Acute aerobic exercise and information processing: Modulation of executive control in a Random Number Generation task

The immediate and short-term aftereffects of a bout of aerobic exercise on young adults’ executive functions were assessed. Sixteen participants performed a Random Number Generation (RNG) task, which measured two aspects of executive function, before, during, and after ergometer cycling exercise. In a separate session, participants completed the same sequence of testing while seated on an ergometer without pedaling. Results suggest that aerobic exercise: (1) selectively influences RNG indices related to the ability to alternate ascending and descending runs throughout the entire exercise bout; (2) induces a shift to a less effortful number generation strategy, particularly during the first few minutes of the exercise; and (3) has no significant influence on RNG performance as soon as the exercise terminates. The strategic adjustments observed during the exercise are interpreted in the framework of Hockey’s [Hockey, G. R. J. (1997). Compensatory control in the regulation of human performance under stress and high workload: A cognitive-energetical framework. Biological Psychology, 45, 73-93.] compensatory control model and suggest that concurrent effortful processes induced by cycling exercise may draw upon available attention resources and influence executive processing.     

Current directions in visual working memory research: An introduction and emerging insights

Visual working memory (VWM) is a core construct in the cognitive (neuro‐)sciences, assumed to serve as a hub for information exchange and thus supporting a multitude of cognitive functions related to processing visual information. Here, we give an introduction into key terms and paradigms and an overview of ongoing debates in the field, to which the articles collected in this Special Issue on ‘Current Directions in Visual Working Memory Research’ contribute. Our aim is to extract, from this overview, some ‘emerging’ theoretical insights concerning questions such as the optimal way to examine VWM, which types of mental representations contribute to performance on VWM tasks, and how VWM keeps features from the same object together and apart from features of concurrently maintained objects (the binding problem).     

The cost of facing fear: Visual working memory is impaired for faces expressing fear

Previous research has identified numerous factors affecting the capacity and accuracy of visual working memory (VWM). One potentially important factor is the emotionality of the stimuli to be encoded and held in VWM. We often must hold in VWM information that is emotionally charged, but much is still unknown about how the emotionality of stimuli impacts VWM performance. In the current research, we performed four studies examining the impact of fearful facial expressions on VWM for faces. Fearful expressions were found to produce a consistent cost to VWM performance. This cost was modulated by encoding time, but not set size. This cost was only present for faces in an upright orientation consistent with this cost being a product of the emotionality of the faces rather than lower‐level perceptual differences between neutral and fearful faces. These findings are discussed in the context of existing theoretical accounts of the impact of emotion on information processing. We suggest that a number of competing effects drive both costs and benefits and are at play when emotional information must be stored in VWM, with the task context determining the balance between them.     

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.     

Separating cue encoding from target processing in the explicit task-cuing procedure: are there "true" task switch effects?

Six experiments were conducted to separate cue encoding from target processing in explicitly cued task switching to determine whether task switch effects could be separated from cue encoding effects and to determine the nature of the representations produced by cue encoding. Subjects were required to respond to the cue, indicating which cue was presented (Experiments 1, 3a, and 4a) or which task was cued (Experiments 2, 3b, and 4b), before performing the cued task on the target. Cue encoding was successfully separated from target processing when the cue response indicated which task was cued but not when it indicated which cue was presented. Task switch effects were found when this separation was successful, suggesting that there are "true" task switch effects independent of cue encoding. Analysis of the conditions required for successful separation suggested that cue encoding results in a semantic categorical representation of the task to be performed rather than verbal or phonological representations of individual cues. Implications for the authors' past modeling of task-switching performance are discussed.     

Investigating the other-race effect in working memory

People have difficulties in remembering other-race faces; this so-called other-race effect (ORE) has been frequently observed in long-term recognition memory (LTM). Several theories argue that the ORE in LTM is caused by differences in earlier processing stages, such as encoding of ingroup and outgroup faces. We test this hypothesis by exploring whether the ORE can already be observed in visual working memory (VWM)—an intermediate system located between encoding processes and LTM storage. In four independent experiments, we observed decreased performance for outgroup faces compared to ingroup faces using three different VWM tasks: an adaptive N-back task, a self-ordered pointing task, and a change detection task. Also, we found that the number of items stored in VWM is smaller for outgroup faces than for ingroup faces. Further, we explored whether performance differences in the change detection task are related to the classic ORE in recognition memory. Our results provide further evidence that the ORE originates during earlier stages of cognitive processing. We discuss that (how) future ORE research may benefit from considering theories and evidence from the VWM literature.     

