Concurrent Working Memory Load Research Articles

Learned switch readiness via concurrent activation of task sets: Evidence from task specificity and memory load.

Cognitive flexibility increases when switch demands increase. In task switching experiments, repeated pairing of flexibility-demanding situations with specific contexts leads subjects to become more prepared to adapt to changing task demands in those contexts. One form of such upregulated cognitive flexibility has been demonstrated with a list-wide switch probability (LWSP) effect, where switch costs are smaller in lists with frequent switches than in lists with rare switches. According to a recent proposal, the LWSP effect is supported by a concurrent activation mechanism whereby both task rules are kept available simultaneously in working memory. We conducted four experiments to test two key features in this concurrent activation account of LWSP effects. First, we asked whether the LWSP effects are limited to only the trained tasks, and second, we asked whether concurrent working memory load would reduce the LWSP effects. In Experiment 1, we replicated and extended previous findings that the LWSP manipulation modulates both performance (switch costs) and voluntary switch rates, indicating that context-driven increases in flexibility are generalizable so long as the task-sets remain the same. Results of Experiments 2 and 3 showed that novel tasks do not benefit from the concurrent activation of the two other tasks, suggesting that the LWSP effect is task specific. Experiment 4 showed that holding additional information in working memory reduces the LWSP effect. While these findings support the hypothesis of concurrent activation underlying the increased flexibility in the LWSP effect, caveats remain; additional research is needed to further test this account.

Mental workload modulates the effects of baroreceptor afferents on sensorimotor processing

The heart–brain interaction is the main mechanism for maintaining normative physiological processes, and its dysregulation underlies the somatic symptoms of various mental disorders. Cortical inhibition, triggered by afferent signals from baroreceptor activation, induces systematic variations in sensorimotor responses within a cardiac cycle, with reaction times (RTs) slower at cardiac systole compared to diastole (known as cardiac cycle time effects). However, recent data suggest that baroreceptor afferents not only inhibit simple responses but also facilitate complex sensorimotor responses during cardiac systole. The mental workload that is implicated in complex responses may modulate the cardiac cycle time effects. The current study aimed to examine whether concurrent mental workloads influenced cardiac cycle time effects on sensorimotor processing. Using a dual-task paradigm, 47 participants (32 female; age = 21.9 ± 2.1 years) performed a choice RT task and a working memory (WM) task. Stimuli were presented during either cardiac systole or diastole. RT data were fitted using the ex-Gaussian distribution, and the parameters, mu and tau, were derived to indicate response speed and high-order attentional processes, respectively. The behavioral data were submitted to 2 (WM load) × 2 (cardiac timing) repeated measures analyses of variances. The results indicated that RT metrics were longer during cardiac systole than diastole under the no-load condition. However, WM load reversed the cardiac timing effects on response speed while inducing more attentional lapses. These findings suggest that concurrent WM load influences cardiac cycle time effects on sensorimotor processing via top-down resources.

Experience of regret is unaffected by concurrent working memory load

Background When facing the consequences of decisions, people often experience evaluative emotions such as regret. The experience of regret is the result of the comparison between the actual outcome of one’s actions and a better counterfactual outcome that could have occurred had one acted differently in the past. Despite increasing interest in counterfactual thinking and regret, little is known about the type of cognitive processes involved with regret –whether it is underpinned by reflective or intuitive processes. The extant literature provides contradictory evidence: theoretical assertions and developmental work point towards reflective processes, requiring access to capacity-limited cognitive resources whereas, some experimental and neuroscientific evidence point towards intuitive processes. Methods In the current study, adults (N = 20) completed a commonly used gambling task known to elicit regret under high or low working memory load. Results Ratings of regret were not affected by concurrent working memory load (Bayes Factors provided strong evidence for the null hypothesis). Conclusions We conclude that the experience of regret in a commonly used gambling task is unaffected by concurrent working memory load. This suggests that, in adults, regret is not always reliant on reflective cognitive processes and does not require access to central cognitive resources.

