Low Working Memory Capacity Individuals Research Articles

Once established, goal reminders provide long-lasting and cumulative benefits for lower working memory capacity individuals.

Previous research has shown that Stroop effects interact with working memory capacity (WMC) more strongly with lists of mostly congruent items. Although the predominant explanation for this relationship is goal maintenance, some research has challenged whether listwide effects truly reflect goal-maintenance abilities. The current study improved upon previous methodology by using both within-subject and between-subjects manipulations of goal reminder, increasing both the number of trials between reminders and the total length of the task to allow for greater goal neglect, and more precisely maintaining congruency proportion within each block. Participants completed the Automated Operation Span followed by a Stroop task in which they stopped every 24 trials to vocalize either a goal-reminder statement ("name the color not the word") or a nongoal statement ("This is part of my intro to psychology class"). In the within-subject manipulation (Experiment 1), there was no consistent benefit for goal reminders over nongoal statements. However, in the between-subjects manipulation (Experiment 2), results demonstrated a strong benefit of goal reminders, such that goal reminders eliminated the relation between WMC and Stroop effects, whereas that relation was robust following nongoal statements. Moreover, the benefit of receiving goal reminders lasted for at least 24 trials and accumulated across the course of the experiment. These data provide strong evidence that goal reminders eliminate the relationship between WMC and Stroop errors and suggest goal reminders can be a useful intervention for those suffering from lapses in controlled attention. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Once established, goal reminders provide long-lasting and cumulative benefits for lower working memory capacity individuals.

Once established, goal reminders provide long-lasting and cumulative benefits for lower working memory capacity individuals.

On the relation between working memory capacity and the antisaccade task.

Eight experiments (N = 2,003) assessed the relation between working memory capacity (WMC) and performance on the antisaccade task. Experiments 1-5 and 7 examined individual differences in aspects of goal management processes occurring during the preparatory delay of the antisaccade task. WMC tended to interact with delay interval suggesting that high WMC individuals better prepared for the upcoming trial by activating the task goal to a higher level than low WMC individuals (although these effects were generally small). Experiments 3a, 4, and 7 further demonstrated that individual differences in the consistency of attention (i.e., lapses of attention) were partially important for the relation between WMC and antisaccade performance. Experiment 5 demonstrated that knowledge of the likelihood of target location increased overall performance, but did not interact with WMC. Experiment 6 manipulated stimulus onset asynchrony and suggested that speed factors are also likely important for the relation between WMC and antisaccade performance. Finally, structural equation models in Experiment 7 suggested that lapses of attention and speed factors partially accounted for the relation between WMC and antisaccade, but WMC still accounted for unique variance in antisaccade. Collectively, the results suggest that multiple factors (goal activation, consistency of attention, and speed factors) contribute to the relation between variation in WMC and performance on the antisaccade task. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Shared and distinct structure-function substrates of heterogenous distractor suppression ability between high and low working memory capacity individuals

Salient stimuli can capture attention in a bottom-up manner; however, this attentional capture can be suppressed in a top-down manner. It has been shown that individuals with high working memory capacity (WMC) can suppress salient‑but-irrelevant distractors better than those with low WMC; however, neural substrates underlying this difference remain unclear. To examine this, participants with high or low WMC (high-/low-WMC, n = 44/44) performed a visual search task wherein a color singleton item served as a salient distractor, and underwent structural and resting-state functional magnetic resonance imaging scans. Behaviorally, the color singleton distractor generally reduced the reaction time (RT). This RT benefit (ΔRT) was higher in the high-WMC group relative to the low-WMC group, indicating the superior distractor suppression ability of the high-WMC group. Moreover, leveraging voxel-based morphometry analysis, gray matter morphology (volume and deformation) in the ventral attention network (VAN) was found to show the same, positive associations with ΔRT in both WMC groups. However, correlations of the opposite sign were found between ΔRT and gray matter morphology in the frontoparietal (FPN)/default mode network (DMN) in the two WMC groups. Furthermore, resting-state functional connectivity analysis centering on regions with a structural-behavioral relationship found that connections between the left orbital and right superior frontal gyrus (hubs of DMN and VAN, respectively) was correlated with ΔRT in the high-WMC group (but not in the low-WMC group). Collectively, our work present shared and distinct neuroanatomical substrates of distractor suppression in high- and low-WMC individuals. Furthermore, intrinsic connectivity of the brain network hubs in high-WMC individuals may account for their superior ability in suppressing salient distractors.

