1 familiar object. The perirhinal cortex lesions reduced time spent exploring novel objects, but did not affect overall time spent exploring the test objects (novel plus familiar). Replications with subsequent cohorts of rats (Experiments 2, 3, 4.1) repeated this pattern of results. When all recognition memory data were combined (Experiments 1–4), giving totals of 44 perirhinal lesion rats and 40 surgical sham controls, the perirhinal cortex lesions caused a marginal reduction in total exploration time. That decrease in time with novel objects was often compensated by increased exploration of familiar objects. Experiment 4 also assessed the impact of proactive interference on recognition memory. Evidence emerged that prior object experience could additionally impair recognition performance in rats with perirhinal cortex lesions. Experiment 5 examined exploration levels when rats were just given pairs of novel objects to explore. Despite their perirhinal cortex lesions, exploration levels were comparable with those of control rats. While the results of Experiment 4 support the notion that perirhinal lesions can increase sensitivity to proactive interference, the overall findings question whether rats lacking a perirhinal cortex typically behave as if novel objects are familiar, that is, show false recognition. Rather, the rats retain a signal of novelty but struggle to discriminate the identity of that signal. PMID:26030425

Proactive interference by cues presented without outcomes: Differences in context specificity of latent inhibition and conditioned inhibition.

PubMed

Miguez, Gonzalo; McConnell, Bridget; Polack, Cody W; Miller, Ralph R

2018-01-08

This report is part of a larger project examining associative interference as a function of the nature of the interfering and target associations. Lick suppression experiments with rats assessed the effects of context shifts on proactive outcome interference by latent inhibition (LI) and Pavlovian conditioned inhibition (CI) treatments on subsequently trained Pavlovian conditioned excitation treatment. LI and CI were trained in Context A during Phase 1, and then excitation treatment was administered in Context B during Phase 2, followed by tests for conditioned excitation in Contexts A, B, or C. Experiment 1 preliminarily established our LI and CI treatments and resulted in equally retarded acquisition of behavioral control when the target cue was subsequently trained as a conditioned excitor and tested in Context A. However, only CI treatment caused the target to pass a summation test for inhibition. Centrally, Experiment 2 consisted of LI and CI treatments in Context A followed by excitatory training in Context B. Testing found low excitatory control by both LI and CI cues in Context A relative to strong excitatory control in Context B, but CI treatment transferred to Context C more strongly than LI treatment. Experiment 3 determined that LI treatment failed to transfer to Context C even when the number of LI trials was greatly increased. Thus, first-learned LI appears to be relatively context specific, whereas first-learned CI generalizes to a neutral context. These observations add to existing evidence that LI and CI treatments result in different types of learning that diverge sharply in transfer to a novel test context.

Measurement of direct f0(980) photoproduction on the proton.

PubMed

Battaglieri, M; De Vita, R; Szczepaniak, A P; Adhikari, K P; Aghasyan, M; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Batourine, V; Bedlinskiy, I; Bellis, M; Benmouna, N; Berman, B L; Bibrzycki, L; Biselli, A S; Bookwalter, C; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Burkert, V D; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Chen, S; Cheng, L; Clinton, E; Cole, P L; Collins, P; Crabb, D; Crannell, H; Crede, V; Cummings, J P; Dale, D; Daniel, A; Dashyan, N; De Masi, R; De Sanctis, E; Degtyarenko, P V; Deur, A; Dhamija, S; Dharmawardane, K V; Dickson, R; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fersch, R; Forest, T A; Fradi, A; Gabrielyan, M Y; Gan, L; Garçon, M; Gasparian, A; Gavalian, G; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Glamazdin, O; Goett, J; Goetz, J T; Gohn, W; Golovatch, E; Gordon, C I O; Gothe, R W; Graham, L; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hanretty, C; Hardie, J; Hassall, N; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Juengst, H G; Kageya, T; Kalantarians, N; Keller, D; Kellie, J D; Khandaker, M; Khetarpal, P; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Konczykowski, P; Kossov, M; Krahn, Z; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Lee, T; Lesniak, L; Li, Ji; Livingston, K; Lowry, M; Lu, H Y; Maccormick, M; Malace, S; Markov, N; Mattione, P; McCracken, M E; McKinnon, B; Mecking, B A; Melone, J J; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Mineeva, T; Minehart, R; Mirazita, M; Miskimen, R; Mochalov, V; Mokeev, V; Moreno, B; Moriya, K; Morrow, S A; Moteabbed, M; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nakagawa, I; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Park, S; Pasyuk, E; Paris, M; Paterson, C; Pereira, S Anefalos; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Pozdniakov, S; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Sabatié, F; Saini, M S; Salamanca, J; Salgado, C; Sandorfi, A; Santoro, J P; Sapunenko, V; Schott, D; Schumacher, R A; Serov, V S; Sharabian, Y G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Starostin, A; Stavinsky, A; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Stopani, K A; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Teymurazyan, A; Tkabladze, A; Tkachenko, S; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Watts, D P; Wei, X; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yurov, M; Zana, L; Zhang, J; Zhao, B; Zhao, Z W

2009-03-13

We report on the results of the first measurement of exclusive f_{0}(980) meson photoproduction on protons for E_{gamma}=3.0-3.8 GeV and -t=0.4-1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the pi;{+}pi;{-} channel by performing a partial wave analysis of the reaction gammap-->ppi;{+}pi;{-}. Clear evidence of the f_{0}(980) meson was found in the interference between P and S waves at M_{pi;{+}pi;{-}} approximately 1 GeV. The S-wave differential cross section integrated in the mass range of the f_{0}(980) was found to be a factor of about 50 smaller than the cross section for the rho meson. This is the first time the f_{0}(980) meson has been measured in a photoproduction experiment.

Pan-arthropod analysis reveals somatic piRNAs as an ancestral defence against transposable elements.

PubMed

Lewis, Samuel H; Quarles, Kaycee A; Yang, Yujing; Tanguy, Melanie; Frézal, Lise; Smith, Stephen A; Sharma, Prashant P; Cordaux, Richard; Gilbert, Clément; Giraud, Isabelle; Collins, David H; Zamore, Phillip D; Miska, Eric A; Sarkies, Peter; Jiggins, Francis M

2018-01-01

In animals, small RNA molecules termed PIWI-interacting RNAs (piRNAs) silence transposable elements (TEs), protecting the germline from genomic instability and mutation. piRNAs have been detected in the soma in a few animals, but these are believed to be specific adaptations of individual species. Here, we report that somatic piRNAs were probably present in the ancestral arthropod more than 500 million years ago. Analysis of 20 species across the arthropod phylum suggests that somatic piRNAs targeting TEs and messenger RNAs are common among arthropods. The presence of an RNA-dependent RNA polymerase in chelicerates (horseshoe crabs, spiders and scorpions) suggests that arthropods originally used a plant-like RNA interference mechanism to silence TEs. Our results call into question the view that the ancestral role of the piRNA pathway was to protect the germline and demonstrate that small RNA silencing pathways have been repurposed for both somatic and germline functions throughout arthropod evolution.

Intragenomic conflict in populations infected by Parthenogenesis Inducing Wolbachia ends with irreversible loss of sexual reproduction

PubMed Central

2010-01-01

Background The maternally inherited, bacterial symbiont, parthenogenesis inducing (PI) Wolbachia, causes females in some haplodiploid insects to produce daughters from both fertilized and unfertilized eggs. The symbionts, with their maternal inheritance, benefit from inducing the production of exclusively daughters, however the optimal sex ratio for the nuclear genome is more male-biased. Here we examine through models how an infection with PI-Wolbachia in a previously uninfected population leads to a genomic conflict between PI-Wolbachia and the nuclear genome. In most natural populations infected with PI-Wolbachia the infection has gone to fixation and sexual reproduction is impossible, specifically because the females have lost their ability to fertilize eggs, even when mated with functional males. Results The PI Wolbachia infection by itself does not interfere with the fertilization process in infected eggs, fertilized infected eggs develop into biparental infected females. Because of the increasingly female-biased sex ratio in the population during a spreading PI-Wolbachia infection, sex allocation alleles in the host that cause the production of more sons are rapidly selected. In haplodiploid species a reduced fertilization rate leads to the production of more sons. Selection for the reduced fertilization rate leads to a spread of these alleles through both the infected and uninfected population, eventually resulting in the population becoming fixed for both the PI-Wolbachia infection and the reduced fertilization rate. Fertilization rate alleles that completely interfere with fertilization ("virginity alleles") will be selected over alleles that still allow for some fertilization. This drives the final resolution of the conflict: the irreversible loss of sexual reproduction and the complete dependence of the host on its symbiont. Conclusions This study shows that dependence among organisms can evolve rapidly due to the resolution of the conflicts between cytoplasmic and nuclear genes, and without requiring a mutualism between the partners. PMID:20667099

Phonetic Encoding and Its Impact on Short-Term Memory Abilities and Academic Tasks for Students with Learning Disabilities.

ERIC Educational Resources Information Center

Marini, Anthony E.

1990-01-01

The verbal encoding ability of 24 students (ages 14-20) with learning disabilities (LD) was compared to that of 24 non-learning-disabled subjects. LD subjects did not show a release from proactive interference, suggesting that such students are less likely to encode the phonetic features of words or use a phonetic code in short-term memory.…

Time-Based Loss in Visual Short-Term Memory is from Trace Decay, not Temporal Distinctiveness

PubMed Central

Ricker, Timothy J.; Spiegel, Lauren R.; Cowan, Nelson

2014-01-01

There is no consensus as to why forgetting occurs in short-term memory tasks. In past work, we have shown that forgetting occurs with the passage of time, but there are two classes of theories that can explain this effect. In the present work, we investigate the reason for time-based forgetting by contrasting the predictions of temporal distinctiveness and trace decay in the procedure in which we have observed such loss, involving memory for arrays of characters or letters across several seconds. The first theory, temporal distinctiveness, predicts that increasing the amount of time between trials will lead to less proactive interference, resulting in less forgetting across a retention interval. In the second theory, trace decay, temporal distinctiveness between trials is irrelevant to the loss over a retention interval. Using visual array change detection tasks in four experiments, we find small proactive interference effects on performance under some specific conditions, but no concomitant change in the effect of a retention interval. We conclude that trace decay is the more suitable class of explanations of the time-based forgetting in short-term memory that we have observed, and we suggest the need for further clarity in what the exact basis of that decay may be. PMID:24884646

Priming can affect naming colours using the study-test procedure. Revealing the role of task conflict.

PubMed

Sharma, Dinkar

2016-11-14

The Stroop paradigm has been widely used to study attention whilst its use to explore implicit memory have been mixed. Using the non-colour word Stroop task we tested contrasting predictions from the proactive-control/task-conflict model (Kalanthroff, Avnit, Henik, Davelaar & Usher, 2015) that implicate response conflict and task conflict for the priming effects. Using the study-test procedure 60 native English speakers were tested to determine whether priming effects from words that had previously been studied would cause interference when presented in a colour naming task. The results replicate a finding by MacLeod (1996) who showed no differences between the response latencies to studied and unstudied words. However, this pattern was predominately in the first half of the study where it was also found that both studied and unstudied words in a mixed block were slower to respond to than a block of pure unstudied words. The second half of the study showed stronger priming interference effects as well as a sequential modulation effect in which studied words slowed down the responses of studied words on the next trial. We discuss the role of proactive and reactive control processes and conclude that task conflict best explains the pattern of priming effects reported. Copyright © 2016. Published by Elsevier B.V.

Baseband pulse shaping for pi /4 FQPSK in nonlinearly amplified mobile channels

NASA Astrophysics Data System (ADS)

Subasinghe-Dias, Dileeka; Feher, Kamilo

1994-10-01

We apply baseband pulse shaping techniques for pi /4 QPSK in order to reduce the spectral regeneration of the bandlimited carrier after nonlinear amplification. These Feher's patented techniques, namely, pi /4 FQPSK (superposed QPSK) and pi /4 CTPSK (controlled transition PSK), may also be noncoherently demodulated. Application of these techniques is in fast fading, power efficient channels, typical of the mobile radio environment. Patents related to FQPSK are described. Computer simulation and experimental studies demonstrate that with these baseband waveshaping techniques, carrier envelope fluctuations are significantly reduced, and the out-of-band power after nonlinear amplification is suppressed by up to 20 dB compared to pi /4 QPSK. In frequency noninterleaved land or satellite mobile radio systems operating in a nonlinear, fading and ACI (adjacent channel interference) environment, these techniques may achieve 20%-50% higher spectral efficiency compared to pi /4 QPSK. In mobile cellular systems using pi /4 QPSK, such as the new North American and the Japanese digital cellular systems, the application of these baseband pulse shapes may allow more convenient and less costly amplifier linearization.

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

PubMed

Verneau, Marion; van der Kamp, John; Savelsbergh, Geert J P; de Looze, Michiel P

2015-03-01

We assessed the effects of aging in the transfer of motor learning in a sequential manual assembly task that is representative for real working conditions. On two different days, young (18-30 years) and middle-aged adults (50-65 years) practiced to build two products that consisted of the same six components but which had to be assembled in a partly different order. Assembly accuracy and movement time during tests, which were performed before and after the practice sessions, were compared to determine proactive and retroactive transfer. The results showed proactive facilitation (i.e., benefits from having learned the first product on learning the second one) in terms of an overall shortening of movement time in both age-groups. In addition, only the middle-aged adults were found to show sequence-specific proactive facilitation, in which the shortening of movement time was limited to components that had the same the order in the two products. Most likely, however, the sequence-specific transfer was an epiphenomenon of the comparatively low rate of learning among the middle-aged adults. The results, however, did reveal genuine differences between the groups for retroactive transfer (i.e., effects from learning the second product on performance of the first). Middle-aged adults tended to show more pronounced retroactive interference in terms of a general decrease in accuracy, while younger adults showed sequence-specific retroactive facilitation (i.e., shortening of movement times for components that had the same order in the two products), but only when they were fully accurate. Together this suggests that in the learning of sequential motor tasks the effects of age are more marked for retroactive transfer than for proactive transfer. Copyright © 2015 Elsevier B.V. All rights reserved.

Tips for Managing Your Classroom. Adapted from Chapter 4 of "What To Do With the Kid Who.... Developing Cooperation, Self-Discipline, and Responsibility in the Classroom, 2nd Edition." A SkyLight Guide.

ERIC Educational Resources Information Center

Burke, Kay

This booklet provides proactive guidelines to help teachers manage the classroom environment. The tips explain how to establish procedures and create rules for behavior that will enable teachers to clarify their expectations for the students and reduce the number of classroom incidents that interfere with instruction. The guidelines are intended…

Laboratory plasma interactions experiments: Results and implications to future space systems

NASA Technical Reports Server (NTRS)

Leung, Philip

1986-01-01

The experimental results discussed show the significance of the effects caused by spacecraft plasma interactions, in particular the generation of Electromagnetic Interference. As the experimental results show, the magnitude of the adverse effects induced by Plasma Interactions (PI) will be more significant for spacecraft of the next century. Therefore, research is needed to control possible adverse effects. Several techniques to control the selected PI effects are discussed. Tests, in the form of flight experiments, are needed to validate these proposed ideas.

Mechanism of Lysergic Acid Diethylamide Interference with Rabbit Antibody Biosynthesis

PubMed Central

Voss, Edward W.; Winkelhake, Jeffrey L.

1974-01-01

Lymphoid cells from hyperimmune rabbits producing antibodies to a hapten, incubated in the presence of d-lysergic acid diethylamide, continued to synthesize protein at a normal rate. Isoelectric focusing analysis of the low-molecular-weight protein secreted by the cells incubated with lysergic acid diethylamide indicated two components, with pI's of 4.9 and 5.2. Immune cells not exposed to lysergic acid diethylamide secreted only 7S IgG molecules with an average pI of approximately 7.0. PMID:4524614

Retroactive interference in short-term memory and the word-length effect.

PubMed

Campoy, Guillermo

2011-09-01

Two experiments investigated the possibility that the word-length effect in short-term memory (STM) is a consequence of long words generating a greater level of retroactive interference than shorter words. In Experiment 1, six-word lists were auditorily presented under articulatory suppression for immediate serial reconstruction of only the first three words. These three words were always drawn from a single set of middle-length words, whereas the last three positions were occupied by either short or long interfering words. The results showed worse memory performance when the to-be-remembered words were followed by long words. In Experiment 2, a recent-probes task was used, in which recent negative probes matched a target word in trial n-2. The results showed lower levels of proactive interference when trial n-1 involved long words instead of short words, suggesting that long words displaced previous STM content to a greater extent. By two different experimental approaches, therefore, this study shows that long words produce more retroactive interference than short words, supporting an interference-based account for the word-length effect. Copyright © 2011 Elsevier B.V. All rights reserved.

Negative Priming in Free Recall Reconsidered

PubMed Central

2015-01-01

Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and retrieval of task-relevant information. In 6 experiments, we tested the inhibitory account of the effect of negative priming in free recall against alternative accounts. We found that ignoring auditory distracters is neither sufficient nor necessary to produce the effect of negative priming in free recall. Instead, the effect is more readily accounted for by a buildup of proactive interference occurring whenever 2 successively presented lists of words are drawn from the same semantic category. PMID:26595066

Separation of Allelopathy from Resource Competition Using Rice/Barnyardgrass Mixed-Cultures

PubMed Central

Fang, Chang Xun; Lin, Zhi Hua; Yu, Zheng Ming; Lin, Wen Xiong

2012-01-01

Plant-plant interference is the combined effect of allelopathy, resource competition, and many other factors. Separating allelopathy from resource competition is almost impossible in natural systems but it is important to evaluate the relative contribution of each of the two mechanisms on plant interference. Research on allelopathy in natural and cultivated plant communities has been hindered in the absence of a reliable method that can separate allelopathic effect from resource competition. In this paper, the interactions between allelopathic rice accession PI312777, non-allelopathic rice accession Lemont and barnyardgrass were explored respectively by using a target (rice)-neighbor (barnyardgrass) mixed-culture in hydroponic system. The relative competitive intensity (RCI), the relative neighbor effect (RNE) and the competitive ratio (CR) were used to quantify the intensity of competition between each of the two different potentially allelopathic rice accessions and barnyardgrass. Use of hydroponic culture system enabled us to exclude any uncontrolled factors that might operate in the soil and we were able to separate allelopathy from resource competition between each rice accession and barnyardgrass. The RCI and RNE values showed that the plant-plant interaction was positive (facilitation) for PI312777 but that was negative (competition) for Lemont and barnyardgrass in rice/barnyardgrass mixed-cultures. The CR values showed that one PI312777 plant was more competitive than 2 barnyardgrass plants. The allelopathic effects of PI312777 were much more intense than the resource competition in rice/barnyardgrass mixed cultures. The reverse was true for Lemont. These results demonstrate that the allelopathic effect of PI312777 was predominant in rice/barnyardgrass mixed-cultures. The most significant result of our study is the discovery of an experimental design, target-neighbor mixed-culture in combination with competition indices, can successfully separate allelopathic effects from competition. PMID:22590655

Study of the K{sup +}{pi}{sup +}{pi}{sup -} final state in B{sup +}{yields}J/{psi}K{sup +}{pi}{sup +}{pi}{sup -} and B{sup +}{yields}{psi}'K{sup +}{pi}{sup +}{pi}{sup -}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guler, H.; McGill University, Montreal; Universite de Montreal, Montreal

Using 535x10{sup 6} B-meson pairs collected by the Belle detector at the KEKB e{sup +}e{sup -} collider, we measure branching fractions of (7.16{+-}0.10(stat){+-}0.60(syst)x10{sup -4} for B{sup +}{yields}J/{psi}K{sup +}{pi}{sup +}{pi}{sup -} and (4.31{+-}0.20(stat){+-}0.50(syst))x10{sup -4} for B{sup +}{yields}{psi}'K{sup +}{pi}{sup +}{pi}{sup -}. We perform amplitude analyses to determine the resonant structure of the K{sup +}{pi}{sup +}{pi}{sup -} final state in B{sup +}{yields}J/{psi}K{sup +}{pi}{sup +}{pi}{sup -} and B{sup +}{yields}{psi}'K{sup +}{pi}{sup +}{pi}{sup -} and find that the K{sub 1}(1270) is a prominent component of both decay modes. There is significant interference among the different intermediate states, which leads, in particular, to a striking distortion ofmore » the {rho} line shape due to the {omega}. Based on the results of the fit to the B{sup +}{yields}J/{psi}K{sup +}{pi}{sup +}{pi}{sup -} data, the relative decay fractions of the K{sub 1}(1270) to K{rho}, K{omega}, and K*(892){pi} are consistent with previous measurements, but the decay fraction to K{sub 0}*(1430) is significantly smaller. Finally, by floating the mass and width of the K{sub 1}(1270) in an additional fit of the B{sup +}{yields}J/{psi}K{sup +}{pi}{sup +}{pi}{sup -} data, we measure a mass of (1248.1{+-}3.3(stat){+-}1.4(syst)) MeV/c{sup 2} and a width of (119.5{+-}5.2(stat){+-}6.7(syst)) MeV/c{sup 2} for the K{sub 1}(1270).« less

PiHOG1, a stress regulator MAP kinase from the root endophyte fungus Piriformospora indica, confers salinity stress tolerance in rice plants

PubMed Central

Jogawat, Abhimanyu; Vadassery, Jyothilakshmi; Verma, Nidhi; Oelmüller, Ralf; Dua, Meenakshi; Nevo, Eviatar; Johri, Atul Kumar

2016-01-01

In this study, yeast HOG1 homologue from the root endophyte Piriformospora indica (PiHOG1) was isolated and functionally characterized. Functional expression of PiHOG1 in S. cerevisiae ∆hog1 mutant restored osmotolerance under high osmotic stress. Knockdown (KD) transformants of PiHOG1 generated by RNA interference in P. indica showed that genes for the HOG pathway, osmoresponse and salinity tolerance were less stimulated in KD-PiHOG1 compared to the wild-type under salinity stress. Furthermore, KD lines are impaired in the colonization of rice roots under salinity stress of 200 mM NaCl, and the biomass of the host plants, their shoot and root lengths, root number, photosynthetic pigment and proline contents were reduced as compared to rice plants colonized by WT P. indica. Therefore, PiHOG1 is critical for root colonisation, salinity tolerance and the performance of the host plant under salinity stress. Moreover, downregulation of PiHOG1 resulted not only in reduced and delayed phosphorylation of the remaining PiHOG1 protein in colonized salinity-stressed rice roots, but also in the downregulation of the upstream MAP kinase genes PiPBS2 and PiSSK2 involved in salinity tolerance signalling in the fungus. Our data demonstrate that PiHOG1 is not only involved in the salinity response of P. indica, but also helping host plant to overcome salinity stress. PMID:27849025

Measurement of the spin of the {xi}(1530) resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Karyotakis, Y.

The properties of the {xi}(1530) resonance are investigated in the {lambda}{sub c}{sup +}{yields}{xi}{sup -}{pi}{sup +}K{sup +} decay process. The data sample was collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collider operating at center-of-mass energies 10.58 and 10.54 GeV. The corresponding integrated luminosity is approximately 230 fb{sup -1}. The spin of the {xi}(1530) is established to be 3/2. The existence of an S-wave amplitude in the {xi}{sup -}{pi}{sup +} system is inferred, and its interference with the {xi}(1530){sup 0} amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the {xi}(1530). Themore » P{sub 1}(cos{theta}{sub {xi}}{sub {sup -}}) Legendre polynomial moment indicates the presence of a significant S-wave amplitude for {xi}{sup -}{pi}{sup +} mass values above 1.6 GeV/c{sup 2}, and a dip in the mass distribution at approximately 1.7 GeV/c{sup 2} is interpreted as due to the coherent addition of a {xi}(1690){sup 0} contribution to this amplitude. This would imply J{sup P}=1/2{sup -} for the {xi}(1690). Attempts at fitting the {xi}(1530){sup 0} line shape yield unsatisfactory results, and this failure is attributed to interference effects associated with the amplitudes describing the K{sup +}{pi}{sup +} and/or {xi}{sup -}K{sup +} systems.« less

Measurement of the Spin of the $$\\Xi(1530)$$ Resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Karyotakis, Y.

The properties of the {Xi}(1530) resonance are investigated in the {Lambda}{sub c}{sup +} {yields} {Xi}{sup -}{pi}{sup +}K{sup +} decay process. The data sample was collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collider operating at center of mass energies 10.58 and 10.54 GeV. The corresponding integrated luminosity is approximately 230 fb{sup -1}. The spin of the {Xi}(1530) is established to be 3/2. The existence of an S-wave amplitude in the {Xi}{sup -}{pi}{sup +} system is inferred, and its interference with the {Xi}(1530)0 amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected formore » the {Xi}(1530). The P{sub 1}(cos {theta}{sub {Xi}{sup -}}) Legendre polynomial moment indicates the presence of a significant S-wave amplitude for {Xi}{sup -}{pi}{sup +} mass values above 1.6 GeV/c{sup 2}, and a dip in the mass distribution at approximately 1.7 GeV/c{sup 2} is interpreted as due to coherent addition of a {Xi}(1690){sup 0} contribution to this amplitude. This would imply J{sup P} = 1/2{sup -} for the {Xi}(1690). Attempts at fitting the {Xi}(1530){sup 0} lineshape yield unsatisfactory results, and this failure is attributed to interference effects associated with the amplitudes describing the K{sup +}{pi}{sup +} and/or {Xi}{sup -}K{sup +} systems.« less

Time-based loss in visual short-term memory is from trace decay, not temporal distinctiveness.

PubMed

Ricker, Timothy J; Spiegel, Lauren R; Cowan, Nelson

2014-11-01

There is no consensus as to why forgetting occurs in short-term memory tasks. In past work, we have shown that forgetting occurs with the passage of time, but there are 2 classes of theories that can explain this effect. In the present work, we investigate the reason for time-based forgetting by contrasting the predictions of temporal distinctiveness and trace decay in the procedure in which we have observed such loss, involving memory for arrays of characters or letters across several seconds. The 1st theory, temporal distinctiveness, predicts that increasing the amount of time between trials will lead to less proactive interference, resulting in less forgetting across a retention interval. In the 2nd theory, trace decay, temporal distinctiveness between trials is irrelevant to the loss over a retention interval. Using visual array change detection tasks in 4 experiments, we find small proactive interference effects on performance under some specific conditions, but no concomitant change in the effect of a retention interval. We conclude that trace decay is the more suitable class of explanations of the time-based forgetting in short-term memory that we have observed, and we suggest the need for further clarity in what the exact basis of that decay may be. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Recovery from Proactive Semantic Interference and MRI Volume: A Replication and Extension Study.

PubMed

Loewenstein, David A; Curiel, Rosie E; DeKosky, Steven; Rosselli, Monica; Bauer, Russell; Grieg-Custo, Maria; Penate, Ailyn; Li, Chunfei; Lizagarra, Gabriel; Golde, Todd; Adjouadi, Malek; Duara, Ranjan

2017-01-01

The rise in incidence of Alzheimer's disease (AD) has led to efforts to advance early detection of the disease during its preclinical stages. To achieve this, the field needs to develop more sensitive cognitive tests that relate to biological markers of disease pathology. Failure to recover from proactive interference (frPSI) is one such cognitive marker that is associated with volumetric reductions in the hippocampus, precuneus, and other AD-prone regions, and to amyloid load in the brain. The current study attempted to replicate and extend our previous findings that frPSI is a sensitive marker of early AD, and related to a unique pattern of volumetric loss in AD prone areas. Three different memory measures were examined relative to volumetric loss and cortical thickness among 45 participants with amnestic mild cognitive impairment. frPSI was uniquely associated with reduced volumes in the hippocampus (r = 0.50) precuneus (r = 0.41), and other AD prone regions, replicating previous findings. Strong associations between frPSI and lower entorhinal cortex volumes and cortical thickness (r≥0.60) and precuneus (r = 0.50) were also observed. Unique and strong associations between volumetric reductions and frPSI as observed by Loewenstein and colleagues were replicated. Together with cortical thickness findings, these results indicate that frPSI is worthy of further study as a sensitive and early cognitive marker of AD.

Using smartphone video “selfies” to monitor change in toothbrushing behavior after a brief intervention: A pilot study

PubMed Central

Kumar, Parangimalai Diwakar Madan; Mohandoss, Anusa Arunachalam; Walls, Theodore; Rooban, Thavarajah; Vernon, Lance T

2018-01-01

Background Attempts to refine toothbrushing (TB) technique, an ingrained habit in adults, can meet with some challenges. Recently, the role of proactive interference as a barrier to improving the learning of proper brushing has been proposed. This pilot feasibility study was designed to investigate TB behavior and to see how it changes after training. Smartphone video “selfies” (SPVSs) are increasingly being used in the medical field to assess, monitor, and determine the progression of diseases. Materials and Methods We used SPVS to study TB skills in a small sample of volunteers. Over a period of 14 days, after a one-time group training session, we observed TB behavior of volunteers using self-captured SPVS. Results Following the brief intervention, we observed an 8% of improvement in TB skills. Discussion To the best of our knowledge, this is the first report using SPVS to study TB behavior. We demonstrated initial feasibility of using SPVS in the dental setting. We observed modest improvements in toothbrushing accuracy and quality, and we generated important experiences about the use of Selfies for TB monitoring and intervention, and some interesting insights about where in the toothbrushing is more or less effective. Conclusion Further investigation using a larger sample size is needed to thoroughly assess the effectiveness of this approach to improve TB skills and better understand the role of proactive interference. PMID:27411655

Analysis of multi-channel microscopy: Spectral self-interference, multi-detector confocal and 4Pi systems

NASA Astrophysics Data System (ADS)

Davis, Brynmor J.

Fluorescence microscopy is an important and ubiquitous tool in biological imaging due to the high specificity with which fluorescent molecules can be attached to an organism and the subsequent nondestructive in-vivo imaging allowed. Focused-light microscopies allow three-dimensional fluorescence imaging but their resolution is restricted by diffraction. This effect is particularly limiting in the axial dimension as the diffraction-limited focal volume produced by a lens is more extensive along the optical axis than perpendicular to it. Approaches such as confocal microscopy and 4Pi microscopy have been developed to improve the axial resolution. Spectral Self-Interference Fluorescence Microscopy (SSFM) is another high-axial-resolution technique and is the principal subject of this dissertation. Nanometer-precision localization of a single fluorescent layer has been demonstrated using SSFM. This accuracy compares favorably with the axial resolutions given by confocal and 4Pi systems at similar operating parameters (these resolutions are approximately 350nm and 80nm respectively). This theoretical work analyzes the expected performance of the SSFM system when imaging a general object, i.e. an arbitrary fluorophore density function rather than a single layer. An existing model of SSFM is used in simulations to characterize the system's resolution. Several statistically-based reconstruction methods are applied to show that the expected resolution for SSFM is similar to 4Pi microscopy for a general object but does give very high localization accuracy when the object is known to consist of a limited number of layers. SSFM is then analyzed in a linear systems framework and shown to have strong connections, both physically and mathematically, to a multi-channel 4Pi microscope. Fourier-domain analysis confirms that SSFM cannot be expected to outperform this multi-channel 4Pi instrument. Differences between the channels in spatial-scanning, multi-channel microscopies are then exploited to show that such instruments can operate at a sub-Nyquist scanning rate but still produce images largely free of aliasing effects. Multi-channel analysis is also used to show how light typically discarded in confocal and 4Pi systems can be collected and usefully incorporated into the measured image.

Dysfunctional overnight memory consolidation in ecstasy users.

PubMed

Smithies, Vanessa; Broadbear, Jillian; Verdejo-Garcia, Antonio; Conduit, Russell

2014-08-01

Sleep plays an important role in the consolidation and integration of memory in a process called overnight memory consolidation. Previous studies indicate that ecstasy users have marked and persistent neurocognitive and sleep-related impairments. We extend past research by examining overnight memory consolidation among regular ecstasy users (n=12) and drug naïve healthy controls (n=26). Memory recall of word pairs was evaluated before and after a period of sleep, with and without interference prior to testing. In addition, we assessed neurocognitive performances across tasks of learning, memory and executive functioning. Ecstasy users demonstrated impaired overnight memory consolidation, a finding that was more pronounced following associative interference. Additionally, ecstasy users demonstrated impairments on tasks recruiting frontostriatal and hippocampal neural circuitry, in the domains of proactive interference memory, long-term memory, encoding, working memory and complex planning. We suggest that ecstasy-associated dysfunction in fronto-temporal circuitry may underlie overnight consolidation memory impairments in regular ecstasy users. © The Author(s) 2014.

The power of instructions: Proactive configuration of stimulus-response translation.

PubMed

Meiran, Nachshon; Pereg, Maayan; Kessler, Yoav; Cole, Michael W; Braver, Todd S

2015-05-01

Humans are characterized by an especially highly developed ability to use instructions to prepare toward upcoming events; yet, it is unclear just how powerful instructions can be. Although prior work provides evidence that instructions can be sufficiently powerful to proactively program working memory to execute stimulus-response (S-R) translations, in a reflexlike fashion (intention-based reflexivity [IBR]), the results to date have been equivocal. To overcome this shortcoming, we developed, and tested in 4 studies, a novel paradigm (the NEXT paradigm) that isolates IBR effects even prior to first task execution. In each miniblock, participants received S-R mapping instructions for a new task. Prior to implementing this mapping, responses were required to advance through screens during a preparatory (NEXT) phase. When the NEXT response was incompatible with the instructed S-R mapping, interference (IBR effect) was observed. This NEXT compatibility effect and performance in the implementation (GO) trials barely changed when prior practice of a few trials was provided. Finally, a manipulation that encouraged preparation resulted in relatively durable NEXT compatibility effects (indicating durable preparatory efforts) coupled with improved GO performance (indicating the success of these efforts). Together, these findings establish IBR as a marker of instructed proactive control. (c) 2015 APA, all rights reserved).

Targeting phosphoinositide 3-kinase: moving towards therapy.

PubMed

Marone, Romina; Cmiljanovic, Vladimir; Giese, Bernd; Wymann, Matthias P

2008-01-01

Phosphoinositide 3-kinases (PI3K) orchestrate cell responses including mitogenic signaling, cell survival and growth, metabolic control, vesicular trafficking, degranulation, cytoskeletal rearrangement and migration. Deregulation of the PI3K pathway occurs by activating mutations in growth factor receptors or the PIK3CA locus coding for PI3Kalpha, by loss of function of the lipid phosphatase and tensin homolog deleted in chromosome ten (PTEN/MMAC/TEP1), by the up-regulation of protein kinase B (PKB/Akt), or the impairment of the tuberous sclerosis complex (TSC1/2). All these events are linked to growth and proliferation, and have thus prompted a significant interest in the pharmaceutical targeting of the PI3K pathway in cancer. Genetic targeting of PI3Kgamma (p110gamma) and PI3Kdelta (p110delta) in mice has underlined a central role of these PI3K isoforms in inflammation and allergy, as they modulate chemotaxis of leukocytes and degranulation in mast cells. Proof-of-concept molecules selective for PI3Kgamma have already successfully alleviated disease progress in murine models of rheumatoid arthritis and lupus erythematosus. As targeting PI3K moves forward to therapy of chronic, non-fatal disease, safety concerns for PI3K inhibitors increase. Many of the present inhibitor series interfere with target of rapamycin (TOR), DNA-dependent protein kinase (DNA-PK(cs)) and activity of the ataxia telangiectasia mutated gene product (ATM). Here we review the current disease-relevant knowledge for isoform-specific PI3K function in the above mentioned diseases, and review the progress of >400 recent patents covering pharmaceutical targeting of PI3K. Currently, several drugs targeting the PI3K pathway have entered clinical trials (phase I) for solid tumors and suppression of tissue damage after myocardial infarction (phases I,II).