Is the alerting-congruency interaction that is seen in experiments with stimulus-response motor associations moderated by a concurrent working-memory load?

The mechanisms underlying attention, distraction, and cognitive control have been widely studied, and results consistently show that reaction times are affected by alerting cues as well as by concurrent distraction. In addition, when distractors have pre-existing directional motor associations, alerting and distractor congruency interact in a manner where distractors have a larger effect when people are alerted to an upcoming target relative to when people are not alerted to the target's presentation. However, does a concurrent working memory load moderate this interaction in multitasking experiments, and if so, does it magnify or suppress this effect? The current study (N = 40) finds that although a memory-load significantly slows reaction times it does not moderate the alerting-congruency interaction. Discussion focuses on theoretical and applied implications of this empirical result.

Inhibition continues to guide search under concurrent visual working memory load.

It is well known that attention can be automatically attracted to salient items. However, recent studies show that it is possible to avoid distraction by a salient item (with a known feature), leading to facilitated search. This article tests a proposed mechanism for distractor inhibition: that a mental representation of the distractor feature held in visual working memory (VWM) allows attention to be guided away from the distractor. We tested this explanation by examining color-based inhibition in visual search for a shape target with and without VWM load. In Experiment 1 the presence of a distractor facilitated visual search under low and high VWM loads, as reflected in faster response times when the distractor was present (compared to absent), and in fewer eye movements to the salient distractor than the non-target items. However, the eye movement inhibition effect was noticeably weakened in the load conditions. Experiment 2 explored further, to distinguish between inhibition of the distractor color and activation of the (irrelevant) target color. Intermittently presenting single-color search trials that contained only either a target, distractor or a neutral-colored singleton revealed that the distractor color attracted attention less than the neutral color with and without VWM load. The target color, however, only attracted attention more than neutral colors under no load, whereas a VWM load completely eliminated this effect. This suggests that although VWM plays a role in guiding attention to the (irrelevant) target color, distractor-feature inhibition can operate independently.

The art of planning ahead: When do we prepare for the future and when is it effective?

Preparing for the future during ongoing activities is an essential skill. Yet it is currently unclear to what extent we can prepare for the future in parallel with another task. In two experiments, we investigated how characteristics of a present task influenced whether and when participants prepared for the future, as well as its usefulness. We focused on the influence of concurrent working memory load, assuming that working memory would interfere most strongly with preparation. In both experiments, participants performed a novel sequential dual-task paradigm, in which they could voluntarily prepare for a second task while performing a first task. We identified task preparation by means of eye tracking, by detecting when participants switched their gaze to information about the second task while performing the first task. The results showed that participants prepared, but also that there were large individual differences in how often they did so. When participants prepared, it was productive, as evidenced by faster RTs on the second task and only a small cost to the present task. The probability of preparation and its productiveness decreased with increases in the difficulty of the first task. In particular, we found that working memory load from the first task interfered with preparation. We conclude from our study that people can productively prepare for the future while performing an ongoing task, and that it is possible to track this preparation process empirically. In addition, we conclude that working memory resources play an important role in task preparation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Resting heart rate variability modulates the effects of concurrent working memory load on affective startle modification.

Vagally mediated heart rate variability (vmHRV) is thought to index top-down control processes in emotion regulation. According to the Generalized Unsafety Theory of Stress (GUTS), resting vmHRV indexes top-down resources that are needed to inhibit subcortical threat circuits, which is important for context-appropriate affective responding. Although this notion has been supported by studies of affective startle (SR) modification, direct evidence that top-down resources are the linking mechanism between vmHRV and context-appropriate affective responding has been lacking. To investigate this possible mechanism, college-aged participants (n=92) were recruited to complete a picture viewing task and a concurrent working memory (WM) task. Concurrent WM load was manipulated, and the auditory SR stimulus was delivered while viewing affective pictures. Electrocardiography and electromyography were recorded to assess vmHRV and SR eyeblink, respectively. Results showed that WM load attenuated affective SR modification. As expected, the attenuating effects of load on affective SR modification were stronger among low vmHRV relative to high vmHRV individuals, indicating that vmHRV is linked to context-appropriate affective responding through the mechanism of top-down resources. These results support the GUTS and suggest that atypical affective responding among low vmHRV individuals is attributed to the lack of WM resources. Our findings highlight the relation between vmHRV and top-down resources that have been implicated in emotion regulation and contribute to a better understanding of emotion dysregulation in psychopathology.