The influence of working memory capacity and lapses of attention for variation in error monitoring.

In two experiments, individual differences in working memory capacity (WMC), lapses of attention, and error monitoring were examined. Participants completed multiple WMC tasks along with a version of the Stroop task. During the Stroop, pupil diameter was continuously monitored. In both experiments, error phasic pupillary responses were larger than phasic pupillary responses associated with correct incongruent and correct congruent trials. WMC and indicators of lapses of attention were correlated with error pupillary response, suggesting that high WMC and low lapse individuals had enhanced error monitoring abilities compared with low WMC and high lapse individuals. Furthermore, in Experiment 2 error awareness abilities were associated with WMC, lapses of attention, and the error phasic pupillary responses. Importantly, individual differences in the susceptibility to lapses of attention largely accounted for the relationship between WMC and error monitoring in both experiments. Collectively, these results suggest that WMC is related to error monitoring abilities, but this association is largely due to individual differences in the ability to consistently maintain task engagement and avoid lapses of attention.

Supplemental Material for Once Established, Goal Reminders Provide Long-Lasting and Cumulative Benefits for Lower Working Memory Capacity Individuals

Supplemental Material for Once Established, Goal Reminders Provide Long-Lasting and Cumulative Benefits for Lower Working Memory Capacity Individuals

Individual differences in working memory capacity moderate effects of post-learning activity on memory consolidation over the long term

Similar to sleeping after learning, a brief period of wakeful resting after encoding new information supports memory retention in contrast to task-related cognition. Recent evidence suggests that working memory capacity (WMC) is related to sleep-dependent declarative memory consolidation. We tested whether WMC moderates the effect of a brief period of wakeful resting compared to performing a distractor task subsequent to encoding a word list. Participants encoded and immediately recalled a word list followed by either an 8 min wakeful resting period (eyes closed, relaxed) or by performing an adapted version of the d2 test of attention for 8 min. At the end of the experimental session (after 12–24 min) and again, after 7 days, participants were required to complete a surprise free recall test of both word lists. Our results show that interindividual differences in WMC are a central moderating factor for the effect of post-learning activity on memory retention. The difference in word retention between a brief period of wakeful resting versus performing a selective attention task subsequent to encoding increased in higher WMC individuals over a retention interval of 12–24 min, as well as over 7 days. This effect was reversed in lower WMC individuals. Our results extend findings showing that WMC seems not only to moderate sleep-related but also wakeful resting-related memory consolidation.

Precrastination and individual differences in working memory capacity.

When ordering tasks, people tend to first perform the task that can be started or completed sooner (precrastination) even if it requires more physical effort. Evidence from transport tasks suggests that precrastination can reduce cognitive effort and will likely not occur if it increases cognitive effort. However, some individuals precrastinate even when it increases cognitive effort. We examined whether individual differences in working memory capacity (WMC) influence this suboptimal choice. Participants retrieved two cups of water along a corridor, in the order of their choosing. We measured the frequency of choosing the close cup first (precrastination) while varying water levels in each cup (attention demand) located at different distances. Results showed that the tendency to select the far cup first (avoid precrastination) increases when the close cup is full (high attention demand) vs. not full (low attention demand). Post-hoc results showed high (vs. low) WMC individuals more frequently bypass decisions with relatively higher costs of cognitive effort, avoiding precrastination when the attentional demand of carrying the close (vs. far) cup is relatively high (close-cup full and far-cup half full), but not when it is relatively low (far-cup full). However, there was no evidence that WMC could explain why some individuals always precrastinated, at costs of cognitive effort. Instead, individuals who always precrastinated reported automatic behavior, and those who avoided precrastinating reported decisions of efficiency. Learning, the relationship between precrastination and tendencies to enjoy/engage in thinking or procrastinate, and evidence that precrastination required more cognitive effort in our task, are discussed.

Working memory capacity and sustained attention: A cognitive-energetic perspective.

