Working memory of highly self‐critical men is impaired by failure

Previous studies have shown self‐criticism to be negatively associated with goal progress. In order to investigate factors that may influence this association, the present study examined the interactive impact of performance (failure vs. success) and self‐criticism on working memory (WM). Goal‐directed behavior in the achievement domain was operationalized as comparative performance on two strongly correlated WM span tasks. The effect of negative or positive performance feedback was assessed by presenting a success or a failure experience between the two WM span tasks in order to examine the influence of failure and success on the second WM span task compared with the first/baseline. A male‐only sample was used as a follow‐up to a previous study that has utilized a female‐only sample. Findings revealed self‐criticism to serve as an individual difference factor that influences men's WM functioning in the context of failure. This interactive effect may contribute to diminished goal progress in men.     

Early adversity in rural India impacts the brain networks underlying visual working memory

There is a growing need to understand the global impact of poverty on early brain and behavioural development, particularly with regard to key cognitive processes that emerge in early development. Although the impact of adversity on brain development can trap children in an intergenerational cycle of poverty, the massive potential for brain plasticity is also a source of hope: reliable, accessible, culturally agnostic methods to assess early brain development in low resource settings might be used to measure the impact of early adversity, identify infants for timely intervention and guide the development and monitor the effectiveness of early interventions. Visual working memory (VWM) is an early marker of cognitive capacity that has been assessed reliably in early infancy and is predictive of later academic achievement in Western countries. Here, we localized the functional brain networks that underlie VWM in early development in rural India using a portable neuroimaging system, and we assessed the impact of adversity on these brain networks. We recorded functional brain activity as young children aged 4–48 months performed a VWM task. Brain imaging results revealed localized activation in the frontal cortex, replicating findings from a Midwestern US sample. Critically, children from families with low maternal education and income showed weaker brain activity and poorer distractor suppression in canonical working memory areas in the left frontal cortex. Implications of this work are far‐reaching: it is now cost‐effective to localize functional brain networks in early development in low‐resource settings, paving the way for novel intervention and assessment methods.     

Attention training improves aberrant neural dynamics during working memory processing in veterans with PTSD

Posttraumatic stress disorder (PTSD) is associated with executive functioning deficits, including disruptions in working memory (WM). Recent studies suggest that attention training reduces PTSD symptomatology, but the underlying neural mechanisms are unknown. We used high-density magnetoencephalography (MEG) to evaluate whether attention training modulates brain regions serving WM processing in PTSD. Fourteen veterans with PTSD completed a WM task during a 306-sensor MEG recording before and after 8 sessions of attention training treatment. A matched comparison sample of 12 combat-exposed veterans without PTSD completed the same WM task during a single MEG session. To identify the spatiotemporal dynamics, each group’s data were transformed into the time-frequency domain, and significant oscillatory brain responses were imaged using a beamforming approach. All participants exhibited activity in left hemispheric language areas consistent with a verbal WM task. Additionally, veterans with PTSD and combat-exposed healthy controls each exhibited oscillatory responses in right hemispheric homologue regions (e.g., right Broca’s area); however, these responses were in opposite directions. Group differences in oscillatory activity emerged in the theta band (4–8 Hz) during encoding and in the alpha band (9–12 Hz) during maintenance and were significant in right prefrontal and right supramarginal and inferior parietal regions. Importantly, following attention training, these significant group differences were reduced or eliminated. This study provides initial evidence that attention training improves aberrant neural activity in brain networks serving WM processing.     

Reward-priming impacts visual working memory maintenance: Evidence from human electrophysiology

Reward can benefit visual processing of reward-associated objects in a non-strategic way. Recent studies have suggested that such influence extends also to visual working memory (VWM) representations of reward-associated stimuli. However, it is not clear yet which mechanisms underlie the behavioural effects in VWM tasks: reward could directly impact on our ability to maintain representations in VWM or it could influence memory indirectly via priming of attentional selection. To distinguish between these alternatives we measured event-related potential indices of selective attention – the N2pc – and VWM maintenance – the CDA (contralateral delay activity) – while participants completed a VWM task. Results show that reward outcome in one trial caused similarly coloured targets to be strongly represented in VWM in subsequent trials, as expressed in a larger-amplitude CDA This was not preceded by a corresponding effect on attentional selection, in so far as our key manipulation had no impact on the N2pc. In a second experiment, we found that reward priming produced a behavioural benefit that emerged over time, suggesting that the representations of reward-associated items stored in VWM are more resistant to interference and decay. We conclude that when the task stresses VWM maintenance, it is at this representational level that reward will have impact.     