Concurrent visual working memory bias in sequential integration of approximate number

Previous work has shown bidirectional crosstalk between Working Memory (WM) and perception such that the contents of WM can alter concurrent percepts and vice versa. Here, we examine WM-perception interactions in a new task setting. Participants judged the proportion of colored dots in a stream of visual displays while concurrently holding location- and color information in memory. Spatiotemporally resolved psychometrics disclosed a modulation of perceptual sensitivity consistent with a bias of visual spatial attention towards the memorized location. However, this effect was short-lived, suggesting that the visuospatial WM information was rapidly deprioritized during processing of new perceptual information. Independently, we observed robust bidirectional biases of categorical color judgments, in that perceptual decisions and mnemonic reports were attracted to each other. These biases occurred without reductions in overall perceptual sensitivity compared to control conditions without a concurrent WM load. The results conceptually replicate and extend previous findings in visual search and suggest that crosstalk between WM and perception can arise at multiple levels, from sensory-perceptual to decisional processing.

A concurrent working memory load does not necessarily impair spatial attention: Evidence from inhibition of return

ABSTRACT Inhibition of return (IOR), an inhibitory aftereffect of attentional orienting, usually reveals itself in slower responses to targets appearing at previously attended locations in spatial cueing tasks. Many of the neural substrates underlying visual working memory are also closely linked to attention. The present study examined whether the contents held in working memory interfere with IOR by requiring participants to keep a set of spatial locations in working memory while they performed a spatial cueing task. Results revealed that the presence of a concurrent working memory load modulated IOR when the cueing task involved saccadic responses (Experiment 4), but not when more resource-demanding responses were required in the cueing task (Experiments 1–3). The present study also revealed that working memory load had little effect on the time course of IOR. We suggest that the attentional control setting (ACS) selected to accommodate the cognitive tasks at hand determines whether working memory will interfere with IOR and spatial attention in general.

Fake news, fast and slow: Deliberation reduces belief in false (but not true) news headlines.

What role does deliberation play in susceptibility to political misinformation and "fake news"? The Motivated System 2 Reasoning (MS2R) account posits that deliberation causes people to fall for fake news, because reasoning facilitates identity-protective cognition and is therefore used to rationalize content that is consistent with one's political ideology. The classical account of reasoning instead posits that people ineffectively discern between true and false news headlines when they fail to deliberate (and instead rely on intuition). To distinguish between these competing accounts, we investigated the causal effect of reasoning on media truth discernment using a 2-response paradigm. Participants (N = 1,635 Mechanical Turkers) were presented with a series of headlines. For each, they were first asked to give an initial, intuitive response under time pressure and concurrent working memory load. They were then given an opportunity to rethink their response with no constraints, thereby permitting more deliberation. We also compared these responses to a (deliberative) 1-response baseline condition where participants made a single choice with no constraints. Consistent with the classical account, we found that deliberation corrected intuitive mistakes: Participants believed false headlines (but not true headlines) more in initial responses than in either final responses or the unconstrained 1-response baseline. In contrast-and inconsistent with the Motivated System 2 Reasoning account-we found that political polarization was equivalent across responses. Our data suggest that, in the context of fake news, deliberation facilitates accurate belief formation and not partisan bias. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Concurrent working memory load may increase or reduce cognitive interference depending on the attentional set.