A facilitative effect of negative affective valence on working memory

Gotoh, F., Kikuchi, T. &Olofsson, U. (2010). A facilitative effect of negative affective valence on working memory. Scandinavian Journal of Psychology, 51, 185–191. Previous studies have shown that negatively valenced information impaired working memory performance due to an attention‐capturing effect. The present study examined whether negative valence could also facilitate working memory. Affective words (negative, neutral, positive) were used as retro‐cues in a working memory task that required participants to remember colors at different spatial locations on a computer screen. Following the cue, a target detection task was used to either shift attention to a different location or keep attention at the same location as the retro‐cue. Finally, participants were required to discriminate the cued color from a set of distractors. It was found that negative cues yielded shorter response times (RTs) in the attention‐shift condition and longer RTs in the attention‐stay condition, compared with neutral and positive cues. The results suggest that negative affective valence may enhance working memory performance (RTs), provided that attention can be disengaged.     

The effects of divided attention on encoding processes in memory: mapping the locus of interference.

Despite the detrimental effects of divided attention at encoding on later memory performance, results described in the literature do not unequivocally specify which processes are interrupted during encoding by participants' occupation with a concurrent task. Using a processing analysis framework where the encoding process is viewed as a multiphase mental activity, the current research investigated this issue using a new differential temporal interference paradigm where the study phase of single words was interrupted at different temporal segments. In two experiments, we used performance on both memory and online choice reaction time tasks to assess whether such differential interference would produce different degrees of reduction in participants' later memory performance, as well as changes in the attentional resources required to execute each of the encoding phases. Measures of memory and concurrent task performance in the two experiments converged on similar patterns, showing that all phases of encoding are affected by the concurrent task. However, the initial encoding phase, which is tentatively associated with the initial registration of information, seems especially vulnerable to interference.     

Two good reasons to say ‘change!’ – ensemble representations as well as item representations impact standard measures of VWM capacity

Visual working memory (VWM) is a central bottleneck in human information processing. Its capacity is most often measured in terms of how many individual‐item representations VWM can hold (k). In the standard task employed to estimate k, an array of highly discriminable colour patches is maintained and, after a short retention interval, compared to a test display (change detection). Recent research has shown that with more complex, structured displays, change‐detection performance is, in addition to individual‐item representations, supported by ensemble representations formed as a result of spatial subgroupings. Here, by asking participants to additionally localize the change, we reveal indication for an influence of ensemble representations even in the very simple, unstructured displays of the colour‐patch change‐detection task. Critically, pure‐item models from which standard formulae of k are derived do not consider ensemble representations and, therefore, potentially overestimate k. To gauge this overestimation, we develop an item‐plus‐ensemble model of change detection and change localization. Estimates of k from this new model are about 1 item (~30%) lower than the estimates from traditional pure‐item models, even if derived from the same data sets.     

Timing in a dual-task in children and adults: when the interference effect is higher with concurrent non-temporal than temporal information

This study used a dual task with participants of different levels of cognitive capacities, assessed with neuropsychological tests, to examine the attentional cost on time judgment of processing concurrent temporal and non-temporal information. Children and adults performed a temporal reproduction task with either an interfering temporal or non-temporal discrimination task. The results showed an underestimation of time in the dual task compared to the single task, the extent of which was directly linked to individual attentional capacities. However, the non-temporal task interfered more than the temporal task on the reproduced durations. Nonetheless, the temporal reproduction task equally affected performance in the non-temporal and the temporal discrimination task. These results reveal the predominant role of the cost of dual-tasking in interference effects on time judgment, and the lesser role of concurrent information, especially of temporal information. This suggests a lack of competition for attentional resources in the processing of multiple durations.     

