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The present studies investigated how three core aspects of executive functioning may be influenced by the presence of depth information. Specifically, participants were assigned to one of three executive functioning tasks: working memory (i.e., a change detection task), selective attention (i.e., a visual search task), or inhibitory control (i.e., a flanker task). For all three tasks, participants completed trials where the items in the display were presented either all in one depth plane or the target item was isolated in depth. For the working memory and selective attention tasks, there was an additional condition where items were evenly distributed across two depth planes. Each task also had multiple levels of difficulty to explore if task conditions influence the effect of depth information. Results indicated that although depth information can improve both working memory and selective attention performance, this benefit is specific to the task difficulty and depth information can even hinder performance under certain circumstances. Depth information did not appear to influence inhibitory control performance. Future work is required to investigate if depth can improve inhibitory control performance, and how/what task conditions influence the benefit of depth information. Until further research is completed, researchers and designers should be cautious when implementing multidimensional (3D) displays, as it remains unclear if the performance benefits of including depth information outweigh the present costs. [ABSTRACT FROM AUTHOR]

The working memory Stroop task is to name the color of a rectangular patch with keypress while holding a color word in working memory. Previous studies using this variant of the Stroop task have shown that congruency between the color patch and the color word significantly affects both color naming and working memory, with the worsening of task performance when the color patch is semantically incongruent rather than congruent with the color word. However, it remains unclear with regard to cognitive mechanisms underlying such congruency effects in the working memory Stroop task. By including a control condition among the congruent and incongruent conditions in a working memory Stroop task, the present study showed that nearly all of the working memory Stroop effect can be facilitation, and that interference, if present, is markedly smaller than facilitation in this form of the Stroop effect. There was also a critical contrast between the working memory and classic Stroop effects in terms of facilitation and interference, with larger facilitation and smaller interference in the working memory Stroop effect than in the classic Stroop effect. Moreover, working memory for a color word can be either facilitated or interfered with by the perceptual judgment (color naming) of an interposed color patch during the retention interval, depending on whether the color patch is semantically congruent or incongruent with the color word. Together, these results suggest that both facilitation and interference mechanisms can contribute to the overall congruency effects in the working memory Stroop task. [ABSTRACT FROM AUTHOR]

Spatial working memory (SWM) refers to a short-term system for temporary manipulation of spatial information and requires the cooperation of multiple brain regions. Despite evidence that the hippocampus (HPC) and prefrontal cortex (PFC) are involved in SWM, how the PFC and HPC interact during SWM remains puzzling. In this study, local field potentials (LFPs) were recorded simultaneously from rat ventral HPC and medial PFC during SWM tasks firstly. A cross-frequency coupling algorithm was used to test for functional connectivity in the PFC and HPC. Granger causality (GC) algorithm was used to test for effective connectivity in the PFC and HPC. Finally, concurrent interactions across two brain regions were analyzed based on functional connectivity and effective connectivity. Experimental results show that the LFPs power in the PFC and HPC decreased during the learning period and peaked before the rats' behavioral selection during SWM. Moreover, the LFPs power mainly distributed in theta and gamma that are related to SWM. In relation to the functional connectivity, the effect of activity transmission during SWM in the PFC and HPC is the same; the phase–amplitude coupling (PAC) between gamma in the PFC and theta in the HPC is correlated with the formation of SWM and supports concurrent interactions between the PFC and HPC. In relation to the effective connectivity, the directed activity transmission in the HPC is greater than that in the PFC during SWM, indicating flow of activity from the HPC to the PFC. [ABSTRACT FROM AUTHOR]

Simultaneous execution of memory retrieval and cognitively demanding interventions alter the subjective experience of aversive memories. This principle can be used in treatment to target traumatic memories. An often-used interpretation is that cognitive demand interferes with memory reconsolidation. Laboratory models applying this technique often do not meet some important procedural steps thought necessary to trigger reconsolidation. It remains therefore unclear whether cognitively demanding interventions can alter the reconsolidation process of aversive memories. Here, 78 (41 included) healthy participants completed an established 3-day threat conditioning paradigm. Two conditioned stimuli were paired with a shock (CS+ s) and one was not (CS-). The next day, one CS+ (CS+ R), but not the other (CS+), was presented as a reminder. After 10 min, participants performed a 2-back working memory task. On day three, we assessed retention. We found successful acquisition of conditioned threat and retention (CS+ s > CS-). However, SCRs to the CS+ R and the CS+ during retention did not significantly differ. Although threat conditioning was successful, the well-established cognitively demanding intervention did not alter the reconsolidation process of conditioned threat memories. These findings challenge current views on how cognitively demand may enhance psychotherapy-outcome. [ABSTRACT FROM AUTHOR]

Maquestiaux, Lyphout-Spitz, Ruthruff, and Arexis (2020) demonstrated that ideomotor-compatible (IM) tasks (e.g., pressing the left key when an arrow points left) can operate automatically, entirely bypassing the central bottleneck that constrains dual-task performance. But is bottleneck bypassing a specific consequence of IM compatibility or is it due to task ease? To answer this question, we tested the automaticity of a task that was easy but not IM. The task was easy due to the high semantic compatibility between the stimulus and the response: saying "ping" when hearing "pong" and "pong" to "ping" in Experiment 1, saying "low" when hearing "high" and "high" to "low" in Experiment 2. We presented it as Task 2, along with a Task 1 that was not easy, due to the use of an arbitrary stimulus-response mapping. Single-task trials were randomly intermixed with dual-task trials and then used as baselines to assess dual-task costs and to simulate distributions of inter-response intervals (IRIs) predictive of bottleneck bypassing vs. bottlenecking. The results of both experiments provided converging evidence that the entire Task 2 bypassed the bottleneck on virtually all trials: very small dual-task costs, high percentages of response reversals, and a close match between the observed IRI distributions and that predicted by bottleneck bypassing. Neither ideomotor compatibility nor task speed (the semantic task was not particularly fast) explain these findings. We therefore propose that the key to bypassing the central bottleneck is the ease with which people can fully load the stimulus-response mapping into working memory. [ABSTRACT FROM AUTHOR]