Time‐of‐day variation of visuo‐spatial attention

Time‐of‐day variation of visuo‐spatial attention in relation to body temperature and subjective arousal was assessed. At five different times of day, alertness, covert, and overt orienting of attention were assessed in fifteen healthy subjects. Based on previous studies reporting a tight coupling of alerting and orienting the present study investigates potential attentional asymmetries induced by diurnal variations of arousal. Both covert and overt orienting of attention improved in the course of the day. However, no asymmetries between left and right visual hemifields could be detected. Covert orienting additionally covaried with body temperature, indicating a quite close relation between the attentional arousal and orienting system. Conversely, overt orienting only improved due to repeated testing but did not correlate with body temperature suggesting a partial independence of both modes of attentional orienting. It can be assumed that due to limited diurnal variations of arousal in the participants and practice effects caused by repeated testing, no attentional asymmetries could be provoked.     

Working memory consolidation is abnormally slow in schizophrenia

This study reports evidence that patients with schizophrenia demonstrate a slowing of working memory (WM) consolidation, which is the process of transforming transient perceptual representations into durable WM representations. Sixteen schizophrenia patients and 16 healthy control participants performed a task measuring the visual WM consolidation rate in a change-detection paradigm. A target display containing 3 colored squares was followed by a variable delay of 17-483 ms, a pattern mask, and then a test stimulus. This pattern mask does not interfere with perception but disrupts WM consolidation. Control participants reached no-mask performance by 250 ms, indicating completed WM consolidation, whereas patients failed to reach no-mask performance by 483 ms. Slowed consolidation may play an important and largely unrecognized role in schizophrenia.     

The Role of Interruptions and Contextual Associations in Delayed‐Execute Prospective Memory

We conducted three experiments to examine the dynamics of a delayed‐execute prospective memory task involving task interruptions. In the delayed‐execute paradigm, participants must delay a response until some future condition is met. After an intention was formed to a salient cue, an interruption reduced prospective memory relative to a no‐interruption condition. Prospective memory for cues encountered during an interrupting task was worse than for cues occurring before an interruption, but the location of the cue in either the ongoing task or the interruption did not affect prospective memory. Importantly, reinstating the prevailing context after the interruption alleviated the negative influence of the interruption. Providing participants with information about the future context for making the delayed‐execute response also alleviated some of these deficits presumably because participants could encode more specific features of the performance context. These results highlight the potential importance of contextual associations and reminders in completing everyday intentions successfully. Copyright © 2013 John Wiley & Sons, Ltd.     

Stroke damages attentional maintenance in working memory

Stroke is the main cause of acquired disability in adults, and specific deficits in working memory (WM) are among the most common cognitive consequences. In neuropsychological routine, WM is most of the time investigated in the framework of the multicomponent model (Baddeley & Hitch, 1974, The psychology of learning and motivation, 47). Using a more recent theoretical WM model, the time-based resource-sharing (TBRS) model (Barrouillet et al., 2011, Psychol. Rev., 118, 175), the aim of the present study was to investigate in young post-stroke patients to which extent attentional maintenance is impaired in WM. To address this question, we discarded other factors known to directly influence WM performance, that is processing speed and short-term memory span. We proposed to 53 post-stroke patients and to 63 healthy controls a complex span paradigm in which participants were asked to alternate between the memorization of a series of images and a concurrent parity judgement task of a series of digits. To investigate the attentional maintenance processes, we manipulated the cognitive load (CL) of the concurrent task. CL effect is typically interpreted as the involvement of attentional maintenance processes. The task was adapted to each participant according to their processing speed and memory span. As expected, the results showed higher recall performance in healthy controls compared with post-stroke patients. Consistent with the literature, we also observed higher performance when the CL was low compared with high. However, the improvement in recall at low CL was smaller for post-stroke patients compared with controls, suggesting that post-stroke WM deficit could be in part due to a deficit of the attentional maintenance processes.     