Development of visual working memory precision in childhood

Visual working memory (VWM) is the facility to hold in mind visual information for brief periods of time. Developmental studies have suggested an increase during childhood in the maximum number of complete items that can simultaneously be stored in VWM. Here, we exploit a recent theoretical and empirical innovation to investigate instead the precision with which items are stored in VWM, where precision is a continuous measure reflecting VWM resolution. Ninety boys aged 7 to 13 years completed one-item and three-item VWM tasks in which stimuli were coloured bars varying in orientation. On each trial, participants used a rotating dial to reproduce the probed stimulus from memory. Results show linear age-related improvement in recall precision for both one-item and three-item VWM tasks. However, even the youngest age group stored a significant amount of information about all three items on the difficult 3-item VWM task. Importantly, the development of VWM precision was not accounted for by development on a sensorimotor control task. Whereas storage of a single complete item was previously thought to be well within the capacity limitations of the current age range, these results suggest protracted development during childhood and early adolescence in the resolution with which single and multiple items are stored in VWM. Probabilistic modelling of response distribution data suggests that improvement in VWM performance is attributable to a specific decrease in variability of stored feature representations, rather than to a decrease in misbinding or random noise. As such, we highlight a novel, potentially developmentally plausible mechanism that may underlie developmental improvement in VWM performance, independent of any alterations in the maximum number of complete items which can be stored.     

Exploring the contributions of spatial and non-spatial working memory to priming of pop-out

Priming of pop-out (PoP) refers to the facilitation of performance that occurs when a target-defining feature is repeated across consecutive trials in a pop-out oddball search task. The underlying mechanism of PoP has been poorly understood and raises important questions about how our visual system is guided by past experiences, even during bottom-up processing. Lee, Mozer, and Vecera (Attention, Perception, & Psychophysics, 71, 1059–1071, 2009) demonstrated that PoP remained unaffected by a concurrent non-spatial visual working memory (VWM) load, and they concluded that PoP occurs through feature gain modulation, essentially eliminating the contribution of memory representations in VWM to PoP. In the present study, we followed up on those results by (a) replicating the null effect of non-spatial VWM load on PoP and (b) examining the effect of spatial VWM load on PoP. The results showed that spatial VWM load does interfere with PoP, supporting the notion that spatial VWM is involved in PoP. In Experiment 2, we extended this finding by manipulating VWM load and observing its consequence on the magnitude of PoP. Increasing spatial VWM load decreased the amount of PoP observed, in a dose-dependent manner, whereas changes in non-spatial VWM load did not. Contrary to Lee et al.’s conclusions, these results suggest that VWM resources appear to contribute to the occurrence of PoP, supporting the theory that PoP is, in fact, a multilevel process in which the deployment of spatial attention, relying on VWM representations, plays an important role.     

Time and cognitive load in working memory

According to the time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004), the cognitive load a given task involves is a function of the proportion of time during which it captures attention, thus impeding other attention-demanding processes. Accordingly, the present study demonstrates that the disruptive effect on concurrent maintenance of memory retrievals and response selections increases with their duration. Moreover, the effect on recall performance of concurrent activities does not go beyond their duration insofar as the processes are attention demanding. Finally, these effects are not modality specific, as spatial processing was found to disrupt verbal maintenance. These results suggest a sequential and time-based function of working memory in which processing and storage rely on a single and general purpose attentional resource needed to run executive processes devoted to constructing, maintaining, and modifying ephemeral representations.     

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.     

视觉工作记忆回溯线索效应的产生机制：认知阶段分离

以往研究关于视觉工作记忆回溯线索效应的产生机制主要存在5种假设, 目前依然存在争议。本研究通过改进前人研究实验范式, 采用包含内源性回溯线索的颜色回忆报告范式, 进一步对这5种假设进行检验。在实验1中, 我们调控了线索与探测阵列之间的时间间隔, 发现不同时间间隔不影响无线索条件的行为表现, 而在正常线索条件中被试的记忆精度以及能记住的项目数量均优于无线索条件; 在实验2中, 我们对回溯线索伴随的干扰刺激类型进行控制, 结果显示, 在不同条件下记忆精度不存在差别, 但当回溯线索伴随干扰刺激呈现时, 被试能记住的项目数量会被降低, 降低程度受干扰刺激的类型调制; 在实验3中, 我们对伴随回溯线索的干扰刺激的呈现时间进行控制, 发现虽然回溯线索效应仍然存在, 但干扰刺激的呈现时间不会影响效应程度。研究结果表明, 回溯线索的出现使得被试能够在决策加工前完成内部注意资源的再分配, 从而避免了同时进行这两种认知加工与记忆表征维持本身竞争认知资源。本研究为认知阶段分离假设提供了支持证据, 对解决回溯线索效应产生机制的争议以及理解内部注意与视觉工作记忆的关系有重要意义。     