Previous examinations of working memory impairments in children with attention-deficit/hyperactivity disorder (ADHD) have predominantly focused on discreet visuospatial and phonological subsystem processes, as well as the domain-general central executive. The episodic buffer component of working memory, a neurocognitive process that allows for temporary storage and maintenance of bound episodes/features of information, is understudied in ADHD and initial findings have been equivocal. Heterogeneity in previous findings may reflect between-study methodological variability, floor effects unrelated to episodic buffer processes (i.e., excessive central executive demands), and limitations associated with previous investigations' use of novel paradigms. This study examined ADHD-related episodic buffer processing via an established paradigm (Allen et al., 2006) in well-defined groups of children with attention-deficit/hyperactivity disorder (ADHD) and typically developing peers (TD). Seventy-one children (ADHD n = 34, TD n = 37) aged 8–12 years (M = 9.81, SD = 1.50; 32% female) completed two conditions of a computerized working memory task that presented single feature stimuli (color and shape), and a third condition that presented dual-feature stimuli (color/shape binding). Overall, the ADHD group exhibited a large-magnitude deficit during the color/shape binding condition (d =.77), and both groups evinced worse performance accuracy in the color/shape binding condition compared to the single feature color and shape conditions. Collectively, these findings appear to provide evidence that children with ADHD exhibit large magnitude episodic buffer deficits that are not attributable to visuospatial subsystem or domain-general central executive processes. [ABSTRACT FROM AUTHOR]

Humans often experience striking performance deficits when their outcomes are determined by their own performance, colloquially referred to as "choking under pressure." Physiological stress responses that have been linked to both choking and thriving are well-conserved in primates, but it is unknown whether other primates experience similar effects of pressure. Understanding whether this occurs and, if so, its physiological correlates, will help clarify the evolution and proximate causes of choking in humans. To address this, we trained capuchin monkeys on a computer game that had clearly denoted high- and low-pressure trials, then tested them on trials with the same signals of high pressure, but no difference in task difficulty. Monkeys significantly varied in whether they performed worse or better on high-pressure testing trials and performance improved as monkeys gained experience with performing under pressure. Baseline levels of cortisol were significantly negatively related to performance on high-pressure trials as compared to low-pressure trials. Taken together, this indicates that less experience with pressure may interact with long-term stress to produce choking behavior in early sessions of a task. Our results suggest that performance deficits (or improvements) under pressure are not solely due to human specific factors but are rooted in evolutionarily conserved biological factors. [ABSTRACT FROM AUTHOR]

Training in working memory tasks is associated with lasting changes in prefrontal cortical activity. To assess the neural activity changes induced by training, we recorded single units, multi-unit activity (MUA) and local field potentials (LFP) with chronic electrode arrays implanted in the prefrontal cortex of two monkeys, throughout the period they were trained to perform cognitive tasks. Mastering different task phases was associated with distinct changes in neural activity, which included recruitment of larger numbers of neurons, increases or decreases of their firing rate, changes in the correlation structure between neurons, and redistribution of power across LFP frequency bands. In every training phase, changes induced by the actively learned task were also observed in a control task, which remained the same across the training period. Our results reveal how learning to perform cognitive tasks induces plasticity of prefrontal cortical activity, and how activity changes may generalize between tasks. It remains unclear whether improvements in one cognitive task transfer to other tasks. Here, the authors show that changes in prefrontal neuronal activation, firing rate, and local field potentials induced during active learning of a working memory task are also evident in a control task. [ABSTRACT FROM AUTHOR]

Many areas of psychology assume that performance on tasks of interest is stable through time. Here, using time-sensitive modeling of working memory task performance, we show not only was this assumption incorrect, but that certain components of the performance trajectory (e.g., final task performance; rate of change) were independently predictive of fluid intelligence. This fact has clear implications for theoretical frameworks linking working memory and fluid intelligence, and beyond. [ABSTRACT FROM AUTHOR]

The present study aimed to separate the neural activities between response inhibition and memory updating processes in the Count/Nocount task. Memory load was manipulated to investigate the memory updating process. Within each trial, participants were asked to count/withhold counting the number of O/X letters in the Count/Nocount task. The participants were asked to silently add 1 if a Count letter was presented in the low load condition, and add 2 in the high load condition. Data from 28 healthy participants showed that: (1) in both high load and low load conditions, the latencies of P2 and N2 components were shorter for the Nocount than Count trials, indicating faster attentional orienting and conflict monitoring processes for the Nocount stimuli (i.e., inhibition processes triggered by the Nocount stimuli against those response execution processes triggered by Count stimuli); (2) more positive frontal P3 amplitudes were evoked for the Nocount relative to the Count stimuli, indicating a more intensive response inhibition process for the Nocount trials; (3) a more positive parietal P3 component was evoked for the low load relative to high load condition, indicating a more intensive working memory updating process for the high load condition. This load effect was absent for the frontal P3 component, suggesting that the frontal P3 might not be associated with the memory updating process. In sum, both the cognitive inhibition process (reflected by the frontal P3 component) and working memory updating process (reflected by the parietal P3 component) appear to be involved in the Count/Nocount task. [ABSTRACT FROM AUTHOR]