Media Access Time-Rearrangement of Wireless LAN for a Multi-Radio Collocated Platform

NASA Astrophysics Data System (ADS)

Shin, Sang-Heon; Kim, Chul; Park, Sang Kyu

With the advent of new Radio Access Technologies (RATs), it is inevitable that several RATs will co-exist, especially in the license-exempt band. In this letter, we present an in-depth adaptation of the proactive time-rearrangement (PATRA) scheme for IEEE 802.11 WLAN. The PATRA is a time division approach for reducing interference from a multi-radio device. Because IEEE 802.11 is based on carrier sensing and contention mechanism, it is the most suitable candidate to adapt the PATRA.

Neuropeptide-Y both Improves and Impairs Delayed Matching-to-Sample Performance in Rats

DTIC Science & Technology

1991-01-01

Neuropeptide Y distribution in the 422 THOMAS AND AHLERS rat brain. Science 221:877-879; 1983. of animal learning. In: Roitblat , H. L.; Bever, T. G.; Terrace, H...Sources of proactive interference in memory. Hillsdale, NJ: Erlbaum; 1976. animal memory. J. Exp. Psychol. (Anim. Behav.) 1456-70; 1988. 32. Roitblat , H...memory processing by neuropeptide Y varies with brain 33. Roitblat , H. L., Scopatz, R. A. Sequential effects in pigeons de- injection site. Brain Res

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Bin; Liu, Ning-Ning; Liu, Wei-Hua

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and GATA Binding Protein 4 (GATA4) are important for the growth of cardiac fibroblasts (CFs). When deregulated, LOX-1 and GATA4 can cause cardiac remodeling. In the present study, we found novel evidence that GATA4 was required for the LOX-1 regulation of CF proliferation. The inhibition of LOX-1 by RNA interference LOX-1 lentivirus resulted in the loss of PI3K/Akt activation and GATA4 protein expression. The overexpression of LOX-1 by lentivirus rescued CF proliferation, PI3K/Akt activation, and GATA4 protein expression. Moreover, GATA4 overexpression enhanced CF proliferation with LOX-1 inhibition. We also found that the inhibition ofmore » PI3K/Akt activation by LY294002, a PI3K inhibitor, reduced cell proliferation and protein level of GATA4. In summary, GATA4 may play an important role in the LOX-1 and PI3K/Akt regulation of CF proliferation. -- Highlights: •GATA4 is regulated by LOX-1 signaling in CFs. •GATA4 is involved in LOX-1 regulating CF proliferation. •GATA4 is regulated by PI3K/Akt signaling in CFs.« less

Auditory proactive interference in monkeys: The role of stimulus set size and intertrial interval

PubMed Central

Bigelow, James; Poremba, Amy

2013-01-01

We conducted two experiments to examine the influence of stimulus set size (the number of stimuli that are used throughout the session) and intertrial interval (ITI, the elapsed time between trials) in auditory short-term memory in monkeys. We used an auditory delayed matching-to-sample task wherein the animals had to indicate whether two sounds separated by a 5-s retention interval were the same (match trials) or different (non-match trials). In Experiment 1, we randomly assigned a stimulus set size of 2, 4, 8, 16, 32, 64, or 192 (trial unique) for each session of 128 trials. Consistent with previous visual studies, overall accuracy was consistently lower when smaller stimulus set sizes were used. Further analyses revealed that these effects were primarily caused by an increase in incorrect “same” responses on non-match trials. In Experiment 2, we held the stimulus set size constant at four for each session and alternately set the ITI at 5, 10, or 20 s. Overall accuracy improved by increasing the ITI from 5 to 10 s, but the 10 and 20 s conditions were the same. As in Experiment 1, the overall decrease in accuracy during the 5-s condition was caused by a greater number of false “match” responses on non-match trials. Taken together, Experiments 1 and 2 show that auditory short-term memory in monkeys is highly susceptible to PI caused by stimulus repetition. Additional analyses from Experiment 1 suggest that monkeys may make same/different judgments based on a familiarity criterion that is adjusted by error-related feedback. PMID:23526232

Interference techniques in fluorescence microscopy

NASA Astrophysics Data System (ADS)

Dogan, Mehmet

We developed a set of interference-based optical microscopy techniques to study biological structures through nanometer-scale axial localization of fluorescent biomarkers. Spectral self-interference fluorescence microscopy (SSFM) utilizes interference of direct and reflected waves emitted from fluorescent molecules in the vicinity of planar reflectors to reveal the axial position of the molecules. A comprehensive calculation algorithm based on Green's function formalism is presented to verify the validity of approximations used in a far-field approach that describes the emission of fluorescent markers near interfaces. Using the validated model, theoretical limits of axial localization were determined with emphasis given to numerical aperture (NA) dependence of localization uncertainty. SSFM was experimentally demonstrated in conformational analysis of nucleoproteins. In particular, interaction between surface-tethered 75-mer double strand DNA and integration host factor (IHF) protein was probed on Si-SiO2 substrates by determining the axial position of fluorescent labels attached to the free ends of DNA molecules. Despite its sub-nanometer precision axial localization capability, SSFM lacks high lateral resolution due to the low-NA requirement for planar reflectors. We developed a second technique, 4Pi-SSFM, which improves the lateral resolution of a conventional SSFM system by an order of magnitude while achieving nanometer-scale axial localization precision. Using two opposing high-NA objectives, fluorescence signal is interferometrically collected and spectral interference pattern is recorded. Axial position of emitters is found from analysis of the spectra. The 4Pi-SSFM technique was experimentally demonstrated by determining the surface profiles of fabricated glass surfaces and outer membranes of Shigella, a type of Gram-negative bacteria. A further discussion is presented to localize surface O antigen, which is an important oligosaccharide structure in the virulence mechanism of the Gram-negative bacteria, including E. coli and Shigella.

4Pi microscopy of the nuclear pore complex.

PubMed

Kahms, Martin; Hüve, Jana; Peters, Reiner

2015-01-01

4Pi microscopy is a far-field fluorescence microscopy technique, in which the wave fronts of two opposing illuminating beams are adjusted to constructively interfere in a common focus. This yields a diffraction pattern in the direction of the optical axis, which essentially consists of a main focal spot accompanied by two smaller side lobes. At optimal conditions, the main peak of this so-called point spread function has a full width at half maximum: fixed phrase of 100 nm in the direction of the optical axis, and thus is 6-7-fold smaller than that of a confocal microscope. In this chapter, we describe the basic features of 4Pi microscopy and its application to cell biology using the example of the nuclear pore complex, a large protein assembly spanning the nuclear envelope.

Effects of prestudy and poststudy rest on memory: Support for temporal interference accounts of forgetting.

PubMed

Ecker, Ullrich K H; Tay, Jia-Xin; Brown, Gordon D A

2015-06-01

According to interference-based theories of memory, including temporal-distinctiveness theory, both prestudy and poststudy rest should have beneficial impacts on memory performance. Specifically, higher temporal isolation of a memorandum should reduce proactive and/or retroactive interference, and thus should result in better recall. In the present study, we investigated the effects of prestudy and poststudy rest in a free recall paradigm. Participants studied three lists of words, separated by either a short or a long period of low mental activity (a tone-detection task). Recall targeted the second list; this list was studied in one of four conditions, defined by the fully crossed factors of prestudy and poststudy rest duration. Two experiments revealed a beneficial effect of prestudy rest (and, to a lesser extent, of poststudy rest) on list recall. This result is in line with interference-based theories of memory. By contrast, a beneficial effect of prestudy rest is not predicted by consolidation accounts of memory and forgetting; our results thus require additional assumptions and/or a better specification of the consolidation process and its time course in order to be reconciled with consolidation theory.

Phosphate-Dependent Root System Architecture Responses to Salt Stress1[OPEN

PubMed Central

Sommerfeld, Hector Montero; ter Horst, Anneliek; Haring, Michel A.

2016-01-01

Nutrient availability and salinity of the soil affect the growth and development of plant roots. Here, we describe how inorganic phosphate (Pi) availability affects the root system architecture (RSA) of Arabidopsis (Arabidopsis thaliana) and how Pi levels modulate responses of the root to salt stress. Pi starvation reduced main root length and increased the number of lateral roots of Arabidopsis Columbia-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75 mm) on all measured RSA components. At higher salt concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid signaling compared with the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general, lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied, and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By genome-wide association mapping, 12 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses. PMID:27208277

Interleukin-10-induced gene expression and suppressive function are selectively modulated by the PI3K-Akt-GSK3 pathway

PubMed Central

Antoniv, Taras T; Ivashkiv, Lionel B

2011-01-01

Interleukin-10 (IL-10) is an immunosuppressive cytokine that inhibits inflammatory gene expression. Phosphatidylinositol 3-kinase (PI3K) -mediated signalling regulates inflammatory responses and can induce IL-10 production, but a role for PI3K signalling in cellular responses to IL-10 is not known. In this study we investigated the involvement of the PI3K-Akt-GSK3 signalling pathway in IL-10-induced gene expression and IL-10-mediated suppression of Toll-like receptor-induced gene expression in primary human macrophages. A combination of loss and gain of function approaches using kinase inhibitors, expression of constitutively active Akt, and RNA interference in primary human macrophages showed that expression of a subset of IL-10-inducible genes was dependent on PI3K-Akt signalling. The effects of PI3K-Akt signalling on IL-10 responses were mediated at least in part by glycogen synthase kinase 3 (GSK3). In accordance with a functional role for PI3K pathways in contributing to the suppressive actions of IL-10, PI3K signalling augmented IL-10-mediated inhibition of lipopolysaccharide-induced IL-1, IL-8 and cyclo-oxygenase-2 expression. The PI3K signalling selectively modulated IL-10 responses, as it was not required for inhibition of tumour necrosis factor expression or for induction of certain IL-10-inducible genes such as SOCS3. These findings identify a new mechanism by which PI3K-mediated signalling can suppress inflammation by regulating IL-10-mediated gene induction and anti-inflammatory function. PMID:21255011

Copper nanocluster coupling europium as an off-to-on fluorescence probe for the determination of phosphate ion in water samples.

PubMed

Cao, Haiyan; Chen, Zhaohui; Huang, Yuming

2015-10-01

This paper reports an "off-to-on" fluorescence (FL) probe for sensitively and selectively detecting phosphate ions (Pi's). Fabrication of the probe was based on the competition between Pi's and tannic acid-stabilized copper nanoclusters (TA-Cu NCs) for Eu(3+) binding. The addition of Eu(3+) ions to TA-Cu NCs triggered the aggregation of TA-Cu NCs, which quenched the FL of TA-Cu NCs. After Pi addition, the aggregated TA-Cu NCs solubilized into the aqueous solution to facilitate the Pi-triggered dispersion of TA-Cu NCs. This phenomenon was due to the stronger binding ability between Pi's and Eu(3+) than that between TA and Eu(3+), leading to FL recovery of Cu NCs. The degree of redispersion of TA-Cu NCs was directly related to Pi concentration. Thus, Pi concentration can be quantitatively determined by the change in FL of the TA-Cu NCs dispersion. Under the optimized conditions, the change in FL presented a linear relationship with Pi concentration from 0.07 μmol L(-1) to 80 μmol L(-1). The limit of detection for Pi was 9.6×10(-3) μmol L(-1) at a signal-to-noise ratio of 3. For Pi determination in real samples, only 1 mL water sample was needed. The proposed probe was highly sensitive, free from the interference of other common species in aqueous media, and particularly useful for the fast and simple diagnosis of water-eutrophication extent. Copyright © 2015 Elsevier B.V. All rights reserved.

Differential changes in hippocampal CaMKII and GluA1 activity after memory training involving different levels of adaptive forgetting

PubMed Central

Fraize, Nicolas; Hamieh, Al Mahdy; Joseph, Mickaël Antoine; Touret, Monique; Parmentier, Régis; Salin, Paul Antoine; Malleret, Gaël

2017-01-01

Phosphorylation of CaMKII and AMPA receptor GluA1 subunit has been shown to play a major role in hippocampal-dependent long-term/reference memory (RM) and in the expression of long-term synaptic potentiation (LTP). In contrast, it has been proposed that dephosphorylation of these proteins could be involved in the opposite phenomenon of hippocampal long-term synaptic depression (LTD) and in adaptive forgetting. Adaptive forgetting allows interfering old memories to be forgotten to give new ones the opportunity to be stored in memory, and in particular in short-term/working memory (WM) that was shown to be very sensitive to proactive interference. To determine the role of CaMKII and GluA1 in adaptive forgetting, we adopted a comparative approach to assess the relative quantity and phosphorylation state of these proteins in the brain of rats trained in one of three radial maze paradigms: a RM task, a WM task involving a high level of adaptive forgetting, or a WM involving a low level of adaptive forgetting. Surprisingly, Western blot analyses revealed that training in a WM task involving a high level of adaptive forgetting specifically increased the expression of AMPA receptor GluA1 subunit and the activity of CaMKII in the dentate gyrus. These results highlight that WM with proactive interference involves mechanisms of synaptic plasticity selectively in the dentate gyrus. PMID:28096498

Differential changes in hippocampal CaMKII and GluA1 activity after memory training involving different levels of adaptive forgetting.

PubMed

Fraize, Nicolas; Hamieh, Al Mahdy; Joseph, Mickaël Antoine; Touret, Monique; Parmentier, Régis; Salin, Paul Antoine; Malleret, Gaël

2017-02-01

Phosphorylation of CaMKII and AMPA receptor GluA1 subunit has been shown to play a major role in hippocampal-dependent long-term/reference memory (RM) and in the expression of long-term synaptic potentiation (LTP). In contrast, it has been proposed that dephosphorylation of these proteins could be involved in the opposite phenomenon of hippocampal long-term synaptic depression (LTD) and in adaptive forgetting. Adaptive forgetting allows interfering old memories to be forgotten to give new ones the opportunity to be stored in memory, and in particular in short-term/working memory (WM) that was shown to be very sensitive to proactive interference. To determine the role of CaMKII and GluA1 in adaptive forgetting, we adopted a comparative approach to assess the relative quantity and phosphorylation state of these proteins in the brain of rats trained in one of three radial maze paradigms: a RM task, a WM task involving a high level of adaptive forgetting, or a WM involving a low level of adaptive forgetting. Surprisingly, Western blot analyses revealed that training in a WM task involving a high level of adaptive forgetting specifically increased the expression of AMPA receptor GluA1 subunit and the activity of CaMKII in the dentate gyrus. These results highlight that WM with proactive interference involves mechanisms of synaptic plasticity selectively in the dentate gyrus. © 2017 Fraize et al.; Published by Cold Spring Harbor Laboratory Press.

Lexical selection in the semantically blocked cyclic naming task: the role of cognitive control and learning

PubMed Central

Crowther, Jason E.; Martin, Randi C.

2014-01-01

Studies of semantic interference in language production have provided evidence for a role of cognitive control mechanisms in regulating the activation of semantic competitors during naming. The present study investigated the relationship between individual differences in cognitive control abilities, for both younger and older adults, and the degree of semantic interference in a blocked cyclic naming task. We predicted that individuals with lower working memory capacity (as measured by word span), lesser ability to inhibit distracting responses (as measured by Stroop interference), and a lesser ability to resolve proactive interference (as measured by a recent negatives task) would show a greater increase in semantic interference in naming, with effects being larger for older adults. Instead, measures of cognitive control were found to relate to specific indices of semantic interference in the naming task, rather than overall degree of semantic interference, and few interactions with age were found, with younger and older adults performing similarly. The increase in naming latencies across naming trials within a cycle was negatively correlated with word span for both related and unrelated conditions, suggesting a strategy of narrowing response alternatives based upon memory for the set of item names. Evidence for a role of inhibition in response selection was obtained, as Stroop interference correlated positively with the change in naming latencies across cycles for the related, but not unrelated, condition. In contrast, recent negatives interference correlated negatively with the change in naming latencies across unrelated cycles, suggesting that individual differences in this tap the degree of strengthening of links in a lexical network based upon prior exposure. Results are discussed in terms of current models of lexical selection and consequences for word retrieval in more naturalistic production. PMID:24478675

Proactive Motor Control Reduces Monetary Risk Taking in Gambling

PubMed Central

Adams, Rachel; Chambers, Christopher D.

2012-01-01

Less supervision by the executive system after disruption of the right prefrontal cortex leads to increased risk taking in gambling because superficially attractive—but risky—choices are not suppressed. Similarly, people might gamble more in multitask situations than in single-task situations because concurrent executive processes usually interfere with each other. In the study reported here, we used a novel monetary decision-making paradigm to investigate whether multitasking could reduce rather than increase risk taking in gambling. We found that performing a task that induced cautious motor responding reduced gambling in a multitask situation (Experiment 1). We then found that a short period of inhibitory training lessened risk taking in gambling at least 2 hr later (Experiments 2 and 3). Our findings indicate that proactive motor control strongly affects monetary risk taking in gambling. The link between control systems at different cognitive levels might be exploited to develop new methods for rehabilitation of addiction and impulse-control disorders. PMID:22692336

Overexpression of the protein phosphatase 2A regulatory subunit a gene ZmPP2AA1 improves low phosphate tolerance by remodeling the root system architecture of maize

PubMed Central

Wang, Jiemin; Pei, Laming; Jin, Zhe; Zhang, Kewei; Zhang, Juren

2017-01-01

Phosphate (Pi) limitation is a constraint for plant growth and development in many natural and agricultural ecosystems. In this study, a gene encoding Zea mays L. protein phosphatase 2A regulatory subunit A, designated ZmPP2AA1, was induced in roots by low Pi availability. The function of the ZmPP2AA1 gene in maize was analyzed using overexpression and RNA interference. ZmPP2AA1 modulated root gravitropism, negatively regulated primary root (PR) growth, and stimulated the development of lateral roots (LRs). A detailed characterization of the root system architecture (RSA) in response to different Pi concentrations with or without indole-3-acetic acid and 1-N-naphthylphthalamic acid revealed that auxin was involved in the RSA response to low Pi availability. Overexpression of ZmPP2AA1 enhanced tolerance to Pi starvation in transgenic maize in hydroponic and soil pot experiments. An increased dry weight (DW), root-to-shoot ratio, and total P content and concentration, along with a delayed and reduced accumulation of anthocyanin in overexpressing transgenic maize plants coincided with their highly branched root system and increased Pi uptake capability under low Pi conditions. Inflorescence development of the ZmPP2AA1 overexpressing line was less affected by low Pi stress, resulting in higher grain yield per plant under Pi deprivation. These data reveal the biological function of ZmPP2AA1, provide insights into a linkage between auxin and low Pi responses, and drive new strategies for the efficient utilization of Pi by maize. PMID:28448624

Anomalous Photoionization in Xe

NASA Astrophysics Data System (ADS)

Klapisch, Marcel; Busquet, Michel

2012-10-01

Photoionization (PI) cross sections are important components of the opacities that are necessary for the simulation of astrophysical and ICF plasmas. Most of PI cross sections (i) start abruptly at threshold and (ii) decrease as an inverse power (e.g.3^rd) of the photon energy. In the framework of the CRASH project [1] we computed Xe opacities with the STA code [2]. We observed that the PI cross section for the 4d shell has neither of these 2 characteristics. We explain this result as interference between the bound 4d wavefunction (wf), the photon, and the free electron wf. Similar, but less pronounced effects are seen for the 5d and 5p shells. Simplified models of PI not involving the actual wf would not show this effect and would probably be inaccurate.[4pt] [1] Doss, F. W., Drake, R. P., and Kuranz, C. C., High Ener. Dens. Phys. 6, 157-61.[0pt] [2] Busquet, M., Klapisch, M., Bar-Shalom, A., et al., Bull. Am. Phys. Soc. 55, 225 (2010).

An individual differences analysis of memory control

PubMed Central

Salthouse, Timothy A.; Siedlecki, Karen L.; Krueger, Lacy E.

2013-01-01

Performance on a wide variety of memory tasks can be hypothesized to be influenced by processes associated with controlling the contents of memory. In this project 328 adults ranging from 18 to 93 years of age performed six tasks (e.g., multiple trial recall with an interpolated interference list, directed forgetting, proactive interference, and retrieval inhibition) postulated to yield measures of the effectiveness of memory control. Although most of the patterns from earlier studies were replicated, only a few of the measures of memory control were reliable at the level of individual differences. Furthermore, the memory control measures had very weak relations with the age of the participant. Analyses examining the relations between established cognitive abilities and variables from the experimental tasks revealed that most of the variables were related only to episodic memory ability. PMID:24347812

Platelet-Derived Growth Factor Receptor Activation Promotes the Prodestructive Invadosome-Forming Phenotype of Synoviocytes from Patients with Rheumatoid Arthritis.

PubMed

Charbonneau, Martine; Lavoie, Roxane R; Lauzier, Annie; Harper, Kelly; McDonald, Patrick P; Dubois, Claire M

2016-04-15

Fibroblast-like synoviocytes (FLS) play a major role in invasive joint destruction in rheumatoid arthritis (RA). This prodestructive phenotype has been shown to involve autocrine TGF-β that triggers formation of matrix-degrading invadosomes through molecular mechanisms that are not fully elucidated. The platelet-derived growth factor (PDGF) receptor (PDGFR) family of receptor tyrosine kinases (RTK) has been shown to cooperate with TGF-β in various pathological conditions. We therefore sought to determine whether RTK activity played a role in invadosome biogenesis. We demonstrated that, among the common RTKs, PDGFR-αβ was specifically phosphorylated in FLS from RA patients. Phosphorylation of PDGFR-αβ was also elevated in RA synovial tissues. Interference with PDGFR activation or PDGF neutralization inhibited invadosome formation in RA synoviocytes, indicating the presence of an autocrine PDGFR activation loop that involved endogenous PDGF. Among the PDGF-A-D isoforms, only PDGF-B was found both significantly elevated in FLS lines from RA patients, and related to high-invadosome forming cells. Addition of TGF-β upregulated invadosome formation, PDGF-B mRNA expression, and phosphorylation of PDGFR. All of these functions were efficiently suppressed by TGF-β neutralization or interference with the Smad/TβR1or PI3K/Akt pathway. Among the class 1 PI3K family proteins known to be expressed in RA synoviocytes, PI3Kα was selectively involved in PDGF-B expression, whereas both PI3Kα and PI3Kδ participated in invadosome formation. Our findings demonstrate that PDGFR is a critical RTK required for the prodestructive phenotype of RA synovial cells. They also provide evidence for an association between autocrine TGF-β and PDGFR-mediated invadosome formation in RA synoviocytes that involves the production of PDGF-B induced by TGF-β. Copyright © 2016 by The American Association of Immunologists, Inc.

Pion Elastic Scattering and the (pion Pion' Proton) Reaction on HELIUM-4 in the DELTA(3,3) Region

NASA Astrophysics Data System (ADS)

Jones, Mark Kevin

This dissertation presents measurements and analyses of pi^+ and pi ^{-} elastic scattering, and ( pi^{+}, pi^ {+^'}p) and ( pi^{-},pi^{-^ '}p) reactions on ^4 He. Both experiments were done at the Los Alamos Meson Physics Facility using the Energetic Pion Channel and Spectrometer. The ^4He( pi,pi) elastic scattering cross sections were measured for pi^{+} scattering at scattering angles theta _{lab} = 110^circ -170^circ and five incident energies between T_{pi } = 90 and 180 MeV. Elastic pi ^{-} cross sections were measured only at T_{pi} = 180 MeV. The ^4He(pi, pi' p) angular correlation functions were measured for pi^{+} and pi^{-} at T_{pi} = 180 and theta_{pi^' } = 30^circ, 40 ^circ, 60^circ , 80^circ and at T _pi = 140 MeV and theta_{pi^'} = 40^circ. Using scintillators at eight angles the protons were detected in coincidence with the inelastically scattered pions. In the ^4He(pi, pi^' p) experiment unexpectedly large ratios R_{pi p} = {sigma(pi^{+}, pi^{+} p)}over{sigma( pi^{-},pi^{-} p)} of up to 50 were observed near the quasi -free angle in the angular correlation functions summed over 30.5 to 39.5 MeV in ^4He excitation energy. The (pi,pi' p) data were analyzed by a distorted wave impulse approximation code 3DEE (Ch 82), (Re 82). 3DEE models the ( pi,pi' p) reaction as a pion -induced proton knock-out and includes distortions in the incident pion, the outgoing pion, and the emitted proton waves. The calculations give R_{pi p} between 6 and 9 at all proton and pion angles. The pi^{+} calculations reproduce the absolute pi^ {+} cross sections fairly well. The pi^{-} calculations have a peak in the angular correlation function near the quasi-free angle, in contrast to the pi^ {-} data which displays a flat distribution. At proton angles near 180^circ in the center of mass of the struck mass 4 system, the measured pi^{-} cross sections are larger than the pi^ {+} cross section which is the reverse of the ratio at 0^circ. These features of the measured pi^- cross sections indicate that interference between a quasi -free process and another process is important in the ( pi,pi^' p) reaction. The measurement of ^4He( pi,pi) elastic scattering data at theta_pi = 110 ^circ-170^circ extends the angular range of previous ^4He(pi,pi) data measured at EPICS. The experiment provides high quality elastic scattering data at backward angles. The pi^{-} elastic cross section at T_pi = 180 MeV measured for this dissertation when extrapolated to theta _{cm} = 180^circ is about a factor of two smaller than the cross section measured previously at CERN (Ref. (Bi 78)). The data were analyzed using a microscopic optical model and by a phase shift fit.

Alcohol Words Elicit Reactive Cognitive Control in Low Sensitivity Drinkers

PubMed Central

Bailey, Kira; Bartholow, Bruce D.

2016-01-01

Previous event-related potential (ERP) studies shown support for the idea that alcohol-related stimuli are particularly salient to individuals who report low sensitivity to alcohol's effects (LS; a known risk factor for alcohol-related problems), leading such stimuli to spontaneously capture their attention and interfere with self-regulatory goal pursuit. The current study investigated LS individuals’ use of reactive and proactive cognitive control in response to alcohol-related stimuli. Participants performed an alcohol Stroop task in which they indicated the font color of alcohol- and nonalcohol-related words while ERPs were recorded. The probability of alcohol and nonalcohol words was manipulated to test predictions derived from Dual Mechanisms of Control theory. Among LS individuals, infrequent alcohol-related words elicited slower responses and larger N2 amplitude, consistent with these stimuli eliciting enhanced reactive control responses. Amplitude of the frontal slow wave (FSW) component, associated with proactive control, was marginally larger among LS individuals when alcohol words were more frequent, but response accuracy was lower. These findings demonstrate that LS individuals experience conflict when presented with task-irrelevant alcohol-related stimuli, even in a context where conflict arguably should not be present. Findings further suggest that LS individuals can effectively implement reactive control to deal with this conflict when it is infrequent, but have difficulty implementing proactive control in the context of more frequent conflict. PMID:27545019

Differential Photoproduction Cross Sections of the Sigma0(1385), Lambda(1405), and Lambda(1520)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moriya, Kei; Schumacher, Reinhard A.

2013-10-01

We report the exclusive photoproduction cross sections for the Sigma(1385), Lambda(1405), and Lambda(1520) in the reactions gamma + p -> K+ + Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective Lagrangian approach and fitted to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Lambda(1405) region are strikingly different for themore » Sigma+pi-, Sigma0 pi0, and Sigma- pi+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.« less

Impaired memory for material related to a problem solved prior to encoding: suppression at learning or interference at recall?

PubMed

Kowalczyk, Marek

2017-07-01

Earlier research by the author revealed that material encoded incidentally in a speeded affective classification task and related to the demands of a divergent problem tends to be recalled worse in participants who solved the problem prior to encoding than in participants in the control, no-problem condition. The aim of the present experiment was to replicate this effect with a new, size-comparison orienting task, and to test for possible mechanisms of impaired recall. Participants either solved a problem before the orienting task or not, and classified each item in this task either once or three times. There was a reliable effect of impaired recall of problem-related items in the repetition condition, but not in the no-repetition condition. Solving the problem did not influence repetition priming for these items. These results support an account that attributes the impaired recall to inhibitory processes at learning and speak against a proactive interference explanation. However, they can be also accommodated by an account that refers to inefficient context cues and competitor interference at retrieval.

X-Ray Absorption Measured in the Resonant Auger Scattering Mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hikosaka, Y.; Shigemasa, E.; Kaneyasu, T.

2008-08-15

We report both experimental and theoretical studies on x-ray absorption measured in the resonant Auger scattering mode of gas phase carbon monoxide near the O1s{yields}2{pi} region. Both experiment and theory display a crucial difference between the x-ray absorption profiles obtained in the conventional and resonant scattering modes. Lifetime vibrational interference is the main source of the difference. It is demonstrated that such interference, which arises from a coherent excitation to overlapping intermediate levels, ruins the idea for obtaining x-ray absorption spectra in a lifetime broadening free regime.

An Experimental Analysis of Memory Processing

PubMed Central

Wright, Anthony A

2007-01-01

Rhesus monkeys were trained and tested in visual and auditory list-memory tasks with sequences of four travel pictures or four natural/environmental sounds followed by single test items. Acquisitions of the visual list-memory task are presented. Visual recency (last item) memory diminished with retention delay, and primacy (first item) memory strengthened. Capuchin monkeys, pigeons, and humans showed similar visual-memory changes. Rhesus learned an auditory memory task and showed octave generalization for some lists of notes—tonal, but not atonal, musical passages. In contrast with visual list memory, auditory primacy memory diminished with delay and auditory recency memory strengthened. Manipulations of interitem intervals, list length, and item presentation frequency revealed proactive and retroactive inhibition among items of individual auditory lists. Repeating visual items from prior lists produced interference (on nonmatching tests) revealing how far back memory extended. The possibility of using the interference function to separate familiarity vs. recollective memory processing is discussed. PMID:18047230

Testing for EMC (electromagnetic compatibility) in the clinical environment.

PubMed

Paperman, D; David, Y; Martinez, M

1996-01-01

Testing for electromagnetic compatibility (EMC) in the clinical environment introduces a host of complex conditions not normally encountered under laboratory conditions. In the clinical environment, various radio-frequency (RF) sources of electromagnetic interference (EMI) may be present throughout the entire spectrum of interest. Isolating and analyzing the impact from the sources of interference to medical devices involves a multidisciplinary approach based on training in, and knowledge of, the following: operation of medical devices and their susceptibility to EMI; RF propagation modalities and interaction theory; spectrum analysis systems and techniques (preferably with signature analysis capabilities) and calibrated antennas; the investigation methodology of suspected EMC problems, and testing protocols and standards. Using combinations of standard test procedures adapted for the clinical environment with personnel that have an understanding of radio-frequency behavior increases the probability of controlling, proactively, EMI in the clinical environment, thus providing for a safe and more effective patient care environment.

Abasic pivot substitution harnesses target specificity of RNA interference

PubMed Central

Lee, Hye-Sook; Seok, Heeyoung; Lee, Dong Ha; Ham, Juyoung; Lee, Wooje; Youm, Emilia Moonkyung; Yoo, Jin Seon; Lee, Yong-Seung; Jang, Eun-Sook; Chi, Sung Wook

2015-01-01

Gene silencing via RNA interference inadvertently represses hundreds of off-target transcripts. Because small interfering RNAs (siRNAs) can function as microRNAs, avoiding miRNA-like off-target repression is a major challenge. Functional miRNA–target interactions are known to pre-require transitional nucleation, base pairs from position 2 to the pivot (position 6). Here, by substituting nucleotide in pivot with abasic spacers, which prevent base pairing and alleviate steric hindrance, we eliminate miRNA-like off-target repression while preserving on-target activity at ∼80–100%. Specifically, miR-124 containing dSpacer pivot substitution (6pi) loses seed-mediated transcriptome-wide target interactions, repression activity and biological function, whereas other conventional modifications are ineffective. Application of 6pi allows PCSK9 siRNA to efficiently lower plasma cholesterol concentration in vivo, and abolish potentially deleterious off-target phenotypes. The smallest spacer, C3, also shows the same improvement in target specificity. Abasic pivot substitution serves as a general means to harness the specificity of siRNA experiments and therapeutic applications. PMID:26679372

I saw where you have been--The topography of human demonstration affects dogs' search patterns and perseverative errors.

PubMed

Péter, András; Topál, József; Miklósi, Ádám; Pongrácz, Péter

2016-04-01

Performance in object search tasks is not only influenced by the subjects' object permanence ability. For example, ostensive cues of the human manipulating the target markedly affect dogs' choices. However, the interference between the target's location and the spatial cues of the human hiding the object is still unknown. In a five-location visible displacement task, the experimental groups differed in the hiding route of the experimenter. In the 'direct' condition he moved straight towards the actual location, hid the object and returned to the dog. In the 'indirect' conditions, he additionally walked behind each screen before returning. The two 'indirect' conditions differed from each other in that the human either visited the previously baited locations before (proactive interference) or after (retroactive interference) hiding the object. In the 'indirect' groups, dogs' performance was significantly lower than in the 'direct' group, demonstrating that for dogs, in an ostensive context, spatial cues of the hider are as important as the observed location of the target. Based on their incorrect choices, dogs were most attracted to the previously baited locations that the human visited after hiding the object in the actual trial. This underlines the importance of retroactive interference in multiple choice tasks. Copyright © 2016 Elsevier B.V. All rights reserved.

The 20-hydroxyecdysone-induced signalling pathway in G2/M arrest of Plodia interpunctella imaginal wing cells.

PubMed

Siaussat, David; Bozzolan, Françoise; Porcheron, Patrick; Debernard, Stéphane

2008-05-01

The mechanisms involved in the control of cellular proliferation by the steroid hormone 20-hydroxyecdysone (20E) in insects are not known. We dissected the 20E signalling pathway responsible for G2/M arrest of imaginal cells from the IAL-PID2 cells of the Indian meal moth Plodia interpunctella. We first used a 5'-3' RACE-based strategy to clone a 4479bp cDNA encoding a putative P. interpunctella HR3 transcription factor named PiHR3. The deduced amino acid sequence of PiHR3 was highly similar to those of HR3 proteins from other lepidopterans, e.g. Manduca sexta and Bombyx mori. Using double-stranded RNA-mediated interference (dsRNAi), we then succeeded in blocking the ability of 20E to induce the expression of PiEcR-B1, PiUSP-2 and PiHR3 genes that encode the P. interpunctella ecdysone receptor B1-isoform, Ultraspiracle-2 isoform, the insect homologue of the vertebrate retinoid X receptor, and the HR3 transcription factor. We showed that inhibiting the 20E induction of PiEcR-B1, PiUSP-2 and PiHR3 mRNAs prevented the decreased expression of B cyclin and consequently the G2/M arrest of IAL-PID2 cells. Using this functional approach, we revealed the participation of EcR, USP and HR3 in a 20E signalling pathway that controls the proliferation of imaginal cells by regulating the expression of B cyclin.