Visual working memory load disrupts the space‐based attentional guidance of target selection

During visual search, the selection of target objects is guided by stored representations of target‐defining features (attentional templates). It is commonly believed that such templates are maintained in visual working memory (WM), but empirical evidence for this assumption remains inconclusive. Here, we tested whether retaining non‐spatial object features (shapes) in WM interferes with attentional target selection processes in a concurrent search task that required spatial templates for target locations. Participants memorized one shape (low WM load) or four shapes (high WM load) in a sample display during a retention period. On some trials, they matched them to a subsequent memory test display. On other trials, a search display including two lateral bars in the upper or lower visual field was presented instead, and participants reported the orientation of target bars that were defined by their location (e.g., upper left or lower right). To assess the efficiency of attentional control under low and high WM load, EEG was recorded and the N2pc was measured as a marker of attentional target selection. Target N2pc components were strongly delayed when concurrent WM load was high, indicating that holding multiple object shapes in WM competes with the simultaneous retention of spatial attentional templates for target locations. These observations provide new electrophysiological evidence that such templates are maintained in WM, and also challenge suggestions that spatial and non‐spatial contents are represented in separate independent visual WM stores.     

Neural substrates of successful working memory and long-term memory formation in a relational spatial memory task

Working memory (WM) tasks may involve brain activation actually implicated in long-term memory (LTM). In order to disentangle these two memory systems, we employed a combined WM/LTM task, using a spatial relational (object-location) memory paradigm and analyzed which brain areas were associated with successful performance for either task using fMRI. Critically, we corrected for the performance on the respective memory task when analyzing subsequent memory effects. The WM task consisted of a delayed-match-to-sample task assessed in an MRI scanner. Each trial consisted of an indoor or outdoor scene in which the exact configuration of four objects had to be remembered. After a short delay (7–13 s), the scene was presented from a different angle and spatial recognition for two objects was tested. After scanning, participants received an unexpected subsequent recognition memory (LTM) task, where the two previously unprobed objects were tested. Brain activity during encoding, delay phase and probe phase was analyzed based on WM and LTM performance. Results showed that successful WM performance, when corrected for LTM performance, was associated with greater activation in the inferior frontal gyrus and left fusiform gyrus during the early stage of the maintenance phase. A correct decision during the WM probe was accompanied by greater activation in a wide network, including bilateral hippocampus, right superior parietal gyrus and bilateral insula. No voxels exhibited supra-threshold activity during the encoding phase, and we did not find any differential activity for correct versus incorrect trials in the WM task when comparing LTM correct versus LTM incorrect trials.     

Working memory affects false memory production for emotional events

Whereas a link between working memory (WM) and memory distortions has been demonstrated, its influence on emotional false memories is unclear. In two experiments, a verbal WM task and a false memory paradigm for negative, positive or neutral events were employed. In Experiment 1, we investigated individual differences in verbal WM and found that the interaction between valence and WM predicted false recognition, with negative and positive material protecting high WM individuals against false remembering; the beneficial effect of negative material disappeared in low WM participants. In Experiment 2, we lowered the WM capacity of half of the participants with a double task request, which led to an overall increase in false memories; furthermore, consistent with Experiment 1, the increase in negative false memories was larger than that of neutral or positive ones. It is concluded that WM plays a critical role in determining false memory production, specifically influencing the processing of negative material.     