The mood induction paradigm has been an important tool for investigating the effects of negative emotional states on working memory (WM) executive functions. Though some evidence showed that negative mood has a differential effect on verbal and visuospatial WM, other findings did not report a similar effect. To explore this issue, we examined the negative mood's impact on verbal and visuospatial WM executive tasks based on grammatical reasoning and visuospatial rotation. Participants with no anxiety or depression disorders performed the tasks before and after negative (n = 14) or neutral (n = 13) mood induction. Participants' mood at the beginning and the end of the session was assessed by the Present Mood States List (LEAP) and word valence rating. The analyses showed changes in the emotional state of the negative group (ps <.03) but not of the neutral group (ps >.83) in the LEAP instrument. No significant differences between groups were observed in the WM tasks (ps >.33). Performance in the visuospatial WM task improved after mood induction for both groups (p <.05), possibly due to a practice effect. In sum, our findings challenge the view that negative mood modulates WM executive functions; thus, they were discussed considering the similarities and differences between studies that found negative mood effects on WM and those that did not find. Different WM tasks tap distinct processes and components, which may underlie behavioral effects of negative mood on WM tasks. [ABSTRACT FROM AUTHOR]

We investigated whether interindividual attentional vulnerability moderates performance on domain-specific cognitive tasks during sleep restriction (SR) and subsequent recovery sleep. Fifteen healthy men (M ± SD, 22.3 ± 2.8 years) were exposed to three nights of baseline, five nights of 5-h time in bed SR, and two nights of recovery sleep. Participants completed tasks assessing working memory, visuospatial processing, and processing speed approximately every two hours during wake. Analyses examined performance across SR and recovery (linear predictor day or quadratic predictor day2) moderated by attentional vulnerability per participant (difference between mean psychomotor vigilance task lapses after the fifth SR night versus the last baseline night). For significant interactions between day/day2 and vulnerability, we investigated the effect of day/day2 at 1 SD below (less vulnerable level) and above (more vulnerable level) the mean of attentional vulnerability (N = 15 in all analyses). Working memory accuracy and speed on the Fractal 2-Back and visuospatial processing speed and efficiency on the Line Orientation Task improved across the entire study at the less vulnerable level (mean − 1SD) but not the more vulnerable level (mean + 1SD). Therefore, vulnerability to attentional lapses after SR is a marker of susceptibility to working memory and visuospatial processing impairment during SR and subsequent recovery. [ABSTRACT FROM AUTHOR]

Alterations in frontal and parietal neural activations during working memory task performance have been suggested as a candidate endophenotype of obsessive-compulsive disorder (OCD) in studies involving first-degree relatives. However, the direct link between genetic risk for OCD and neuro-functional alterations during working memory performance has not been investigated to date. Thus, the aim of the current functional magnetic resonance imaging (fMRI) study was to test the direct association between polygenic risk for OCD and neural activity during the performance of a numeric n-back task with four working memory load conditions in 128 participants, including patients with OCD, unaffected first-degree relatives of OCD patients, and healthy controls. Behavioral results show a significant performance deficit at high working memory load in both patients with OCD and first-degree relatives (p < 0.05). A whole-brain analysis of the fMRI data indicated decreased neural activity in bilateral inferior parietal lobule and dorsolateral prefrontal cortex in both patients and relatives. Most importantly, OCD polygenic risk scores predicted neural activity in orbitofrontal cortex. Results indicate that genetic risk for OCD can partly explain alterations in brain response during working memory performance, supporting the notion of a neuro-functional endophenotype for OCD. [ABSTRACT FROM AUTHOR]

People respond to small numbers faster with the left hand and respond to large numbers faster with the right hand, a phenomenon known as the Spatial-Numerical Association of Response Codes (SNARC) effect. Whether the SNARC effect originates from culturally determined long-term experience or the task-set-influenced temporary associations among spaces, locations, and numerical magnitudes in working memory (WM) is still controversial. In the present study, we used a trisection paradigm in which numbers were divided into three categories (small: 1, 2; middle: 4, 5, 6; and large: 8, 9) to explore whether the central executive control can modulate the SNARC effect. Participants were serially presented with a cue and a target number. The cue denoted a task rule, which informed participants to compare the target number with either 3 or 7. The cue was either switched or repeated across trials. We found that the SNARC effects were observed in the cue-switching condition. In the cue-repeat condition, the SNARC effect disappeared. These findings suggest that the SNARC effect is modulated by set-shifting-related central executive control in WM, supporting the view that the SNARC effect is WM-dependent. [ABSTRACT FROM AUTHOR]

Prior research has shown that interruptions lead to a variety of performance costs. However, these costs are heterogenous and poorly understood. Under some circumstances, interruptions lead to large decreases in accuracy on the primary task, whereas in others task duration increases, but task accuracy is unaffected. Presently, the underlying cause of these costs is unclear. The Memory for Goals model suggests that interruptions interfere with the ability to represent the current goal of the primary task. Here, we test the idea that working memory (WM) may play a critical role in representing the current goal and thus may underlie the observed costs associated with interruption. In two experiments, we utilized laboratory-based visual search tasks, which differed in their WM demands, in order to assess how this difference influenced the observed interruption costs. Interruptions led to more severe performance costs when the target of the search changed on each trial. When the search target was consistent across trials, the cost of interruption was greatly reduced. This suggests that the WM demands associated with the primary task play an important role in determining the performance costs of interruption. Our findings suggest that it is important for research to consider the cognitive processes a task engages in order to predict the nature of the adverse effects of interruption in applied settings such as radiology. [ABSTRACT FROM AUTHOR]

In a retro-cue paradigm, after memorizing a set of objects, people are cued to remember only a subset. Improved memory from the retro-cue suggests that selection processes can benefit items stored in working memory. Does selection in working memory require attention? If so, an attention-demanding task should disrupt retro-cue effects. Studies using a dual-task paradigm have found mixed results, with only one study (Janczyk & Berryhill, Attention, Perception, and Psychophysics, 76 (3), 715–724, 2014) showing a decreased retro-cue effect by a secondary task. Here we explore a potential issue in that study – the temporal overlap of the secondary task response with the memory test presentation. This raises questions about whether the secondary task was impairing selection processes in memory or was impacting the memory response. We replicated their paradigm by inserting a tone discrimination task at the retro-cue offset, but we also included a condition in which the tone task and the memory test were temporally separated. In Experiment 1, performing the tone task did not impair the retro-cue effect. In Experiment 2, we added an articulatory suppression task as in Janczyk and Berryhill's study, and we found that the requirement to execute the tone task impaired retro-cue effects. This impairment was independent of whether the tone and memory tasks overlapped. These findings suggest that internal prioritization can be impaired by dual-task interference, but may only occur when such interference is robust enough, for example, due to switching between multiple tasks. [ABSTRACT FROM AUTHOR]