A cognitive-energetic account of individual differences in working memory capacity (WMC) and sustained attention performance is proposed suggesting that variation in the voluntary control of the intensity of attention (intrinsic alertness) is critical for the relation between WMC and attention control. Four experiments examining individual differences were conducted to test this account. The results suggested that WMC was consistently related to the slowest reaction times in conditions where the interstimulus interval (ISI) was varied or was fixed at a long interval. Variation in WMC was not related to performance when the ISI was fixed at a short interval which is thought to decrease demands on intrinsic alertness. The current results are consistent with the hypothesis that normal variation in WMC and sustained attention performance are partially the result of individual differences in intrinsic alertness whereby low WMC individuals are less able to consistently control the intensity of attention than high WMC individuals. Other possible reasons for the relation between WMC and sustained attention performance such as differences in goal activation, speed of goal activation, goal maintenance during a trial, or sustaining goal maintenance across the duration of the task were associated with weaker and inconsistent evidence. Collectively we suggest that the current cognitive-energetic account can be used to understand individual differences in WMC and attention control and their relations with other cognitive abilities. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Individual differences in working memory capacity and long-term memory: The influence of intensity of attention to items at encoding as measured by pupil dilation

Abstract The present study used pupil dilation as an index of the intensity of attention to determine if variation in attention at encoding partially accounts for the relation between working memory capacity (WMC) and long-term memory (LTM). In Experiment 1, participants completed a delayed free recall task while pupil dilation was simultaneously recorded. Results revealed high WMC individuals displayed an increase in pupil dilation across serial positions, whereas low WMC individuals exhibited a decline in pupil dilation. Experiment 2 employed a similar method but manipulated encoding conditions via value–directed remembering. Results demonstrated when later serial positions were labeled as more important, the pupillary response no longer declined for low WMC individuals. Instead, low WMC individuals increased attention across serial positions, with the caveat being that these individuals devoted less attention than high WMC individuals to all items under these conditions. Overall, results support the notion that high WMC individuals outperform low WMC individuals in delayed free recall, which is partly explained by the amount of attention devoted to items at encoding.

Working memory and attentional bias on reinforcing efficacy of food

Reinforcing efficacy of food, or the relationship between food prices and purchasing, is related to obesity status and energy intake in adults. Determining how to allocate resources for food is a decision making process influenced by executive functions. Attention to appetitive cues, as well as working memory capacity, or the ability to flexibly control attention while mentally retaining information, may be important executive functions involved in food purchasing decisions. In two studies, we examined how attention bias to food and working memory capacity are related to reinforcing efficacy of both high energy-dense and low energy-dense foods. The first study examined 48 women of varying body mass index (BMI) and found that the relationship between attentional processes and reinforcing efficacy was moderated by working memory capacity. Those who avoid food cues and had high working memory capacity had the lowest reinforcing efficacy, as compared to those with low working memory capacity. Study 2 systematically replicated the methods of study 1 with assessment of maintained attention in a sample of 48 overweight/obese adults. Results showed the relationship between maintained attention to food cues and reinforcing efficacy was moderated by working memory capacity. Those with a maintained attention to food and high working memory capacity had higher reinforcing efficacy than low working memory capacity individuals. These studies suggest working memory capacity moderated the relationship between different aspects of attention and food reinforcement. Understanding how decision making process are involved in reinforcing efficacy may help to identify future intervention targets.

A locus coeruleus-norepinephrine account of individual differences in working memory capacity and attention control.

Studies examining individual differences in working memory capacity (WMC) have suggested that low WMC individuals have particular deficits in attention control processes compared to high WMC individuals. In the current article we suggest that part of the WMC-attention control relation is due to variation in the functioning of the locus coeruleus-norepinephrine system (LC-NE). Specifically, we suggest that because of dysregulation of LC-NE functioning, the fronto-parietal control network for low WMC individuals is only weakly activated, resulting in greater default-mode network activity (and greater mind-wandering) for low WMC individuals compared to high WMC individuals. This results in disrupted attention control and overall more erratic performance (more lapses of attention) for low WMC individuals than for high WMC individuals. This framework is used to examine previous studies of individual differences in WMC and attention control, and new evidence is examined on the basis of predictions of the framework to pupillary responses as an indirect marker of LC-NE functioning.

Working Memory Capacity, Visual Attention and Hazard Perception in Driving

In two experiments we explored the influence of individual differences in working memory capacity (WMC) on hazard perception performance in a simulated driving task. In Experiment 1, we examined the relationship between WMC and hazard perception performance under control and dual task conditions, and self-reported driving behavior. Results revealed significant relationships between WMC, hazard perception performance and self-reported driving behavior. Participants lower in WMC performed poorer in dual task conditions and reported more instances of inattention when driving. In Experiment 2, we explored the gaze behavior of low and high WMC individuals whilst completing the hazard perception test under control and dual task conditions. Results revealed that low-WMC individuals had poorer hazard perception performance under dual task conditions and these performance decrements were mirrored in reductions in mean fixation durations on the hazard. Interestingly, pupillary dilation appears to discriminate between low- and high-WMC individuals and might be a useful index of attention for future research.