Executive working memory processes in dyslexia: Behavioral and fMRI evidence

Beneventi, H., Tønnessen, F. E., Ersland, L. & Hugdahl, K. (2010). Executive working memory processes in dyslexia: Behavioral and fMRI evidence. Scandinavian Journal of Psychology, 51, 192–202. Dyslexia is an impairment in learning to read and write, primarily associated with a phonological core deficit. However, the manifestation of symptoms in dyslexia also includes impaired working memory (WM). The aim of this study was to investigate cortical activation related to verbal WM in dyslexic and normal readers aged around 13 years, controlling for phonological awareness processing. We used a modified WM n‐back task where the participants remembered the first or last speech segment (phonemes) of the names of common objects shown as pictures. Dyslexic readers were impaired compared with the control group. Compared with the dyslexic readers, controls showed increased fMRI activation in the left superior parietal lobule and the right inferior prefrontal gyrus. Unlike controls, dyslexics did not show a significant increase in activation in WM areas with increased memory load. These findings provide support for a specific working memory deficit in dyslexic individuals.     

视觉工作记忆对注意选择的自动导向作用

对Downing(2000)的实验范式加以改进使得实验设计完全符合检验记忆驱动注意捕获所需要满足的标准,实验一采用要求被试在工作记忆保持阶段完成探测区分任务的双任务范式,结果发现被试对呈现在匹配物体空间位置上的探测项反应时显著快于对呈现在非匹配物体空间位置上的探测项反应时,而在实验二中当对被试没有记忆要求时却没有发现这种空间位置一致的优势效应,说明视觉工作记忆内容对选择性注意产生了自动导向作用。     

Flexible representations in visual working memory and interactions with long‐term learning: Commentary on the special issue

This special issue of the British Journal of Psychology brings together cutting edge research on a range of topics in visual working memory (VWM). In this commentary, we attempt to summarize common themes in current VWM research exemplified in this issue. The articles include several reviews of important topics as well as empirical papers covering three main themes. The first concerns the nature of mental representations of memoranda in the commonly used delayed estimation task, where both fine‐grained and broad categorical details appear to be represented, and their susceptibility to interference. The second concerns interactions between VWM representations, both those that produce individuation of representations and those that create an overarching ensemble structure. Finally, the third main topic concerns the use of VWM during visual search and in the learning of repeated configurations in search displays. The work presented here, and other work in the field, points to a rich interplay between representations in VWM but also between VWM and information in long‐term memory. Opportunities for further investigation are highlighted throughout.     

基于客体工作记忆内容的保持对时间判断的影响

本研究通过操作工作记忆内容的有效性,探讨了记忆内容的保持对时间判断的影响。采用不规则的客体作为实验材料,使时间任务中的刺激与工作记忆内容匹配或不匹配。实验1采用工作记忆和时间判断的双任务范式,要求被试首先记忆一个客体,然后在每个试次的最后判断测试刺激是否与记忆项相同。在延迟阶段,被试判断连续出现的两个刺激的时距哪个更长（或更短）。实验2中,要求被试忽略第一个刺激,仅完成时间判断任务。结果发现,相比单任务的计时,双任务条件下,工作记忆内容的保持延长了时间判断的时间。而且,在记忆匹配和知觉匹配条件下,匹配刺激呈现的时间越长,正确率越低,反应时越长。这说明记忆内容的保持增加了决策的难度,工作记忆内容对时间判断的可能是由记忆内容引起的注意定向造成的。     

长时联结表征对工作记忆的抑制效应

本研究通过两个实验探讨了长时记忆联结表征如何影响当下工作记忆任务的加工。长时记忆联结表征采用无语义联系、无视觉相似性的Emoji图片对, 提前一天让被试完成联结表征的建立, 正式工作记忆任务采用独立探测的变化觉察范式。实验1控制呈现时间(500 ms / 1000 ms)与呈现方式(联结/独立), 发现两种呈现时间均显示出联结条件的正确率与记忆容量显著低于独立条件, 说明长时记忆联结表征抑制了当前工作记忆的加工。实验2设置了记忆项目数(2/4/6项)与呈现方式(联结/独立), 采用alpha震荡作为脑电指标, 考察长时联结表征在工作记忆维持阶段的作用。结果发现在维持阶段, 独立条件的alpha震荡随着记忆项目数量的增加而增大(2项 < 4项 < 6项), 而联结条件在4项已经到达顶点(2项 < 4项 = 6项)。实验2进一步说明长时联结表征在维持阶段降低了当前工作记忆容量。本研究的两个实验结果表明, 长时记忆联结表征对当前的工作记忆任务有一定的抑制作用, 这种抑制作用产生的机制可能来自于联结表征干扰了维持阶段的注意分配。     