Previous work investigating the effect of rTMS of left Dorso-Lateral Prefrontal Cortex (DLPFC) on Stroop task performance reports no changes to the Stroop effect but reduced reaction times on both congruent and incongruent trials relative to sham stimulation; an effect attributed to an enhanced attentional (or task) set for colour classification. The present study tested this account by investigating whether, relative to vertex stimulation, rTMS of the left DLPFC modifies task conflict, a form of conflict that arises when task sets for colour classification and word reading compete, given that this particular type of conflict would be reduced by an enhanced task set for colour classification. Furthermore, the present study included measures of other forms of conflict present in the Stroop task (response and semantic conflict), the potential effects on which would have been hidden in previous studies employing only incongruent and congruent stimuli. Our data showed that left DLPFC stimulation had no effect on the magnitude of task conflict, nor did it affect response, semantic or overall conflict (where the null is supported by sensitive Bayes Factors in most cases). However, consistent with previous research left DLPFC stimulation had the general effect of reducing reaction times. We, therefore, show for the first time that relative to real vertex stimulation left DLPFC stimulation does not modify Stroop interference. Alternative accounts of the role of the left DLPFC in Stroop task performance in which it either modifies response thresholds or facilitates responding by keeping the correct response keys active in working memory are discussed. [ABSTRACT FROM AUTHOR]

To date, the emotion regulation literature has focused primarily on the down-regulation of negative emotion, with far fewer studies interrogating the mechanisms at work in positive emotion regulation. This body of work has suggested that nonaffective mechanisms, such as cognitive load have a role to play in reducing emotional response. For example, the late positive potential (LPP), which tracks attention to salient stimuli, is reduced when task-irrelevant negative and neutral stimuli are presented under high compared with low working memory load. Using positive stimuli, working memory load has been shown to reduce the LPP elicited by positive words and faces but has not previously been shown to modulate the LPP elicited by positive scenes. Emotional scenes are the predominant type of stimuli used in the broader emotion regulation literature, are more arousing than faces, and have been shown to more strongly modulate the LPP. Here, 41 participants performed a working memory task interspersed with the presentation of positive and neutral scenes, while electroencephalography was recorded. Results showed that the LPP was increased for positive compared with neutral pictures and reduced on high-load compared to low-load trials. Working memory performance was worse on high-load compared with low-load trials, although it was not significantly correlated with the LPP, and picture type did not affect working memory performance. Results bridge to the willful emotion regulation literature to increase understanding of the mechanisms underlying positive emotion regulation, which has been relatively unexamined. [ABSTRACT FROM AUTHOR]

It is debated whether training with a working memory (WM) task, particularly n-back, can improve general WM and reasoning skills. Most training studies found substantial improvement in the trained task, with little to no transfer to untrained tasks. We hypothesized that training does not increase WM capacity, but instead provides opportunities to develop an efficient task-specific strategy. We derived a strategy for the task that optimizes WM resources and taught it to participants. In two sessions, 14 participants who were taught this strategy performed as well as fourteen participants who trained for 40 sessions without strategy instructions. To understand the mechanisms underlying the no-instruction group's improvement, participants answered questionnaires during their training period. Their replies indicate that successful learners discovered the same strategy and their improvement was associated with this discovery. We conclude that n-back training allows the discovery of strategies that enable better performance with the same WM resources. [ABSTRACT FROM AUTHOR]

The literature suggests that semantic similarity has a weak or null effect for immediate serial reconstruction and a facilitative effect for immediate serial recall. These observed semantic similarity effects are inconsistent with the assumptions of short-term memory (STM) models on the detrimental effect of similarity (e.g., confusion) and with observations of a robust detrimental effect of phonological similarity. Our review indicates that the experimental results are likely dependent on the manipulation strength for semantic similarity and that manipulations used in previous studies might have affected semantic assvociation as well as semantic similarity. To address these possible issues, two indices are proposed: (a) strength of manipulation on semantic similarity, gained by quantifying semantic similarity based on Osgood and associates' dimensional view of semantics, and (b) inter-item associative strength, a possible confounding factor. Our review and the results of a meta-regression analysis using these two indices suggest that semantic similarity has a detrimental effect on both serial reconstruction and serial recall, while semantic association, which is correlated with semantic similarity, contributes to an apparent facilitative effect. An effect that is not attributable to similarity or association was also implied. Review on item and order memory further suggests the facilitative effect of semantic association on item memory and the detrimental effect of the semantic similarity on order memory. Based on our findings, we propose a unified explanation of observations of semantic similarity effects for both serial reconstruction and serial recall that is in good accord with STM models. [ABSTRACT FROM AUTHOR]

There is still a need to analyze the factors that enhance navigation accuracy. This study aims to examine how success in environment learning relates to task goals and WM. A total of 90 undergraduates (46 females) learned a route from a virtual navigation experience after being given a goal that involved tracing the route (a route-based goal) or finding a shortcut (a survey-based goal). The two groups thus formed were each divided into three subgroups according to the dual-task paradigm: one only navigated (control condition); the other two did so while simultaneously performing a visuo-spatial or verbal secondary task. Afterwards, participants traced the previously seen route and found a shortcut. Several visuo-spatial and verbal WM tasks were also administered. The results showed that participants given a route-based goal performed better in the route-tracing task; and those given a survey-based goal were better at finding shortcuts. An influence of WM was also shown: higher WM (visuo-spatial and verbal) ability significantly reduced the number of route-tracing errors made while performing a secondary visuo-spatial task, regardless of the goal, whereas no such effects emerged for shortcut finding. These results offer new insight on how task goals and WM support successful navigation. [ABSTRACT FROM AUTHOR]