Differently confident: Susceptibility to bias in perceptual judgments of size interacts with working memory capacity.

Much prior research has shown that retrieval of information from long-term memory (LTM) can influence many aspects of complex cognition in situ. However, research also has shown that not all individuals manage information retrieved from LTM in equivalent fashions. Specifically, high working memory capacity (WMC) individuals have been shown to be better able to manage not only what information is retrieved from LTM, but also whether it is applied to the task-at-hand. As such, it is likely that WMC will interact with the biasing influences of prior knowledge on current task performance. In this series of studies, high and low WMC individuals were asked to make perceptual judgments of size that either did or did not activate biasing prior knowledge. Results indicate that when retrieving information from LTM, high WMC individuals are actually more susceptible to perceptual bias and also are erroneously more confident in the accuracy of their response. However, when no retrieval from LTM is necessary, this effect reverses. This suggests that high WMC individuals are indeed able to inhibit such biasing information; however, their overconfidence in the quality of information retrieved from their own LTM can make them susceptible to making errors in perceptual judgments.

The rostral prefrontal cortex underlies individual differences in working memory capacity: An approach from the hierarchical model of the cognitive control

Neuroimaging and behavioral evidence has suggested that the lateral prefrontal cortex is involved in individual differences in working memory capacity (WMC). However, few studies have localized the neural structures that differentiate high and low WMC individuals, considering the functional architecture of the prefrontal cortex. The present study aimed to identify a frontal region that underlies individual differences from the perspective of the hierarchical architecture of the frontal cortex. By manipulating an episodic factor of cognitive control (control in selecting an appropriate task set according to a temporal context) and using a parametric modulation analysis, we found that both high- and low- WMC individuals have similar activation patterns in the premotor cortex (BA6, 8), caudal prefrontal cortex (BA44, 45), and frontopolar cortex (BA10, 11), but differed in the rostral part of the prefrontal cortex (BA46/47); high WMC individuals showed greater activation in the higher episodic control condition, whereas low WMC individuals showed reduced activation when episodic control was required. Similar patterns of activation were found in the right inferior parietal and middle/inferior temporal cortices. These results indicate that the rostral prefrontal cortex, which supports episodic cognitive control, possibly by sending a weighting signal toward the inferior parietal and middle/inferior temporal cortices that modulate saliency and sensory processing, underlies individual differences in WMC. Episodic control account, which considers the organization of the prefrontal cortex, fits well with previous findings of individual differences in WMC.

P600 Dominance Predicts Comprehension of Garden-Path Sentences

P600 Dominance Predicts Comprehension of Garden-Path Sentences

High Working Memory Capacity Predicts Less Retrieval Induced Forgetting

BackgroundWorking Memory Capacity (WMC) is thought to be related to executive control and focused memory search abilities. These two hypotheses make contrasting predictions regarding the effects of retrieval on forgetting. Executive control during memory retrieval is believed to lead to retrieval induced forgetting (RIFO) because inhibition of competing memory traces during retrieval renders them temporarily less accessible. According to this suggestion, superior executive control should increase RIFO. Alternatively, superior focused search abilities could diminish RIFO, because delimiting the search set reduces the amount of competition between traces and thus the need for inhibition. Some evidence suggests that high WMC is related to more RIFO, which is inconsistent with the focused search hypothesis.Methodology/Principal FindingsUsing the RIFO paradigm, we created distinct and overlapping categories to manipulate the amount of competition between them. This overlap increased competition between some categories while exclusive use of weak exemplars ensured negligible effects of output interference and integration.Low WMC individuals exhibited RIFO within and between overlapping categories, indicating the effect of resolving competition during retrieval. High WMC individuals only exhibited between-category RIFO, suggesting they experienced reduced competition resolution demands. Low WMC Individuals exhibited the strongest RIFO and no retrieval benefits when interference resolution demands were high.Conclusions/SignificanceOur findings qualify the inhibitory explanation for RIFO by incorporating the focused search hypothesis for materials that are likely to pose extraordinary challenges at retrieval. The results highlight the importance of considering individual differences in retrieval-induced effects and qualify existing models of these effects.