Rice OsMYB5P improves plant phosphate acquisition by regulation of phosphate transporter

PubMed Central

Yun, Dae-Jin; Lee, Kwang Sik; Hong, So Yeon; Bae, Ki Deuk; Chung, Young Soo; Kwon, Yong Sham; Kim, Du Hyun; Jung, Ki Hong

2018-01-01

Myeloblastosis (MYB) transcription factors play central roles in plant developmental processes and in responses to nutrient deficiency. In this study, OsMYB5P, an R2R3-MYB transcription factor, was isolated and identified from rice (Oryza sativa L. ‘Dongjin’) under inorganic phosphate (Pi)-deficient conditions. OsMYB5P protein is localized to the nucleus and functions as a transcription activator in plant development. Overexpression of OsMYB5P in rice and Arabidopsis (Arabidopsis thaliana Col-0) increases tolerance to phosphate starvation, whereas OsMYB5P knock-out through RNA interference increases sensitivity to Pi depletion in rice. Furthermore, shoots and roots of transgenic rice plants overexpressing OsMYB5P were longer than those of wild plants under both normal and Pi-deficient conditions. These results indicate that OsMYB5P is associated with the regulation of shoot development and root- system architecture. Overexpression of OsMYB5P led to increased Pi accumulation in shoots and roots. Interestingly, OsMYB5P directly bound to MBS (MYB binding site) motifs on the OsPT5 promoter and induced transcription of OsPT5 in rice. In addition, overexpression of OsMYB5P in Arabidopsis triggered increased expression of AtPht1;3, an Arabidopsis Pi transporter, in shoots and roots under normal and Pi-deficient conditions. Together, these results demonstrate that overexpression of OsMYB5P increases tolerance to Pi deficiency in plants by modulating Pi transporters at the transcriptional level in monocots and dicots. PMID:29566032

Prefrontal Cortical GABA Modulation of Spatial Reference and Working Memory

PubMed Central

Auger, Meagan L.

2015-01-01

Background: Dysfunction in prefrontal cortex (PFC) GABA transmission has been proposed to contribute to cognitive dysfunction in schizophrenia, yet how this system regulates different cognitive and mnemonic functions remains unclear. Methods: We assessed the effects of pharmacological reduction of GABAA signaling in the medial PFC of rats on spatial reference/working memory using different versions of the radial-arm maze task. We used a massed-trials procedure to probe how PFC GABA regulates susceptibility to proactive interference. Male rats were well-trained to retrieve food from the same 4 arms of an 8-arm maze, receiving 5 trials/day (1–2min intervals). Results: Infusions of the GABAA receptor antagonist bicuculline (12.5–50ng) markedly increased working and reference memory errors and response latencies. Similar treatments also impaired short-term memory on an 8-baited arm task. These effects did not appear to be due to increased susceptibility to proactive interference. In contrast, PFC inactivation via infusion of GABA agonists baclofen/muscimol did not affect reference/working memory. In comparison to the pronounced effects on the 8-arm maze tasks, PFC GABAA antagonism only causes a slight and transient decrease in accuracy on a 2-arm spatial discrimination. Conclusions: These findings demonstrate that prefrontal GABA hypofunction severely disrupts spatial reference and short-term memory and that disinhibition of the PFC can, in some instances, perturb memory processes not normally dependent on the frontal lobes. Moreover, these impairments closely resemble those observed in schizophrenic patients, suggesting that perturbation in PFC GABA signaling may contribute to these types of cognitive deficits associated with the disorder. PMID:25552433

Guardian small RNAs and sex determination.

PubMed

Katsuma, Susumu; Kawamoto, Munetaka; Kiuchi, Takashi

2014-01-01

The W chromosome of the silkworm Bombyx mori has been known to determine femaleness for more than 80 years. However, the feminizing gene has not been molecularly identified, because the B. mori W chromosome is almost fully occupied by a large number of transposable elements. The W chromosome-derived feminizing factor of B. mori was recently shown to be a female-specific PIWI-interacting RNA (piRNA). piRNAs are small RNAs that potentially repress invading "non-self" elements (e.g., transposons and virus-like elements) by associating with PIWI proteins. Our results revealed that female-specific piRNA precursors, which we named Fem, are transcribed from the sex-determining region of the W chromosome at the early embryonic stage and are processed into a single mature piRNA (Fem piRNA). Fem piRNA forms a complex with Siwi (silkworm Piwi), which cleaves a protein-coding mRNA transcribed from the Z chromosome. RNA interference of this Z-linked gene, which we named Masc, revealed that this gene encodes a protein required for masculinization and dosage compensation. Fem and Masc both participate in the ping-pong cycle of the piRNA amplification loop by associating with the 2 B. mori PIWI proteins Siwi and BmAgo3 (silkworm Ago3), respectively, indicating that the piRNA-mediated interaction between the 2 sex chromosomes is the primary signal for the B. mori sex determination cascade. Fem is a non-transposable repetitive sequence on the W chromosome, whereas Masc is a single-copy protein-coding gene. It is of great interest how the piRNA system recognizes "self "Masc mRNA as "non-self" RNA.

The Biological Effects of Bilirubin Photoisomers

PubMed Central

Jasprova, Jana; Dal Ben, Matteo; Vianello, Eleonora; Goncharova, Iryna; Urbanova, Marie; Vyroubalova, Karolina; Gazzin, Silvia; Tiribelli, Claudio; Sticha, Martin; Cerna, Marcela; Vitek, Libor

2016-01-01

Although phototherapy was introduced as early as 1950’s, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells. PMID:26829016

Modelling seasonal variations in presentations at a paediatric emergency department.

PubMed

Takase, Miyuki; Carlin, John

2012-09-01

Overcrowding is a phenomenon commonly observed at emergency departments (EDs) in many hospitals, and negatively impacts patients, healthcare professionals and organisations. Health care organisations are expected to act proactively to cope with a high patient volume by understanding and predicting the patterns of ED presentations. The aim of this study was, therefore, to identify the patterns of patient flow at a paediatric ED in order to assist the management of EDs. Data for ED presentations were collected from the Royal Children's Hospital in Melbourne, Australia, with the time-frame of July 2003 to June 2008. A linear regression analysis with trigonometric functions was used to identify the pattern of patient flow at the ED. The results showed that a logarithm of the daily average ED presentations was increasing exponentially (as explained by 0.004t + 0.00005t2 with t representing time, p<0.001). The model also indicated that there was a yearly oscillation in the frequency of ED presentations, in which lower frequencies were observed in summer and higher frequencies during winter (as explained by -0.046 sin(2(pi)t/12)-0.083 cos(2(pi)t/12), p<0.001). In addition, the variation of the oscillations was increasing over time (as explained by -0.002t*sin(2(pi)t/12)-0.001t*cos(2(pi)t/12), p<0.05). The identified regression model explained a total of 96% of the variance in the pattern of ED presentations. This model can be used to understand the trend of the current patient flow as well as to predict the future flow at the ED. Such an understanding will assist health care managers to prepare resources and environment more effectively to cope with overcrowding.

Down-regulation of Gab1 inhibits cell proliferation and migration in hilar cholangiocarcinoma.

PubMed

Sang, Haiquan; Li, Tingting; Li, Hangyu; Liu, Jingang

2013-01-01

Hilar cholangiocarcinoma is a highly aggressive malignancy originating from the hilar biliary duct epithelium. Due to few effective comprehensive treatments, the prognosis of hilar cholangiocarcinoma is poor. In this study, immunohistochemistry was first used to detect and analyze the expression of Gab1, VEGFR-2, and MMP-9 in hilar cholangiocarcinoma solid tumors and the relationships to the clinical pathological features. Furthermore, Gab1 and VEGFR-2 siRNA were used to interfere the hilar cholangiocarcinoma cell line ICBD-1 and then detect the PI3K/Akt signaling pathway, MMP-9 levels and malignant biological behaviors of tumor cells. The data showed that 1. Gab1, VEGFR-2, and MMP-9 were highly expressed and positively correlated with each other in hilar cholangiocarcinoma tissues, which were related to lymph node metastasis and differentiation. 2. After Gab1 or VEGFR-2 siRNA interference, PI3K/Akt pathway activity and MMP-9 levels were decreased in ICBD-1 cells. At the same time, cell proliferation decreased, cell cycle arrested in G1 phase, apoptosis increased and invasion decreased. These results suggest that the expression of Gab1, VEGFR-2, and MMP-9 are significantly related to the malignant biological behavior of hilar cholangiocarcinoma. Gab1 regulates growth, apoptosis and invasion through the VEGFR-2/Gab1/PI3K/Akt signaling pathway in hilar cholangiocarcinoma cells and influences the invasion of tumor cells via MMP-9.

Down-Regulation of Gab1 Inhibits Cell Proliferation and Migration in Hilar Cholangiocarcinoma

PubMed Central

Sang, Haiquan; Li, Tingting; Li, Hangyu; Liu, Jingang

2013-01-01

Hilar cholangiocarcinoma is a highly aggressive malignancy originating from the hilar biliary duct epithelium. Due to few effective comprehensive treatments, the prognosis of hilar cholangiocarcinoma is poor. In this study, immunohistochemistry was first used to detect and analyze the expression of Gab1, VEGFR-2, and MMP-9 in hilar cholangiocarcinoma solid tumors and the relationships to the clinical pathological features. Furthermore, Gab1 and VEGFR-2 siRNA were used to interfere the hilar cholangiocarcinoma cell line ICBD-1 and then detect the PI3K/Akt signaling pathway, MMP-9 levels and malignant biological behaviors of tumor cells. The data showed that 1. Gab1, VEGFR-2, and MMP-9 were highly expressed and positively correlated with each other in hilar cholangiocarcinoma tissues, which were related to lymph node metastasis and differentiation. 2. After Gab1 or VEGFR-2 siRNA interference, PI3K/Akt pathway activity and MMP-9 levels were decreased in ICBD-1 cells. At the same time, cell proliferation decreased, cell cycle arrested in G1 phase, apoptosis increased and invasion decreased. These results suggest that the expression of Gab1, VEGFR-2, and MMP-9 are significantly related to the malignant biological behavior of hilar cholangiocarcinoma. Gab1 regulates growth, apoptosis and invasion through the VEGFR-2/Gab1/PI3K/Akt signaling pathway in hilar cholangiocarcinoma cells and influences the invasion of tumor cells via MMP-9. PMID:24312291

Advanced glycation end-products and insulin signaling in granulosa cells

PubMed Central

Chatzigeorgiou, Antonios; Papageorgiou, Efstathia; Koundouras, Dimitrios; Koutsilieris, Michael

2016-01-01

Advanced glycation end-products (AGEs) may interfere with insulin intracellular signaling and glucose transport in human granulosa cells, potentially affecting ovarian function, follicular growth, linked with diminished fertility. The potential interaction of AGEs with insulin signaling pathways and glucose transport was investigated in human granulosa KGN cells. KGN cells were cultured with variable concentrations of human glycated albumin (HGA, 50–200 µg/mL) or insulin (100 ng/mL). Combined treatments of KGN cells with insulin (100 ng/mL) and HGA (200 µg/mL) were also performed. p-AKT levels and glucose transporter type 4 (Glut-4) translocation analysis were performed by Western blot. Phosphatidylinositol-3-kinase (PI3K)-specific signaling was checked by using the PI3K-inhibitor, LY294002. p-AKT levels were significantly increased following insulin treatment compared to basal levels or HGA exposure. This insulin-mediated AKT-phosphorylation was PI3K-specific and it was inhibited after combined treatment of insulin and HGA. Furthermore, Glut-4 translocation from the cytoplasm to the membrane compartments of KGN cells was remarkably reduced after the combined treatment of insulin and HGA. The present findings support that AGEs interfere with insulin signaling in granulosa cells and prevent Glut-4 membrane translocation suggesting that intra ovarian AGEs accumulation, from endogenous or exogenous sources, may contribute to the pathophysiology of states characterized with anovulation and insulin resistance such as polycystic ovary syndrome. PMID:25956684

The Impact of Social Isolation on Pain Interference: A Longitudinal Study.

PubMed

Karayannis, Nicholas V; Baumann, Isabel; Sturgeon, John A; Melloh, Markus; Mackey, Sean C

2018-04-12

Evidence suggests social interactions play an important role in pain perception. The aim of this study was to determine whether social isolation (SI) in people with persistent pain determines pain interference (PI) and physical function over time. Patients seeking care at a tertiary pain management referral center were administered the Patient Reported Outcome Measurement Information System (PROMIS®) SI, PI, physical function, depression, and average pain intensity item banks at their initial consultation and subsequent visits as part of their routine clinical care. We used a post hoc simulation of an experiment using propensity score matching (n = 4,950) and carried out a cross-lagged longitudinal analysis (n = 312) of retrospective observational data. Cross-lagged longitudinal analysis showed that SI predicted PI at the next time point, above and beyond the effects of pain intensity and covariates, but not vice versa. These data support the importance of SI as a factor in pain-related appraisal and coping and demonstrate that a comprehensive assessment of the individuals' social context can provide a better understanding of the differential trajectories for a person living with pain. Our study provides evidence that the impact of pain is reduced in individuals who perceive a greater sense of inclusion from and engagement with others. This study enhances the understanding of how social factors affect pain and have implications for how the effectiveness of therapeutic interventions may be improved. Therapeutic interventions aimed at increasing social connection hold merit in reducing the impact of pain on engagement with activities.

RNA Interference Restricts Rift Valley Fever Virus in Multiple Insect Systems.

PubMed

Dietrich, Isabelle; Jansen, Stephanie; Fall, Gamou; Lorenzen, Stephan; Rudolf, Martin; Huber, Katrin; Heitmann, Anna; Schicht, Sabine; Ndiaye, El Hadji; Watson, Mick; Castelli, Ilaria; Brennan, Benjamin; Elliott, Richard M; Diallo, Mawlouth; Sall, Amadou A; Failloux, Anna-Bella; Schnettler, Esther; Kohl, Alain; Becker, Stefanie C

2017-01-01

The emerging bunyavirus Rift Valley fever virus (RVFV) is transmitted to humans and livestock by a large number of mosquito species. RNA interference (RNAi) has been characterized as an important innate immune defense mechanism used by mosquitoes to limit replication of positive-sense RNA flaviviruses and togaviruses; however, little is known about its role against negative-strand RNA viruses such as RVFV. We show that virus-specific small RNAs are produced in infected mosquito cells, in Drosophila melanogaster cells, and, most importantly, also in RVFV vector mosquitoes. By addressing the production of small RNAs in adult Aedes sp. and Culex quinquefasciatus mosquitoes, we showed the presence of virus-derived Piwi-interacting RNAs (piRNAs) not only in Aedes sp. but also in C. quinquefasciatus mosquitoes, indicating that antiviral RNA interference in C. quinquefasciatus mosquitoes is similar to the described activities of RNAi in Aedes sp. mosquitoes. We also show that these have antiviral activity, since silencing of RNAi pathway effectors enhances viral replication. Moreover, our data suggest that RVFV does not encode a suppressor of RNAi. These findings point toward a significant role of RNAi in the control of RVFV in mosquitoes. IMPORTANCE Rift Valley fever virus (RVFV; Phlebovirus , Bunyaviridae ) is an emerging zoonotic mosquito-borne pathogen of high relevance for human and animal health. Successful strategies of intervention in RVFV transmission by its mosquito vectors and the prevention of human and veterinary disease rely on a better understanding of the mechanisms that govern RVFV-vector interactions. Despite its medical importance, little is known about the factors that govern RVFV replication, dissemination, and transmission in the invertebrate host. Here we studied the role of the antiviral RNA interference immune pathways in the defense against RVFV in natural vector mosquitoes and mosquito cells and draw comparisons to the model insect Drosophila melanogaster . We found that RVFV infection induces both the exogenous small interfering RNA (siRNA) and piRNA pathways, which contribute to the control of viral replication in insects. Furthermore, we demonstrate the production of virus-derived piRNAs in Culex quinquefasciatus mosquitoes. Understanding these pathways and the targets within them offers the potential of the development of novel RVFV control measures in vector-based strategies.

RNA Interference Restricts Rift Valley Fever Virus in Multiple Insect Systems

PubMed Central

Jansen, Stephanie; Fall, Gamou; Lorenzen, Stephan; Rudolf, Martin; Huber, Katrin; Heitmann, Anna; Schicht, Sabine; Ndiaye, El Hadji; Watson, Mick; Castelli, Ilaria; Elliott, Richard M.; Diallo, Mawlouth; Sall, Amadou A.; Failloux, Anna-Bella; Schnettler, Esther

2017-01-01

ABSTRACT The emerging bunyavirus Rift Valley fever virus (RVFV) is transmitted to humans and livestock by a large number of mosquito species. RNA interference (RNAi) has been characterized as an important innate immune defense mechanism used by mosquitoes to limit replication of positive-sense RNA flaviviruses and togaviruses; however, little is known about its role against negative-strand RNA viruses such as RVFV. We show that virus-specific small RNAs are produced in infected mosquito cells, in Drosophila melanogaster cells, and, most importantly, also in RVFV vector mosquitoes. By addressing the production of small RNAs in adult Aedes sp. and Culex quinquefasciatus mosquitoes, we showed the presence of virus-derived Piwi-interacting RNAs (piRNAs) not only in Aedes sp. but also in C. quinquefasciatus mosquitoes, indicating that antiviral RNA interference in C. quinquefasciatus mosquitoes is similar to the described activities of RNAi in Aedes sp. mosquitoes. We also show that these have antiviral activity, since silencing of RNAi pathway effectors enhances viral replication. Moreover, our data suggest that RVFV does not encode a suppressor of RNAi. These findings point toward a significant role of RNAi in the control of RVFV in mosquitoes. IMPORTANCE Rift Valley fever virus (RVFV; Phlebovirus, Bunyaviridae) is an emerging zoonotic mosquito-borne pathogen of high relevance for human and animal health. Successful strategies of intervention in RVFV transmission by its mosquito vectors and the prevention of human and veterinary disease rely on a better understanding of the mechanisms that govern RVFV-vector interactions. Despite its medical importance, little is known about the factors that govern RVFV replication, dissemination, and transmission in the invertebrate host. Here we studied the role of the antiviral RNA interference immune pathways in the defense against RVFV in natural vector mosquitoes and mosquito cells and draw comparisons to the model insect Drosophila melanogaster. We found that RVFV infection induces both the exogenous small interfering RNA (siRNA) and piRNA pathways, which contribute to the control of viral replication in insects. Furthermore, we demonstrate the production of virus-derived piRNAs in Culex quinquefasciatus mosquitoes. Understanding these pathways and the targets within them offers the potential of the development of novel RVFV control measures in vector-based strategies. PMID:28497117

Role of Host Type IA Phosphoinositide 3-Kinase Pathway Components in Invasin-Mediated Internalization of Yersinia enterocolitica.

PubMed

Dowd, Georgina C; Bhalla, Manmeet; Kean, Bernard; Thomas, Rowan; Ireton, Keith

2016-06-01

Many bacterial pathogens subvert mammalian type IA phosphoinositide 3-kinase (PI3K) in order to induce their internalization into host cells. How PI3K promotes internalization is not well understood. Also unclear is whether type IA PI3K affects different pathogens through similar or distinct mechanisms. Here, we performed an RNA interference (RNAi)-based screen to identify components of the type IA PI3K pathway involved in invasin-mediated entry of Yersinia enterocolitica, an enteropathogen that causes enteritis and lymphadenitis. The 69 genes targeted encode known upstream regulators or downstream effectors of PI3K. A similar RNAi screen was previously performed with the food-borne bacterium Listeria monocytogenes The results of the screen with Y. enterocolitica indicate that at least nine members of the PI3K pathway are needed for invasin-mediated entry. Several of these proteins, including centaurin-α1, Dock180, focal adhesion kinase (FAK), Grp1, LL5α, LL5β, and PLD2 (phospholipase D2), were recruited to sites of entry. In addition, centaurin-α1, FAK, PLD2, and mTOR were required for remodeling of the actin cytoskeleton during entry. Six of the human proteins affecting invasin-dependent internalization also promote InlB-mediated entry of L. monocytogenes Our results identify several host proteins that mediate invasin-induced effects on the actin cytoskeleton and indicate that a subset of PI3K pathway components promote internalization of both Y. enterocolitica and L. monocytogenes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Appetitive context conditioning proactively, but transiently, interferes with expression of counterconditioned context fear

PubMed Central

Holmes, Nathan M.

2014-01-01

Four experiments used rats to study appetitive–aversive transfer. Rats trained to eat a palatable food in a distinctive context and shocked in that context ate and did not freeze when tested 1 d later but froze and did not eat when tested 14 d later. These results were associatively mediated (Experiments 1 and 2), observed when rats were or were not food deprived (Experiments 1 and 2), and were not due to latent inhibition (Experiment 3). In contrast, rats trained to eat in the context and shocked there 13 d later froze and did not eat when tested 1 d after the shocked exposure. However, rats that received an additional eating session in the context 1 d before the shocked exposure ate and did not freeze when tested 1 d after the shocked exposure (Experiment 4). The results show that appetitive conditioning transiently interferes with aversive conditioning. They are discussed in terms of a weak context–shock association becoming stronger with the lapse of time (so-called fear incubation) or of the interference by the context–food association becoming weaker with the lapse of time. PMID:25320352

Memory, priority encoding, and overcoming high-value proactive interference in younger and older adults.

PubMed

Friedman, Michael C; Castel, Alan D

2013-01-01

It is often necessary to remember important information while directing attention away from encoding less valuable information. To examine how aging influences the ability to control and update the encoding of high-value information, younger and older adults studied six lists of words that varied in terms of the point values associated with each word. The words were paired with the same high and low point values for three study-test cycles, but on the fourth and subsequent cycles the value-word pairings were switched such that the lowest value pairs became the highest values (and vice versa). For the first three study-test cycles, younger adults outperformed older adults in terms of the number of words recalled and overall point totals, but performance was similar in terms of selectively remembering high-value words. When the values were switched, both groups displayed substantial interference from the previous pairings. Although both groups improved with additional study-test cycles, only younger adults were able to fully recover from the interference effects. A similar, and more pronounced, set of results were obtained when positive and negative point values were paired with the words. The findings are interpreted in a value-directed remembering framework, emphasizing the role of benefits and costs of strategic encoding and age-related differences in the effects of interference on memory.

Targeting Phosphatidylinositol 4-Kinase IIIα for Radiosensitization: A Potential Model of Drug Repositioning Using an Anti-Hepatitis C Viral Agent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwon, Jeanny; Kim, Dan Hyo; Park, Ji Min

Purpose: To investigate which isotype of phosphatidylinositol 4-kinase (PI4K) may affect radiosensitivity and examine whether anti–hepatitis C viral (HCV) agents, some of which have been shown to inhibit PI4K IIIα activity, could be repositioned as a radiosensitizer in human cancer cells. Methods and Materials: U251, BT474, and HepG2 cell lines and normal human astrocyte were used. Ribonucleic acid interference, clonogenic assays, Western blotting, immunofluorescence, annexin V assay, lysotracker staining, and β-galactosidase assay were performed. Results: Of the 4 PI4K isotypes, specific inhibition of IIIα increased radiosensitivity. For pharmacologic inhibition of PI4K IIIα, we screened 9 anti-HCV agents by half-maximal inhibitorymore » concentration assay. Simeprevir was selected, and its inhibition of PI4K IIIα activity was confirmed. Combination of simeprevir treatment and radiation significantly attenuated expression of phospho-phospho-PKC and phospho-Akt and increased radiation-induced cell death in tested cell lines. Pretreatment with simeprevir prolonged γH2AX foci formation and down-regulation of phospho-DNA-PKcs, indicating impairment of nonhomologous end-joining repair. Cells pretreated with simeprevir exhibited mixed modes of cell death, including apoptosis and autophagy. Conclusion: These data demonstrate that targeting PI4K IIIα using an anti-HCV agent is a viable approach to enhance the therapeutic efficacy of radiation therapy in various human cancers, such as glioma, breast, and hepatocellular carcinoma.« less

Branching ratio measurements of B meson decays to J/psi meson eta meson kaon and charged B meson decays to neutral D meson charged kaon with neutral D meson decays to positive pion negative pion neutral pion

NASA Astrophysics Data System (ADS)

Zeng, Qinglin

Results are presented for the decays of B → J/psietaK and B+/- → DK+/-, respectively, with experimental data collected with BABAR detector at PEP-II, located at Stanford Linear Accelerator Center (SLAC). With 90 x 106 BB¯ events at the Upsilon(4S) resonance, we obtained branching fractions of B (B+/- → J/psietaK +/-) = [10.8 +/- 2.3(stat) +/- 2.4(syst)] x 10-5 and B (B0 → J/psieta K0S ) = [8.4 +/- 2.6(stat) +/- 2.7( syst)] x 10-5; and we set an upper limit of B [B+/- → X(3872) K+/- → J/psietaK +/-] < 7.7 x 10-6 at 90% confidence level. The branching fraction of decay chain B (B+/- → DK +/- → pi+pi-pi 0K+/-) = [5.5 +/- 1.0( stat) +/- 0.7(syst)] x 10-6 with 229 x 106 BB¯ events at Upsilon(4S) resonance, here D represents the neutral D meson. The decay rate asymmetry is A = 0.02 +/- 0.16(stat) +/- 0.03(syst) for this full decay chain. This decay can be used to extract the unitarity angle gamma, a weak CP violation phase, through the interference of decay production of D0 and D¯ 0 to pi+pi-pi 0.

Auditory proactive interference in monkeys: the roles of stimulus set size and intertrial interval.

PubMed

Bigelow, James; Poremba, Amy

2013-09-01

We conducted two experiments to examine the influences of stimulus set size (the number of stimuli that are used throughout the session) and intertrial interval (ITI, the elapsed time between trials) in auditory short-term memory in monkeys. We used an auditory delayed matching-to-sample task wherein the animals had to indicate whether two sounds separated by a 5-s retention interval were the same (match trials) or different (nonmatch trials). In Experiment 1, we randomly assigned stimulus set sizes of 2, 4, 8, 16, 32, 64, or 192 (trial-unique) for each session of 128 trials. Consistent with previous visual studies, overall accuracy was consistently lower when smaller stimulus set sizes were used. Further analyses revealed that these effects were primarily caused by an increase in incorrect "same" responses on nonmatch trials. In Experiment 2, we held the stimulus set size constant at four for each session and alternately set the ITI at 5, 10, or 20 s. Overall accuracy improved when the ITI was increased from 5 to 10 s, but it was the same across the 10- and 20-s conditions. As in Experiment 1, the overall decrease in accuracy during the 5-s condition was caused by a greater number of false "match" responses on nonmatch trials. Taken together, Experiments 1 and 2 showed that auditory short-term memory in monkeys is highly susceptible to proactive interference caused by stimulus repetition. Additional analyses of the data from Experiment 1 suggested that monkeys may make same-different judgments on the basis of a familiarity criterion that is adjusted by error-related feedback.

Prefrontal cortical GABA modulation of spatial reference and working memory.

PubMed

Auger, Meagan L; Floresco, Stan B

2014-10-31

Dysfunction in prefrontal cortex (PFC) GABA transmission has been proposed to contribute to cognitive dysfunction in schizophrenia, yet how this system regulates different cognitive and mnemonic functions remains unclear. We assessed the effects of pharmacological reduction of GABAA signaling in the medial PFC of rats on spatial reference/working memory using different versions of the radial-arm maze task. We used a massed-trials procedure to probe how PFC GABA regulates susceptibility to proactive interference. Male rats were well-trained to retrieve food from the same 4 arms of an 8-arm maze, receiving 5 trials/day (1-2 min intervals). Infusions of the GABAA receptor antagonist bicuculline (12.5-50 ng) markedly increased working and reference memory errors and response latencies. Similar treatments also impaired short-term memory on an 8-baited arm task. These effects did not appear to be due to increased susceptibility to proactive interference. In contrast, PFC inactivation via infusion of GABA agonists baclofen/muscimol did not affect reference/working memory. In comparison to the pronounced effects on the 8-arm maze tasks, PFC GABAA antagonism only causes a slight and transient decrease in accuracy on a 2-arm spatial discrimination. These findings demonstrate that prefrontal GABA hypofunction severely disrupts spatial reference and short-term memory and that disinhibition of the PFC can, in some instances, perturb memory processes not normally dependent on the frontal lobes. Moreover, these impairments closely resemble those observed in schizophrenic patients, suggesting that perturbation in PFC GABA signaling may contribute to these types of cognitive deficits associated with the disorder. © The Author 2014. Published by Oxford University Press on behalf of CINP.

Recovery from Proactive Semantic Interference in Mild Cognitive Impairment and Normal Aging: Relationship to Atrophy in Brain Regions Vulnerable to Alzheimer's Disease.

PubMed

Loewenstein, David A; Curiel, Rosie E; Wright, Clinton; Sun, Xiaoyan; Alperin, Noam; Crocco, Elzabeth; Czaja, Sara J; Raffo, Arlene; Penate, Ailyn; Melo, Jose; Capp, Kimberly; Gamez, Monica; Duara, Ranjan

2017-01-01

There is growing evidence that proactive semantic interference (PSI) and failure to recover from PSI may represent early features of Alzheimer's disease (AD). This study investigated the association between PSI, recovery from PSI, and reduced MRI volumes in AD signature regions among cognitively impaired and unimpaired older adults. Performance on the LASSI-L (a novel test of PSI and recovery from PSI) and regional brain volumetric measures were compared between 38 cognitively normal (CN) elders and 29 older participants with amnestic mild cognitive impairment (MCI). The relationship between MRI measures and performance on the LASSI-L as well as traditional memory and non-memory cognitive measures was also evaluated in both diagnostic groups. Relative to traditional neuropsychological measures, MCI patients' failure to recover from PSI was associated with reduced volumes in the hippocampus (rs = 0.48), precuneus (rs = 0.50); rostral middle frontal lobules (rs = 0.54); inferior temporal lobules (rs = 0.49), superior parietal lobules (rs = 0.47), temporal pole (rs = 0.44), and increased dilatation of the inferior lateral ventricle (rs = -0.49). For CN elders, only increased inferior lateral ventricular size was associated with vulnerability to PSI (rs = -0.49), the failure to recover from PSI (rs = -0.57), and delayed recall on the Hopkins Verbal Learning Test-Revised (rs = -0.48). LASSI-L indices eliciting failure to recover from PSI were more highly associated with more MRI regional biomarkers of AD than other traditional cognitive measures. These results as well as recent amyloid imaging studies with otherwise cognitively normal subjects, suggest that recovery from PSI may be a sensitive marker of preclinical AD and deserves further investigation.

Estradiol enhances retention but not organization of hippocampus-dependent memory in intact male mice.

PubMed

Al Abed, Alice Shaam; Sellami, Azza; Brayda-Bruno, Laurent; Lamothe, Valérie; Noguès, Xavier; Potier, Mylène; Bennetau-Pelissero, Catherine; Marighetto, Aline

2016-07-01

Because estrogens have mostly been studied in gonadectomized females, effects of chronic exposure to environmental estrogens in the general population are underestimated. Estrogens can enhance hippocampus-dependent memory through the modulation of information storage. However, declarative memory, the hippocampus-dependent memory of facts and events, demands more than abilities to retain information. Specifically, memory of repetitive events of everyday life such as "where I parked" requires abilities to organize/update memories to prevent proactive interference from similar memories of previous "parking events". Whether such organizational processes are estrogen-sensitive is unknown. We here studied, in intact young and aged adult mice, drinking-water (1μM) estradiol effects on both retention and organizational components of hippocampus-dependent memory, using a radial-maze task of everyday-like memory. Demand on retention vs organization was manipulated by varying the time-interval separating repetitions of similar events. Estradiol increased performance in young and aged mice under minimized organizational demand, but failed to improve the age-associated memory impairment and diminished performance in young mice under high organizational demand. In fact, estradiol prolonged mnemonic retention of successive events without improving organization abilities, hence resulted in more proactive interference from irrelevant memories. c-Fos imaging of testing-induced brain activations showed that the deterioration of young memory was associated with dentate gyrus dysconnectivity, reminiscent of that seen in aged mice. Our findings support the view that estradiol is promnesic but also reveal that such property can paradoxically impair memory. These findings have important outcomes regarding health issues relative to the impact of environmental estrogens in the general population. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determining the phase and amplitude distortion of a wavefront using a plenoptic sensor

NASA Astrophysics Data System (ADS)

Wu, Chensheng; Ko, Jonathan; Davis, Christopher C.

2015-05-01

We have designed a plenoptic sensor to retrieve phase and amplitude changes resulting from a laser beam's propagation through atmospheric turbulence. Compared with the commonly restricted domain of (-pi, pi) in phase reconstruction by interferometers, the reconstructed phase obtained by the plenoptic sensors can be continuous up to a multiple of 2pi. When compared with conventional Shack-Hartmann sensors, ambiguities caused by interference or low intensity, such as branch points and branch cuts, are less likely to happen and can be adaptively avoided by our reconstruction algorithm. In the design of our plenoptic sensor, we modified the fundamental structure of a light field camera into a mini Keplerian telescope array by accurately cascading the back focal plane of its object lens with a microlens array's front focal plane and matching the numerical aperture of both components. Unlike light field cameras designed for incoherent imaging purposes, our plenoptic sensor operates on the complex amplitude of the incident beam and distributes it into a matrix of images that are simpler and less subject to interference than a global image of the beam. Then, with the proposed reconstruction algorithms, the plenoptic sensor is able to reconstruct the wavefront and a phase screen at an appropriate depth in the field that causes the equivalent distortion on the beam. The reconstructed results can be used to guide adaptive optics systems in directing beam propagation through atmospheric turbulence. In this paper we will show the theoretical analysis and experimental results obtained with the plenoptic sensor and its reconstruction algorithms.

Pterostilbene protects against UVB-induced photo-damage through a phosphatidylinositol-3-kinase-dependent Nrf2/ARE pathway in human keratinocytes.