Dual-task performance typically leads to performance impairments in comparison to single tasks (i.e., dual-task costs). The literature discusses the contribution to these dual-task costs due to (1) bottleneck limitations in the dual-component tasks and (2) executive control processes regulating access to this bottleneck. Previous studies investigated the characteristics of executive control processes primarily triggered by external stimulus information. In the present study, however, we investigated the existence as well as the characteristics of internally triggered and driven endogenous control processes to regulate bottleneck access. In detail, we presented dual-task blocks with varying task orders and informed participants in advance about repetitions of the same task order as well as switches between different task orders (i.e., task-order repetitions and switches were predictable). Experiment 1 demonstrated that task-order information and an increased preparation time generally increase the efficiency for endogenous task-order control and improves preparation for task-order switches. This finding is basically consistent with the assumption of the existence of endogenous control processes. Experiment 2, however, did not provide evidence that this endogenous control is related with working-memory maintenance mechanisms. Experiment 3 showed that endogenous control does not only fully complete task-order preparation but also requires exogenous, stimulus-driven components. [ABSTRACT FROM AUTHOR]

This study aimed to elucidate the mechanism of detecting differences between a current line orientations and line orientations retained in working memory (WM). The results were compared with the data obtained in a WM experiment for spatial patterns. The study involved 33 healthy subjects with normal vision. The subjects performed a WM task, and the visual event-related potentials (ERPs) and dipole simulation were analyzed in the interval 160–280 ms after the stimulus. An increase in ERP amplitude was identified as an informative marker of a mismatch between the current and retained stimuli. The increase arose simultaneously in the frontal and parietal-occipital cortical areas and was stimulus type independent. An analysis of distributed dipole sources showed that the topography of match vs. mismatch differences depends on the stimulus type. In the case of orientations, differences were more local and predominated in the caudal areas of the left hemisphere. In the case of spatial patterns, differences were more extended and prevailed in the right hemisphere. The results indicate that a common organization is characteristic of neural networks detecting a mismatch between current and retained stimuli and, on the other hand, that some rearrangements can arise in these neural networks depending on the type of information processed. [ABSTRACT FROM AUTHOR]

Motivationally/emotionally engaging stimuli are strong competitors for the limited capacity of sensory and cognitive systems. Thus, they often act as distractors, interfering with performance in concurrent primary tasks. Keeping task-relevant information in focus while suppressing the impact of distracting stimuli is one of the functions of working memory (WM). Macroscopic brain oscillations in the alpha band (8–13 Hz) have recently been identified as a neural correlate of WM processing. Using electroencephalography, we examined the extent to which changes in alpha power and inter-site connectivity during a typical WM task are sensitive to load and emotional distraction. Participants performed a lateralized change-detection task with two levels of load (four vs. two items), which was preceded by naturalistic scenes rated either as unpleasant or neutral, acting as distractors. The results showed the expected parieto-occipital alpha reduction in the hemisphere contralateral to the WM task array, compared to the ipsilateral hemisphere, during the retention interval. Selectively heightened oscillatory coupling between frontal and occipital sensors was observed (1) during the retention interval as a function of load, and (2) upon the onset of the memory array, after viewing neutral compared to unpleasant distractors. At the end of the retention interval, we observed greater coupling during the unpleasant compared to the neutral condition. These findings are consistent with the notions that (1) representing more items in WM requires greater interconnectivity across cortical areas, and (2) unpleasant emotional distractors interfere with subsequent WM processing by disrupting processing during the encoding stage. [ABSTRACT FROM AUTHOR]

Working memory is thought to be divided into distinct visual and verbal subsystems. Studies of visual working memory frequently use verbal working memory tasks as control conditions and/or use articulatory suppression to ensure that visual load is not transferred to verbal working memory. Using these verbal tasks relies on the assumption that the verbal working memory load will not interfere with the same processes as visual working memory. In the present study, participants maintained a visual or verbal working memory load as they simultaneously viewed scenes while their eye movements were recorded. Because eye movements and visual working memory are closely linked, we anticipated the visual load would interfere with scene-viewing (and vice versa), while the verbal load would not. Surprisingly, both visual and verbal memory loads interfered with scene-viewing behavior, while eye movements during scene-viewing did not significantly interfere with performance on either memory task. These results suggest that a verbal working memory load can interfere with eye movements in a visual task. [ABSTRACT FROM AUTHOR]

Rationale: Working memory deficits are present in schizophrenia (SZ) but remain insufficiently resolved by medications. Similar cognitive dysfunctions can be produced acutely in animals by elevating brain levels of kynurenic acid (KYNA). KYNA's effects may reflect interference with the function of both the α7 nicotinic acetylcholine receptor (α7nAChR) and the glycineB site of the NMDA receptor. Objectives: The aim of the present study was to examine, using pharmacological tools, the respective roles of these two receptor sites on performance in a delayed non-match-to-position working memory (WM) task (DNMTP). Methods: DNMTP consisted of 120 trials/session (5, 10, and 15 s delays). Rats received two doses (25 or 100 mg/kg, i.p.) of L-kynurenine (KYN; bioprecursor of KYNA) or L-4-chlorokynurenine (4-Cl-KYN; bioprecursor of the selective glycineB site antagonist 7-Cl-kynurenic acid). Attenuation of KYN- or 4-Cl-KYN-induced deficits was assessed by co-administration of galantamine (GAL, 3 mg/kg) or PAM-2 (1 mg/kg), two positive modulators of α7nAChR function. Reversal of 4-Cl-KYN-induced deficits was examined using D-cycloserine (DCS; 30 mg/kg), a partial agonist at the glycineB site. Results: Both KYN and 4-Cl-KYN administration produced dose-related deficits in DNMTP accuracy that were more severe at the longer delays. In KYN-treated rats, these deficits were reversed to control levels by GAL or PAM-2 but not by DCS. In contrast, DCS eliminated performance deficits in 4-Cl-KYN-treated animals. Conclusions: These experiments reveal that both α7nAChR and NMDAR activity are necessary for normal WM accuracy. They provide substantive new support for the therapeutic potential of positive modulators at these two receptor sites in SZ and other major brain diseases. [ABSTRACT FROM AUTHOR]