Perceptual grouping leads to interference when target and distractors are integrated within the same percept. Cognitive control allows breaking this automatic tendency by focusing selectively on target information. Thus, interference can be modulated either by goal-directed mechanisms or by physical features of stimuli that help to segregate the target from distractors. In three experiments, participants had to respond to the left-right direction of a central arrow, flanked by two arrows on each side. Sometimes, instructions requested to also stay vigilant for detecting an infrequent vertical/horizontal displacement of the target, thus loading working memory. Although it has been usually shown that concurrent working memory load hinders target selection, the present research provides evidence that interference may either increase or decrease depending on whether dual tasking draws attention to the grouping (horizontal displacement) or to an orthogonal dimension (vertical displacement), revealing counterintuitive benefits of working memory load. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Trial-by-Trial Fluctuations in Brain Responses to Stress Predict Subsequent Smoking Decisions That Occur Several Seconds Later

BackgroundTo investigate the neurobiological mechanisms that determine self-regulation of smoking urges when a person encounters stress, we investigated brain network interactions of smoking self-regulation by employing a real-time smoking (nicotine delivery) decision paradigm and a brain-as-predictor neuroimaging approach. MethodsWhile in the functional magnetic resonance imaging scanner, 25 cigarette smokers who abstained from smoking overnight made 200 real smoking decisions regarding whether or not to take a puff of an electronic cigarette during 3 different stress conditions (cognitive stress, emotional stress, and no stress). Cognitive stress was induced by a concurrent working memory load, and emotional stress was induced by manipulating a chance of aversive electric shock. ResultsBehaviorally, both cognitive and emotional stress manipulations increased the probability of making a decision to smoke (i.e., taking a puff). In magnetic resonance imaging trial-by-trial analyses, the dorsolateral prefrontal cortex activity measured at the time of the stress cue significantly predicted future smoking decisions that occurred several seconds later. Furthermore, the influence of dorsolateral prefrontal cortex activity on smoking decisions was mediated by the ventral striatum activity at the time of smoking decisions. ConclusionsOur study demonstrated that brain responses at the time of a stressful moment determine subsequent trial-by-trial smoking decisions by systematically altering brain executive (dorsolateral prefrontal cortex) and reward (ventral striatum) system network activities. Our results further suggest potential translational importance of neuroscientific approaches to predicting self-regulation failures at critical stressful moments.

Concurrent verbal working memory load constrains cross-linguistic translation activation: A visual world eye-tracking study on Hindi–English bilinguals

AbstractDoes a concurrent verbal working memory (WM) load constrain cross-linguistic activation? In a visual world study, participants listened to Hindi (L1) or English (L2) spoken words and viewed a display containing the phonological cohort of the translation equivalent (TE cohort) of the spoken word and 3 distractors. Experiment 1 was administered without a load. Participants then maintained two or four letters (Experiment 2) or two, six or eight letters (Experiment 3) in WM and were tested on backward sequence recognition after the visual world display. Greater looks towards TE cohorts were observed in both the language directions in Experiment 1. With a load, TE cohort activation was inhibited in the L2 – L1 direction and observed only in the early stages after word onset in the L1 – L2 direction suggesting a critical role of language direction. These results indicate that cross-linguistic activation as seen through eye movements depends on cognitive resources such as WM.

Intrusive memories and voluntary memory of a trauma film: Differential effects of a cognitive interference task after encoding.