Cognitive deficits of executive functions and decision‐making in obsessive‐compulsive disorder

The nature of cognitive deficits in obsessive‐compulsive disorder (OCD) is characterized by contradictory findings in terms of specific neuropsychological deficits. Selective impairments have been suggested to involve visuospatial memory, set shifting, decision‐making and response inhibition. The aim of this study was to investigate cognitive deficits in decision‐making and executive functioning in OCD. It was hypothesized that the OCD patients would be less accurate in their responses compared to the healthy controls in rational decision‐making on a version of the Cambridge gambling task (CGT) and on the color‐word interference test and on a version of the Tower of Hanoi test (tower test) of executive functioning. Thirteen participants with OCD were compared to a group of healthy controls (n = 13) matched for age, gender, education and verbal IQ. Results revealed significant differences between the OCD group and the healthy control group on quality of decision‐making on the CGT and for achievement score on the tower test. On these two tasks the OCD group performed worse than the healthy control group. The symptom‐dimension analysis revealed performance differences where safety checking patients were impaired on the tower test compared to contamination patients. Results are discussed in the framework of cognition and emotion processing and findings implicate that OCD models should address, specifically, the interaction between cognition and emotion. Here the emotional disruption hypothesis is forwarded to account for the dysfunctional behaviors in OCD. Further implications regarding methodological and inhibitory factors affecting cognitive information processing are highlighted.     

Dynamic states in working memory modulate guidance of visual attention: Evidence from an n-back paradigm

Items held in working memory (WM) can automatically bias attention when they reappear in visual displays. Recent evidence, however, suggests that WM biases of attention may be reduced under certain conditions, for example with increasing memory load. We employed a dual task paradigm to investigate how WM biases are affected by dynamic updating of memory contents. 1-back and 2-back versions of a memory task with colour stimuli were interrupted at intervals by an unrelated visual search task. Reappearance in the search display of the item that was currently active in WM guided attention, while suppressed or inactive items did not. We conclude that the rapid updating of memory contents facilitates the shifting of memory representations into different activity states on a moment-to-moment basis. The finding is consistent with models that propose that only one item can be “active” in WM at any one time to guide attention.     

视觉工作记忆对前注意阶段注意定向的调节

在注意阶段,视觉工作记忆与注意共享某些特征时,视觉工作记忆内容会引导注意定向。在前注意阶段的影响又是如何？对此问题的研究却很少见,本研究采用工作记忆与基于特征的视觉搜索相结合的任务深入探讨了此问题。研究结果发现：即使在前注意阶段,注意定向也会受到视觉工作记忆自上而下的调节。然而与注意阶段不同的是：当视觉工作记忆内容与随后视觉搜索任务的目标相关时,与记忆内容匹配的搜索项目会引导注意定向到该项目所在的位置,但只有此项目作为分心物时,才会明显地延迟对靶子的加工,而此项目作为靶子时,这种影响并不明显;当视觉工作记忆中保持的项目与随后视觉搜索任务的目标无关时,注意会忽略视觉工作记忆中保持的项目,有效地检测靶子     

Selective interference with image retention and generation: Evidence for the workspace model

We address three types of model of the relationship between working memory (WM) and long-term memory (LTM): (a) the gateway model, in which WM acts as a gateway between perceptual input and LTM; (b) the unitary model, in which WM is seen as the currently activated areas of LTM; and (c) the workspace model, in which perceptual input activates LTM, and WM acts as a separate workspace for processing and temporary retention of these activated traces. Predictions of these models were tested, focusing on visuospatial working memory and using dual-task methodology to combine two main tasks (visual short-term retention and image generation) with two interference tasks (irrelevant pictures and spatial tapping). The pictures selectively disrupted performance on the generation task, whereas the tapping selectively interfered with the retention task. Results are consistent with the predictions of the workspace model.