Studies have shown improved cognitive performance of action video game players (AVGPs); however, the corresponding neural correlates are still unclear. The present study aims to investigate whether the unsupervised training on action video games contributes to the visuomotor adaptation of working memory or not, considering neural measures. Twenty-seven-Channel electroencephalogram (EEG) signals from 35 participants are recorded while performing Corsi block-tapping task (CBTT), a working memory task incorporating recall of visual and sequential–spatial information, and are analyzed employing wavelet transform-based feature extraction techniques. For removing artifacts, we have used the wavelet denoising method. Different mother wavelet functions, with different thresholding algorithms, are compared. The dmeyer mother wavelet function along with Rigorous SURE soft thresholding emerged as the best combination for denoising. Comparison of wavelet energy features has revealed improved rhythmic activity in AVGPs. Also, two measures of engagement index β/(α + θ) and β/α are computed which has provided good classification accuracies with ANFIS classifier. Higher engagement indexes are found in the frontal, right parietal and occipital cortex of AVGPs. These results evidence the neurocortical modulation among the players that may attribute to the effective cognitive processes in AVGPs related to the task. [ABSTRACT FROM AUTHOR]

Math anxiety (MA) is associated with negative thoughts and emotions when encountering mathematics, often resulting in under-performance on math tasks. One hypothesized mechanism by which MA affects performance is through anxiety-related increases in working memory (WM) load, diverting resources away from mathematical computations. We examined whether this effect is specific to WM or whether the impact of MA extends to an overall depletion of executive function (EF) resources. In this fMRI experiment, we manipulated two separate factors known to impact EF demands—task-switching (TS) and increased WM load—in order to evaluate how MA relates to behavioral performance and neural activity related to mathematical calculations. Relative to a difficult non-math task (analogies), we observed MA-related deficits in math performance and reduced neural activity in a network of regions in the brain associated with arithmetic processing. In response to TS demands, higher levels of math anxiety were associated with a pattern of avoidance and disengagement. When switching from the control task, high math anxiety (HMA) was associated with disengagement from math trials, speeding through these trials, and exhibiting reduced neural activity in regions associated with arithmetic processing. The effects of math anxiety and WM were most pronounced at the lowest levels of WM load. Overall, the results of this study indicate that the effects of MA are broader than previously demonstrated and provide further insight into how EF deficits in MA might impact recruitment of neural resources that are important for successful math computations. [ABSTRACT FROM AUTHOR]

Cognitive offloading refers to the act of reducing the mental processing requirements of a task through physical actions like writing down information or storing information on a cell phone or computer. Offloading can lead to improved performance on ongoing tasks with high cognitive demand, such as tasks where multiple pieces of information must be simultaneously maintained. However, less is known about why some individuals choose to engage in offloading and under what conditions they might choose to do so. In the present study, offloading behavior is investigated in a short-term memory task requiring memory for letters. The present study is a replication and extension of a previous study conducted by Risko and Dunn, and tests the new prediction that individuals with lower working memory capacity will be more likely to offload. Here, we find that offloading information confers a performance advantage over relying on internal memory stores, particularly at higher memory loads. However, we fail to observe that those with poorer memory abilities have a greater propensity for offloading or benefit more from it. Instead, our findings suggest that cognitive offloading may be a valid compensatory strategy to improve performance of memory-based tasks for individuals with a wide range of memory ability. [ABSTRACT FROM AUTHOR]

Complex span and content-embedded tasks are two kinds of tasks that are designed to measure maintenance and processing in the working memory system. However, a key functional difference between these task types is that complex span tasks require the maintenance of information that is not relevant to the processing task, whereas content-embedded tasks require the maintenance of task-relevant information. The purpose of the present research was to test the hypothesis that more unique variance in inductive reasoning would be explained by content-embedded tasks than by complex span tasks, given that inductive reasoning requires reasoners to maintain and manipulate task-relevant information in order to arrive to a solution. A total of 384 participants completed three complex span tasks, three content-embedded tasks, and three inductive reasoning tasks. The primary structural equation model explained 51% of the variance in inductive reasoning; 45% of the variance in inductive reasoning was uniquely predicted by the content-embedded latent factor, 6% of the variance was predicted by shared variance between the content-embedded and complex span latent factors, and less than 1% was uniquely predicted by the complex span latent factor. These outcomes provide a novel extension to the small but growing literature showing an advantage of using content-embedded rather than complex span tasks for predicting higher-level cognition. [ABSTRACT FROM AUTHOR]

Previous research has shown that holding a color word in working memory can produce interference effects in an intervening color-identification task, which mimics the classic color-word Stroop effect. Although this finding has previously been considered to suggest that the content of working memory can have behavioral consequences similar to those of externally perceived stimuli, it has remained unclear whether active internal maintenance of a color word indeed makes a critical contribution to the working memory Stroop effect. In the present study, we addressed this matter by asking participants to perform a color-identification task following display of either a congruent or an incongruent color word. By controlling for encoding strategy and/or maintenance demand across Experiments 1–4, we consistently showed that the magnitude of the congruency effect in color-identification performance was markedly larger when the recently presented color word was actively retained in working memory, as compared to when the color word was perceptually identified without working memory processing, when the color word had once been remembered but was no longer being actively maintained in working memory, or when the color word was retro-cued to be irrelevant to the working memory task. The findings therefore demonstrate a critical role for active internal maintenance of a color word in producing the working memory Stroop effect. In addition, Experiment 5 further showed that the working memory Stroop effect was sustained over time during the retention interval. Moreover, we found that the intervening color-identification task conversely influenced working memory maintenance, leading to poorer memory performance on incongruent than on congruent trials. We discuss the implications of these findings for understanding the linkage between working memory and attention. [ABSTRACT FROM AUTHOR]