Study of a cognitive effects model in Dohsa‐hou for the elderly

This study investigates the primary factors responsible for cognitive performance improvements as a result of dohsa‐hou (Japanese body‐oriented psychotherapy) for the elderly. The study divided participants into two homogeneous groups: an experimental group that attempted to improve upright balance by performing dohsa‐hou, and a control group to establish the drop‐off period for the effect of performing the given activities. The task processing time of Stroop Test and body sway and the situational anxiety during task processing of Stroop Tests were measured before and after the dohsa‐hou and drop‐off period. The results confirm that only the experimental group improved in body sway, had a shorter Stroop Color Test processing time and lower situational anxiety. From this study, it has been identified that: (a) information‐processing capacities spared for posture control are affected by distribution of processing resources towards solving other cognitive tasks; and (b) the effect of the release of attention from threat‐related information due to a decrease in attentional bias, which accompanied the decrease in situational anxiety, are primary factors in improving cognitive task performance.     

Implicit Affect Primes Effort: Basic Processes,Moderators, and Boundary Conditions

This article informs about the implicit‐affect‐primes‐effort (IAPE) model – a theory on the impact of implicit affect on resource mobilization – and research testing this account. Beside basic influences of implicitly processed affective stimuli on behavior, this article highlights moderators and boundary conditions of this process. The IAPE model posits that affect primes implicitly activate mental representations of affective states containing information about performance ease and difficulty. This influences subjective task demand during performance, which determines effort. A series of experiments assessing implicit affect's impact on effort‐related cardiovascular response in cognitive tasks revealed replicated support for the IAPE model. Moreover, objective task difficulty and incentive moderated the effect of implicit affect on effort, and especially controlled processing of affect primes and activated concepts turned out to be boundary conditions.     

Concurrent cognitive task modulates coordination dynamics

Does a concurrent cognitive task affect the dynamics of bimanual rhythmic coordination? In‐phase coordination was performed under manipulations of phase detuning and movement frequency and either singly or in combination with an arithmetic task. Predicted direction‐specific shifts in stable relative phase from 0° due to detuning and movement frequency were amplified by the cognitive task. Nonlinear cross‐recurrence analysis suggested that this cognitive influence on the locations of the stable points or attractors of coordination entailed a magnification of attractor noise without a reduction in attractor strength. An approximation to these findings was achieved through parameter changes in a motion equation in relative phase. Results are discussed in terms of dual‐task performance as limited resources, dynamics rather than chronometrics, and reparameterization rather than degradation.     

Acute aerobic exercise and information processing: energizing motor processes during a choice reaction time task

The immediate and short-term after effects of a bout of aerobic exercise on young adults’ information processing were investigated. Seventeen participants performed an auditory two-choice reaction time (RT) task before, during, and after 40 min of ergometer cycling. In a separate session, the same sequence of testing was completed while seated on an ergometer without pedalling. Results indicate that exercise (1) improves the speed of reactions by energizing motor outputs; (2) interacts with the arousing effect of a loud auditory signal suggesting a direct link between arousal and activation; (3) gradually reduces RT and peaks between 15 and 20 min; (4) effects on RT disappear very quickly after exercise cessation; and (5) effects on motor processes cannot be explained by increases in body temperature caused by exercise. Taken together, these results support a selective influence of acute aerobic exercise on motor adjustment stage.     

视觉工作记忆负载类型对注意选择的影响

通过操纵Flanker任务相对于视觉工作记忆任务的呈现位置, 探讨在视觉工作记忆编码和保持阶段, 精度负载和容量负载对注意选择的影响。行为结果发现, Flanker任务呈现位置和视觉工作记忆负载类型影响注意选择; ERP结果发现, 在保持阶段, 当搜索目标和干扰项不一致时, 负载类型影响N2成分。研究表明, 在编码阶段, 视觉工作记忆负载主要通过占用更多知觉资源降低干扰效应, 支持知觉负载理论; 而在保持阶段, 当Flanker任务位于记忆项内部时, 两类负载在工作记忆表征过程中不同的神经活动导致投入到注意选择的认知控制资源不同, 可能是两类负载影响保持阶段注意选择的机制。