PubMed

Li, Huaping; Jiang, Na; Liang, Bihua; Liu, Qing; Zhang, Erting; Peng, Liqian; Deng, Huiyan; Li, Runxiang; Li, Zhenjie; Zhu, Huilan

2017-11-01

Ultraviolet B (UVB) irradiation is the initial etiological factor for various skin disorders, including erythema, sunburn, photoaging, and photocarcinogenesis. Pterostilbene (Pter) displayed remarkable antioxidant, anti-inflammatory, and anticarcinogenic activities. This study aimed to investigate the effective mechanism of Pter against UVB-induced photodamage in immortalized human keratinocytes. Human keratinocytes were pretreated with Pter (5 and 10 μM) for 24 h prior to UVB irradiation (300 mJ/cm 2 ). Harvested cells were analyzed by MTT, DCFH-DA, comet, western blotting, luciferase promoter, small interference RNA transfection, and quantitative real-time polymerase chain reaction assay. Pter significantly attenuated UVB-induced cell death and reactive oxygen species (ROS) generation, and effectively increased nuclear translocation of NF-E2-related factor-2 (Nrf2), expression of Nrf2-dependent antioxidant enzymes, and DNA repair activity. Moreover, the protective effects of Pter were abolished by small interference RNA-mediated Nrf2 silencing. Furthermore, Pter was also found to induce the phosphorylation of Nrf2 and the known phosphatidylinositol-3-kinase (PI3K) phosphorylated kinase, Akt. The specific inhibitor of PI3K, LY294002, successfully abrogated Pter-induced Nrf2 phosphorylation, activation of Nrf2-antioxidant response element pathway, ROS scavenging ability, and DNA repair activity. The present study indicated that Pter effectively protected against UVB-induced photodamage by increasing endogenous defense mechanisms, scavenging UVB-induced ROS, and aiding in damaged DNA repair through a PI3K-dependent activation of Nrf2/ARE pathway.

Functional interdependence at the chromatin level between the MKK6/p38 and IGF1/PI3K/AKT pathways during muscle differentiation.

PubMed

Serra, Carlo; Palacios, Daniela; Mozzetta, Chiara; Forcales, Sonia V; Morantte, Ianessa; Ripani, Meri; Jones, David R; Du, Keyong; Jhala, Ulupi S; Simone, Cristiano; Puri, Pier Lorenzo

2007-10-26

During muscle regeneration, the mechanism integrating environmental cues at the chromatin of muscle progenitors is unknown. We show that inflammation-activated MKK6-p38 and insulin growth factor 1 (IGF1)-induced PI3K/AKT pathways converge on the chromatin of muscle genes to target distinct components of the muscle transcriptosome. p38 alpha/beta kinases recruit the SWI/SNF chromatin-remodeling complex; AKT1 and 2 promote the association of MyoD with p300 and PCAF acetyltransferases, via direct phosphorylation of p300. Pharmacological or genetic interference with either pathway led to partial assembly of discrete chromatin-bound complexes, which reflected two reversible and distinct cellular phenotypes. Remarkably, PI3K/AKT blockade was permissive for chromatin recruitment of MEF2-SWI/SNF complex, whose remodeling activity was compromised in the absence of MyoD and acetyltransferases. The functional interdependence between p38 and IGF1/PI3K/AKT pathways was further established by the evidence that blockade of AKT chromatin targets was sufficient to prevent the activation of the myogenic program triggered by deliberate activation of p38 signaling.

Functional interdependence at the chromatin level between the MKK6/p38 and IGF1/Pi3K/AKT pathways during muscle differentiation

PubMed Central

Carlo, Serra; Daniela, Palacios; Chiara, Mozzetta; Sonia, Forcales; Ianessa, Morantte; Meri, Ripani; Jones David, R.; Keyong, Du; Jhala Ulupi, S.; Cristiano, Simone; Lorenzo, Puri Pier

2009-01-01

During muscle regeneration, the mechanism integrating environmental cues at the chromatin of muscle progenitors is unknown. We show that inflammation-activated MKK6-p38 and IGF1-induced Pi3K/AKT pathways converge on the chromatin of muscle genes to target distinct components of the muscle transcriptosome. p38 α/β kinases recruit the SWI/SNF chromatin-remodeling complex; AKT 1 and 2 promote the association of MyoD with p300 and PCAF acetyltransferases, via direct phosphorylation of p300. Pharmacological or genetic interference with either pathway led to partial assembly of discrete chromatin-bound complexes, which reflected two reversible and distinct cellular phenotypes. Remarkably, Pi3K/AKT blockade was permissive for chromatin recruitment of MEF2-SWI/SNF complex, whose remodeling activity was compromised in the absence of MyoD and acetyltransferases. The functional interdependence between p38 and IGF1/Pi3K/AKT pathways was further established by the evidence that blockade of AKT chromatin targets was sufficient to prevent the activation of the myogenic program triggered by deliberate activation of p38 signaling PMID:17964260

Bit error rate performance of pi/4-DQPSK in a frequency-selective fast Rayleigh fading channel

NASA Technical Reports Server (NTRS)

Liu, Chia-Liang; Feher, Kamilo

1991-01-01

The bit error rate (BER) performance of pi/4-differential quadrature phase shift keying (DQPSK) modems in cellular mobile communication systems is derived and analyzed. The system is modeled as a frequency-selective fast Rayleigh fading channel corrupted by additive white Gaussian noise (AWGN) and co-channel interference (CCI). The probability density function of the phase difference between two consecutive symbols of M-ary differential phase shift keying (DPSK) signals is first derived. In M-ary DPSK systems, the information is completely contained in this phase difference. For pi/4-DQPSK, the BER is derived in a closed form and calculated directly. Numerical results show that for the 24 kBd (48 kb/s) pi/4-DQPSK operated at a carrier frequency of 850 MHz and C/I less than 20 dB, the BER will be dominated by CCI if the vehicular speed is below 100 mi/h. In this derivation, frequency-selective fading is modeled by two independent Rayleigh signal paths. Only one co-channel is assumed in this derivation. The results obtained are also shown to be valid for discriminator detection of M-ary DPSK signals.

Symmetry relations in charmless B{yields}PPP decays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gronau, Michael; Rosner, Jonathan L.; Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637

2005-11-01

Strangeness-changing decays of B mesons to three-body final states of pions and kaons are studied, assuming that they are dominated by a {delta}I=0 penguin amplitude with flavor structure b{yields}s. Numerous isospin relations for B{yields}K{pi}{pi} and for underlying quasi-two-body decays are compared successfully with experiment, in some cases resolving ambiguities in fitting resonance parameters. The only exception is a somewhat small branching ratio noted in B{sup 0}{yields}K*{sup 0}{pi}{sup 0}, interpreted in terms of destructive interference between a penguin amplitude and an enhanced electroweak penguin contribution. Relations for B decays into three kaons are derived in terms of final states involving K{submore » S} or K{sub L}, assuming that {phi}K-subtracted decay amplitudes are symmetric in K and K, as has been observed experimentally. Rates due to nonresonant backgrounds are studied using a simple model, which may reduce discrete ambiguities in Dalitz plot analyses.« less

PI3K pathway dependencies in endometrioid endometrial cancer cell lines

PubMed Central

Weigelt, Britta; Warne, Patricia H; Lambros, Maryou B; Reis-Filho, Jorge S; Downward, Julian

2013-01-01

Purpose Endometrioid endometrial cancers (EECs) frequently harbor coexisting mutations in PI3K pathway genes, including PTEN, PIK3CA, PIK3R1, and KRAS. We sought to define the genetic determinants of PI3K pathway inhibitor response in EEC cells, and whether PTEN-mutant EEC cell lines rely on p110β signaling for survival. Experimental Design Twenty-four human EEC cell lines were characterized for their mutation profile and activation state of PI3K and MAPK signaling pathway proteins. Cells were treated with pan-class I PI3K, p110α and p110β isoform-specific, allosteric mTOR, mTOR kinase, dual PI3K/mTOR, MEK and RAF inhibitors. RNA interference (RNAi) was employed to assess effects of KRAS silencing in EEC cells. Results EEC cell lines harboring PIK3CA and PTEN mutations were selectively sensitive to the pan-class I PI3K inhibitor GDC-0941 and allosteric mTOR inhibitor Temsirolimus, respectively. Subsets of EEC cells with concurrent PIK3CA and/or PTEN and KRAS mutations were sensitive to PI3K pathway inhibition, and only 2/6 KRAS-mutant cell lines showed response to MEK inhibition. KRAS RNAi silencing did not induce apoptosis in KRAS-mutant EEC cells. PTEN-mutant EEC cell lines were resistant to the p110β inhibitors GSK2636771 and AZD6482, and only in combination with the p110α selective inhibitor A66, a decrease in cell viability was observed. Conclusions Targeted pan-PI3K and mTOR inhibition in EEC cells may be most effective in PIK3CA-mutant and PTEN-mutant tumors, respectively, even in a subset of EECs concurrently harboring KRAS mutations. Inhibition of p110β alone may not be sufficient to sensitize PTEN-mutant EEC cells and combination with other targeted agents may be required. PMID:23674493

PI3K pathway dependencies in endometrioid endometrial cancer cell lines.

PubMed

Weigelt, Britta; Warne, Patricia H; Lambros, Maryou B; Reis-Filho, Jorge S; Downward, Julian

2013-07-01

Endometrioid endometrial cancers (EEC) frequently harbor coexisting mutations in phosphoinositide 3-kinase (PI3K) pathway genes, including PTEN, PIK3CA, PIK3R1, and KRAS. We sought to define the genetic determinants of PI3K pathway inhibitor response in EEC cells, and whether PTEN-mutant EEC cell lines rely on p110β signaling for survival. Twenty-four human EEC cell lines were characterized for their mutation profile and activation state of PI3K and mitogen-activated protein kinase (MAPK) signaling pathway proteins. Cells were treated with pan-class I PI3K, p110α, and p110β isoform-specific, allosteric mTOR, mTOR kinase, dual PI3K/mTOR, mitogen-activated protein/extracellular signal-regulated kinase (MEK), and RAF inhibitors. RNA interference (RNAi) was used to assess effects of KRAS silencing in EEC cells. EEC cell lines harboring PIK3CA and PTEN mutations were selectively sensitive to the pan-class I PI3K inhibitor GDC-0941 and allosteric mTOR inhibitor temsirolimus, respectively. Subsets of EEC cells with concurrent PIK3CA and/or PTEN and KRAS mutations were sensitive to PI3K pathway inhibition, and only 2 of 6 KRAS-mutant cell lines showed response to MEK inhibition. KRAS RNAi silencing did not induce apoptosis in KRAS-mutant EEC cells. PTEN-mutant EEC cell lines were resistant to the p110β inhibitors GSK2636771 and AZD6482, and only in combination with the p110α selective inhibitor A66 was a decrease in cell viability observed. Targeted pan-PI3K and mTOR inhibition in EEC cells may be most effective in PIK3CA- and PTEN-mutant tumors, respectively, even in a subset of EECs concurrently harboring KRAS mutations. Inhibition of p110β alone may not be sufficient to sensitize PTEN-mutant EEC cells and combination with other targeted agents may be required. ©2013 AACR.

Suppression of transforming growth factor-beta-induced apoptosis through a phosphatidylinositol 3-kinase/Akt-dependent pathway.

PubMed

Chen, R H; Su, Y H; Chuang, R L; Chang, T Y

1998-10-15

Insulin and insulin receptor substrate 1 (IRS-1) are capable of protecting liver cells from apoptosis induced by transforming growth factor-beta1 (TGF-beta). The Ras/mitogen-activated protein kinase (MAP kinase) and the phosphatidylinositol 3-kinase (PI 3-kinase)/Akt pathways are both activated upon insulin stimulation and can protect against apoptosis under certain circumstances. We investigated which of these pathways is responsible for the protective effect of insulin on TGF-beta-induced apoptosis. An activated Ras, although elicited a strong mitogenic effect, could not protect Hep3B cells from TGF-beta-induced apoptosis. Furthermore, PD98059, a selective inhibitor of MEK, did not suppress the antiapoptotic effect of insulin. In contrast, the PI 3-kinase inhibitor, LY294002, efficiently blocked the effect of insulin. Protection against TGF-beta-induced apoptosis conferred by PI 3-kinase was further verified by stable transfection of an activated PI 3-kinase. Downstream targets of PI 3-kinase involved in this protection was further investigated. An activated Akt mimicked the antiapoptotic effect of insulin, whereas a dominant-negative Akt inhibited such effect. However, rapamycin, the p70S6 kinase inhibitor, had no effect on the protectivity of insulin against TGF-beta-induced apoptosis, suggesting that the antiapoptotic target of PI 3-kinase/Akt pathway is independent or lies upstream of the p70S6 kinase. The mechanism by which PI 3-kinase/Akt pathway interferes with the apoptotic signaling of TGF-beta was explored. Activation of PI 3-kinase did not lead to a suppression of Smad hetero-oligomerization or nuclear translocation but blocked TGF-beta-induced caspase-3-like activity. In summary, the PI 3-kinase/Akt pathway, but not the Ras/MAP kinase pathway, protects against TGF-beta-induced apoptosis by inhibiting a step downstream of Smad but upstream of caspase-3.

Visualizing Trumps Vision in Training Attention.

PubMed

Reinhart, Robert M G; McClenahan, Laura J; Woodman, Geoffrey F

2015-07-01

Mental imagery can have powerful training effects on behavior, but how this occurs is not well understood. Here we show that even a single instance of mental imagery can improve attentional selection of a target more effectively than actually practicing visual search. By recording subjects' brain activity, we found that these imagery-induced training effects were due to perceptual attention being more effectively focused on targets following imagined training. Next, we examined the downside of this potent training by changing the target after several trials of training attention with imagery and found that imagined search resulted in more potent interference than actual practice following these target changes. Finally, we found that proactive interference from task-irrelevant elements in the visual displays appears to underlie the superiority of imagined training relative to actual practice. Our findings demonstrate that visual attention mechanisms can be effectively trained to select target objects in the absence of visual input, and this results in more effective control of attention than practicing the task itself. © The Author(s) 2015.

How might flukes and tapeworms maintain genome integrity without a canonical piRNA pathway?

PubMed Central

Skinner, Danielle E.; Rinaldi, Gabriel; Koziol, Uriel; Brehm, Klaus; Brindley, Paul J.

2014-01-01

Surveillance by RNA interference is central to controlling the mobilization of transposable elements (TEs). In stem cells, Piwi argonaute (Ago) proteins and associated proteins repress mobilization of TEs to maintain genome integrity. This defense mechanism targeting TEs is termed the Piwi-interacting RNA (Piwi-piRNA) pathway. In this Opinion, we draw attention to the situation that the genomes of cestodes and trematodes have lost the piwi and vasa genes that are hallmark characters of the germline multipotency program. This absence of Piwi-like Agos and Vasa helicases prompts the question: how does the germline of these flatworms withstand mobilization of TEs? Here we present an interpretation of mechanisms likely to defend the germline integrity of parasitic flatworms. PMID:24485046

Autophagy promotes escape from phosphatidylinositol 3-kinase inhibition in estrogen receptor-positive breast cancer.

PubMed

Yang, Wei; Hosford, Sarah R; Traphagen, Nicole A; Shee, Kevin; Demidenko, Eugene; Liu, Stephanie; Miller, Todd W

2018-03-01

Hyperactivation of the PI3K pathway has been implicated in resistance to antiestrogen therapies in estrogen receptor α (ER)-positive breast cancer, prompting the development of therapeutic strategies to inhibit this pathway. Autophagy has tumor-promoting and -suppressing roles and has been broadly implicated in resistance to anticancer therapies, including antiestrogens. Chloroquine (CQ) is an antimalarial and amebicidal drug that inhibits autophagy in mammalian cells and human tumors. Herein, we observed that CQ inhibited proliferation and autophagy in ER + breast cancer cells. PI3K inhibition with GDC-0941 (pictilisib) induced autophagy. Inhibition of autophagy using CQ or RNA interference potentiated PI3K inhibitor-induced apoptosis. Combined inhibition of PI3K and autophagy effectively induced mitochondrial membrane depolarization, which required the BH3-only proapoptotic proteins Bim and PUMA. Treatment with GDC-0941, CQ, or the combination, significantly suppressed the growth of ER + breast cancer xenografts in mice. In an antiestrogen-resistant xenograft model, GDC-0941 synergized with CQ to provide partial, but durable, tumor regression. These findings warrant clinical evaluation of therapeutic strategies to target ER, PI3K, and autophagy for the treatment of ER + breast cancer.-Yang, W., Hosford, S. R., Traphagen, N. A., Shee, K., Demidenko, E., Liu, S., Miller, T. W. Autophagy promotes escape from phosphatidylinositol 3-kinase inhibition in estrogen receptor-positive breast cancer.

Neural correlates of impaired cognitive control over working memory in schizophrenia.

PubMed

Eich, Teal S; Nee, Derek Evan; Insel, Catherine; Malapani, Chara; Smith, Edward E

2014-07-15

One of the most common deficits in patients with schizophrenia (SZ) is in working memory (WM), which has wide-reaching impacts across cognition. However, previous approaches to studying WM in SZ have used tasks that require multiple cognitive-control processes, making it difficult to determine which specific cognitive and neural processes underlie the WM impairment. We used functional magnetic resonance imaging to investigate component processes of WM in SZ. Eighteen healthy controls (HCs) and 18 patients with SZ performed an item-recognition task that permitted separate neural assessments of 1) WM maintenance, 2) inhibition, and 3) interference control in response to recognition probes. Before inhibitory demands, posterior ventrolateral prefrontal cortex (VLPFC), an area involved in WM maintenance, was activated to a similar degree in both HCs and patients, indicating preserved maintenance operations in SZ. When cued to inhibit items from WM, HCs showed reduced activation in posterior VLPFC, commensurate with appropriately inhibiting items from WM. However, these inhibition-related reductions were absent in patients. When later probed with items that should have been inhibited, patients showed reduced behavioral performance and increased activation in mid-VLPFC, an area implicated in interference control. A mediation analysis indicated that impaired inhibition led to increased reliance on interference control and reduced behavioral performance. In SZ, impaired control over memory, manifested through proactive inhibitory deficits, leads to increased reliance on reactive interference-control processes. The strain on interference-control processes results in reduced behavioral performance. Thus, inhibitory deficits in SZ may underlie widespread impairments in WM and cognition. © 2013 Society of Biological Psychiatry Published by Society of Biological Psychiatry All rights reserved.

Induction of autophagy by PI3K/MTOR and PI3K/MTOR/BRD4 inhibitors suppresses HIV-1 replication.

PubMed

Campbell, Grant R; Bruckman, Rachel S; Herns, Shayna D; Joshi, Shweta; Durden, Donald L; Spector, Stephen A

2018-04-20

In this study, we investigated the effects of the dual phosphatidylinositol 3-kinase/mechanistic target of rapamycin (PI3K/MTOR) inhibitor dactolisib (NVP-BEZ235), the PI3K/MTOR/bromodomain-containing protein 4 (BRD4) inhibitor SF2523, and the bromodomain and extra terminal domain inhibitor JQ1 on the productive infection of primary macrophages with human immunodeficiency type-1 (HIV). These inhibitors did not alter the initial susceptibility of macrophages to HIV infection. However, dactolisib, JQ1, and SF2523 all decreased HIV replication in macrophages in a dose-dependent manner via degradation of intracellular HIV through autophagy. Macrophages treated with dactolisib, JQ1, or SF2523 displayed an increase in LC3B lipidation combined with SQSTM1 degradation without inducing increased cell death. LC3B-II levels were further increased in the presence of pepstatin A suggesting that these inhibitors induce autophagic flux. RNA interference for ATG5 and ATG7 and pharmacological inhibitors of autophagosome-lysosome fusion and of lysosomal hydrolases all blocked the inhibition of HIV. Thus, we demonstrate that the mechanism of PI3K/MTOR and PI3K/MTOR/BRD4 inhibitor suppression of HIV requires the formation of autophagosomes, as well as their subsequent maturation into autolysosomes. These data provide further evidence in support of a role for autophagy in the control of HIV infection and open new avenues for the use of this class of drugs in HIV therapy. © 2018 Campbell et al.

OsWRKY74, a WRKY transcription factor, modulates tolerance to phosphate starvation in rice.

PubMed

Dai, Xiaoyan; Wang, Yuanyuan; Zhang, Wen-Hao

2016-02-01

The WRKY transcription factor family has 109 members in the rice genome, and has been reported to be involved in the regulation of biotic and abiotic stress in plants. Here, we demonstrated that a rice OsWRKY74 belonging to group III of the WRKY transcription factor family was involved in tolerance to phosphate (Pi) starvation. OsWRKY74 was localized in the nucleus and mainly expressed in roots and leaves. Overexpression of OsWRKY74 significantly enhanced tolerance to Pi starvation, whereas transgenic lines with down-regulation of OsWRKY74 were sensitive to Pi starvation. Root and shoot biomass, and phosphorus (P) concentration in rice OsWRKY74-overexpressing plants were ~16% higher than those of wild-type (WT) plants in Pi-deficient hydroponic solution. In soil pot experiments, >24% increases in tiller number, grain weight and P concentration were observed in rice OsWRKY74-overexpressing plants compared to WT plants when grown in P-deficient medium. Furthermore, Pi starvation-induced changes in root system architecture were more profound in OsWRKY74-overexpressing plants than in WT plants. Expression patterns of a number of Pi-responsive genes were altered in the OsWRKY74-overexpressing and RNA interference lines. In addition, OsWRKY74 may also be involved in the response to deficiencies in iron (Fe) and nitrogen (N) as well as cold stress in rice. In Pi-deficient conditions, OsWRKY74-overexpressing plants exhibited greater accumulation of Fe and up-regulation of the cold-responsive genes than WT plants. These findings highlight the role of OsWRKY74 in modulation of Pi homeostasis and potential crosstalk between P starvation and Fe starvation, and cold stress in rice. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Measurement of CP-Violating Asymmetries in B0 to (rho pi)0 Using a Time-Dependent Dalitz Plot Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, J.

We present the preliminary measurement of CP-violating asymmetries in B{sup 0} {yields} ({rho}{pi}){sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} decays using a time-dependent Dalitz plot analysis. The results are obtained from a data sample of 213 million {Upsilon}(4S) {yields} B{bar B} decays, collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. This analysis extends the narrow-rho quasi-two-body approximation used in the previous analysis, by taking into account the interference between the rho resonances of the three charges. We measure 16 coefficients of the bilinear form factor terms occurring in the time-dependent decay rate of the B{supmore » 0} meson with the use of a maximum-likelihood fit. We derive the physically relevant quantities from these coefficients. We measure the direct CP-violation parameters A{sub {rho}{pi}} = -0.088 {+-} 0.049 {+-} 0.013 and C = 0.34 {+-} 0.11 {+-} 0.05, where the first errors are statistical and the second systematic. For the mixing-induced CP-violation parameter we find S = -0.10 {+-} 0.14 {+-} 0.04, and for the dilution and strong phase shift parameters respectively, we obtain {Delta}C = 0.15 {+-} 0.11 {+-} 0.03 and {Delta}S = 0.22 {+-} 0.15 {+-} 0.03. For the angle alpha of the Unitarity Triangle we measure (113{sub -17}{sup +27} {+-} 6){sup o}, while only a weak constraint is achieved at the significance level of more than two standard deviations. Finally, for the relative strong phase {delta}{sub {+-}} between the B{sup 0} {yields} {rho}{sup -}{pi}{sup +} and B{sup 0} {yields} {rho}{sup +}{pi}{sup -} transitions we find (-67{sub -31}{sup +28} {+-} 7) deg, with a similarly weak constraint at two standard deviations and beyond.« less

Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan.

PubMed

Whitson, Lisa R; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T; Heathcote, Andrew; Hsieh, Shulan

2014-01-01

In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these "mixed" repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility.

Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan

PubMed Central

Whitson, Lisa R.; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T.; Heathcote, Andrew; Hsieh, Shulan

2014-01-01

In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these “mixed” repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility. PMID:24817859

How might flukes and tapeworms maintain genome integrity without a canonical piRNA pathway?

PubMed

Skinner, Danielle E; Rinaldi, Gabriel; Koziol, Uriel; Brehm, Klaus; Brindley, Paul J

2014-03-01

Surveillance by RNA interference is central to controlling the mobilization of transposable elements (TEs). In stem cells, Piwi argonaute (Ago) proteins and associated proteins repress mobilization of TEs to maintain genome integrity. This defense mechanism targeting TEs is termed the Piwi-interacting RNA (piRNA) pathway. In this opinion article, we draw attention to the situation that the genomes of cestodes and trematodes have lost the piwi and vasa genes that are hallmark characters of the germline multipotency program. This absence of Piwi-like Agos and Vasa helicases prompts the question: how does the germline of these flatworms withstand mobilization of TEs? Here, we present an interpretation of mechanisms likely to defend the germline integrity of parasitic flatworms. Copyright © 2014 Elsevier Ltd. All rights reserved.

RhoG regulates anoikis through a phosphatidylinositol 3-kinase-dependent mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamaki, Nao; Negishi, Manabu; Katoh, Hironori

2007-08-01

In normal epithelial cells, cell-matrix interaction is required for cell survival and proliferation, whereas disruption of this interaction causes epithelial cells to undergo apoptosis called anoikis. Here we show that the small GTPase RhoG plays an important role in the regulation of anoikis. HeLa cells are capable of anchorage-independent cell growth and acquire resistance to anoikis. We found that RNA interference-mediated knockdown of RhoG promoted anoikis in HeLa cells. Previous studies have shown that RhoG activates Rac1 and induces several cellular functions including promotion of cell migration through its effector ELMO and the ELMO-binding protein Dock180 that function as amore » Rac-specific guanine nucleotide exchange factor. However, RhoG-induced suppression of anoikis was independent of the ELMO- and Dock180-mediated activation of Rac1. On the other hand, the regulation of anoikis by RhoG required phosphatidylinositol 3-kinase (PI3K) activity, and constitutively active RhoG bound to the PI3K regulatory subunit p85{alpha} and induced the PI3K-dependent phosphorylation of Akt. Taken together, these results suggest that RhoG protects cells from apoptosis caused by the loss of anchorage through a PI3K-dependent mechanism, independent of its activation of Rac1.« less

Type II PI4-kinases control Weibel-Palade body biogenesis and von Willebrand factor structure in human endothelial cells.

PubMed

Lopes da Silva, Mafalda; O'Connor, Marie N; Kriston-Vizi, Janos; White, Ian J; Al-Shawi, Raya; Simons, J Paul; Mössinger, Julia; Haucke, Volker; Cutler, Daniel F

2016-05-15

Weibel-Palade bodies (WPBs) are endothelial storage organelles that mediate the release of molecules involved in thrombosis, inflammation and angiogenesis, including the pro-thrombotic glycoprotein von Willebrand factor (VWF). Although many protein components required for WPB formation and function have been identified, the role of lipids is almost unknown. We examined two key phosphatidylinositol kinases that control phosphatidylinositol 4-phosphate levels at the trans-Golgi network, the site of WPB biogenesis. RNA interference of the type II phosphatidylinositol 4-kinases PI4KIIα and PI4KIIβ in primary human endothelial cells leads to formation of an increased proportion of short WPB with perturbed packing of VWF, as exemplified by increased exposure of antibody-binding sites. When stimulated with histamine, these cells release normal levels of VWF yet, under flow, form very few platelet-catching VWF strings. In PI4KIIα-deficient mice, immuno-microscopy revealed that VWF packaging is also perturbed and these mice exhibit increased blood loss after tail cut compared to controls. This is the first demonstration that lipid kinases can control the biosynthesis of VWF and the formation of WPBs that are capable of full haemostatic function. © 2016. Published by The Company of Biologists Ltd.

Blocking the PI3K pathway enhances the efficacy of ALK-targeted therapy in EML4-ALK-positive nonsmall-cell lung cancer.

PubMed

Yang, Lin; Li, Guangchao; Zhao, Likun; Pan, Fei; Qiang, Jiankun; Han, Siqi

2014-10-01

Targeted therapy based on ALK tyrosine kinase inhibitors (ALK-TKIs) has made significant achievements in individuals with EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene) fusion positive nonsmall-cell lung cancer (NSCLC). However, a high fraction of patients receive inferior clinical response to such treatment in the initial therapy, and the exact mechanisms underlying this process need to be further investigated. In this study, we revealed a persistently activated PI3K/AKT signaling that mediates the drug ineffectiveness. We found that genetic or pharmacological inhibition of ALK markedly abrogated phosphorylated STAT3 and ERK, but it failed to suppress AKT activity or induce apoptosis, in EML4-ALK-positive H2228 cells. Furthermore, targeted RNA interference of PI3K pathway components restored sensitivity to TAE684 treatment at least partially due to increased apoptosis. Combined TAE684 with PI3K inhibitor synergistically inhibited the proliferation of EML4-ALK-positive cells in vitro and significantly suppressed the growth of H2228 xenografts in vivo, suggesting the potential clinical application of such combinatorial therapy regimens in patients with EML4-ALK positive lung cancer.

Variability in Proactive and Reactive Cognitive Control Processes Across the Adult Lifespan

PubMed Central

Karayanidis, Frini; Whitson, Lisa Rebecca; Heathcote, Andrew; Michie, Patricia T.

2011-01-01

Task-switching paradigms produce a highly consistent age-related increase in mixing cost [longer response time (RT) on repeat trials in mixed-task than single-task blocks] but a less consistent age effect on switch cost (longer RT on switch than repeat trials in mixed-task blocks). We use two approaches to examine the adult lifespan trajectory of control processes contributing to mixing cost and switch cost: latent variables derived from an evidence accumulation model of choice, and event-related potentials (ERP) that temporally differentiate proactive (cue-driven) and reactive (target-driven) control processes. Under highly practiced and prepared task conditions, aging was associated with increasing RT mixing cost but reducing RT switch cost. Both effects were largely due to the same cause: an age effect for mixed-repeat trials. In terms of latent variables, increasing age was associated with slower non-decision processes, slower rate of evidence accumulation about the target, and higher response criterion. Age effects on mixing costs were evident only on response criterion, the amount of evidence required to trigger a decision, whereas age effects on switch cost were present for all three latent variables. ERPs showed age-related increases in preparation for mixed-repeat trials, anticipatory attention, and post-target interference. Cue-locked ERPs that are linked to proactive control were associated with early emergence of age differences in response criterion. These results are consistent with age effects on strategic processes controlling decision caution. Consistent with an age-related decline in cognitive flexibility, younger adults flexibly adjusted response criterion from trial-to-trial on mixed-task blocks, whereas older adults maintained a high criterion for all trials. PMID:22073037

Tempering Proactive Cognitive Control by Transcranial Direct Current Stimulation of the Right (but Not the Left) Lateral Prefrontal Cortex

PubMed Central

Gómez-Ariza, Carlos J.; Martín, María C.; Morales, Julia

2017-01-01

Behavioral and neuroimaging data support the distinction of two different modes of cognitive control: proactive, which involves the active and sustained maintenance of task-relevant information to bias behavior in accordance with internal goals; and reactive, which entails the detection and resolution of interference at the time it occurs. Both control modes may be flexibly deployed depending on a variety of conditions (i.e., age, brain alterations, motivational factors, prior experience). Critically, and in line with specific predictions derived from the dual mechanisms of control account (Braver, 2012), findings from neuroimaging studies indicate that the same lateral prefrontal regions (i.e., left dorsolateral cortex and right inferior frontal junction) may implement different control modes on the basis of temporal dynamics of activity, which would be modulated in response to external or internal conditions. In the present study, we aimed to explore whether transcraneal direct current stimulation over either the left dorsolateral prefrontal cortex or the right inferior frontal junction would differentially modulate performance on the AX-CPT, a well-validated task that provides sensitive and reliable behavioral indices of proactive/reactive control. The study comprised six conditions of real stimulation [3 (site: left dorsolateral, right dorsolateral and right inferior frontal junction) × 2 (polarity: anodal and cathodal)], and one sham condition. The reference electrode was always placed extracephalically. Performance on the AX-CPT was assessed through two blocks of trials. The first block took place while stimulation was being delivered, whereas the second block was administered after stimulation completion. The results indicate that both offline cathodal stimulation of the right dorsolateral prefrontal cortex and online anodal stimulation of the right inferior frontal junction led participants to be much less proactive, with such a dissociation suggesting that both prefrontal regions differentially contribute to the adjustment of cognitive control modes. tDCS of the left-DLPFC failed to modulate cognitive control. These results partially support the predictions derived from the dual mechanisms of control account. PMID:28588441

Does increasing steps per day predict improvement in physical function and pain interference in adults with fibromyalgia?

PubMed

Kaleth, Anthony S; Slaven, James E; Ang, Dennis C

2014-12-01

To examine the concurrent and predictive associations between the number of steps taken per day and clinical outcomes in patients with fibromyalgia (FM). A total of 199 adults with FM (mean age 46.1 years, 95% women) who were enrolled in a randomized clinical trial wore a hip-mounted accelerometer for 1 week and completed self-report measures of physical function (Fibromyalgia Impact Questionnaire-Physical Impairment [FIQ-PI], Short Form 36 [SF-36] health survey physical component score [PCS], pain intensity and interference (Brief Pain Inventory [BPI]), and depressive symptoms (Patient Health Questionnaire-8 [PHQ-8]) as part of their baseline and followup assessments. Associations of steps per day with self-report clinical measures were evaluated from baseline to week 12 using multivariate regression models adjusted for demographic and baseline covariates. Study participants were primarily sedentary, averaging 4,019 ± 1,530 steps per day. Our findings demonstrate a linear relationship between the change in steps per day and improvement in health outcomes for FM. Incremental increases on the order of 1,000 steps per day were significantly associated with (and predictive of) improvements in FIQ-PI, SF-36 PCS, BPI pain interference, and PHQ-8 (all P < 0.05). Although higher step counts were associated with lower FIQ and BPI pain intensity scores, these were not statistically significant. Step count is an easily obtained and understood objective measure of daily physical activity. An exercise prescription that includes recommendations to gradually accumulate at least 5,000 additional steps per day may result in clinically significant improvements in outcomes relevant to patients with FM. Future studies are needed to elucidate the dose-response relationship between steps per day and patient outcomes in FM. Copyright © 2014 by the American College of Rheumatology.

The relationship between self-reported oral health, self-regulation, proactive coping, procrastination and proactive attitude.

PubMed

Dumitrescu, A L; Dogaru, B C; Dogaru, C D; Manolescu, B

2011-06-01

This cross-sectional study investigated the relationship between self-regulation, proactive coping, procrastination and proactive attitude, perceived oral health and self-reported oral-health behaviours. The study sample consisted of 198 first year medical students. The questionnaire included information about socio-demographic factors, behavioural variables, self-reported oral health status, proactive coping (proactive coping subscale of the Proactive Coping Inventory), procrastination (Procrastination Scale) and proactive attitude (Proactive Attitude Scale). Significant differences were found on self-regulation, proactive coping, procrastination and proactive attitude scales between participants who rated their gingival condition as very good/excellent and those who evaluated it as being poor, very poor or normal (p < 0.05). Results revealed significant differences in procrastination level among individuals who never visit their dentist and those who visit their dentist for check-up or for tooth cleaning and scaling (p = 0.001) or when treatment is needed or when in pain (p < 0.05). In multiple linear regression analyses, proactive coping was associated with toothbrushing frequency and reason for dental visiting. The result suggested that procrastination and proactive coping are important determinants of perceived oral health and self-reported oral-health behaviours.

Activating PIK3CA mutations coexist with BRAF or NRAS mutations in a limited fraction of melanomas.