Experimental pain inhibits primary motor cortex (M1) excitability. Attenuating pain-related inhibition of M1 excitability may be useful during rehabilitation in individuals with pain. One strategy to attenuate M1 excitability is to influence prefrontal and premotor cortex activity. Working memory tasks, e.g. the two-back task (TBT), engage prefrontal and premotor cortices and may influence M1 excitability. We hypothesized that performing the TBT during pain would influence pain-related changes in M1 excitability. Participants (n = 28) received rigorous training in the TBT before baseline testing. Experimental pain was induced by injecting hypertonic saline into the first dorsal interosseous (FDI) muscle. Participants rated pain intensity on a 0–10 numerical rating scale (NRS) every second min until pain-resolved (PR) during the performance of the TBT (n = 14) or during REST (n = 14). In the TBT, letters were presented pseudo-randomly, and accuracy and reaction time to identified letters corresponding to letters shown two times back were recorded. M1 excitability was assessed using transcranial magnetic stimulation. Motor-evoked potentials (MEPs) were recorded at baseline, and at PR, PR + 10, PR + 20, and PR + 30 min. Four minutes after hypertonic saline injection, the pain NRS scores were higher in the TBT group than the REST group (p = 0.009). No time × group interaction was found for MEPs (p = 0.73), but a main effect of time (p < 0.0005) revealed a reduction of MEPs at PR up until PR + 30 (p < 0.008). The TBT accuracy improved at PR + 30 in both groups (p = 0.019). In conclusion, the pain-induced reduction in corticomotor excitability was unaffected by performing a working memory task, despite greater pain in the TBT group. [ABSTRACT FROM AUTHOR]

The effects of working memory (WM) capacity on mathematical ability are well known. This relationship is seen mainly for the capacity of visuospatial WM, while the capacity of the phonological loop of WM, which is associated with processing sound and speech information, has been suggested to have a minor effect on mathematical ability in adults. Nonetheless, involvement of the language neural networks in mathematical thought remains controversial. We have studied the effects of the capacity of the phonological loop of WM on the rate and correctness of solution of mathematical and verbal tasks in young, healthy, right-handed volunteers who either had higher education or were students at institutions teaching mathematics and humanities. Subjects in the mathematics group (N = 10) solved all tasks with measures of solution correctness (CA) and response time (RT) which were significantly better than values for subjects of the humanities group (N = 10). The capacity of the phonological loop of WM showed no difference between the two groups but had different effects on CA and RT values for tasks in mathematicians and humanities specialists. Spearman correlation analysis for each group separately showed that the capacity of WM had positive effects on CA for all mathematical tasks only in the mathematicians group, where it had no effect on RT, while the reverse tendency was seen in the humanities group. The capacity of WM in the mathematicians group correlated inversely with RT for logical tasks on arithmetic sequences. Our results provide indirect evidence that WM in the verbal domain can influence mathematical ability, especially when tasks require the involvement of logical thought. [ABSTRACT FROM AUTHOR]

Previous literature demonstrated that the processing of emotional stimuli can interfere with goal-directed behavior. This has been shown primarily in the context of working memory tasks, but "emotional distraction" may affect also other processes, such as the orienting of visuo-spatial attention. During fMRI, we presented human subjects with emotional stimuli embedded within complex everyday life visual scenes. Emotional stimuli could be either the current target to be searched for or task-irrelevant distractors. Behavioral and eye-movement data revealed faster detection of emotional than neutral targets. Emotional distractors were found to be fixated later and for a shorter duration than emotional targets, suggesting efficient top-down control in avoiding emotional distraction. The fMRI data demonstrated that negative (but not positive) stimuli were mandatorily processed by limbic/para-limbic regions (namely, the right amygdala and the left insula), irrespective of current task relevance: that is, these regions activated for both emotional targets and distractors. However, analyses of inter-regional connectivity revealed a functional coupling between the left insula and the right prefrontal cortex that increased specifically during search in the presence of emotional distractors. This indicates that increased functional coupling between affective limbic/para-limbic regions and control regions in the frontal cortex can attenuate emotional distraction, permitting the allocation of spatial attentional resources toward task-relevant neutral targets in the presence of distracting emotional signals. [ABSTRACT FROM AUTHOR]

The change detection task is a common method for assessing the storage capacity of working memory, but estimates of memory capacity from this task can be distorted by lapses of attention. When combined with appropriate mathematical models, some versions of the change detection task make it possible to separately estimate working memory and the probability of attentional lapses. In principle, these models should allow researchers to isolate the effects of experimental manipulations, group differences, and individual differences on working memory capacity and on the rate of attentional lapses. However, the present research found that two variants of a widely accepted model of the change detection task are not mathematically identified. [ABSTRACT FROM AUTHOR]

The online version of the original article can be found at https://doi.org/10.3758/s13428-021-01645-y B Correction to: Behav Res b https://doi.org/10.3758/s13428-021-01645-y In the discussion section of the paper, we suggest that researchers might address the issue of a processing-based performance criterion by setting the criterion higher than 50% (chance criterion). For a task with 75 processing steps (RSpan, OSpan), the criterion for being above guessing probability with 95% confidence should read as 60% (rather than 69%). [Extracted from the article]