Methods to reduce intrusive memories (e.g., of traumatic events) should ideally spare voluntary memory for the same event (e.g., to report on the event in court). Single-trace memory accounts assume that interfering with a trace should impact both its involuntary and voluntary expressions, whereas separate-trace accounts assume these two can dissociate, allowing for selective interference. This possibility was investigated in 3 experiments. Nonclinical participants viewed a trauma film followed by an interference task (Tetris game-play after reminder cues). Next, memory for the film was assessed with various measures. The interference task reduced the number of intrusive memories (diary-based, Experiments 1 and 2), but spared performance on well-matched measures of voluntary retrieval—free recall (Experiment 1) and recognition (Experiments 1 and 2)—challenging single-trace accounts. The interference task did not affect other measures of involuntary retrieval—perceptual priming (Experiment 1) or attentional bias (Experiment 2). However, the interference task did reduce the number of intrusive memories in a laboratory-based vigilance-intrusion task (Experiments 2 and 3), irrespective of concurrent working memory load during intrusion retrieval (Experiment 3). Collectively, results reveal a robust dissociation between intrusive and voluntary memories, having ruled out key methodological differences between how these two memory expressions are assessed, namely cue overlap (Experiment 1), attentional capture (Experiment 2), and retrieval load (Experiment 3). We argue that the inability of these retrieval factors to explain the selective interference is more compatible with separate-trace than single-trace accounts. Further theoretical developments are needed to account for this clinically important distinction between intrusive memories and their voluntary counterpart.

Visual working memory load constrains language non-selective activation under task-demands

Abstract Visual world studies with bilinguals have demonstrated spontaneous cross-linguistic activations. In two experiments, we examined whether concurrent visual working memory (VWM) load constrains bilingual parallel activation during spoken word comprehension. Hindi-English bilinguals heard a spoken word in Hindi (L1) or English (L2) and saw a display containing the spoken word-referent, a phonological cohort of the spoken word’s translation and two unrelated objects. Participants completed a concurrent WM task of remembering an array of five coloured squares and judging its similarity with a test array. Participants were asked to click on the spoken word-referent in Experiment 1 but not in Experiment 2. Reduced parallel activation and enhanced target activation was observed under the load for L2 spoken words in Experiment 1 (where the task-demands were high). The findings suggest that a VWM load can constrain the spontaneous activation of an irrelevant lexicon, under certain conditions.

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.

Attention biases in preoccupation with body image: An ERP study of the role of social comparison and automaticity when processing body size

Appearance-related attention biases are thought to contribute to body image disturbances. We investigated how preoccupation with body image is associated with attention biases to body size, focusing on the role of social comparison processes and automaticity. Thirty-six women varying on self-reported preoccupation compared their actual body size to size-modified images of either themselves or a figure-matched peer. Amplification of earlier (N170, P2) and later (P3, LPP) ERP components recorded under low vs. high concurrent working memory load were analyzed. Women with high preoccupation exhibited an earlier bias to larger bodies of both self and peer. During later processing stages, they exhibited a stronger bias to enlarged as well as reduced self-images and a lack of sensitivity to size-modifications of the peer-image. Working memory load did not affect these biases systematically. Current findings suggest that preoccupation with body image involves an earlier attention bias to weight increase cues and later over-engagement with own figure.

Cognitive load during route selection increases reliance on spatial heuristics.

Planning routes from maps involves perceiving the symbolic environment, identifying alternate routes and applying explicit strategies and implicit heuristics to select an option. Two implicit heuristics have received considerable attention, the southern route preference and initial segment strategy. This study tested a prediction from decision-making theory that increasing cognitive load during route planning will increase reliance on these heuristics. In two experiments, participants planned routes while under conditions of minimal (0-back) or high (2-back) working memory load. In Experiment 1, we examined how memory load impacts the southern route heuristic. In Experiment 2, we examined how memory load impacts the initial segment heuristic. Results replicated earlier results demonstrating a southern route preference (Experiment 1) and initial segment strategy (Experiment 2) and further demonstrated that evidence for heuristic reliance is more likely under conditions of concurrent working memory load. Furthermore, the extent to which participants maintained efficient route selection latencies in the 2-back condition predicted the magnitude of this effect. Together, results demonstrate that working memory load increases the application of heuristics during spatial decision making, particularly when participants attempt to maintain quick decisions while managing concurrent task demands.

A concurrent working memory load task does not impair visual selective attention: A meta-analysis

A concurrent working memory load task does not impair visual selective attention: A meta-analysis

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.