PubMed

Manca, Antonella; Lissia, Amelia; Capone, Mariaelena; Ascierto, Paolo A; Botti, Gerardo; Caracò, Corrado; Stanganelli, Ignazio; Colombino, Maria; Sini, MariaCristina; Cossu, Antonio; Palmieri, Giuseppe

2015-01-28

Activated PI3K-AKT pathway may contribute to decrease sensitivity to inhibitors of key pathogenetic effectors (mutated BRAF, active NRAS or MEK) in melanoma. Functional alterations are deeply involved in PI3K-AKT activation, with a minimal role reported for mutations in PIK3CA, the catalytic subunit of the PI3K gene. We here assessed the prevalence of the coexistence of BRAF/NRAS and PIK3CA mutations in a series of melanoma samples. A total of 245 tumor specimens (212 primary melanomas and 33 melanoma cell lines) was screened for mutations in BRAF, NRAS, and PIK3CA genes by automated direct sequencing. Overall, 110 (44.9%) samples carried mutations in BRAF, 26 (10.6%) in NRAS, and 24 (9.8%) in PIK3CA. All identified PIK3CA mutations have been reported to induce PI3K activation; those detected in cultured melanomas were investigated for their interference with the antiproliferative activity of the BRAF-mutant inhibitor vemurafenib. A reduced suppression in cell growth was observed in treated cells carrying both BRAF and PIK3CA mutations as compared with those presenting a mutated BRAF only. Among the analysed melanomas, 12/245 (4.9%) samples presented the coexistence of PIK3CA and BRAF/NRAS mutations. Our study further suggests that PIK3CA mutations account for a small fraction of PI3K pathway activation and have a limited impact in interfering with the BRAF/NRAS-driven growth in melanoma.

When in doubt, seize the day? Security values, prosocial values, and proactivity under ambiguity.

PubMed

Grant, Adam M; Rothbard, Nancy P

2013-09-01

Researchers have suggested that both ambiguity and values play important roles in shaping employees' proactive behaviors, but have not theoretically or empirically integrated these factors. Drawing on theories of situational strength and values, we propose that ambiguity constitutes a weak situation that strengthens the relationship between the content of employees' values and their proactivity. A field study of 204 employees and their direct supervisors in a water treatment plant provided support for this contingency perspective. Ambiguity moderated the relationship between employees' security and prosocial values and supervisor ratings of proactivity. Under high ambiguity, security values predicted lower proactivity, whereas prosocial values predicted higher proactivity. Under low ambiguity, values were not associated with proactivity. We replicated these findings in a laboratory experiment with 232 participants in which we measured proactivity objectively as initiative taken to correct errors: Participants with strong security values were less proactive, and participants with strong prosocial values were more proactive, but only when performance expectations were ambiguous. We discuss theoretical implications for research on proactivity, values, and ambiguity and uncertainty. PsycINFO Database Record (c) 2013 APA, all rights reserved

Transcranial doppler in sickle cell anaemia: evaluation of brain blood flow parameters in children of Aracaju, Northeast-Brazil.

PubMed

Melo, Hyder Aragão de; Barreto-Filho, José Augusto S; Prado, Roberto César P do; Cipolotti, Rosana

2008-06-01

Environmental factors interfere on sickle cell anaemia (SCA). Transcanial Doppler (TCD) is important to evaluate cerebrovascular disease. To evaluate brain haemodynamic profile of children with SCA in Sergipe. Cross sectional study (group1: SCA patients aged 3-18; group2: age and sex matched healthy individuals). Baseline brain flow was evaluated. Group1=34 patients; group 2=81 controls. SCA patients had mean velocity (MV)=125.69 cm/s+/-23.40; pulsatility index (PI)=0.66+/-0.10; middle cerebral artery ratio (MCAr)=14.53+/-15.23; right anterior cerebral artery/right middle cerebral artery=0.77+/-0.20; left anterior cerebral artery/left middle cerebral artery=0.78+/-0.20. Controls had MV=79.44+/-15.54; PI=0.82+/-0.11; MCAr=13.19+/-13.77; right anterior cerebral artery/right middle cerebral artery=0.80+/-0.16; left anterior cerebral artery/left middle cerebral artery=0.84+/-0.18. MV and PI differences were statistically significant between groups. MV was related to age but not to gender. MV evaluation using TCD was similar to international standards and possible to be used in our setting.

Observation of hard X-rays from the Crab pulsar and A0535+26

NASA Technical Reports Server (NTRS)

Wu, M.; Dai, C.; Lu, Z.; Ma, Y.; Li, G.; Fan, Z.; Zhang, C.; Xu, C.; Zhang, X.; Gu, Y.

1985-01-01

The Crab pulsar PSR0531+21 was observed in a balloon flight from the Xianghe Balloon Station (China). Data were obtained in the range 20 to 200 keV with a poswish hard X-ray telescope which comprised a 150 sq cm primary crystal of 5 mm thick CsI(T1) which actively shielded the lower 2 pi steradians by a 5 cm thick NaI(T1) crystal. The scintillation pulses originating in CsI and NaI crystals are distinguished by pulse shape discrimination. The telescope has a field of view of approximately 4 deg H psi H pi determined by graded shield and collimator. The effective geometric area of the detector is 116 sq cm. It is noted that when folding a data flow on a long period interference from the data acquisition, transmission and recording system considerably affect the result.

Anomalous photo-ionization of 4d shell in medium-Z ionized atoms

NASA Astrophysics Data System (ADS)

Klapisch, M.; Busquet, M.

2013-09-01

Photoionization (PI) cross sections (PICS) are necessary for the simulation of astrophysical and ICF plasmas. In order to be used in plasma modeling, the PICS are usually fit to simple analytical formulas. We observed an unusual spectral shape of the PICS of the 4d shell of ionized Xe and other elements, computed with different codes: a local minimum occurs around twice the threshold energy. We explain this phenomenon as interference between the bound 4d wavefunction and the free electron wavefunction, which is similar to the Cooper minima for neutral atoms. Consequently, the usual fitting formulas, which consist of a combination of inverse powers of the frequency beyond threshold, may yield rates for PI and radiative recombination (RR) that are incorrect by orders of magnitude. A new fitting algorithm is proposed and is included in the latest version of HULLAC.v9.5.

Correlates of Pure and Co-Occurring Proactive and Reactive Aggressors In Hong Kong

ERIC Educational Resources Information Center

Chan, Jacob Yuichung; Fung, Annis L.; Gerstein, Lawrence H.

2013-01-01

Research on aggression in the West has focused mainly on the dichotomy between proactive and reactive aggression, but not the co-occurring proactive-reactive aggression subtype, despite its prevalence. The authors investigated the differences in psychological and behavioral correlates among proactive, reactive, and proactive-reactive student…

Interference Rejection and Management

DTIC Science & Technology

2009-07-01

performance of a DS CDMA receiver. And it was shown in [34] that in order to successfully have a CDMA system overlay narrowband users, i.e., to deploy... CDMA transmitters and the CDMA receivers. 9.2.1.2 Multicarrier Direct Sequence In a multicarrier DS system, multiple narrowband DS waveforms, each at...1)] mmax(i−1) m=mmin(i−1) Detection of the (i−1)th path Pi,Di Pi−1,Di−1 channel estimator \\ data detector Fig. 9.1 Low-pass equivalent of the DS / CDMA

Orientation observed by Zeeman spectra of dissociated atoms and the interference in photoexcitations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimura, Yasuyuki; Kasahara, Shunji; Kato, Hajime

2003-06-01

In a magnetic field, the wave number of a pump laser light polarized along the field was fixed to the isolated Cs{sub 2}D {sup 1}{sigma}{sub u}{sup +}(v=46, J=54)(leftarrow)X {sup 1}{sigma}{sub g}{sup +}(v=0, J=55) line, and the excitation spectrum of the dissociated Cs(6p {sup 2}P{sub 3/2}) atoms was measured by scanning the wave number of a probe laser light polarized perpendicular to the field. The population of each sublevel 6p {sup 2}P{sub 3/2,m{sub j}} of the dissociated atoms was determined from the line intensities in the m{sub j}-resolved excitation spectrum. The unequal population between the 6p {sup 2}P{sub 3/2,+verticalbarm{sub j}}{sub verticalbar}more » and 6p {sup 2}P{sub 3/2,-verticalbarm{sub j}}{sub verticalbar} levels (atomic orientation) was observed and it was enhanced as the magnetic-field strength was increased. The atomic orientation is shown to be induced by the interference between the indirect predissociation, which occurs by a combination of the spin-orbit coupling of the D {sup 1}{sigma}{sub u}{sup +} state with the (2){sup 3}{pi}{sub 0u} state and the L-uncoupling and Zeeman interactions between the (2){sup 3}{pi}{sub 0u} and dissociative (2){sup 3}{sigma}{sub u}{sup +} states, and the dissociation following a direct excitation to the (2){sup 3}{sigma}{sub u}{sup +} state, which is allowed by spin-orbit coupling of the (2){sup 3}{sigma}{sub u}{sup +} state with the B {sup 1}{pi}{sub u} state. It is demonstrated that the atomic orientation is produced by the photodissociation in the presence of an external magnetic field even when all degenerated molecular M=J,...,0,...,-J sublevels are excited by a light polarized linearly along the field.« less

Reciprocal relationship between proactive personality and work characteristics: a latent change score approach.

PubMed

Li, Wen-Dong; Fay, Doris; Frese, Michael; Harms, Peter D; Gao, Xiang Yu

2014-09-01

Previous proactivity research has predominantly assumed that proactive personality generates positive environmental changes in the workplace. Grounded in recent research on personality development from a broad interactionist theoretical approach, the present article investigates whether work characteristics, including job demands, job control, social support from supervisors and coworkers, and organizational constraints, change proactive personality over time and, more important, reciprocal relationships between proactive personality and work characteristics. Latent change score analyses based on longitudinal data collected in 3 waves across 3 years show that job demands and job control have positive lagged effects on increases in proactive personality. In addition, proactive personality exerts beneficial lagged effects on increases in job demands, job control, and supervisory support, and on decreases in organizational constraints. Dynamic reciprocal relationships are observed between proactive personality with job demands and job control. The revealed corresponsive change relationships between proactive personality and work characteristics contribute to the proactive personality literature by illuminating more nuanced interplays between the agentic person and work characteristics, and also have important practical implications for organizations and employees. PsycINFO Database Record (c) 2014 APA, all rights reserved.

African swine fever virus infection in Classical swine fever subclinically infected wild boars.

PubMed

Cabezón, Oscar; Muñoz-González, Sara; Colom-Cadena, Andreu; Pérez-Simó, Marta; Rosell, Rosa; Lavín, Santiago; Marco, Ignasi; Fraile, Lorenzo; de la Riva, Paloma Martínez; Rodríguez, Fernando; Domínguez, Javier; Ganges, Llilianne

2017-08-01

Recently moderate-virulence classical swine fever virus (CSFV) strains have been proven capable of generating postnatal persistent infection (PI), defined by the maintenance of viremia and the inability to generate CSFV-specific immune responses in animals. These animals also showed a type I interferon blockade in the absence of clinical signs. In this study, we assessed the infection generated in 7-week-old CSFV PI wild boars after infection with the African swine fever virus (ASFV). The wild boars were divided in two groups and were infected with ASFV. Group A comprised boars who were CSFV PI in a subclinical form and Group B comprised pestivirus-free wild boars. Some relevant parameters related to CSFV replication and the immune response of CSFV PI animals were studied. Additionally, serum soluble factors such as IFN-α, TNF-α, IL-6, IL-10, IFN-γ and sCD163 were analysed before and after ASFV infection to assess their role in disease progression. After ASFV infection, only the CSFV PI wild boars showed progressive acute haemorrhagic disease; however, the survival rates following ASFV infection was similar in both experimental groups. Notwithstanding, the CSFV RNA load of CSFV PI animals remained unaltered over the study; likewise, the ASFV DNA load detected after infection was similar between groups. Interestingly, systemic type I FN-α and IL-10 levels in sera were almost undetectable in CSFV PI animals, yet detectable in Group B, while detectable levels of IFN-γ were found in both groups. Finally, the flow cytometry analysis showed an increase in myelomonocytic cells (CD172a + ) and a decrease in CD4 + T cells in the PBMCs from CSFV PI animals after ASFV infection. Our results showed that the immune response plays a role in the progression of disease in CSFV subclinically infected wild boars after ASFV infection, and the immune response comprised the systemic type I interferon blockade. ASFV does not produce any interference with CSFV replication, or vice versa. ASFV infection could be a trigger factor for the disease progression in CSFV PI animals, as their survival after ASFV was similar to that of the pestivirus-free ASFV-infected group. This fact suggests a high resistance in CSFV PI animals even against a virus like ASFV; this may mean that there are relevant implications for CSF control in endemic countries. The diagnosis of ASFV and CSFV co-infection in endemic countries cannot be ruled out and need to be studied in greater depth.

PPARbeta/delta agonist stimulates human lung carcinoma cell growth through inhibition of PTEN expression: the involvement of PI3K and NF-kappaB signals.

PubMed

Han, ShouWei; Ritzenthaler, Jeffrey D; Zheng, Ying; Roman, Jesse

2008-06-01

Recent studies suggest that activation of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) promotes cancer cell survival. We previously demonstrated that a selective PPARbeta/delta agonist, GW501516, stimulated human non-small cell lung carcinoma (NSCLC) cell growth. Here, we explore the mechanisms responsible for this effect. We show that GW501516 decreased phosphate and tensin homolog deleted on chromosome 10 (PTEN), a tumor suppressor known to decrease cell growth and induce apoptosis. Activation of PPARbeta/delta and phosphatidylinositol 3-kinase (PI3K)/Akt signaling was associated with inhibition of PTEN. GW501516 increased NF-kappaB DNA binding activity and p65 protein expression through activation of PPARbeta/delta and PI3K/Akt signals and enhanced the physical interactions between PPARbeta/delta and p65 protein. Conversely, inhibition of PI3K and silencing of p65 by small RNA interference (siRNA) blocked the effect of GW501516 on PTEN expression and on NSCLC cell proliferation. GW501516 also inhibited IKBalpha protein expression. Silencing of IKBalpha enhanced the effect of GW501516 on PTEN protein expression and on cell proliferation. It also augmented the GW501516-induced complex formation of PPARbeta/delta and p65 proteins. Overexpression of PTEN suppressed NSCLC cell growth and eliminated the effect of GW501516 on phosphorylation of Akt. Together, our observations suggest that GW501516 induces the proliferation of NSCLC cells by inhibiting the expression of PTEN through activation of PPARbeta/delta, which stimulates PI3K/Akt and NF-kappaB signaling. Overexpression of PTEN overcomes this effect and unveils PPARbeta/delta and PTEN as potential therapeutic targets in NSCLC.

4Pi-SHG imaging of mammalian myofibrillar structures

NASA Astrophysics Data System (ADS)

Vogel, Martin; Hahn, Dorothea; Schürmann, Sebastian; Lang, Marion; Wegner, Frederic v.; Friedrich, Oliver; Engelhardt, Johann; Hell, Stefan W.; Fink, Rainer H.

2006-02-01

Intrinsic Second Harmonic Generation (SHG) signals obtained from the motor protein myosin are of particular interest for 3D-imaging of living muscle cells. In addition, the new and powerful tool of 4Pi microscopy allows to markedly enhance the optical resolution of microscopy as well as the sensitivity for small objects because of the high peak intensities due to the interference pattern created in the focus. In the present study, we report, to our knowledge for the first time, measurements of intrinsic SHG signals under 4Pi conditions of type A. These measurements on mammalian myofibrilar structures are combined with very high resolution 4Pi fluorescence data obtained from the same preparations. We have chosen myofibrillar preparations of isolated mammalian muscle fibers as they (i) possess a regular repetitive pattern of actin and myosin filaments within sarcomers 2 to 3 μm in length, (ii) consist of single myofibrils of small total diameter of approximately 1 μm and (iii) are ideally suited to study the biomedically important process of force generation via calcium regulated motor protein interactions. Myofibrillar preparations were obtained from murine skeletal and heart muscle by using a combined chemical and mechanical fractionation1 (Both et al. 2004, JBO 9(5):882-892). BODIPY FL phallacidin has been used to fluorescently label the actin filaments. The experiments were carried out with a Leica SP2 multi photon microscope modified for 4Pi measurements using a Ti:Sa laser tuned to 850-900 nm. SHG as well as fluorescence photons were detected confocally by a counting APD detector. The approach taken our study provides new 3D-data for the analysis and simulation of the important process of excitation-contraction coupling under normal physiological as well as under pathophysiological conditions.

MicroRNA-Dependent Transcriptional Silencing of Transposable Elements in Drosophila Follicle Cells.

PubMed

Mugat, Bruno; Akkouche, Abdou; Serrano, Vincent; Armenise, Claudia; Li, Blaise; Brun, Christine; Fulga, Tudor A; Van Vactor, David; Pélisson, Alain; Chambeyron, Séverine

2015-05-01

RNA interference-related silencing mechanisms concern very diverse and distinct biological processes, from gene regulation (via the microRNA pathway) to defense against molecular parasites (through the small interfering RNA and the Piwi-interacting RNA pathways). Small non-coding RNAs serve as specificity factors that guide effector proteins to ribonucleic acid targets via base-pairing interactions, to achieve transcriptional or post-transcriptional regulation. Because of the small sequence complementarity required for microRNA-dependent post-transcriptional regulation, thousands of microRNA (miRNA) putative targets have been annotated in Drosophila. In Drosophila somatic ovarian cells, genomic parasites, such as transposable elements (TEs), are transcriptionally repressed by chromatin changes induced by Piwi-interacting RNAs (piRNAs) that prevent them from invading the germinal genome. Here we show, for the first time, that a functional miRNA pathway is required for the piRNA-mediated transcriptional silencing of TEs in this tissue. Global miRNA depletion, caused by tissue- and stage-specific knock down of drosha (involved in miRNA biogenesis), AGO1 or gawky (both responsible for miRNA activity), resulted in loss of TE-derived piRNAs and chromatin-mediated transcriptional de-silencing of TEs. This specific TE de-repression was also observed upon individual titration (by expression of the complementary miRNA sponge) of two miRNAs (miR-14 and miR-34) as well as in a miR-14 loss-of-function mutant background. Interestingly, the miRNA defects differentially affected TE- and 3' UTR-derived piRNAs. To our knowledge, this is the first indication of possible differences in the biogenesis or stability of TE- and 3' UTR-derived piRNAs. This work is one of the examples of detectable phenotypes caused by loss of individual miRNAs in Drosophila and the first genetic evidence that miRNAs have a role in the maintenance of genome stability via piRNA-mediated TE repression.

Monobromobimane occupies a distinct xenobiotic substrate site in glutathione S-transferase pi.

PubMed

Ralat, Luis A; Colman, Roberta F

2003-11-01

Monobromobimane (mBBr), functions as a substrate of porcine glutathione S-transferase pi (GST pi): The enzyme catalyzes the reaction of mBBr with glutathione. S-(Hydroxyethyl)bimane, a nonreactive analog of monobromobimane, acts as a competitive inhibitor with respect to mBBr as substrate but does not affect the reaction of GST pi with another substrate, 1-chloro-2,4-dinitrobenzene (CDNB). In the absence of glutathione, monobromobimane inactivates GST pi at pH 7.0 and 25 degrees C as assayed using mBBr as substrate, with a lesser effect on the enzyme's use of CDNB as substrate. These results indicate that the sites occupied by CDNB and mBBr are not identical. Inactivation is proportional to the incorporation of 2 moles of bimane/mole of subunit. Modification of GST pi with mBBr does not interfere with its binding of 8-anilino-1-naphthalene sulfonate, indicating that this hydrophobic site is not the target of monobromobimane. S-Methylglutathione and S-(hydroxyethyl)bimane each yield partial protection against inactivation and decrease reagent incorporation, while glutathionyl-bimane protects completely against inactivation. Peptide analysis after trypsin digestion indicates that mBBr modifies Cys45 and Cys99 equally. Modification of Cys45 is reduced in the presence of S-methylglutathione, indicating that this residue is at or near the glutathione binding region. In contrast, modification of Cys99 is reduced in the presence of S-(hydroxyethyl)bimane, suggesting that this residue is at or near the mBBr xenobiotic substrate binding site. Modification of Cys99 can best be understood by reaction with monobromobimane while it is bound to its xenobiotic substrate site in an alternate orientation. These results support the concept that glutathione S-transferase accomplishes its ability to react with a diversity of substrates in part by harboring distinct xenobiotic substrate sites.

A concept analysis of proactive behaviour in midwifery.

PubMed

Mestdagh, Eveline; Van Rompaey, Bart; Beeckman, Katrien; Bogaerts, Annick; Timmermans, Olaf

2016-06-01

To report an analysis of the concept of proactive behaviour and apply the findings to midwifery. Proactive behaviour is a universal phenomenon generalizable to multiple professions. The purpose of this work was to establish a link with midwifery. Concept analysis by Walker and Avant's method. Literature was searched in PubMed, ERIC, NARCIS, Emerald and reference lists of related journal articles with a timeline of 1990 - April 2015 in the period of November 2014 - June 2015. Next key words were combined by the use of Boolean operators: 'proactive behaviour', 'midwifery', 'midwife', 'proactivity' and 'proactive'. Fifteen studies were included. A focused review of scientific publications in midwifery, health care, healthcare education and social sciences, which highlighted the concept of proactive behaviour. In the studied literature, several attributes of proactive behaviour were cited. These attributes were narrowed by applying it on a midwifery model case, borderline case and contrary case. Related concepts were elaborated and distinguished of the concept of proactive behaviour in midwifery. Proactive behaviour is triggered by different individual and contextual antecedents and has consequences at multiple levels. A midwife who behaves proactive would not look at changes as a boundary, persistently improves things she experienced as wrong, anticipates future barriers and looks for viable alternatives to carry out her work as efficiently and effectively as possible. Various individual and/or contextual antecedents trigger proactive behaviour in midwifery, and this behaviour could cause multiple future benefits for the constant evolving reproductive health care. © 2016 John Wiley & Sons Ltd.

Subthalamic stimulation, oscillatory activity and connectivity reveal functional role of STN and network mechanisms during decision making under conflict.

PubMed

Hell, Franz; Taylor, Paul C J; Mehrkens, Jan H; Bötzel, Kai

2018-05-01

Inhibitory control is an important executive function that is necessary to suppress premature actions and to block interference from irrelevant stimuli. Current experimental studies and models highlight proactive and reactive mechanisms and claim several cortical and subcortical structures to be involved in response inhibition. However, the involved structures, network mechanisms and the behavioral relevance of the underlying neural activity remain debated. We report cortical EEG and invasive subthalamic local field potential recordings from a fully implanted sensing neurostimulator in Parkinson's patients during a stimulus- and response conflict task with and without deep brain stimulation (DBS). DBS made reaction times faster overall while leaving the effects of conflict intact: this lack of any effect on conflict may have been inherent to our task encouraging a high level of proactive inhibition. Drift diffusion modelling hints that DBS influences decision thresholds and drift rates are modulated by stimulus conflict. Both cortical EEG and subthalamic (STN) LFP oscillations reflected reaction times (RT). With these results, we provide a different interpretation of previously conflict-related oscillations in the STN and suggest that the STN implements a general task-specific decision threshold. The timecourse and topography of subthalamic-cortical oscillatory connectivity suggest the involvement of motor, frontal midline and posterior regions in a larger network with complementary functionality, oscillatory mechanisms and structures. While beta oscillations are functionally associated with motor cortical-subthalamic connectivity, low frequency oscillations reveal a subthalamic-frontal-posterior network. With our results, we suggest that proactive as well as reactive mechanisms and structures are involved in implementing a task-related dynamic inhibitory signal. We propose that motor and executive control networks with complementary oscillatory mechanisms are tonically active, react to stimuli and release inhibition at the response when uncertainty is resolved and return to their default state afterwards. Copyright © 2018 Elsevier Inc. All rights reserved.

Suppression of the auxin response pathway enhances susceptibility to Phytophthora cinnamomi while phosphite-mediated resistance stimulates the auxin signalling pathway

PubMed Central

2014-01-01

Background Phytophthora cinnamomi is a devastating pathogen worldwide and phosphite (Phi), an analogue of phosphate (Pi) is highly effective in the control of this pathogen. Phi also interferes with Pi starvation responses (PSR), of which auxin signalling is an integral component. In the current study, the involvement of Pi and the auxin signalling pathways in host and Phi-mediated resistance to P. cinnamomi was investigated by screening the Arabidopsis thaliana ecotype Col-0 and several mutants defective in PSR and the auxin response pathway for their susceptibility to this pathogen. The response to Phi treatment was also studied by monitoring its effect on Pi- and the auxin response pathways. Results Here we demonstrate that phr1-1 (phosphate starvation response 1), a mutant defective in response to Pi starvation was highly susceptible to P. cinnamomi compared to the parental background Col-0. Furthermore, the analysis of the Arabidopsis tir1-1 (transport inhibitor response 1) mutant, deficient in the auxin-stimulated SCF (Skp1 − Cullin − F-Box) ubiquitination pathway was also highly susceptible to P. cinnamomi and the susceptibility of the mutants rpn10 and pbe1 further supported a role for the 26S proteasome in resistance to P. cinnamomi. The role of auxin was also supported by a significant (P < 0.001) increase in susceptibility of blue lupin (Lupinus angustifolius) to P. cinnamomi following treatment with the inhibitor of auxin transport, TIBA (2,3,5-triiodobenzoic acid). Given the apparent involvement of auxin and PSR signalling in the resistance to P. cinnamomi, the possible involvement of these pathways in Phi mediated resistance was also investigated. Phi (especially at high concentrations) attenuates the response of some Pi starvation inducible genes such as AT4, AtACP5 and AtPT2 in Pi starved plants. However, Phi enhanced the transcript levels of PHR1 and the auxin responsive genes (AUX1, AXR1and AXR2), suppressed the primary root elongation, and increased root hair formation in plants with sufficient Pi. Conclusions The auxin response pathway, particularly auxin sensitivity and transport, plays an important role in resistance to P. cinnamomi in Arabidopsis, and phosphite-mediated resistance may in some part be through its effect on the stimulation of the PSR and auxin response pathways. PMID:24649892

From proactive personality to organizational citizenship behavior: mediating role of harmony.

PubMed

Gan, Yiqun; Cheung, Fanny M

2010-06-01

The objective of the present study was to examine the moderating role of interpersonal harmony in the relation of proactive personality with organizational citizenship behavior. 158 employees in Chinese state-owned companies completed the Proactive Personality Scale (Bateman & Crant, 1993), Harmony scale, and Organizational Citizenship Behavior Questionnaire. Proactive personality had insignificant correlation with job dedication. The correlation between interpersonal facilitation and proactive personality was significant but quite low. Results of the hierarchical regression analyses indicated that when demographic variables were controlled, Harmony had significant moderating effects on the relations of proactive behavior and job dedication/interpersonal facilitation. In the high Harmony group, the correlation between proactive personality and organizational citizenship behavior was significant; whereas in the low Harmony group, this correlation was not significant.

Emerging strategies for RNA interference (RNAi) applications in insects.

PubMed

Nandety, Raja Sekhar; Kuo, Yen-Wen; Nouri, Shahideh; Falk, Bryce W

2015-01-01

RNA interference (RNAi) in insects is a gene regulatory process that also plays a vital role in the maintenance and in the regulation of host defenses against invading viruses. Small RNAs determine the specificity of the RNAi through precise recognition of their targets. These small RNAs in insects comprise small interfering RNAs (siRNAs), micro RNAs (miRNAs) and Piwi interacting RNAs (piRNAs) of various lengths. In this review, we have explored different forms of the RNAi inducers that are presently in use, and their applications for an effective and efficient fundamental and practical RNAi research with insects. Further, we reviewed trends in next generation sequencing (NGS) technologies and their importance for insect RNAi, including the identification of novel insect targets as well as insect viruses. Here we also describe a rapidly emerging trend of using plant viruses to deliver the RNAi inducer molecules into insects for an efficient RNAi response.

Palliative systemic therapy for young women with metastatic breast cancer.

PubMed

Eng, Lee Guek; Dawood, Shaheenah; Dent, Rebecca

2015-09-01

Breast cancer in young women age less than 40 years remains a relatively rare disease. Emerging data suggest that the biology of breast cancer in younger women may differ from that of older women. Although metastatic breast cancer remains incurable, it is definitely treatable; especially in this era of emerging novel therapeutics. Most women have hormone receptor-positive disease and strategies that interfere with proliferation and the PI3 kinase pathway are reporting exciting results. The prognosis of the metastatic HER2 subtype has been extended to a median survival of 56 months with dual HER2 targeting agents in the first-line setting. Finally, triple negative breast cancer has an enlarging range of therapeutic options including immunotherapy, antiangiogenesis therapy, and targeted therapies including agents that interfere with androgen receptor signaling. Combined palliative and holistic approaches are essential to help young women navigate the marathon of treatment for metastatic breast cancer.

Drawbacks of proactivity: Effects of daily proactivity on daily salivary cortisol and subjective well-being.

PubMed

Fay, Doris; Hüttges, Annett

2017-10-01

The benefit of proactive work behaviors for performance-related outcomes has been well established. However, this approach to studying proactivity has not yet acknowledged its potential implications for the actor's well-being. Drawing on the fact that resources at work are limited and that the workplace is a social system characterized by interdependencies, we proposed that daily proactivity could have a negative effect on daily well-being. We furthermore proposed that this effect should be mediated by work overload and negative affect. We conducted a daily diary study (N = 72) to test the potential negative effects of proactivity on daily well-being. Data was collected across 3 consecutive work days. During several daily measurement occasions, participants reported proactivity, work overload, negative affect, and fatigue. They also provided 4 saliva samples per day, from which cortisol was assayed. Based on the 4 samples, a measure of daily cortisol output was produced. Multilevel analyses showed that daily proactivity was positively associated with higher daily cortisol output. The positive association of daily proactivity with bedtime fatigue was marginally significant. There was no support for a mediating effect of work overload and negative affect. Implications for theory-building on the proactivity-well-being link are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors

PubMed Central

Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; Vanden Broeck, Jozef

2016-01-01

Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects. PMID:27581362

Gab1 regulates proliferation and migration through the PI3K/Akt signaling pathway in intrahepatic cholangiocarcinoma.

PubMed

Sang, Haiquan; Li, Tingting; Li, Hangyu; Liu, Jingang

2015-11-01

Intrahepatic cholangiocarcinoma is the second most common primary malignant tumor of the liver, and it originates from the intrahepatic biliary duct epithelium. Prognosis is poor due to lack of effective comprehensive treatments. In this study, we assessed the expression of Gab1, VEGFR-2, and MMP-9 in intrahepatic cholangiocarcinoma solid tumors by immunohistochemistry and determined whether their expression was associated with clinical and pathological features. We found that expression of Gab1, VEGFR-2, and MMP-9 was highly and positively correlated with each other and with lymph node metastasis and TNM stage in intrahepatic cholangiocarcinoma tissues. Interference of Gab1 and VEGFR-2 expression via siRNA in the intrahepatic cholangiocarcinoma cell line RBE resulted in decreased PI3K/Akt pathway activity. Inhibition of Gab1 and VEGFR-2 expression also caused decreased cell proliferation, cell cycle arrested in G1 phase, increased apoptosis, and decreased invasion in RBE cells. These results suggest that Gab1, VEGFR-2, and MMP-9 contribute significantly to the highly malignant behavior of intrahepatic cholangiocarcinoma. The regulation of growth, apoptosis, and invasion by Gab1 through the VEGFR-2/Gab1/PI3K/Akt signaling pathway may represent potential targets for improving the treatment of intrahepatic cholangiocarcinoma.

The ζ Toxin Induces a Set of Protective Responses and Dormancy

PubMed Central

Tabone, Mariangela; Gonzalez-Pastor, José E.; Daugelavicius, Rimantas; Ayora, Silvia; Alonso, Juan C.

2012-01-01

The ζε module consists of a labile antitoxin protein, ε, which in dimer form (ε2) interferes with the action of the long-living monomeric ζ phosphotransferase toxin through protein complex formation. Toxin ζ, which inhibits cell wall biosynthesis and may be bactericide in nature, at or near physiological concentrations induces reversible cessation of Bacillus subtilis proliferation (protective dormancy) by targeting essential metabolic functions followed by propidium iodide (PI) staining in a fraction (20–30%) of the population and selects a subpopulation of cells that exhibit non-inheritable tolerance (1–5×10−5). Early after induction ζ toxin alters the expression of ∼78 genes, with the up-regulation of relA among them. RelA contributes to enforce toxin-induced dormancy. At later times, free active ζ decreases synthesis of macromolecules and releases intracellular K+. We propose that ζ toxin induces reversible protective dormancy and permeation to PI, and expression of ε2 antitoxin reverses these effects. At later times, toxin expression is followed by death of a small fraction (∼10%) of PI stained cells that exited earlier or did not enter into the dormant state. Recovery from stress leads to de novo synthesis of ε2 antitoxin, which blocks ATP binding by ζ toxin, thereby inhibiting its phosphotransferase activity. PMID:22295078

Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors

NASA Astrophysics Data System (ADS)

Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; vanden Broeck, Jozef

2016-09-01

Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects.

Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors.

PubMed

Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; Vanden Broeck, Jozef

2016-09-01

Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects.

The ζ toxin induces a set of protective responses and dormancy.

PubMed

Lioy, Virginia S; Machon, Cristina; Tabone, Mariangela; Gonzalez-Pastor, José E; Daugelavicius, Rimantas; Ayora, Silvia; Alonso, Juan C

2012-01-01

The ζε module consists of a labile antitoxin protein, ε, which in dimer form (ε(2)) interferes with the action of the long-living monomeric ζ phosphotransferase toxin through protein complex formation. Toxin ζ, which inhibits cell wall biosynthesis and may be bactericide in nature, at or near physiological concentrations induces reversible cessation of Bacillus subtilis proliferation (protective dormancy) by targeting essential metabolic functions followed by propidium iodide (PI) staining in a fraction (20-30%) of the population and selects a subpopulation of cells that exhibit non-inheritable tolerance (1-5×10(-5)). Early after induction ζ toxin alters the expression of ∼78 genes, with the up-regulation of relA among them. RelA contributes to enforce toxin-induced dormancy. At later times, free active ζ decreases synthesis of macromolecules and releases intracellular K(+). We propose that ζ toxin induces reversible protective dormancy and permeation to PI, and expression of ε(2) antitoxin reverses these effects. At later times, toxin expression is followed by death of a small fraction (∼10%) of PI stained cells that exited earlier or did not enter into the dormant state. Recovery from stress leads to de novo synthesis of ε(2) antitoxin, which blocks ATP binding by ζ toxin, thereby inhibiting its phosphotransferase activity.