Focusing on Attention: The Effects of Working Memory Capacity and Load on Selective Attention

BackgroundWorking memory (WM) is imperative for effective selective attention. Distractibility is greater under conditions of high (vs. low) concurrent working memory load (WML), and in individuals with low (vs. high) working memory capacity (WMC). In the current experiments, we recorded the flanker task performance of individuals with high and low WMC during low and high WML, to investigate the combined effect of WML and WMC on selective attention.Methodology/Principal FindingsIn Experiment 1, distractibility from a distractor at a fixed distance from the target was greater when either WML was high or WMC was low, but surprisingly smaller when both WML was high and WMC low. Thus we observed an inverted-U relationship between reductions in WM resources and distractibility. In Experiment 2, we mapped the distribution of spatial attention as a function of WMC and WML, by recording distractibility across several target-to-distractor distances. The pattern of distractor effects across the target-to-distractor distances demonstrated that the distribution of the attentional window becomes dispersed as WM resources are limited. The attentional window was more spread out under high compared to low WML, and for low compared to high WMC individuals, and even more so when the two factors co-occurred (i.e., under high WML in low WMC individuals). The inverted-U pattern of distractibility effects in Experiment 1, replicated in Experiment 2, can thus be explained by differences in the spread of the attentional window as a function of WM resource availability.Conclusions/SignificanceThe current findings show that limitations in WM resources, due to either WML or individual differences in WMC, affect the spatial distribution of attention. The difference in attentional constraining between high and low WMC individuals demonstrated in the current experiments helps characterise the nature of previously established associations between WMC and controlled attention.

Why does working memory capacity predict RAPM performance? A possible role of distraction

Current theories concerning individual differences in working memory capacity (WMC) suggest that WMC reflects the ability to control the focus of attention and resist interference and distraction. The current set of experiments tested whether susceptibility to distraction is partially responsible for the established relationship between performance on complex span tasks and the Raven's Advanced Progressive Matrices (RAPM). This hypothesis was examined by manipulating the level of distraction among the incorrect responses contained in RAPM problems, by varying whether the response bank included the most commonly selected incorrect response. When entered hierarchically into a regression predicting a composite score on span tasks, items with highly distracting incorrect answers significantly improved the predictive power of a model predicting an individual's WMC, compared to the model containing only items with less distracting incorrect responses. Additional analyses were performed examining the types of errors that were made. A second experiment used eye-tracking to demonstrate that these effects seem to be rooted in differences in susceptibility to distraction as well as strategy differences between high and low WMC individuals. Results are discussed in terms of current theories about the role of attentional control in performance on general fluid intelligence tasks.

Parietal Contributions to Visual Working Memory Depend on Task Difficulty

The nature of parietal contributions to working memory (WM) remain poorly understood but of considerable interest. We previously reported that posterior parietal damage selectively impaired WM probed by recognition (Berryhill and Olson, 2008a). Recent studies provided support using a neuromodulatory technique, transcranial direct current stimulation (tDCS) applied to the right parietal cortex (P4). These studies confirmed parietal involvement in WM because parietal tDCS altered WM performance: anodal current tDCS improved performance in a change detection task, and cathodal current tDCS impaired performance on a sequential presentation task. Here, we tested whether these complementary results were due to different degrees of parietal involvement as a function of WM task demands, WM task difficulty, and/or participants’ WM capacity. In Experiment 1, we applied cathodal and anodal tDCS to the right parietal cortex and tested participants on both previously used WM tasks. We observed an interaction between tDCS (anodal, cathodal), WM task difficulty, and participants’ WM capacity. When the WM task was difficult, parietal stimulation (anodal or cathodal) improved WM performance selectively in participants with high WM capacity. In the low WM capacity group, parietal stimulation (anodal or cathodal) impaired WM performance. These nearly equal and opposite effects were only observed when the WM task was challenging, as in the change detection task. Experiment 2 probed the interplay of WM task difficulty and WM capacity in a parametric manner by varying set size in the WM change detection task. Here, the effect of parietal stimulation (anodal or cathodal) on the high WM capacity group followed a linear function as WM task difficulty increased with set size. The low WM capacity participants were largely unaffected by tDCS. These findings provide evidence that parietal involvement in WM performance depends on both WM capacity and WM task demands. We discuss these findings in terms of alternative WM strategies employed by low and high WM capacity individuals. We speculate that low WM capacity individuals do not recruit the posterior parietal lobe for WM tasks as efficiently as high WM capacity individuals. Consequently, tDCS provides greater benefit to individuals with high WM capacity.