Heterogeneity in the development of proactive and reactive aggression in childhood: Common and specific genetic - environmental factors

PubMed Central

Lacourse, Eric; Brendgen, Mara; Vitaro, Frank; Dionne, Ginette; Tremblay, Richard Ernest; Boivin, Michel

2017-01-01

Background Few studies are grounded in a developmental framework to study proactive and reactive aggression. Furthermore, although distinctive correlates, predictors and outcomes have been highlighted, proactive and reactive aggression are substantially correlated. To our knowledge, no empirical study has examined the communality of genetic and environmental underpinning of the development of both subtypes of aggression. The current study investigated the communality and specificity of genetic-environmental factors related to heterogeneity in proactive and reactive aggression’s development throughout childhood. Methods Participants were 223 monozygotic and 332 dizygotic pairs. Teacher reports of aggression were obtained at 6, 7, 9, 10 and 12 years of age. Joint development of both phenotypes were analyzed through a multivariate latent growth curve model. Set point, differentiation, and genetic maturation/environmental modulation hypotheses were tested using a biometric decomposition of intercepts and slopes. Results Common genetic factors accounted for 64% of the total variation of proactive and reactive aggression’s intercepts. Two other sets of uncorrelated genetic factors accounted for reactive aggression’s intercept (17%) on the one hand, and for proactive (43%) and reactive (13%) aggression’s slopes on the other. Common shared environmental factors were associated with proactive aggression’s intercept (21%) and slope (26%) and uncorrelated shared environmental factors were also associated with reactive aggression’s slope (14%). Common nonshared environmental factors explained most of the remaining variability of proactive and reactive aggression slopes. Conclusions A genetic differentiation hypothesis common to both phenotypes was supported by common genetic factors associated with the developmental heterogeneity of proactive and reactive aggression in childhood. A genetic maturation hypothesis common to both phenotypes, albeit stronger for proactive aggression, was supported by common genetic factors associated with proactive and reactive aggression slopes. A shared environment set point hypothesis for proactive aggression was supported by shared environmental factors associated with proactive aggression baseline and slope. Although there are many common features to proactive and reactive aggression, the current research underscores the advantages of differentiating them when studying aggression. PMID:29211810

Effects of small interfering RNA inhibit Class I phosphoinositide 3-kinase on human gastric cancer cells

PubMed Central

Zhu, Bao-Song; Yu, Li-Yan; Zhao, Kui; Wu, Yong-You; Cheng, Xiao-Li; Wu, Yong; Zhong, Feng-Yun; Gong, Wei; Chen, Qiang; Xing, Chun-Gen

2013-01-01

AIM: To investigate the effects of small interfering RNA (siRNA)-mediated inhibition of Class I phosphoinositide 3-kinase (Class I PI3K) signal transduction on the proliferation, apoptosis, and autophagy of gastric cancer SGC7901 and MGC803 cells. METHODS: We constructed the recombinant replication adenovirus PI3K(I)-RNA interference (RNAi)-green fluorescent protein (GFP) and control adenovirus NC-RNAi-GFP, and infected it into human gastric cancer cells. MTT assay was used to determine the growth rate of the gastric cancer cells. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after adenovirus PI3K(I)-RNAi-GFP and control adenovirus NC-RNAi-GFP treatment. Immunofluorescence staining was used to detect the expression of microtubule-associated protein 1 light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. The expression of autophagy was monitored with MDC, LC3 staining, and transmission electron microscopy. Western blotting was used to detect p53, Beclin-1, Bcl-2, and LC3 protein expression in the culture supernatant. RESULTS: The viability of gastric cancer cells was inhibited after siRNA targeting to the Class I PI3K blocked Class I PI3K signal pathway. MTT assays revealed that, after SGC7901 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 27.48% ± 2.71% at 24 h, 41.92% ± 2.02% at 48 h, and 50.85% ± 0.91% at 72 h. After MGC803 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 24.39% ± 0.93% at 24 h, 47.00% ± 0.87% at 48 h, and 70.30% ± 0.86% at 72 h (P < 0.05 compared to control group). It was determined that when 50 MOI, the transfection efficiency was 95% ± 2.4%. Adenovirus PI3K(I)-RNAi-GFP (50 MOI) induced mitochondrial dysfunction and activated cell apoptosis in SGC7901 cells, and the results described here prove that RNAi of Class I PI3K induced apoptosis in SGC7901 cells. The results showed that adenovirus PI3K(I)-RNAi-GFP transfection induced punctate distribution of LC3 immunoreactivity, indicating increased formation of autophagosomes. The results showed that the basal level of Beclin-1 and LC3 protein in SGC7901 cells was low. After incubating with adenovirus PI3K(I)-RNAi-GFP (50 MOI), Beclin-1, LC3, and p53 protein expression was significantly increased from 24 to 72 h. We also found that Bcl-2 protein expression down-regulated with the treatment of adenovirus PI3K(I)-RNAi-GFP (50 MOI). A number of isolated membranes, possibly derived from ribosome-free endoplasmic reticulum, were seen. These isolated membranes were elongated and curved to engulf a cytoplasmic fraction and organelles. We used transmission electron microscopy to identify ultrastructural changes in SGC7901 cells after adenovirus PI3K(I)-RNAi-GFP (50 MOI) treatment. Control cells showed a round shape and contained normal-looking organelles, nucleus, and chromatin, while adenovirus PI3K(I)-RNAi-GFP (50 MOI)-treated cells exhibited the typical signs of autophagy. CONCLUSION: After the Class I PI3K signaling pathway has been blocked by siRNA, the proliferation of cells was inhibited and the apoptosis of gastric cancer cells was enhanced. PMID:23555164

Other Types Of LCDs

NASA Astrophysics Data System (ADS)

Kobayashi, Shunsuke; Mochizuki, Akihiro

The following sections are included: * INTRODUCTION * TUNABLE BIREFRINGENCE LCDs * Nematic Device with Homogeneous Alignment * Nematic Device with Homeotropic Alignment * ELECTRICALLY CONTROLLED BIREFRINGENCE EFFECT LCDs WITH A COMPENSATING CELL OR POLYMER LAYERS * Super Homeotropic LCDs * Black and White STN LCDs * Optical mode interference * Guest-host mode * Double-layered STN * Retardation film compensated STN * DUAL FREQUENCY ADDRESSING LCDs * Application for DSM LCDs * Application for TN LCDs * PI-CELL * CHOLESTERIC-NEMATIC PHASE CHANGE LCDs * Storage Mode LCDs * Stabilized Hysteresis Mode LCDs * THERMALLY ADDRESSED LCDs (CHOLESTERIC) * BISTABLE LCD * WIDE VIEWING ANGLE TN LCDs USING RETARDATION SHEETS * Type 1 Cells * Type 2 Cells * REFERENCES

Ad-hoc and context-dependent adjustments of selective attention in conflict control: an ERP study with visual probes.

PubMed

Nigbur, R; Schneider, J; Sommer, W; Dimigen, O; Stürmer, B

2015-02-15

Cognitive conflict control in flanker tasks has often been described using the zoom-lens metaphor of selective attention. However, whether and how selective attention - in terms of suppression and enhancement - operates in this context has remained unclear. To examine the dynamic interplay of selective attention and cognitive control we used electrophysiological measures and presented task-irrelevant visual probe stimuli at foveal, parafoveal, and peripheral display positions. Target-flanker congruency varied either randomly from trial to trial (mixed-block) or block-wise (fixed-block) in order to induce reactive versus proactive control modes, respectively. Three EEG measures were used to capture ad-hoc adjustments within trials as well as effects of context-based predictions: the N1 component of the visual evoked potential (VEP) to probes, the VEP to targets, and the conflict-related midfrontal N2 component. Results from probe-VEPs indicate that enhanced processing of the foveal target rather than suppression of the peripheral flankers supports interference control. In incongruent mixed-block trials VEPs were larger to probes near the targets. In the fixed-blocks probe-VEPs were not modulated, but contrary to the mixed-block the preceding target-related VEP was affected by congruency. Results of the control-related N2 reveal largest amplitudes in the unpredictable context, which did not differentiate for stimulus and response incongruency. In contrast, in the predictable context, N2 amplitudes were reduced overall and differentiated between stimulus and response incongruency. Taken together these results imply that predictability alters interference control by a reconfiguration of stimulus processing. During unpredictable sequences participants adjust their attentional focus dynamically on a trial-by-trial basis as reflected in congruency-dependent probe-VEP-modulation. This reactive control mode also elicits larger N2 amplitudes. In contrast, when task demands are predictable, participants focus selective attention earlier as reflected in the target-related VEPs. This proactive control mode leads to smaller N2 amplitudes and absent probe effects. Copyright © 2014 Elsevier Inc. All rights reserved.

Proactive Policing by Post and Community Officers

ERIC Educational Resources Information Center

Famega, Christine N.

2009-01-01

Using data collected through social observations of 188 police officer shifts, the current research examines the time allocated to proactive and reactive activities by traditional and community police officers to assess (a) the extent to which post officers engage in proactive activities, (b) whether these activities differ from the (proactive)…

Comparison of force plate gait analysis and owner assessment of pain using the Canine Brief Pain Inventory in dogs with osteoarthritis.

PubMed

Brown, D C; Boston, R C; Farrar, J T

2013-01-01

Lameness assessment using force plate gait analysis (FPGA) and owner assessment of chronic pain using the Canine Brief Pain Inventory (CBPI) are valid and reliable methods of evaluating canine osteoarthritis. There are no studies comparing these 2 outcome measures. Evaluate the relationship between CBPI pain severity (PS) and interference (PI) scores with the vertical forces of FPGA as efficacy measures in canine osteoarthritis. Sixty-eight client-owned dogs with osteoarthritis (50 hind limb and 18 forelimb). Double-blind, randomized. Owners completed the CBPI, and dogs underwent FPGA on days 0 and 14. Dogs received carprofen or placebo on days 1 through 14. The change in PS and PI scores from day 0 to 14 were compared to the change in peak vertical force (PVF) and vertical impulse (VI). PS and PI scores significantly decreased in carprofen- compared with placebo-treated dogs (P = .002 and P = .03, respectively). PVF and VI significantly increased in carprofen- compared with placebo-treated dogs (P = .006 and P = .02, respectively). There was no correlation or concordance between the PS or PI score changes and change in PVF or VI. In these dogs with hind limb or forelimb osteoarthritis, owner assessment of chronic pain using the CBPI and assessment of lameness using FPGA detected significant improvement in dogs treated with carprofen. The lack of correlation or concordance between the change in owner scores and vertical forces suggests that owners were focused on behaviors other than lameness when making efficacy evaluations in their dogs. Copyright © 2012 by the American College of Veterinary Internal Medicine.

Involvement of PI3K and ROCK signaling pathways in migration of bone marrow-derived mesenchymal stem cells through human brain microvascular endothelial cell monolayers.

PubMed

Lin, Mei-Na; Shang, De-Shu; Sun, Wei; Li, Bo; Xu, Xin; Fang, Wen-Gang; Zhao, Wei-Dong; Cao, Liu; Chen, Yu-Hua

2013-06-04

Bone marrow-derived mesenchymal stem cells (MSC) represent an important and easily available source of stem cells for potential therapeutic use in neurological diseases. The entry of circulating cells into the central nervous system by intravenous administration requires, firstly, the passage of the cells across the blood-brain barrier (BBB). However, little is known of the details of MSC transmigration across the BBB. In the present study, we employed an in vitro BBB model constructed using a human brain microvascular endothelial cell monolayer to study the mechanism underlying MSC transendothelial migration. Transmigration assays, transendothelial electrical resistance (TEER) and horseradish peroxidase (HRP) flux assays showed that MSC could transmigrate through human brain microvascular endothelial cell monolayers by a paracellular pathway. Cell fractionation and immunofluorescence assays confirmed the disruption of tight junctions. Inhibition assays showed that a Rho-kinase (ROCK) inhibitor (Y27632) effectively promoted MSC transendothelial migration; conversely, a PI3K inhibitor (LY294002) blocked MSC transendothelial migration. Interestingly, adenovirus-mediated interference with ROCK in MSC significantly increased MSC transendothelial migration, and overexpression of a PI3K dominant negative mutant in MSC cells could block transendothelial migration. Our findings provide clear evidence that the PI3K and ROCK pathways are involved in MSC migration through human brain microvascular endothelial cell monolayers. The information yielded by this study may be helpful in constructing gene-modified mesenchymal stem cells that are able to penetrate the BBB effectively for cell therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

The C-terminal SH2 domain of p85 accounts for the high affinity and specificity of the binding of phosphatidylinositol 3-kinase to phosphorylated platelet-derived growth factor beta receptor.

PubMed Central

Klippel, A; Escobedo, J A; Fantl, W J; Williams, L T

1992-01-01

Upon stimulation by its ligand, the platelet-derived growth factor (PDGF) receptor associates with the 85-kDa subunit of phosphatidylinositol (PI) 3-kinase. The 85-kDa protein (p85) contains two Src homology 2 (SH2) domains and one SH3 domain. To define the part of p85 that interacts with the PDGF receptor, a series of truncated p85 mutants was analyzed for association with immobilized PDGF receptor in vitro. We found that a fragment of p85 that contains a single Src homology domain, the C-terminal SH2 domain (SH2-C), was sufficient for directing the high-affinity interaction with the receptor. Half-maximal binding of SH2-C to the receptor was observed at an SH2-C concentration of 0.06 nM. SH2-C, like full-length p85, was able to distinguish between wild-type PDGF receptor and a mutant receptor lacking the PI 3-kinase binding site. An excess of SH2-C blocked binding of full-length p85 and PI 3-kinase to the receptor but did not interfere with the binding of two other SH2-containing proteins, phospholipase C-gamma and GTPase-activating protein. These results demonstrate that a region of p85 containing a single SH2 domain accounts both for the high affinity and specificity of binding of PI 3-kinase to the PDGF receptor. Images PMID:1312663

New duel fluorescent "on-off" and colorimetric sensor for Copper(II): Copper(II) binds through N coordination and pi cation interaction to sensor.

PubMed

Kumar, Jutika; Bhattacharyya, Pradip K; Das, Diganta Kumar

2015-03-05

Schiff base derived from naphthylamine and benzil (L) binds to two Cu(2+) ions, one by coordination through N of the Schiff base and another by pi cation interaction through benzil rings. This bonding pattern determined by DFT calculation has been proved by matching electronic spectrum obtained from TDDFT calculation to the experimental one. L acts as "on-off" fluorescent and bare eye detectable colorimetric (purple color) sensor for Cu(2+) ion over the metal ions - Na(+), K(+), Ca(2+) Mn(2+), Co(2+) Ni(2+), Zn(2+), Pb(2+), Cd(2+), Hg(2+), Ag(+), Hg(2+) and Al(3+) in 1:1 v/v CH3CN:H2O. These metal ions do not interfere the fluorescent/colorimetric sensing. As fluorescent sensor the linear range of detection is 5×10(-5) to 3×10(-4)M and detection limit 10(-5)M. Copyright © 2014 Elsevier B.V. All rights reserved.

New duel fluorescent 'on-off' and colorimetric sensor for Copper(II): Copper(II) binds through N coordination and pi cation interaction to sensor

NASA Astrophysics Data System (ADS)

Kumar, Jutika; Bhattacharyya, Pradip K.; Das, Diganta Kumar

2015-03-01

Schiff base derived from naphthylamine and benzil (L) binds to two Cu2+ ions, one by coordination through N of the Schiff base and another by pi cation interaction through benzil rings. This bonding pattern determined by DFT calculation has been proved by matching electronic spectrum obtained from TDDFT calculation to the experimental one. L acts as "on-off" fluorescent and bare eye detectable colorimetric (purple color) sensor for Cu2+ ion over the metal ions - Na+, K+, Ca2+ Mn2+, Co2+ Ni2+, Zn2+, Pb2+, Cd2+, Hg2+, Ag+, Hg2+ and Al3+ in 1:1 v/v CH3CN:H2O. These metal ions do not interfere the fluorescent/colorimetric sensing. As fluorescent sensor the linear range of detection is 5 × 10-5 to 3 × 10-4 M and detection limit 10-5 M.

When does transformational leadership enhance employee proactive behavior? The role of autonomy and role breadth self-efficacy.

PubMed

Den Hartog, Deanne N; Belschak, Frank D

2012-01-01

Two multisource studies address the interactive effects of personal and contextual variables on employees' proactive behavior. In line with previous work, we find positive main effects of transformational leadership, role breadth self-efficacy, and job autonomy on employee proactive behavior (personal initiative in Study 1 and prosocial proactive behavior in Study 2). As expected, a 3-way interaction qualifies these main effects: In situations of high autonomy, transformational leadership relates positively to proactive behavior for individuals high (but not low) on self-efficacy. Vice versa, in situations low on job autonomy, transformational leadership relates positively to proactive behavior for individuals low (but not high) on self-efficacy. This pattern is found both for self-ratings and peer-ratings of employees' proactive behavior in Study 1 and for supervisor ratings of such behavior in Study 2.

The variability puzzle in human memory.

PubMed

Kahana, Michael J; Aggarwal, Eash V; Phan, Tung D

2018-04-26

Memory performance exhibits a high level of variability from moment to moment. Much of this variability may reflect inadequately controlled experimental variables, such as word memorability, past practice and subject fatigue. Alternatively, stochastic variability in performance may largely reflect the efficiency of endogenous neural processes that govern memory function. To help adjudicate between these competing views, the authors conducted a multisession study in which subjects completed 552 trials of a delayed free-recall task. Applying a statistical model to predict variability in each subject's recall performance uncovered modest effects of word memorability, proactive interference, and other variables. In contrast to the limited explanatory power of these experimental variables, performance on the prior list strongly predicted current list recall. These findings suggest that endogenous factors underlying successful encoding and retrieval drive variability in performance. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

An experimental study of the intersystem crossing and reactions of C2(X1Sigmag+) and C2(a3Pi(u)) with O2 and NO at very low temperature (24-300 K).

PubMed

Páramo, Alejandra; Canosa, André; Le Picard, Sébastien D; Sims, Ian R

2006-03-09

A low-temperature gas-phase kinetics study of the reactions and collisional relaxation processes involving C2(X1Sigma(g)+) and C2(a3Pi(u)) in collision with O2 and NO partners at temperatures from 300 to 24 K is reported. The experiments employed a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme) apparatus to attain low temperatures. The C2 species were created using pulsed laser photolysis at 193 nm of mixtures containing C2Cl4 diluted in N2, Ar, or He carrier gas. C2(X1Sigma(g)+) molecules were detected via pulsed laser-induced fluorescence in the (D1Sigma(u)+ <-- X1Sigma(g)+) system, and C2(a3Pi(u)) molecules were detected via pulsed laser-induced fluorescence in the (d 3Pi(g) <-- a 3Pi(u)) system. Relaxation of 3C2 by intersystem crossing induced by oxygen was measured at temperatures below 200 K, and it was found that this process remains very efficient in the temperature range 50-200 K. Reactivity of C2(X1Sigma(g)+) with oxygen became very inefficient below room temperature. Using these two observations, it was found to be possible to obtain the C2(X1Sigma(g)+) state alone at low temperatures by addition of a suitable concentration of O2 and then study its reactivity with NO without any interference coming from the possible relaxation of C2(a3Pi(u)) to C2(X1Sigma(g)+) induced by this reagent. The rate coefficient for reaction of C2(X1Sigma(g)+) with NO was found to be essentially constant over the temperature range 36-300 K with an average value of (1.6 +/- 0.1) x 10(-10) cm3 molecule(-1) s(-1). Reactivity of C2(a3Pi(u)) with NO was found to possess a slight negative temperature dependence over the temperature range 50-300 K, which is in very good agreement with data obtained at higher temperatures.

NASA's Agency-wide Strategy for Environmental Regulatory Risk Analysis and Communication

NASA Technical Reports Server (NTRS)

Duda, Kristen; Scroggins. Sharon

2008-01-01

NASA's mission is to pioneer the future in space exploration, scientific discovery, and aeronautics research. To help enable existing and future programs to pursue this mission, NASA has established the Principal Center for Regulatory Risk Analysis and Communication (RRAC PC) to proactively identify, analyze, and communicate environmental regulatory risks to the NASA community. The RRAC PC is chartered to evaluate the risks posed to NASA Programs and facilities by environmentally related drivers. The RRAC PC focuses on emerging environmental regulations, as well as risks related to operational changes that can trigger existing environmental requirements. Changing regulations have the potential to directly affect program activities. For example, regulatory changes can restrict certain activities or operations by mandating changes in how operations may be done or limiting where or how certain operations can take place. Regulatory changes also can directly affect the ability to use certain materials by mandating a production phase-out or restricting usage aPi'iications of certain materials. Such changes can result in NASA undertaking material replacement efforts. Even if a regulation does not directly affect NASA operations, U.S. and international regulations can pose program risks indirectly through requirements levied on manufacturers and vendors of components and materials. For example, manufacturers can change their formulations to comply with new regulatory requirements. Such changes can require time-consuming and costly requalification certification for use in human spaceflight programs. The RRAC PC has implemented several strategies for proactively managing regulatory change to minimize potential adverse impacts to NASA Programs and facilities. This presentation highlights the lessons learned through establishing the RRAC PC, the process by which the RRAC PC monitors and distributes information about emerging regulatory requirements, and the cross-Agency cooperation that is vital to supporting NASA's mission.

What Is Engagement? Proactivity as the Missing Link in the HEXACO Model of Personality.

PubMed

de Vries, Reinout E; Wawoe, Kilian W; Holtrop, Djurre

2016-04-01

We tested the hypothesis that proactivity represents the engagement vector in the HEXACO model of personality. Questionnaire data were obtained in five studies, three of which consisted (mostly) of students: Study 1 (N = 188, Mage  = 20.0, 89.4% women), Study 3 (N = 315, Mage  = 20.4, 80.6% women), and Study 4 (N = 309 self-ratings, Mage  = 20.0, 78.3% women; N = 307 other-ratings, Mage  = 24.5, 62.2% women). Participants in the other two studies came from an ISO-certified representative community panel: Study 2 (N = 525, Mage  = 51.2, 52.0% women) and Study 5 (N = 736, Mage  = 42.2, 48.0% women). Proactive Personality and Proactivity were positively related to Extraversion, Conscientiousness, and Openness to Experience, but only weakly related or unrelated to Honesty-Humility, Emotionality, and Agreeableness, supporting the alignment of Proactive Personality/Proactivity with the hypothesized HEXACO engagement vector. Additionally, Proactivity explained incremental variance in self-rated job performance on top of the HEXACO facets that were most closely associated with Proactive Personality/Proactivity, that is, Social Boldness (an Extraversion facet), Diligence (a Conscientiousness facet), and Creativity (an Openness to Experience facet), but not in entrepreneurship and intrapreneurship. Proactivity is the missing engagement link in the HEXACO model of personality. The results are discussed in light of higher-order factors (e.g., general factor of personality and Alpha and Beta) of personality and bandwidth-fidelity controversies. © 2014 Wiley Periodicals, Inc.

Doppler color flow analysis of the uterine arteries before and after intrauterine device insertion: a prospective study.

PubMed

de Souza, Marco Aurélio Martins; Geber, Selmo

2006-02-01

An intrauterine device (IUD) is one of the most frequently used methods of birth control around the world. Although a relationship between its use and menstrual disorders has been well documented, only a few studies have tried to show whether there are any vascular modifications. The aim of our study was to evaluate the influence of an IUD on uterine artery blood flow using Doppler assessment. A total of 100 patients selected for IUD use were prospectively evaluated with Doppler analysis before and 30 days after insertion. The resistive index (RI) and pulsatility index (PI) were used to evaluate uterine artery vascular resistance. Patients were allocated in 2 groups according to whether they were (group 2) or were not (group 1) lactating. The PI and RI of the patients in groups 1 and 2 before and after IUD insertion were not statistically significantly different (P = .298 and .23). When we compared uterine artery blood flow indices before and after IUD insertion for groups 1 and 2 separately, we observed in group 1 that the mean +/- SD PI values were 2.45 +/- 0.62 and 2.55 +/- 0.55 (P = .38) and the RI values were 0.87 +/- 0.08 and 0.87 +/- 0.06 (P = .88) before and after IUD insertion, respectively. In group 2, the PI values were 2.31 +/- 0.55 and 2.37 +/- 0.69 (P = .68) and the RI values were 0.85 +/- 0.07 and 0.86 +/- 0.07 (P = .44) before and after IUD insertion. Finally, we used the mean blood flow indices of the uterine arteries of all patients to compare the effect of IUD insertion. Results were also not statistically significant when we compared PI and RI before and after IUD insertion. The presence of an IUD does not interfere with the vascular resistance of the uterine arteries that can be shown by Doppler flow assessments 1 month after insertion.

Understanding the relationship between proactive and reactive aggression, and cyberbullying across United States and Singapore adolescent samples.

PubMed

Ang, Rebecca P; Huan, Vivien S; Florell, Dan

2014-01-01

This study examined cyberbullying among adolescents across United States and Singapore samples. Specifically, the purpose of the investigation was to study the differential associations between proactive and reactive aggression, and cyberbullying across two cultures. A total of 425 adolescents from the United States (M age = 13 years) and a total of 332 adolescents from Singapore (M age = 14.2 years) participated in the study. Results of the moderator analyses suggested that nationality was not a moderator of the relationship between proactive aggression and cyberbullying, and between reactive aggression and cyberbullying. As expected, findings showed proactive aggression to be positively associated with cyberbullying, after controlling for reactive aggression, across both samples. Likewise, as hypothesized, reactive aggression and cyberbullying was not found to be significant after controlling for proactive aggression across both samples. Implications of these findings were discussed: (a) Proactive aggression is a possible risk factor for both bullying and cyberbullying; (b) proactive and reactive aggression could be argued to be distinct as they have different correlates-only proactive aggression contributed to cyberbullying after controlling for reactive aggression; (c) this research extends previous work and contributes toward cross-cultural work using similar and comparable measures across different samples; and (d) prevention and intervention programs targeted at proactive aggressive adolescents could adopt a two-pronged approach by changing mind sets, and by understanding and adopting a set of rules for Internet etiquette.

Hepatic-targeted RNA interference provides robust and persistent knockdown of alpha-1 antitrypsin levels in ZZ patients.

PubMed

Turner, Alice M; Stolk, Jan; Bals, Robert; Lickliter, Jason D; Hamilton, James; Christianson, Dawn R; Given, Bruce D; Burdon, Jonathan G; Loomba, Rohit; Stoller, James K; Teckman, Jeffery H

2018-03-21

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder causing pulmonary and liver disease. The PiZ mutation in AAT (SERPINA1) results in mis-folded AAT protein (Z-AAT) accumulating in hepatocytes, leading to fibrosis and cirrhosis. RNAi-based therapeutics silencing production of hepatic Z-AAT might benefit patients with AATD-associated liver disease. This study evaluated an RNAi therapeutic to silence production of AAT. Part A of this double-blind first-in-human study randomized 54 healthy volunteers (HVs) into single dose cohorts (two placebo: four active), receiving escalating doses of the investigational agent ARC-AAT from 0.38 to 8.0 mg/kg or placebo. Part B randomized 11 patients with PiZZ (homozygous for Z-AAT) genotype AATD, who received up to 4.0 mg/kg of ARC-AAT or placebo. Patients with baseline FibroScan® >11 kPa or forced expiratory volume in one second (FEV1) <60% were excluded. Assessments included safety, pharmacokinetics, and change in serum AAT concentrations. A total of 36 HVs received ARC-AAT and 18 received placebo (part A). Seven PiZZ individuals received ARC-AAT and four received placebo (part B). A dose response in serum AAT reduction was observed at doses ≥4 mg/kg with similar relative reductions in PiZZ patients and HVs at 4 mg/kg and a maximum reduction of 76.1% (HVs) vs. 78.8% (PiZZ) at this dose. The time it took for serum AAT to return to baseline was similar for HV and PiZZ. There were no notable differences between HV and PiZZ safety parameters. The study was terminated early because of toxicity findings related to the delivery vehicle (ARC-EX1) seen in a non-human primate study. PiZZ patients and HVs responded similarly to ARC-AAT. Deep and durable knockdown of hepatic AAT production based on observed reduction in serum AAT concentrations was demonstrated. Accumulation of abnormal proteins in the livers of patients with alpha-1 antitrypsin deficiency may lead to decreased liver function and potentially liver failure. Therapeutics targeting the production of these abnormal proteins may be used to prevent or treat liver disease in patients with alpha-1 antitrypsin deficiency. NCT02363946. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Differences in cortisol response affect the distinction of observed reactive and proactive aggression in children with aggressive behaviour disorders.

PubMed

Kempes, M; de Vries, H; Matthys, W; van Engeland, H; van Hooff, J

2008-01-01

Various researchers distinguished two categories of aggressive behaviour, namely reactive and proactive aggression. Reactive aggression is an aggressive response to a perceived threat or provocation, whereas proactive aggression is behaviour that anticipates a reward. In the present study, including both a sample of disruptive behaviour disordered (DBD) and normal control (NC) children, we observed reactive and proactive aggressive behaviour during an experimental dyadic play session. DBD children showed more observed reactive and proactive aggression. Subsequently, we investigated whether the observed measures correlated with parent-rated measures of reactive and proactive aggression in. We distinguished in both NC and DBD children a subgroup showing a rise in cortisol level, i.e. responders, and a subgroup who did not show a rise in cortisol, i.e. non-responders. Results suggest that differences in the cortisol response affects the correspondence between observed and parent-rated reactive and proactive aggression since only DBD non-responders showed the expected correlations.

Role Breadth Self-Efficacy and Foci of Proactive Behavior: Moderating Role of Collective, Relational, and Individual Self-Concept.

PubMed

Hwang, Pin-Chyuan; Han, Ming-Chuan; Chiu, Su-Fen

2015-01-01

This study aims to identify the interactive effect of role breadth self-efficacy (RBSE) and the three levels of self-concept (collective, relational, and individual) in predicting of different foci of proactive behaviors. Results from 259 matched responses from an airline company in Taiwan showed that RBSE had a positive effect on (1) pro-organizational proactive behavior among those with higher collective self-concept, (2) pro-supervisor proactive behavior among those with higher relational self-concept, and (3) pro-self proactive behavior among those with higher individual self-concept. Our findings provide insights into the moderating role of different levels of self-concept on RBSE-proactive behavior process in terms of specific targets or beneficiaries. Further implications for organizational research and practice are discussed.

Callous-Unemotional Traits, Proactive Aggression, and Treatment Outcomes of Aggressive Children with Attention-Deficit/Hyperactivity Disorder

PubMed Central

Blader, Joseph C.; Pliszka, Steven R.; Kafantaris, Vivian; Foley, Carmel A.; Crowell, Judith A.; Carlson, Gabrielle A.; Sauder, Colin; Margulies, David M.; Sinha, Christa; Sverd, Jeffrey; Matthews, Thomas L.; Bailey, Brigitte Y.; Daviss, W. Burleson

2013-01-01

Objective Stimulant treatment improves impulse control among children with attention-deficit/hyperactivity disorder (ADHD). Decreased aggression often accompanies stimulant pharmacotherapy, suggesting that impulsiveness is integral to their aggressive behavior. However, children with high callous-unemotional (CU) traits and proactive aggression may benefit less from ADHD pharmacotherapy because their aggressive behavior seems more purposeful and deliberate. This study’s objective was to determine if pretreatment CU traits and proactive aggression affect treatment outcomes among aggressive children with ADHD receiving stimulant monotherapy. Method We implemented a stimulant optimization protocol with 160 6- to 13-year-olds (mean [SD] age of 9.31 [2.02] years; 78.75% males) with ADHD, oppositional defiant or conduct disorder, and significant aggressive behavior. Family-focused behavioral intervention was provided concurrently. Primary outcome was the Retrospective Modified Overt Aggression Scale. The Antisocial Process Screening Device and the Aggression Scale, also completed by parents, measured CU traits and proactive aggression, respectively. Analyses examined moderating effects of CU traits and proactive aggression on outcomes. Results 82 children (51%) experienced remission of aggressive behavior. Neither CU traits nor proactive aggression predicted remission (CU traits: odds ratio=0.94, 95% CI=0.80–1.11; proactive aggression, odds ratio=1.05, 95% CI=0.86–1.29). Children whose overall aggression remitted showed decreases in CU traits (effect size=−0.379, 95% CI=−0.60 to −0.16) and proactive aggression (effect size=−0.463, 95% CI=−0.69 to −0.23). Conclusions Findings suggest that pretreatment CU traits and proactive aggression do not forecast worse outcomes for aggressive children with ADHD receiving optimized stimulant pharmacotherapy. With such treatment, CU traits and proactive aggression may decline alongside other behavioral improvements. PMID:24290461

A model of human motor sequence learning explains facilitation and interference effects based on spike-timing dependent plasticity.

PubMed

Wang, Quan; Rothkopf, Constantin A; Triesch, Jochen

2017-08-01

The ability to learn sequential behaviors is a fundamental property of our brains. Yet a long stream of studies including recent experiments investigating motor sequence learning in adult human subjects have produced a number of puzzling and seemingly contradictory results. In particular, when subjects have to learn multiple action sequences, learning is sometimes impaired by proactive and retroactive interference effects. In other situations, however, learning is accelerated as reflected in facilitation and transfer effects. At present it is unclear what the underlying neural mechanism are that give rise to these diverse findings. Here we show that a recently developed recurrent neural network model readily reproduces this diverse set of findings. The self-organizing recurrent neural network (SORN) model is a network of recurrently connected threshold units that combines a simplified form of spike-timing dependent plasticity (STDP) with homeostatic plasticity mechanisms ensuring network stability, namely intrinsic plasticity (IP) and synaptic normalization (SN). When trained on sequence learning tasks modeled after recent experiments we find that it reproduces the full range of interference, facilitation, and transfer effects. We show how these effects are rooted in the network's changing internal representation of the different sequences across learning and how they depend on an interaction of training schedule and task similarity. Furthermore, since learning in the model is based on fundamental neuronal plasticity mechanisms, the model reveals how these plasticity mechanisms are ultimately responsible for the network's sequence learning abilities. In particular, we find that all three plasticity mechanisms are essential for the network to learn effective internal models of the different training sequences. This ability to form effective internal models is also the basis for the observed interference and facilitation effects. This suggests that STDP, IP, and SN may be the driving forces behind our ability to learn complex action sequences.

Proactivity in VTE prevention: a concept analysis.

PubMed

Adams, Averil

Venous thromboembolism (VTE) prevention is an international patient safety issue. The author has observed gaps in prescription and provision of VTE prophylaxis, and that the attitude to VTE is often reactive rather than proactive. This concept analysis aims to explore proactivity and apply it to VTE prevention to address this. Ten databases were searched (1992-2012) using the keywords proactive, proactivity, nurse, nursing, VTE/venous thromboembolism, prevent/prevention/preventing, behaviour, DVT/PE (deep vein thrombosis, pulmonary embolism). The Walker and Avant (2010) method of concept analysis identified the defining attributes as personal initiative, taking charge and feedback-seeking behaviour. Antecedents and consequences have been identified, and empirical referents are demonstrated. Defining proactivity in VTE prevention has the potential to increase prescription and, crucially, provision of prophylaxis, thereby improving patient care, reducing avoidable harm and improving the patient experience.

Proactive aggression in early school-aged children with externalizing behavior problems: A longitudinal study on the influence of empathy in response to distress.

PubMed

Deschamps, Peter K; Verhulp, Esmee E; de Castro, Bram Orobio; Matthys, Walter

2018-01-01

The course of proactive aggressive behavior may be affected by empathy in response to sadness and distress of others. The aim of the current study is to examine empathy in response to sadness and distress and its relation to proactive and reactive aggression in a clinical sample of children with externalizing behavior problems. At baseline (T1) and 12 months later (T2), parents and teachers of 104 six- and seven-year-old children completed the Instrument for Reactive and Proactive Aggression. At T1, parents and teachers also reported empathy in response to sadness and distress on the Griffith Empathy Measure. Findings show that low levels of parent-reported empathy at baseline were specifically associated with high parent-reported proactive aggression but not with reactive aggression. Similarly, low teacher-reported empathy was specifically related to high teacher-reported proactive aggression. Furthermore, high parent-reported but not teacher-reported empathy at baseline was associated with low proactive aggression at 12 months after controlling for proactive aggression at baseline. The conclusions support the notion that in the study of the course of aggression in clinical groups, the distinction between proactive and reactive aggression as well as the study of empathy in response to distress is relevant for a better understanding and might be taken into account in the development of future interventions. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The Phosphoinositide 3-Kinase p110α Isoform Regulates Leukemia Inhibitory Factor Receptor Expression via c-Myc and miR-125b to Promote Cell Proliferation in Medulloblastoma

PubMed Central

von Bueren, André O.; Ćwiek, Paulina; Rehrauer, Hubert; Djonov, Valentin; Anderle, Pascale; Arcaro, Alexandre

2015-01-01

Medulloblastoma (MB) is the most common malignant brain tumor in childhood and represents the main cause of cancer-related death in this age group. The phosphoinositide 3-kinase (PI3K) pathway has been shown to play an important role in the regulation of medulloblastoma cell survival and proliferation, but the molecular mechanisms and downstream effectors underlying PI3K signaling still remain elusive. The impact of RNA interference (RNAi)-mediated silencing of PI3K isoforms p110α and p110δ on global gene expression was investigated by DNA microarray analysis in medulloblastoma cell lines. A subset of genes with selectively altered expression upon p110α silencing in comparison to silencing of the closely related p110δ isoform was revealed. Among these genes, the leukemia inhibitory factor receptor α (LIFR α) was validated as a novel p110α target in medulloblastoma. A network involving c-Myc and miR-125b was shown to be involved in the control of LIFRα expression downstream of p110α. Targeting the LIFRα by RNAi, or by using neutralizing reagents impaired medulloblastoma cell proliferation in vitro and induced a tumor volume reduction in vivo. An analysis of primary tumors revealed that LIFRα and p110α expression were elevated in the sonic hedgehog (SHH) subgroup of medulloblastoma, indicating its clinical relevance. Together, these data reveal a novel molecular signaling network, in which PI3K isoform p110α controls the expression of LIFRα via c-Myc and miR-125b to promote MB cell proliferation. PMID:25915540

Group interventions for co-morbid insomnia and osteoarthritis pain in primary care: the lifestyles cluster randomized trial design.

PubMed

Von Korff, Michael; Vitiello, Michael V; McCurry, Susan M; Balderson, Benjamin H; Moore, Amy L; Baker, Laura D; Yarbro, Patricia; Saunders, Kathleen; Keefe, Francis J; Rybarczyk, Bruce D

2012-07-01

Six weekly sessions of group cognitive-behavioral therapy for insomnia and osteoarthritis pain (CBT-PI), and for osteoarthritis pain alone (CBT-P) were compared to an education only control (EOC). Basic education about pain and sleep was comparable, so EOC controlled for information and group participation. Active interventions differed from EOC in training pain coping skills (CBT-P and CBT-PI) and sleep enhancement techniques (CBT-PI). Persons with osteoarthritis age 60 or older were screened for osteoarthritis pain and insomnia severity via mailed survey. Primary outcomes were pain severity (pain intensity and interference ratings from the Graded Chronic Pain Scale) and insomnia severity (Insomnia Severity Index). Secondary outcomes were arthritis pain (AIMS-2 symptom scale) and sleep efficiency assessed by wrist actigraphy. Ancillary outcomes included: cognitive function, depression, and health care use. A clustered randomized design provided adequate power to identify moderate effects on primary outcomes (effect size>0.35). Modified intent to treat analyses, including all participants who attended the first session, assessed effects across CBT-PI, CBT-P, and EOC groups. Treatment effects were assessed post-intervention (2 months) and at 9 months, with durability of intervention effects evaluated at 18 months. The trial was executed in 6 primary clinics, randomizing 367 participants, with 93.2% of randomized patients attending at least 4 group sessions. Response rates for post-intervention and 9 month assessments were 96.7% and 92.9% respectively. This hybrid efficacy-effectiveness trial design evaluates whether interventions yield specific benefits for clinical and behavioral outcomes relative to an education only control when implemented in a primary care setting. Copyright © 2012 Elsevier Inc. All rights reserved.

Akt-mediated regulation of NFkappaB and the essentialness of NFkappaB for the oncogenicity of PI3K and Akt.

PubMed

Bai, Dong; Ueno, Lynn; Vogt, Peter K

2009-12-15

The serine/threonine kinase Akt (cellular homolog of murine thymoma virus akt8 oncogene), also known as PKB (protein kinase B), is activated by lipid products of phosphatidylinositol 3-kinase (PI3K). Akt phosphorylates numerous protein targets that control cell survival, proliferation and motility. Previous studies suggest that Akt regulates transcriptional activity of the nuclear factor-kappaB (NFkappaB) by inducing phosphorylation and subsequent degradation of inhibitor of kappaB (IkappaB). We show here that NFkappaB-driven transcription increases in chicken embryonic fibroblasts (CEF) transformed by myristylated Akt (myrAkt). Accordingly, both a dominant negative mutant of Akt and Akt inhibitors repress NFkappaB-dependent transcription. The degradation of the IkappaB protein is strongly enhanced in Akt-transformed cells, and the loss of NFkappaB activity by introduction of a super-repressor of NFkappaB, IkappaBSR, interferes with PI3K- and Akt-induced oncogenic transformation of CEF. The phosphorylation of the p65 subunit of NFkappaB at serine 534 is also upregulated in Akt-transformed cells. Our data suggest that the stimulation of NFkappaB by Akt is dependent on the phosphorylation of p65 at S534, mediated by IKK (IkappaB kinase) alpha and beta. Akt phosphorylates IKKalpha on T23, and this phosphorylation event is a prerequisite for the phosphorylation of p65 at S534 by IKKalpha and beta. Our results demonstrate two separate functions of the IKK complex in NFkappaB activation in cells with constitutive Akt activity: the phosphorylation and consequent degradation of IkappaB and the phosphorylation of p65. The data further support the conclusion that NFkappaB activity is essential for PI3K- and Akt-induced oncogenic transformation. Copyright (c) 2009 UICC.

Factor Structure of the Reactive-Proactive Aggression Questionnaire in Turkish Children and Gender, Grade-Level, and Socioeconomic Status Differences in Reactive and Proactive Aggression

ERIC Educational Resources Information Center

Uz Bas, Asli; Yurdabakan, Irfan

2012-01-01

The present study aimed to evaluate the factor structure of the Reactive-Proactive Aggression Questionnaire (RPQ) with Turkish children, and to investigate gender, grade-level, and socioeconomic status (SES) differences in reactive and proactive aggression. Participants consisted of 1,081 Turkish children (544 boys and 537 girls) aged 9 to 14…

Are Empowered Employees More Proactive? The Contingency of How They Evaluate Their Leader

PubMed Central

Yin, Kui; Xing, Lu; Li, Can; Guo, Yungui

2017-01-01

Finding ways to enhance employee proactive behavior is a focal concern for academics and practitioners. Previous studies have found a positive association between empowering leadership and proactive behavior (Martin et al., 2013; Li et al., 2017). However, these studies lack elaboration on mechanisms and do not rule out the effect of employees’ proactive personality during empirical testing. We investigate empowering leadership from individual perspective due to the variation of empowerment levels even in the same team. Our research proposes a more elaborated theoretical model that explains why, and when, empowering leadership might promote employee proactive behavior. Specifically, we examine mediating mechanisms based on social cognitive theory and propose trust in leader competency as boundary condition. Using a sample of 280 leader–follower dyads from a large state-owned Chinese company, our results revealed that (1) empowering leadership was positively related to proactive behavior, with role breadth self-efficacy acting as a mediator for this relationship; (2) employees’ trust in leader competency moderated both the empowering leadership–subordinate proactive behavior relationship and the mediating effect of role breadth self-efficacy, such that the empowering leadership–subordinate proactive behavior relationship was weaker, and the mediating effect of role breadth self-efficacy was stronger, for employees with high levels of trust in leader competency. PMID:29163249

Are Empowered Employees More Proactive? The Contingency of How They Evaluate Their Leader.

PubMed

Yin, Kui; Xing, Lu; Li, Can; Guo, Yungui

2017-01-01

Finding ways to enhance employee proactive behavior is a focal concern for academics and practitioners. Previous studies have found a positive association between empowering leadership and proactive behavior (Martin et al., 2013; Li et al., 2017). However, these studies lack elaboration on mechanisms and do not rule out the effect of employees' proactive personality during empirical testing. We investigate empowering leadership from individual perspective due to the variation of empowerment levels even in the same team. Our research proposes a more elaborated theoretical model that explains why, and when, empowering leadership might promote employee proactive behavior. Specifically, we examine mediating mechanisms based on social cognitive theory and propose trust in leader competency as boundary condition. Using a sample of 280 leader-follower dyads from a large state-owned Chinese company, our results revealed that (1) empowering leadership was positively related to proactive behavior, with role breadth self-efficacy acting as a mediator for this relationship; (2) employees' trust in leader competency moderated both the empowering leadership-subordinate proactive behavior relationship and the mediating effect of role breadth self-efficacy, such that the empowering leadership-subordinate proactive behavior relationship was weaker, and the mediating effect of role breadth self-efficacy was stronger, for employees with high levels of trust in leader competency.

Proactivity despite discouraging supervisors: The powerful role of prosocial motivation.

PubMed

Lebel, R David; Patil, Shefali V

2018-03-26

Although considerable research demonstrates that employees are unlikely to be proactive when they view their supervisors as discouraging this type of behavior, we challenge the assumption that this is true for all employees. Drawing on motivated information processing theory, we argue that prosocial motivation can spark employees to be proactive even when supervisors are perceived as discouraging. Specifically, prosocial motivation may weaken the negative relationship between perceived discouraging supervisor behaviors and proactivity by driving employees to bring about change to impact coworkers or the organization. Because they are less focused on self-interest and more focused on benefitting others, prosocially motivated employees are able to maintain their reason-to (felt responsibility for change) and can-do (efficacy to be proactive) motivation even when supervisors do not welcome proactivity. We test our hypotheses across three studies, using multisource data from employees and supervisors in two organizations (Studies 1a and 1b), and lagged data from employees working in a range of industries (Study 2). By identifying the mechanisms driving prosocially motivated employees to be proactive despite having supervisors who are perceived to be discouraging, we offer novel theoretical and practical insights regarding the effects of context on proactivity at work. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Adolescents' aggressive and prosocial behavior: associations with jealousy and social anxiety.

PubMed

Culotta, Carmen M; Goldstein, Sara E

2008-03-01

The authors examined how relational aggression, physical aggression, and proactive prosocial behavior were associated with jealousy and social anxiety in a diverse sample of 60 middle school students. After the authors controlled for gender and race, jealousy predicted relational aggression and proactive prosocial behavior, but it did not predict physical aggression. Additionally, social anxiety predicted proactive prosocial behavior. Adolescents who were more jealous in their peer relationships also tended to engage in relational aggression and proactive prosocial behavior, and adolescents who were more socially anxious also tended to be proactively prosocial. The authors discuss the implications of these findings and suggest directions for future research.

Proactive personality and career success.

PubMed

Seibert, S E; Crant, J M; Kraimer, M L

1999-06-01

This study examined the relationship between proactive personality and career success by surveying a sample of 496 employees (320 men and 176 women) from a diverse set of occupations and organizations. Proactive personality was positively associated with both self-reported objective (salary and promotions) and subjective (career satisfaction) indicators of career success. Hierarchical regression analyses showed that proactive personality explained additional variance in both objective and subjective career success even after controlling for several relevant variables (demographic, human capital, motivational, organizational, and industry) that have previously been found to be predictive of career outcomes. These findings were consistent using both self-report and significant--other ratings of proactive personality.

A whole genome screening and RNA interference identify a juvenile hormone esterase-like gene of the diamondback moth, Plutella xylostella.

PubMed

Gu, Xiaojun; Kumar, Sunil; Kim, Eunjin; Kim, Yonggyun

2015-09-01

Juvenile hormone (JH) plays a crucial role in preventing precocious metamorphosis and stimulating reproduction. Thus, its hemolymph titer should be under a tight control. As a negative controller, juvenile hormone esterase (JHE) performs a rapid breakdown of residual JH in the hemolymph during last instar to induce a larval-to-pupal metamorphosis. A whole genome of the diamondback moth (DBM), Plutella xylostella, has been annotated and proposed 11 JHE candidates. Sequence analysis using conserved motifs commonly found in other JHEs proposed a putative JHE (Px004817). Px004817 (64.61 kDa, pI=5.28) exhibited a characteristic JHE expression pattern by showing high peak at the early last instar, at which JHE enzyme activity was also at a maximal level. RNA interference of Px004817 reduced JHE activity and interrupted pupal development with a significant increase of larval period. This study identifies Px004817 as a JHE-like gene of P. xylostella. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genetic and Environmental Stability Differs in Reactive and Proactive Aggression

PubMed Central

Tuvblad, Catherine; Raine, Adrian; Zheng, Mo; Baker, Laura A.

2009-01-01

The aim of this study was to examine stability and change in genetic and environmental influences on reactive (impulsive and affective) and proactive (planned and instrumental) aggression from childhood to early adolescence. The sample was drawn from an ongoing longitudinal twin study of risk factors for antisocial behavior at the University of Southern California (USC). The twins were measured on two occasions: ages 9–10 years (N = 1,241) and 11–14 years (N = 874). Reactive and proactive aggressive behaviors were rated by parents. The stability in reactive aggression was due to genetic and nonshared environmental influences, whereas the continuity in proactive aggression was primarily genetically mediated. Change in both reactive and proactive aggression between the two occasions was mainly explained by nonshared environmental influences, although some evidence for new genetic variance at the second occasion was found for both forms of aggression. These results suggest that proactive and reactive aggression differ in their genetic and environmental stability, and provide further evidence for some distinction between reactive and proactive forms of aggression. PMID:19688841

Meta-cognitive processes in executive control development: The case of reactive and proactive control

PubMed Central

Chevalier, Nicolas; Martis, Shaina Bailey; Curran, Tim; Munakata, Yuko

2015-01-01

Young children engage cognitive control reactively in response to events, rather than proactively preparing for events. Such limitations in executive control have been explained in terms of fundamental constraints on children’s cognitive capacities. Alternatively, young children might be capable of proactive control but differ from older children in their meta-cognitive decisions regarding when to engage proactive control. We examined these possibilities in three conditions of a task-switching paradigm, varying in whether task cues were available before or after target onset. Reaction times, ERPs, and pupil dilation showed that 5-year-olds did engage in advance preparation, a critical aspect of proactive control, but only when reactive control was made more difficult, whereas 10-year-olds engaged proactive control whenever possible. These findings highlight meta-cognitive processes in children’s cognitive control, an understudied aspect of executive control development. PMID:25603026

Training the removal of negative information from working memory: A preliminary investigation of a working memory bias modification task.

PubMed

Robinaugh, Donald J; Crane, Margaret E; Enock, Philip M; McNally, Richard J

2016-01-01

Rumination in depressed adults is associated with a bias toward retaining negative information in working memory. We developed a task designed to modify this cognitive bias by having subjects repeatedly practice removing negative words from working memory, thereby enabling them to retain positive and neutral words. To assess the efficacy of this task, we recruited 60 adults who reported elevated repetitive negative thought (RNT) and randomly assigned them to receive a single administration of either the working memory bias modification (WMBM) task or a control task. Subjects in the WMBM condition exhibited greater reduction in proactive interference for negative information than did those in the control condition. These results suggest that the WMBM task reduces biased retention of negative information in working memory and, thus, may be useful in investigating the possible causal role of this cognitive bias in RNT or depression.

Intentional forgetting: note-taking as a naturalistic example.

PubMed

Eskritt, Michelle; Ma, Sierra

2014-02-01

In the present study, we examined whether note-taking as a memory aid may provide a naturalistic example of intentional forgetting. In the first experiment, participants played Concentration, a memory card game in which the identity and location of pairs of cards need to be remembered. Before the game started, half of the participants were allowed to study the cards, and the other half made notes that were then unexpectedly taken away. No significant differences emerged between the two groups for remembering identity information, but the study group remembered significantly more location information than did the note-taking group. In a second experiment, we examined whether note-takers would show signs of proactive interference while playing Concentration repeatedly. The results indicated that they did not. The findings suggest that participants adopted an intentional-forgetting strategy when using notes to store certain types of information.

Proactive tobacco treatment and population-level cessation: a pragmatic randomized clinical trial.

PubMed

Fu, Steven S; van Ryn, Michelle; Sherman, Scott E; Burgess, Diana J; Noorbaloochi, Siamak; Clothier, Barbara; Taylor, Brent C; Schlede, Carolyn M; Burke, Randy S; Joseph, Anne M

2014-05-01

Current tobacco use treatment approaches require smokers to request treatment or depend on the provider to initiate smoking cessation care and are therefore reactive. Most smokers do not receive evidence-based treatments for tobacco use that include both behavioral counseling and pharmacotherapy. To assess the effect of a proactive, population-based tobacco cessation care model on use of evidence-based tobacco cessation treatments and on population-level smoking cessation rates (ie, abstinence among all smokers including those who use and do not use treatment) compared with usual care among a diverse population of current smokers. The Veterans Victory Over Tobacco Study, a pragmatic randomized clinical trial involving a population-based registry of current smokers aged 18 to 80 years. A total of 6400 current smokers, identified using the Department of Veterans Affairs (VA) electronic medical record, were randomized prior to contact to evaluate both the reach and effectiveness of the proactive care intervention. Current smokers were randomized to usual care or proactive care. Proactive care combined (1) proactive outreach and (2) offer of choice of smoking cessation services (telephone or in-person). Proactive outreach included mailed invitations followed by telephone outreach to motivate smokers to seek treatment with choice of services. The primary outcome was 6-month prolonged smoking abstinence at 1 year and was assessed by a follow-up survey among all current smokers regardless of interest in quitting or treatment utilization. A total of 5123 participants were included in the primary analysis. The follow-up survey response rate was 66%. The population-level, 6-month prolonged smoking abstinence rate at 1 year was 13.5% for proactive care compared with 10.9% for usual care (P = .02). Logistic regression mixed model analysis showed a significant effect of the proactive care intervention on 6-month prolonged abstinence (odds ratio [OR], 1.27 [95% CI, 1.03-1.57]). In analyses accounting for nonresponse using likelihood-based not-missing-at-random models, the effect of proactive care on 6-month prolonged abstinence persisted (OR, 1.33 [95% CI, 1.17-1.51]). Proactive, population-based tobacco cessation care using proactive outreach to connect smokers to evidence-based telephone or in-person smoking cessation services is effective for increasing long-term population-level cessation rates. clinicaltrials.gov Identifier: NCT00608426.

Cue competition effects in human causal learning.

PubMed

Vogel, Edgar H; Glynn, Jacqueline Y; Wagner, Allan R

2015-01-01

Five experiments involving human causal learning were conducted to compare the cue competition effects known as blocking and unovershadowing, in proactive and retroactive instantiations. Experiment 1 demonstrated reliable proactive blocking and unovershadowing but only retroactive unovershadowing. Experiment 2 replicated the same pattern and showed that the retroactive unovershadowing that was observed was interfered with by a secondary memory task that had no demonstrable effect on either proactive unovershadowing or blocking. Experiments 3a, 3b, and 3c demonstrated that retroactive unovershadowing was accompanied by an inflated memory effect not accompanying proactive unovershadowing. The differential pattern of proactive versus retroactive cue competition effects is discussed in relationship to amenable associative and inferential processing possibilities.

Development of a PROMIS item bank to measure pain interference.

PubMed

Amtmann, Dagmar; Cook, Karon F; Jensen, Mark P; Chen, Wen-Hung; Choi, Seung; Revicki, Dennis; Cella, David; Rothrock, Nan; Keefe, Francis; Callahan, Leigh; Lai, Jin-Shei

2010-07-01

This paper describes the psychometric properties of the PROMIS-pain interference (PROMIS-PI) bank. An initial candidate item pool (n=644) was developed and evaluated based on the review of existing instruments, interviews with patients, and consultation with pain experts. From this pool, a candidate item bank of 56 items was selected and responses to the items were collected from large community and clinical samples. A total of 14,848 participants responded to all or a subset of candidate items. The responses were calibrated using an item response theory (IRT) model. A final 41-item bank was evaluated with respect to IRT assumptions, model fit, differential item function (DIF), precision, and construct and concurrent validity. Items of the revised bank had good fit to the IRT model (CFI and NNFI/TLI ranged from 0.974 to 0.997), and the data were strongly unidimensional (e.g., ratio of first and second eigenvalue=35). Nine items exhibited statistically significant DIF. However, adjusting for DIF had little practical impact on score estimates and the items were retained without modifying scoring. Scores provided substantial information across levels of pain; for scores in the T-score range 50-80, the reliability was equivalent to 0.96-0.99. Patterns of correlations with other health outcomes supported the construct validity of the item bank. The scores discriminated among persons with different numbers of chronic conditions, disabling conditions, levels of self-reported health, and pain intensity (p<0.0001). The results indicated that the PROMIS-PI items constitute a psychometrically sound bank. Computerized adaptive testing and short forms are available. Copyright 2010 International Association for the Study of Pain. All rights reserved.

Resumes as a Proactive Career Development Tool: An Innovation at Keuka College Career Center.

ERIC Educational Resources Information Center

Miner, Todd

2000-01-01

A proactive resume can help individuals understand workplace demands and their fit with them. Development of proactive resumes focuses first on employability skills and then on skills and attributes of specific professions or careers. (SK)

Structure-guided cancer blockade between bioactive bursehernin and proteins: Molecular docking and molecular dynamics study.

PubMed

Tedasen, Aman; Choomwattana, Saowapak; Graidist, Potchanapond; Tipmanee, Varomyalin

2017-06-01

Bursehernin (5'-desmethoxyyatein) is a natural lignan, which has anti-tumor activity in vitro. In this study, the binding-inhibitory effects of bursehernin were screening on selected 80 proteins associated with cancer pathway. The computational analysis suggested inhibitory effect due to bursehernin towards proteins related to cancer proliferation, including FMS kinase receptor, heat shock protein 90-α (Hsp90-α), adenylate cyclase 10 (ADCY10), mitogen-activated protein kinase kinase (MEK1), and α-tubulin. Moreover, bursehernin could interfere with cell cycle progression via binding to cyclin B proteins. Among all screened proteins, the compound showed an interesting binding affinity to the FMS kinase receptor. The binding mode studies by molecular dynamic technique showed that aromatic ring of bursehernin compound was responsible for compound-protein interaction through pi-pi stacking with Tyr105 and Phe178 of the FMS kinase receptor. This study suggests that bursehernin has potential for development as an anti-tumor agent with an anti-proliferation, and cell cycle arrest inducing, although further studies are needed. Copyright © 2017 Elsevier Inc. All rights reserved.

Photon asymmetry measurements of $$\\overrightarrow{\\gamma}p \\rightarrow \\pi^{0} p$$ γ → p → π 0 p for $$E_{\\gamma}=$$ 320-650 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gardner, S.; Howdle, D.; Sikora, M. H.

High-statistics measurements of the photon asymmetry Σ for themore » $$\\overrightarrow{\\gamma}p \\rightarrow \\pi^{0} p$$ reaction have been made in the center-of-mass energy range W = 1214–1450 MeV. The data were measured with the MAMI A2 real photon beam and Crystal Ball/TAPS detector systems in Mainz, Germany. The resulting measurements significantly improve the existing world data and are shown to be in good agreement with previous measurements, and with the MAID, SAID, and Bonn-Gatchina predictions. We have also combined the photon asymmetry results with recent cross-section measurements from Mainz to calculate the profile functions, $$\\check{Σ}$$ (= σ 0Σ), and perform a moment analysis. Comparison with calculations from the Bonn-Gatchina model shows that the precision of the data is good enough to further constrain the higher partial waves, and there is an indication of interference between the very small F-waves and the N(1520)3/2 - and N(1535)1/2 - resonances.« less

Aberration control in 4Pi nanoscopy: definitions, properties, and applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hao, Xiang; Allgeyer, Edward S.; Velasco, Mary Grace M.; Booth, Martin J.; Bewersdorf, Joerg

2016-03-01

The development of fluorescence microscopy, which allows live-cell imaging with high labeling specificity, has made the visualization of cellular architecture routine. However, for centuries, the spatial resolution of optical microscopy was fundamentally limited by diffraction. The past two decades have seen a revolution in far-field optical nanoscopy (or "super-resolution" microscopy). The best 3D resolution is achieved by optical nanoscopes like the isoSTED or the iPALM/4Pi-SMS, which utilize two opposing objective lenses in a coherent manner. These system are, however, also more complex and the required interference conditions demand precise aberration control. Our research involves developing novel adaptive optics techniques that enable high spatial and temporal resolution imaging for biological applications. In this talk, we will discuss how adaptive optics can enhance dual-objective lens nanoscopes. We will demonstrate how adaptive optics devices provide unprecedented freedom to manipulate the light field in isoSTED nanoscopy, allow to realize automatic beam alignment, suppress the inherent side-lobes of the point-spread function, and dynamically compensate for sample-induced aberrations. We will present both the theoretical groundwork and the experimental confirmations.

Photon asymmetry measurements of $$\\overrightarrow{\\gamma}p \\rightarrow \\pi^{0} p$$ γ → p → π 0 p for $$E_{\\gamma}=$$ 320-650 MeV

DOE PAGES

Gardner, S.; Howdle, D.; Sikora, M. H.; ...

2016-11-17

High-statistics measurements of the photon asymmetry Σ for themore » $$\\overrightarrow{\\gamma}p \\rightarrow \\pi^{0} p$$ reaction have been made in the center-of-mass energy range W = 1214–1450 MeV. The data were measured with the MAMI A2 real photon beam and Crystal Ball/TAPS detector systems in Mainz, Germany. The resulting measurements significantly improve the existing world data and are shown to be in good agreement with previous measurements, and with the MAID, SAID, and Bonn-Gatchina predictions. We have also combined the photon asymmetry results with recent cross-section measurements from Mainz to calculate the profile functions, $$\\check{Σ}$$ (= σ 0Σ), and perform a moment analysis. Comparison with calculations from the Bonn-Gatchina model shows that the precision of the data is good enough to further constrain the higher partial waves, and there is an indication of interference between the very small F-waves and the N(1520)3/2 - and N(1535)1/2 - resonances.« less

Proactive tobacco treatment offering free nicotine replacement therapy and telephone counselling for socioeconomically disadvantaged smokers: a randomised clinical trial

PubMed Central

Fu, Steven S; van Ryn, Michelle; Nelson, David; Burgess, Diana J; Thomas, Janet L; Saul, Jessie; Clothier, Barbara; Nyman, John A; Hammett, Patrick; Joseph, Anne M

2016-01-01

Background Evidenced-based tobacco cessation treatments are underused, especially by socioeconomically disadvantaged smokers. This contributes to widening socioeconomic disparities in tobacco-related morbidity and mortality. Methods The Offering Proactive Treatment Intervention trial tested the effects of a proactive outreach tobacco treatment intervention on population-level smoking abstinence and tobacco treatment use among a population-based sample of socioeconomically disadvantaged smokers. Current smokers (n=2406), regardless of interest in quitting, who were enrolled in the Minnesota Health Care Programs, the state's publicly funded healthcare programmes for low-income populations, were randomly assigned to proactive outreach or usual care. The intervention comprised proactive outreach (tailored mailings and telephone calls) and free cessation treatment (nicotine replacement therapy and intensive, telephone counselling). Usual care comprised access to a primary care physician, insurance coverage of Food and Drug Administration-approved smoking cessation medications, and the state's telephone quitline. The primary outcome was self-reported 6-month prolonged smoking abstinence at 1 year and was assessed by follow-up survey. Findings The proactive intervention group had a higher prolonged abstinence rate at 1 year than usual care (16.5% vs 12.1%, OR 1.47, 95% CI 1.12 to 1.93). The effect of the proactive intervention on prolonged abstinence persisted in selection models accounting for non-response. In analysis of secondary outcomes, use of evidence-based tobacco cessation treatments were significantly greater among proactive outreach participants compared with usual care, particularly combination counselling and medications (17.4% vs 3.6%, OR 5.69, 95% CI 3.85 to 8.40). Interpretation Population-based proactive tobacco treatment increases engagement in evidence-based treatment and is effective in long-term smoking cessation among socioeconomically disadvantaged smokers. Findings suggest that dissemination of population-based proactive treatment approaches is an effective strategy to reduce the prevalence of smoking and socioeconomic disparities in tobacco use. Trial registration number NCT01123967. PMID:26931362

The relationship between personality disorder traits and reactive versus proactive motivation for aggression.

PubMed

Lobbestael, Jill; Cima, Maaike; Lemmens, Anke

2015-09-30

There is a strong link between personality disorders (PDs) and aggression. This is reflected in high prevalence rates of PD diagnoses in forensic samples, and in several diagnostic criteria of PDs directly referring to elevated levels of aggression. Aggression can stem from two distinct types of motivation; reactive or impulsive aggression that serves as a defensive reaction to provocation, and proactive or premeditated aggression used to gain extrinsic benefits. Although some clinical conditions like antisocial, borderline, and narcissistic PDs or PD traits, have been empirically linked to reactive and/or proactive aggression, the current study pioneers assessing the relationship between reactive and proactive aggression and traits of all 10 PDs. A mixed sample of patient and non-patient (N=238) participants were administered with the SCID II to assess the level of PD traits; they also completed the Reactive Proactive Questionnaire to determine levels of reactive and proactive aggression. Results showed that paranoid PD traits were positively related to reactive aggression, whereas proactive aggression was uniquely related to antisocial PD traits. This highlights the importance of differentiating between distinct motivations for aggression in PD samples. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Novel Cognitive Stress Test for the Detection of Preclinical Alzheimer Disease: Discriminative Properties and Relation to Amyloid Load.

PubMed

Loewenstein, David A; Curiel, Rosie E; Greig, Maria T; Bauer, Russell M; Rosado, Marian; Bowers, Dawn; Wicklund, Meredith; Crocco, Elizabeth; Pontecorvo, Michael; Joshi, Abhinay D; Rodriguez, Rosemarie; Barker, Warren W; Hidalgo, Jacqueline; Duara, Ranjan

2016-10-01

To examine the utility of a novel "cognitive stress test" to detect subtle cognitive impairments and amyloid load within the brains of neuropsychologically normal community-dwelling elders. Participants diagnosed as cognitively normal (CN), subjective memory impairment (SMI), mild cognitive impairment (MCI), and preclinical mild cognitive impairment (PreMCI) were administered the Loewenstein-Acevedo Scale for Semantic Interference and Learning (LASSI-L), a sensitive test of proactive semantic interference (PSI), retroactive semantic interference, and, uniquely, the ability to recover from the effects of PSI. Ninety-three subjects (31 men and 62 women) were recruited from three academic institutions in a research consortium. A subset of these individuals underwent 18F florbetapir positron emission tomography scanning. Relative percentages of impairment for each diagnostic group on the LASSI-L were calculated by χ(2) and Fisher's exact tests. Spearman's rho was used to examine associations between amyloid load and different cognitive measures. LASSI-L deficits were identified among 89% of those with MCI, 47% with PreMCI, 33% with SMI, and 13% classified as CN. CN subjects had no difficulties with recovery from PSI, whereas SMI, preMCI, and MCI participants evidenced deficits in recovery from PSI effects. Among a subgroup of participants with normal scores on traditional neuropsychological tests, the strong associations were between the failure to recover from the effects of PSI and amyloid load in the brain. Failure to recover or compensate for the effects of PSI on the LASSI-L distinguishes the LASSI-L from other widely used neuropsychological tests and appears to be sensitive to subtle cognitive impairments and increasing amyloid load. Copyright © 2016 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Piloting proactive marketing to recruit disadvantaged adults to a community-wide obesity prevention program.

PubMed

O'Hara, Blythe J; Eggins, Dianne; Phongsavan, Philayrath; Milat, Andrew J; Bauman, Adrian E; Wiggers, John

2015-03-30

Population-wide obesity prevention and treatment programs are fundamental to addressing the increasing overweight and obesity rates in socioeconomically disadvantaged populations. Innovative recruitment strategies, including proactive marketing strategies, are needed to ensure such programs have universal reach and target vulnerable populations. This study aimed to determine the success of proactive recruitment to Australia's Get Healthy Information and Coaching Service® (GHS) and to assess whether the recruitment strategy influenced participants' outcomes. Sociodemographic information was collected from all GHS participants who joined the service between February 2009 and August 2013, and anthropometric information regarding behavioural risk factors was collected from all GHS coaching participants at baseline and six months. Data were analysed according to the participants' referral source (self-referral and secondary referral versus proactive recruitment). Participants recruited through proactive marketing were more likely to be male, aged 50 years or older, have high school education, not be in paid employment and be from the lowest three quintiles of socioeconomic advantage. The risk factor profile of coaching participants recruited through proactive marketing did not vary significantly from those recruited via other mechanisms, although they were less likely to be obese and less likely to have a higher 'at risk' waist circumference measurement. Proactively recruited coaching participants reported significant improvements from baseline to six months (consistent with improvements made by participants recruited through other strategies), although they were significantly more likely to withdraw from coaching before they completed the six-month program.Proactive marketing facilitated use of an obesity prevention service; similar services may have greater reach if proactive marketing recruitment strategies are used. These strategies could be encouraged to assist such services to achieve optimal population impact among hard-to-reach populations.

Popularity differentially predicts reactive and proactive aggression in early adolescence.

PubMed

Stoltz, Sabine; Cillessen, Antonius H N; van den Berg, Yvonne H M; Gommans, Rob

2016-01-01

Previous research has indicated that peer popularity is associated with aggressive behavior. However, it is not yet clear whether popularity is uniquely related to different functions of aggression. In this study, we examined associations between peer-perceived popularity, and reactive and proactive aggression using a cross-sectional and a longitudinal design. Yearly sociometric measures of popularity, and reactive and proactive aggression were gathered from 266 seventh and eight grade adolescents (Mage grade 7 = 12.80, SDage  = .40). Popularity was positively correlated with proactive aggression and negatively correlated with reactive aggression, both concurrently as over time. Curvilinear trends indicated that a significant minority of low versus high popular adolescents showed both functions of aggression. Somewhat stronger effects of popularity on proactive aggression were found for boys than girls. Stably popular adolescents showed the highest levels of proactive aggression, whereas stably unpopular youth showed the highest levels of reactive aggression. Implications and directions for future research are discussed. © 2015 Wiley Periodicals, Inc.

Making things happen through challenging goals: leader proactivity, trust, and business-unit performance.

PubMed

Crossley, Craig D; Cooper, Cecily D; Wernsing, Tara S

2013-05-01

Building on decades of research on the proactivity of individual performers, this study integrates research on goal setting and trust in leadership to examine manager proactivity and business unit sales performance in one of the largest sales organizations in the United States. Results of a moderated-mediation model suggest that proactive senior managers establish more challenging goals for their business units (N = 50), which in turn are associated with higher sales performance. We further found that employees' trust in the manager is a critical contingency variable that facilitates the relationship between challenging sales goals and subsequent sales performance. This research contributes to growing literatures on trust in leadership and proactivity by studying their joint effects at a district-unit level of analysis while identifying district managers' tendency to set challenging goals as a process variable that helps translate their proactivity into the collective performance of their units. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Cognitive characteristics of learning Java, an object-oriented programming language

NASA Astrophysics Data System (ADS)

White, Garry Lynn

Industry and Academia are moving from procedural programming languages (e.g., COBOL) to object-oriented programming languages, such as Java for the Internet. Past studies in the cognitive aspects of programming have focused primarily on procedural programming languages. Some of the languages used have been Pascal, C, Basic, FORTAN, and COBOL. Object-oriented programming (OOP) represents a new paradigm for computing. Industry is finding that programmers are having difficulty shifting to this new programming paradigm. This instruction in OOP is currently starting in colleges and universities across the country. What are the cognitive aspects for this new OOP language Java? When is a student developmentally ready to handle the cognitive characteristics of the OOP language Java? Which cognitive teaching style is best for this OOP language Java? Questions such as the aforementioned are the focus of this research Such research is needed to improve understanding of the learning process and identify students' difficulties with OOP methods. This can enhance academic teaching and industry training (Scholtz, 1993; Sheetz, 1997; Rosson, 1990). Cognitive development as measured by the Propositional Logic Test, cognitive style as measured by the Hemispheric Mode Indicator, and physical hemispheric dominance as measured by a self-report survey were obtained from thirty-six university students studying Java programming. Findings reveal that physical hemispheric dominance is unrelated to cognitive and programming language variables. However, both procedural and object oriented programming require Piaget's formal operation cognitive level as indicated by the Propositional Logic Test. This is consistent with prior research A new finding is that object oriented programming also requires formal operation cognitive level. Another new finding is that object oriented programming appears to be unrelated to hemispheric cognitive style as indicated by the Hemispheric Mode Indicator (HMI). This research suggests that object oriented programming is hemispheric thinking style friendly, while procedural programming is left hemispheric cognitive style. The conclusion is that cognitive characteristics are not the cause for the difficulty in shifting from procedural to this new programming paradigm of object oriented programming. An alternative possibility to the difficulty is proactive interference. Prior learning of procedural programming makes it harder to learning object oriented programming. Further research is needed to determine if proactive interference is the cause for the difficulty in shifting from procedural programming to object oriented programming.

Switching regimens in virologically suppressed HIV-1-infected patients: evidence base and rationale for integrase strand transfer inhibitor (INSTI)-containing regimens.

PubMed

Raffi, F; Esser, S; Nunnari, G; Pérez-Valero, I; Waters, L

2016-10-01

In an era when most individuals with treated HIV infection can expect to live into old age, clinicians should proactively review their patients' current and future treatment needs and challenges. Clinical guidelines acknowledge that, in the setting of virological suppression, treatment switch may yield benefits in terms of tolerability, regimen simplification, adherence, convenience and long-term health considerations, particularly in the context of ageing. In this paper, we review evidence from six key clinical studies on switching virologically suppressed patients to regimens based on integrase strand transfer inhibitors (INSTIs), the antiretroviral class increasingly preferred as initial therapy in clinical guidelines. We review these studies and focus on the virological efficacy, safety, and tolerability of switching to INSTI-based regimens in suppressed HIV-positive individuals. We review the early switch studies SWITCHMRK and SPIRAL [assessing a switch from a ritonavir-boosted protease inhibitor (PI/r) to raltegravir (RAL)-containing regimens], together with data from STRATEGY-PI [assessing a switch to elvitegravir (EVG)-containing regimens; EVG/cobicistat (COBI)/emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) vs. remaining on a PI/r-containing regimen], STRATEGY-NNRTI [assessing a switch to EVG/COBI/FTC/TDF vs. continuation of a nonnucleoside reverse transcriptase inhibitor (NNRTI) and two nucleoside reverse transcriptase inhibitors (NRTIs)], STRIIVING [assessing a switch to a dolutegravir (DTG)-containing regimen (abacavir (ABC)/lamivudine (3TC)/DTG) vs. staying on the background regimen], and GS study 109 [assessing a switch to EVG/COBI/FTC/tenofovir alafenamide fumarate (TAF) vs. continuation of FTC/TDF-based regimens]. Switching to INSTI-containing regimens has been shown to support good virological efficacy, with evidence from two studies demonstrating superior virological efficacy for a switch to EVG-containing regimens. In addition, switching to INSTI regimens was associated with improved tolerability and greater reported patient satisfaction and outcomes in some studies. INSTI-based regimens offer an important contemporary switch option that may be tailored to meet and optimize the needs of many patients. © 2016 British HIV Association.

Working Memory Systems in the Rat.

PubMed

Bratch, Alexander; Kann, Spencer; Cain, Joshua A; Wu, Jie-En; Rivera-Reyes, Nilda; Dalecki, Stefan; Arman, Diana; Dunn, Austin; Cooper, Shiloh; Corbin, Hannah E; Doyle, Amanda R; Pizzo, Matthew J; Smith, Alexandra E; Crystal, Jonathon D

2016-02-08

A fundamental feature of memory in humans is the ability to simultaneously work with multiple types of information using independent memory systems. Working memory is conceptualized as two independent memory systems under executive control [1, 2]. Although there is a long history of using the term "working memory" to describe short-term memory in animals, it is not known whether multiple, independent memory systems exist in nonhumans. Here, we used two established short-term memory approaches to test the hypothesis that spatial and olfactory memory operate as independent working memory resources in the rat. In the olfactory memory task, rats chose a novel odor from a gradually incrementing set of old odors [3]. In the spatial memory task, rats searched for a depleting food source at multiple locations [4]. We presented rats with information to hold in memory in one domain (e.g., olfactory) while adding a memory load in the other domain (e.g., spatial). Control conditions equated the retention interval delay without adding a second memory load. In a further experiment, we used proactive interference [5-7] in the spatial domain to compromise spatial memory and evaluated the impact of adding an olfactory memory load. Olfactory and spatial memory are resistant to interference from the addition of a memory load in the other domain. Our data suggest that olfactory and spatial memory draw on independent working memory systems in the rat. Copyright © 2016 Elsevier Ltd. All rights reserved.

Interference within the focus of attention: working memory tasks reflect more than temporary maintenance.

PubMed

Shipstead, Zach; Engle, Randall W

2013-01-01

One approach to understanding working memory (WM) holds that individual differences in WM capacity arise from the amount of information a person can store in WM over short periods of time. This view is especially prevalent in WM research conducted with the visual arrays task. Within this tradition, many researchers have concluded that the average person can maintain approximately 4 items in WM. The present study challenges this interpretation by demonstrating that performance on the visual arrays task is subject to time-related factors that are associated with retrieval from long-term memory. Experiment 1 demonstrates that memory for an array does not decay as a product of absolute time, which is consistent with both maintenance- and retrieval-based explanations of visual arrays performance. Experiment 2 introduced a manipulation of temporal discriminability by varying the relative spacing of trials in time. We found that memory for a target array was significantly influenced by its temporal compression with, or isolation from, a preceding trial. Subsequent experiments extend these effects to sub-capacity set sizes and demonstrate that changes in the size of k are meaningful to prediction of performance on other measures of WM capacity as well as general fluid intelligence. We conclude that performance on the visual arrays task does not reflect a multi-item storage system but instead measures a person's ability to accurately retrieve information in the face of proactive interference.

Functional Relationships for Investigating Cognitive Processes

PubMed Central

Wright, Anthony A.

2013-01-01

Functional relationships (from systematic manipulation of critical variables) are advocated for revealing fundamental processes of (comparative) cognition—through examples from my work in psychophysics, learning, and memory. Functional relationships for pigeon wavelength (hue) discrimination revealed best discrimination at the spectral points of hue transition for pigeons—a correspondence (i.e., functional relationship) similar to that for humans. Functional relationships for learning revealed: Item-specific or relational learning in matching to sample as a function of the pigeons’ sample-response requirement, and same/different abstract-concept learning as a function of the training set size for rhesus monkeys, capuchin monkeys, and pigeons. Functional relationships for visual memory revealed serial position functions (a 1st order functional relationship) that changed systematically with retention delay (a 2nd order relationship) for pigeons, capuchin monkeys, rhesus monkeys, and humans. Functional relationships for rhesus-monkey auditory memory also revealed systematic changes in serial position functions with delay, but these changes were opposite to those for visual memory. Functional relationships for proactive interference revealed interference that varied as a function of a ratio of delay times. Functional relationships for change detection memory revealed (qualitative) similarities and (quantitative) differences in human and monkey visual short term memory as a function of the number of memory items. It is concluded that these findings were made possible by varying critical variables over a substantial portion of the manipulable range to generate functions and derive relationships. PMID:23174335

Cognitive and Affective Empathy as Predictors of Proactive and Reactive Aggression

ERIC Educational Resources Information Center

Gordon, Gina M.

2013-01-01

This study examined cognitive and affective empathy as predictors of proactive and reactive aggression. This study also explored whether levels of cognitive and affective empathy differed among children who use proactive and reactive aggression. Cognitive and affective empathy were measured by the Basic Empathy Scale (Jolliffe & Farrington,…

Proactive and Preventive Coping in Adjustment to College

ERIC Educational Resources Information Center

Gan, Yiqun; Hu, Yueqin; Zhang, Yiwen

2010-01-01

The current study compared the relative importance of proactive coping and preventive coping in the adjustment to university life among 403 freshmen at a Chinese university and evaluated the function of proactive coping in the stress process. Participants completed the Future-Oriented Coping Inventory (Gan, Yang, Zhou, & Zhang, 2007), the…

The Role of Hostile Attributions in the Associations between Child Maltreatment and Reactive and Proactive Aggression

PubMed Central

Richey, Allora; Brown, Shaquanna; Fite, Paula J.; Bortolato, Marco

2017-01-01

The present study examined the relations between child maltreatment and reactive and proactive functions of aggression, and whether hostile attribution biases partially accounted for these associations in a sample of 339 college students (mean age = 19; 51% male). Child maltreatment was associated with reactive, but not proactive, aggression, and instrumental hostile attribution biases accounted for this association. Relational hostile attributions were correlated with both reactive and proactive aggression, but did not play a role in the link between child maltreatment and reactive aggression. PMID:29386881

The Role of Affect Spin in the Relationships between Proactive Personality, Career Indecision, and Career Maturity

PubMed Central

Park, In-Jo

2015-01-01

This study attempted to investigate the influence of proactive personality on career indecision and career maturity, and to examine the moderating effects of affect spin. The author administered proactive personality, career indecision, and career maturity scales to 70 college students. Affect spin was calculated using the day reconstruction method, wherein participants evaluated their affective experiences by using 20 affective terms at the same time each day for 21 consecutive days. Hierarchical regression analyses showed that proactive personality significantly predicted career indecision and career maturity, even after controlling for valence and activation variability, neuroticism, age, and gender. Furthermore, affect spin moderated the associations of proactive personality with career indecision and maturity. The theoretical and practical implications of the moderating effects of affect spin are discussed. PMID:26635665

Differential Expression of Alpha 4 Integrins on Effector Memory T Helper Cells during Bordetella Infections. Delayed Responses in Bordetella pertussis

PubMed Central

Ferguson, Ryan; Tarlton, Nicole; Wu, Victoria; Sequeira, Christopher S.; Bremer, Martina; Abramson, Tzvia

2012-01-01

Bordetella pertussis (B. pertussis) is the causative agent of whooping cough, a respiratory disease that is reemerging worldwide. Mechanisms of selective lymphocyte trafficking to the airways are likely to be critical in the immune response to this pathogen. We compared murine infection by B. pertussis, B. parapertussis, and a pertussis toxin-deleted B. pertussis mutant (BpΔPTX) to test the hypothesis that effector memory T-helper cells (emTh) display an altered pattern of trafficking receptor expression in B. pertussis infection due to a defect in imprinting. Increased cell recruitment to the lungs at 5 days post infection (p.i.) with B. parapertussis, and to a lesser extent with BpΔPTX, coincided with an increased frequency of circulating emTh cells expressing the mucosal-associated trafficking receptors α4β7 and α4β1 while a reduced population of these cells was observed in B. pertussis infection. These cells were highly evident in the blood and lungs in B. pertussis infection only at 25 days p.i. when B. parapertussis and BpΔPTX infections were resolved. Although at 5 days p.i., an equally high percentage of lung dendritic cells (DCs) from all infections expressed maturation markers, this expression persisted only in B. pertussis infection at 25 days p.i. Furthermore, at 5 days p.i with B. pertussis, lung DCs migration to draining lymph nodes may be compromised as evidenced by decreased frequency of CCR7+ DCs, inhibited CCR7-mediated in vitro migration, and fewer DCs in lung draining lymph nodes. Lastly, a reduced frequency of allogeneic CD4+ cells expressing α4β1 was detected following co-culture with lung DCs from B. pertussis-infected mice, suggesting a defect in DC imprinting in comparison to the other infection groups. The findings in this study suggest that B. pertussis may interfere with imprinting of lung-associated trafficking receptors on T lymphocytes leading to extended survival in the host and a prolonged course of disease. PMID:23300813

A chimeric cyclic interferon-α2b peptide induces apoptosis by sequential activation of phosphatidylinositol 3-kinase, protein kinase Cδ and p38 MAP kinase.

PubMed

Blank, V C; Bertucci, L; Furmento, V A; Peña, C; Marino, V J; Roguin, L P

2013-06-10

We have previously demonstrated that tyrosine phosphorylation of STAT1/3 and p38 mitogen-activated protein kinase (p38 MAPK) activation are involved in the apoptotic response triggered by a chimeric cyclic peptide of the interferon-α2b (IFN-α2b) in WISH cells. Since the peptide also induced serine phosphorylation of STAT proteins, in the present study we examined the kinase involved in serine STAT1 phosphorylation and the signaling effectors acting upstream such activation. We first found that p38 MAPK is involved in serine STAT1 phosphorylation, since a reduction of phophoserine-STAT1 levels was evident after incubating WISH cells with cyclic peptide in the presence of a p38 pharmacological inhibitor or a dominant-negative p38 mutant. Next, we demonstrated that the peptide induced activation of protein kinase Cδ (PKCδ). Based on this finding, the role of this kinase was then evaluated. After incubating WISH cells with a PKCδ inhibitor or after decreasing PKCδ expression levels by RNA interference, both peptide-induced serine STAT1 and p38 phosphorylation levels were significantly decreased, indicating that PKCδ functions as an upstream regulator of p38. We also showed that PKCδ and p38 activation stimulated by the peptide was inhibited by a specific pharmacological inhibitor of phosphatidylinositol 3-kinase (PI3K) or by a dominant-negative p85 PI3K-regulatory subunit, suggesting that PI3K is upstream in the signaling cascade. In addition, the role of PI3K and PKCδ in cyclic peptide-induced apoptosis was examined. Both signaling effectors were found to regulate the antiproliferative activity and the apoptotic response triggered by the cyclic peptide in WISH cells. In conclusion, we herein demonstrated that STAT1 serine phosphorylation is mediated by the sequential activation of PI3K, PKCδ and p38 MAPK. This signaling cascade contributes to the antitumor effect induced by the chimeric IFN-α2b cyclic peptide in WISH cells. Copyright © 2013 Elsevier Inc. All rights reserved.

Does Motivation Matter? Analysis of a Randomized Trial of Proactive Outreach to VA Smokers.

PubMed

Danan, Elisheva R; Joseph, Anne M; Sherman, Scott E; Burgess, Diana J; Noorbaloochi, Siamak; Clothier, Barbara; Japuntich, Sandra J; Taylor, Brent C; Fu, Steven S

2016-08-01

Current guidelines advise providers to assess smokers' readiness to quit, then offer cessation therapies to smokers planning to quit and motivational interventions to smokers not planning to quit. We examined the relationship between baseline stage of change (SOC), treatment utilization, and smoking cessation to determine whether the effect of a proactive smoking cessation intervention was dependent on smokers' level of motivation to quit. Secondary analysis of a multicenter randomized controlled trial. A total of 3006 current smokers, aged 18-80 years, at four Veterans Affairs (VA) medical centers. Proactive care included proactive outreach (mailed invitation followed by telephone outreach), offer of smoking cessation services (telephone or face-to-face), and access to pharmacotherapy. Usual care participants had access to VA smoking cessation services and state telephone quitlines. Baseline SOC measured with Readiness to Quit Ladder, and 6-month prolonged abstinence self-reported at 1 year. At baseline, 35.8 % of smokers were in preparation, 38.2 % in contemplation, and 26.0 % in precontemplation. The overall interaction between SOC and treatment arm was not statistically significant (p = 0.30). Among smokers in preparation, 21.1 % of proactive care participants achieved 6-month prolonged abstinence, compared to 13.1 % of usual care participants (OR, 1.8 [95 % CI, 1.2-2.6]). Similarly, proactive care increased abstinence among smokers in contemplation (11.0 % vs. 6.5 %; OR, 1.8 [95 % CI, 1.1-2.8]). Smokers in precontemplation quit smoking at similar rates (5.3 % vs. 5.6 %; OR, 0.9 [95 % CI, 0.5-1.9]). Within each stage, uptake of smoking cessation treatments increased with higher SOC and with proactive care as compared with usual care. Mostly male participants limits generalizability. Randomization was not stratified by SOC. Proactive care increased treatment uptake compared to usual care across all SOC. Proactive care increased smoking cessation among smokers in preparation and contemplation but not in precontemplation. Proactively offering cessation therapies to smokers at all SOC will increase treatment utilization and population-level smoking cessation.

Callous-unemotional traits, proactive aggression, and treatment outcomes of aggressive children with attention-deficit/hyperactivity disorder.

PubMed

Blader, Joseph C; Pliszka, Steven R; Kafantaris, Vivian; Foley, Carmel A; Crowell, Judith A; Carlson, Gabrielle A; Sauder, Colin L; Margulies, David M; Sinha, Christa; Sverd, Jeffrey; Matthews, Thomas L; Bailey, Brigitte Y; Daviss, W Burleson

2013-12-01

Stimulant treatment improves impulse control among children with attention-deficit/hyperactivity disorder (ADHD). Decreased aggression often accompanies stimulant pharmacotherapy, suggesting that impulsiveness is integral to aggressive behavior in these children. However, children with high callous-unemotional (CU) traits and proactive aggression may benefit less from ADHD pharmacotherapy, because their aggressive behavior seems more purposeful and deliberate. This study's objective was to determine whether pretreatment CU traits and proactive aggression affect treatment outcomes among aggressive children with ADHD receiving stimulant monotherapy. We implemented a stimulant optimization protocol with 160 children 6 to 13 years of age (mean [SD] age of 9.31 [2.02] years; 78.75% male) with ADHD, oppositional defiant or conduct disorder, and significant aggressive behavior. Family-focused behavioral intervention was provided concurrently. The primary outcome was the Retrospective Modified Overt Aggression Scale. The Antisocial Process Screening Device and the Aggression Scale, also completed by parents, measured CU traits and proactive aggression, respectively. Analyses examined moderating effects of CU traits and proactive aggression on outcomes. In all, 82 children (51%) experienced remission of aggressive behavior. Neither CU traits nor proactive aggression predicted remission (CU traits: odds ratio [OR] = 0.94, 95% CI = 0.80-1.11; proactive aggression, OR = 1.05, 95% CI = 0.86-1.29). Children whose overall aggression remitted showed decreases in CU traits (effect size = -0.379, 95% CI = -0.60 to -0.16) and proactive aggression (effect size = -0.463, 95% CI = -0.69 to -0.23). Findings suggest that pretreatment CU traits and proactive aggression do not forecast worse outcomes for aggressive children with ADHD receiving optimized stimulant pharmacotherapy. With such treatment, CU traits and proactive aggression may decline alongside other behavioral improvements. Clinical trial registration information--Medication Strategies for Treating Aggressive Behavior in Youth With Attention Deficit Hyperactivity Disorder; http://clinicaltrials.gov/; NCT00228046; and Effectiveness of Combined Medication Treatment for Aggression in Children With Attention Deficit With Hyperactivity Disorder (The SPICY Study); http://clinicaltrials.gov/; NCT00794625. Copyright © 2013 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Proactive tobacco treatment offering free nicotine replacement therapy and telephone counselling for socioeconomically disadvantaged smokers: a randomised clinical trial.

PubMed

Fu, Steven S; van Ryn, Michelle; Nelson, David; Burgess, Diana J; Thomas, Janet L; Saul, Jessie; Clothier, Barbara; Nyman, John A; Hammett, Patrick; Joseph, Anne M

2016-05-01

Evidenced-based tobacco cessation treatments are underused, especially by socioeconomically disadvantaged smokers. This contributes to widening socioeconomic disparities in tobacco-related morbidity and mortality. The Offering Proactive Treatment Intervention trial tested the effects of a proactive outreach tobacco treatment intervention on population-level smoking abstinence and tobacco treatment use among a population-based sample of socioeconomically disadvantaged smokers. Current smokers (n=2406), regardless of interest in quitting, who were enrolled in the Minnesota Health Care Programs, the state's publicly funded healthcare programmes for low-income populations, were randomly assigned to proactive outreach or usual care. The intervention comprised proactive outreach (tailored mailings and telephone calls) and free cessation treatment (nicotine replacement therapy and intensive, telephone counselling). Usual care comprised access to a primary care physician, insurance coverage of Food and Drug Administration-approved smoking cessation medications, and the state's telephone quitline. The primary outcome was self-reported 6-month prolonged smoking abstinence at 1 year and was assessed by follow-up survey. The proactive intervention group had a higher prolonged abstinence rate at 1 year than usual care (16.5% vs 12.1%, OR 1.47, 95% CI 1.12 to 1.93). The effect of the proactive intervention on prolonged abstinence persisted in selection models accounting for non-response. In analysis of secondary outcomes, use of evidence-based tobacco cessation treatments were significantly greater among proactive outreach participants compared with usual care, particularly combination counselling and medications (17.4% vs 3.6%, OR 5.69, 95% CI 3.85 to 8.40). Population-based proactive tobacco treatment increases engagement in evidence-based treatment and is effective in long-term smoking cessation among socioeconomically disadvantaged smokers. Findings suggest that dissemination of population-based proactive treatment approaches is an effective strategy to reduce the prevalence of smoking and socioeconomic disparities in tobacco use. NCT01123967. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Testosterone and Proactive-Reactive Aggression in Youth: the Moderating Role of Harsh Discipline.

PubMed

Chen, Frances R; Raine, Adrian; Granger, Douglas A

2018-01-20

This study tests a biosocial model of the link between testosterone and proactive-reactive aggression in youth at varying levels of harsh discipline. Given that proactive aggression is used to gain power and status and the importance of social learning in its formation, we hypothesized that testosterone would be associated with proactive aggression at higher levels of harsh discipline, and that this relationship would be more pronounced in boys than girls. Participants (n = 445; 50% male; M age = 11.92 years; 80% African-American) and their caregivers completed questionnaires including demographics, conflict tactics, and proactive-reactive aggression. Youth also provided a saliva sample for testosterone. Analyses revealed an interaction between testosterone and harsh discipline on proactive aggression in both boys and girls, and an interaction between testosterone and harsh discipline on reactive aggression in boys only. For those experiencing high levels of harsh discipline, testosterone was positively associated with proactive aggression, with the magnitude of the association increasing as harsh discipline increased. For below average levels of harsh discipline, there were protective effects of high testosterone for boy's reactive aggression and for girl's proactive aggression. The findings support basic tenets of the biosocial model which suggest that links between testosterone and aggressive behavior are dependent on contextual forces, highlighting the complex relationship between hormones, social context, and aggression. Novel findings include protective effects of high testosterone for those exposed to low levels of harsh discipline. Findings are discussed in light of the context-contingency effect and also within the differential susceptibility framework.

Linking Extroversion and Proactive Personality to Career Success: The Role of Mentoring Received and Knowledge

ERIC Educational Resources Information Center

Turban, Daniel B.; Moake, Timothy R.; Wu, Sharon Yu-Hsien; Cheung, Yu Ha

2017-01-01

Although extroversion and proactive personality are related to career success, the mechanisms through which the relationships occur are unclear. Based on the contest- and sponsored-mobility processes, we examine a model linking extroversion and proactive personality to career success through the mediating effects of mentoring received and…

Associations among Empathy, Social Competence, & Reactive/Proactive Aggression Subtypes

ERIC Educational Resources Information Center

Mayberry, Megan L.; Espelage, Dorothy L.

2007-01-01

Differences between proactive and reactive aggression subtypes on self-reported measures of empathy, social competence, and expectation for reward were examined among 433 middle school students (65.4% White, 33.9% Black). As hypothesized, males scored higher on proactive and reactive aggression scales and lower on empathy measures than females.…

Improved Academic Performance and Enhanced Employability? The Potential Double Benefit of Proactivity for Business Graduates

ERIC Educational Resources Information Center

Tymon, Alex; Batistic, Sasa

2016-01-01

This study contributes to proactivity theory and debate on how universities meet competing stakeholder demands in an increasingly marketized higher education environment. We explore how the interplay between the stable facet of proactive personality and the situated behaviour of personal initiative influence academic performance. We hypothesized…

The Influence of Proactive Socialization Behaviors and Team Socialization on Individual Performance in the Team

ERIC Educational Resources Information Center

Pennaforte, Antoine

2016-01-01

On the basis of the role and the social exchange theories, this research investigated the direct and indirect antecedents of three dimensions of team performance (proficiency, adaptivity, proactivity) developed through cooperative education. The theoretical model examined how proactive socialization behaviors led to team socialization and team…

New Directions in Measuring Reactive and Proactive Aggression: Validation of a Teacher Questionnaire

ERIC Educational Resources Information Center

Polman, Hanneke; de Castro, Bram Orobio; Thomaes, Sander; van Aken, Marcel

2009-01-01

The well-known distinction between reactive and proactive aggression is theoretically important but empirically controversial. Recently, aggression researchers have argued that we should separate the form and function of aggression to make a clearer distinction between reactive and proactive aggression. This article describes the validation of a…

Functions of Aggression and Delinquency: The Moderating Role of Parent Criminality and Friends' Gang Membership.

PubMed

Ang, Rebecca P; Huan, Vivien S; Li, Xiang; Chan, Wei Teng

2016-03-02

This study examined the relationships between two functions of aggression (i.e., reactive and proactive) and delinquency, including the moderating effects of parent criminality and friends' gang membership, in a sample of 1,027 Singaporean adolescents from Grade 7 to Grade 9, with age ranging from 12 to 19 years (M = 14.10, SD = 1.15). Findings suggested that both reactive aggression and proactive aggression significantly and positively predicted delinquency (after controlling for proactive aggression and reactive aggression, respectively), with proactive aggression being a stronger predictor. Friends' gang membership was found to moderate the relationship between reactive aggression and delinquency, and proactive aggression and delinquency, with stronger moderator effects for the latter. Those who were aggressive proactively and who had friends in a gang appear to be impacted most negatively with respect to delinquency. Parent criminality did not moderate these relationships. These findings highlight the need to effectively address the issues of child and adolescent aggression. Also, developing positive peer relations early is crucial for delinquency prevention. © The Author(s) 2016.

Amustaline (S-303) treatment inactivates high levels of Zika virus in red blood cell components.

PubMed

Laughhunn, Andrew; Santa Maria, Felicia; Broult, Julien; Lanteri, Marion C; Stassinopoulos, Adonis; Musso, Didier; Aubry, Maite

2017-03-01

The potential for Zika virus (ZIKV) transfusion-transmission (TT) has been demonstrated in French Polynesia and Brazil. Pathogen inactivation (PI) of blood products is a proactive strategy to inactivate TT pathogens including arboviruses. Inactivation of West Nile, dengue, Zika, and chikungunya viruses was previously demonstrated by photochemical treatment with amotosalen and ultraviolet A (UVA) illumination. In this study, we evaluated ZIKV inactivation in red blood cell (RBC) components by a chemical approach that uses amustaline (S-303) and glutathione (GSH). RBC components were spiked with a high titer of ZIKV. Viral titers (infectivity) and ZIKV RNA loads (reverse transcription-polymerase chain reaction) were measured in spiked RBCs before and after S-303 and GSH treatment and confirmed using repetitive passages in cell culture. A mock-treated arm validated the approach by demonstrating stability of the virus (infectivity and RNA load) during the process. The mean ZIKV infectivity titer and RNA load in RBCs were 5.99 ± 0.2 log 50% tissue culture infectious dose (TCID 50 )/mL and 7.75 ± 0.16 log genomic equivalents/mL before inactivation. No infectivity was detected immediately after S-303 and GSH treatment and after five serial passages in cell culture. Complete ZIKV inactivation of more than 5.99 log TCID 50 /mL in RBCs was achieved using S-303 and GSH at levels higher than those found in asymptomatic ZIKV-infected blood donors. Therefore, the S-303 and GSH PI system is promising for mitigating the risk of ZIKV TT. © 2016 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

Building a highly available and intrusion tolerant Database Security and Protection System (DSPS).

PubMed

Cai, Liang; Yang, Xiao-Hu; Dong, Jin-Xiang

2003-01-01

Database Security and Protection System (DSPS) is a security platform for fighting malicious DBMS. The security and performance are critical to DSPS. The authors suggested a key management scheme by combining the server group structure to improve availability and the key distribution structure needed by proactive security. This paper detailed the implementation of proactive security in DSPS. After thorough performance analysis, the authors concluded that the performance difference between the replicated mechanism and proactive mechanism becomes smaller and smaller with increasing number of concurrent connections; and that proactive security is very useful and practical for large, critical applications.

Are proactive personalities always beneficial? Political skill as a moderator.

PubMed

Sun, Shuhua; van Emmerik, Hetty I J

2015-05-01

Does proactive personality always enhance job success? The authors of this study draw on socioanalytic theory of personality and organizational political perspectives to study employees' political skill in moderating the effects of proactive personality on supervisory ratings of employee task performance, helping behaviors, and learning behaviors. Multisource data from 225 subordinates and their 75 immediate supervisors reveal that proactive personality is associated negatively with supervisory evaluations when political skill is low, and the negative relationship disappears when political skill is high. Implications and future research directions are discussed. (c) 2015 APA, all rights reserved.

Antitumor Lipids--Structure, Functions, and Medical Applications.

PubMed

Kostadinova, Aneliya; Topouzova-Hristova, Tanya; Momchilova, Albena; Tzoneva, Rumiana; Berger, Martin R

2015-01-01

Cell proliferation and metastasis are considered hallmarks of tumor progression. Therefore, efforts have been made to develop novel anticancer drugs that inhibit both the proliferation and the motility of tumor cells. Synthetic antitumor lipids (ATLs), which are chemically divided into two main classes, comprise (i) alkylphospholipids (APLs) and (ii) alkylphosphocholines (APCs). They represent a new entity of drugs with distinct antiproliferative properties in tumor cells. These compounds do not interfere with the DNA or mitotic spindle apparatus of the cell, instead, they incorporate into cell membranes, where they accumulate and interfere with lipid metabolism and lipid-dependent signaling pathways. Recently, it has been shown that the most commonly studied APLs inhibit proliferation by inducing apoptosis in malignant cells while leaving normal cells unaffected and are potent sensitizers of conventional chemo- and radiotherapy, as well as of electrical field therapy. APLs resist catabolic degradation to a large extent, therefore accumulate in the cell and interfere with lipid-dependent survival signaling pathways, notably PI3K-Akt and Raf-Erk1/2, and de novo phospholipid biosynthesis. They are internalized in the cell membrane via raft domains and cause downstream reactions as inhibition of cell growth and migration, cell cycle arrest, actin stress fibers collapse, and apoptosis. This review summarizes the in vitro, in vivo, and clinical trials of most common ATLs and their mode of action at molecular and biochemical levels. © 2015 Elsevier Inc. All rights reserved.

Proactive and reactive sibling aggression and adjustment in adolescence.

PubMed

Tucker, Corinna Jenkins; Van Gundy, Karen T; Wiesen-Martin, Desireé; Hiley Sharp, Erin; Rebellon, Cesar J; Stracuzzi, Nena F

2015-03-01

Existing research on aggression tends to narrowly focus on peers; less is known about sibling aggression, most likely due to its historical acceptance. Aggression is characterized by its forms (i.e., physical vs. social or relational aggression) and its functions (i.e., the motivations behind the aggressive act and categorized as proactive vs. reactive aggression). We use data from a two-wave study of middle (n = 197; M age = 12.63 years at Wave 1) and older (n = 159; M age = 16.50 years at Wave 1) adolescents to assess the extent to which proactive and reactive functions of sibling aggression make unique or conditional contributions to adolescent adjustment (i.e., depression, delinquency, and substance use). We find that proactive sibling aggression increases risk for problem substance use and delinquent behavior, reactive sibling aggression increases risk for depressed mood and delinquent behavior, and such results are observed even with statistical adjustments for sociodemographic and family variables, stressful life events, and prior adjustment. Few conditional effects of proactive or reactive sibling aggression by sex or grade are observed; yet, for all three outcomes, the harmful effects of reactive sibling aggression are strongest among adolescents who report low levels of proactive sibling aggression. The results speak to the importance of understanding the proactive and reactive functions of sibling aggressive behaviors for adolescent adjustment. © The Author(s) 2014.

Edge Triggered Apparatus and Method for Measuring Strain in Bragg Gratings

NASA Technical Reports Server (NTRS)

Froggatt, Mark E. (Inventor)

2003-01-01

An apparatus and method for measuring strain of gratings written into an optical fiber. Optical radiation is transmitted over one or more contiguous predetermined wavelength ranges into a reference optical fiber network and an optical fiber network under test to produce a plurality of reference interference fringes and measurement interference fringes, respectively. The reference and measurement fringes are detected, and the reference fringes trigger the sampling of the measurement fringes. This results in the measurement fringes being sampled at 2(pi) increments of the reference fringes. Each sampled measurement fringe of each wavelength sweep is transformed into a spatial domain waveform. The spatial domain waveforms are summed to form a summation spatial domain waveform that is used to determine location of each grating with respect to a reference reflector. A portion of each spatial domain waveform that corresponds to a particular grating is determined and transformed into a corresponding frequency spectrum representation. The strain on the grating at each wavelength of optical radiation is determined by determining the difference between the current wavelength and an earlier, zero-strain wavelength measurement.

Proactive Personality and the Successful Job Search : A Field Investigation with College Graduates

ERIC Educational Resources Information Center

Brown, Douglas J.; Cober, Richard T.; Kane, Kevin; Levy, Paul E.; Shalhoop, Jarrett

2006-01-01

The current article tests a model of proactive personality and job search success with a sample of 180 graduating college students. Using structural equation modeling, the authors tested a theoretical model that specified the relations among proactive personality, job search self-efficacy, job search behaviors, job search effort, and job search…