The retro-cue effect (RCE) describes superior working memory performance for validly cued stimulus locations long after encoding has ended. Importantly, this happens with delays beyond the range of iconic memory. In general, the RCE is a stable phenomenon that emerges under varied stimulus configurations and timing parameters. We investigated its susceptibility to dual-task interference to determine the attentional requirements at the time point of cue onset and encoding. In Experiment 1, we compared single- with dual-task conditions. In Experiment 2, we borrowed from the psychological refractory period paradigm and compared conditions with high and low (dual-) task overlap. The secondary task was always binary tone discrimination requiring a manual response. Across both experiments, an RCE was found, but it was diminished in magnitude in the critical dual-task conditions. A previous study did not find evidence that sustained attention is required in the interval between cue offset and test. Our results apparently contradict these findings and point to a critical time period around cue onset and briefly thereafter during which attention is required. [ABSTRACT FROM AUTHOR]

Research has indicated that highly trait-anxious (HTA) individuals exhibit a specific deficit in filtering threat-related distractors from visual-spatial working memory (WM). Prior demonstrations of impaired inhibition control in HTA individuals have mainly focused on tasks that required the inhibition of prepotent response tendencies. Studies on the suppression of emotionally neutral distractors from WM in trait anxiety have also been minimal. In this article, we present a study on the manifestation of general inefficient filtering of neutral distractors during visual-spatial WM maintenance stages in HTA individuals. Female participants performed a visual-spatial WM task while event-related potentials were recorded. They were made to remember the orientations of red rectangles within half of the screen and to ignore all salient green rectangles. As predicted, no significant main effect of group and no interaction between group and condition were found in the N2pc component, suggesting that group differences did not manifest in the initial process of object individuation. During the subsequent WM maintenance phase, HTA individuals were highly inefficient at filtering the irrelevant items from WM, as reflected not only by parallel late contralateral delay activity (CDA; 450 to 900 ms) amplitudes for the distractor condition and the four red items, but also by a smaller filtering efficiency score in the HTA group than in the low-trait-anxiety group. Extending previous studies, our findings verify a general filtering impairment in HTA individuals for task-irrelevant salient distractors during a WM maintenance phase. [ABSTRACT FROM AUTHOR]

The concept of capacity has become increasingly important in discussions of working memory (WM), in so far as most models of WM conceptualize it as a limited-capacity mechanism for maintaining information in an active state, and as capacity estimates from at least one type of WM task-complex span-are valid predictors of real-world cognitive performance. However, the term capacity is also often used in the context of a distinct set of WM tasks, change detection, and may or may not refer to the same cognitive capability. We here develop maximum-likelihood models of capacity from each of these tasks-as well as from a third WM task that places heavy demands on cognitive control, the self-ordered WM task (SOT)-and show that the capacity estimates from change detection and complex span tasks are not correlated with each other, although capacity estimates from change detection tasks do correlate with those from the SOT. Furthermore, exploratory factor analysis confirmed that performance on the SOT and change detection load on the same factor, with performance on our complex span task loading on its own factor. These findings suggest that at least two distinct cognitive capabilities underlie the concept of WM capacity as it applies to each of these three tasks. [ABSTRACT FROM AUTHOR]

The interest in the influence of videogame experience in our daily life is constantly growing. 'First Person Shooter' (FPS) games require players to develop a flexible mindset to rapidly react and monitor fast moving visual and auditory stimuli, and to inhibit erroneous actions. This study investigated whether and to which degree experience with such videogames generalizes to other cognitive control tasks. Experienced video game players (VGPs) and individuals with little to no videogame experience (NVGPs) performed on a N-back task and a stop-signal paradigm that provide a relatively well-established diagnostic measure of the monitoring and updating of working memory (WM) and response inhibition (an index of behavioral impulsivity), respectively. VGPs were faster and more accurate in the monitoring and updating of WM than NVGPs, which were faster in reacting to go signals, but showed comparable stopping performance. Our findings support the idea that playing FPS games is associated with enhanced flexible updating of task-relevant information without affecting impulsivity. [ABSTRACT FROM AUTHOR]

The purpose of the present studies was to evaluate the utility of a group-administered version of the n-back, or lag task. Experiments 1 and 2 describe the construction of the task and reveal that the modified lag task (MLT) produces the same performance trends as have been observed in individually administered versions of the lag task; performance decreased significantly as lag conditions increased in difficulty. Experiments 3 and 4 established convergent validity by comparing the MLT to another common working memory task, the operation-word span task, as well as the updated version of this task, the automatic operation span task. The results showed that MLT performance was significantly correlated to scores on both measures. These experiments provide important details about the MLT as a measure of working memory, in a group- or individual-administration setting. [ABSTRACT FROM AUTHOR]

Serial position effects in implicit and explicit memory were investigated in a short-term memory task. A study list composed of four, spatially distributed, two-digit numbers was presented, followed by an item recognition task (explicit test) and an implicit memory task in which participants were asked to verify a simple addition equation where the presented answer was either primed or not primed by one of the number pairs in the study list. Similar serial position effects were observed in explicit and implicit memory, with faster response times for correct decisions on the first than on the later list positions. The presence of a primacy effect but no recency effect is consistent with previous studies of explicit memory with visual presentation. The results suggest that similar principles of temporal information processing govern priming and episodic short-term memory. [ABSTRACT FROM AUTHOR]

Background: What can theories regarding memory-related gaze preference contribute to the field of deception detection? While abundant research has examined the ability to detect concealed information through physiological responses, only recently has the scientific community started to explore how eye tracking can be utilized for that purpose. However, previous attempts to detect deception through eye movements have led to relatively low detection ability in comparison to physiological measures. In the current study, we demonstrate that the modulation of gaze behavior by familiarity, changes considerably when participants perform a visual detection task in comparison to a short-term memory task (that was used in a previous study). Thus, we highlight the importance of theory-based selection of task demands for improving the ability to detect concealed information using eye-movement measures. Results: During visual exploration of four faces (some familiar and some unfamiliar) gaze was allocated preferably on familiar faces, manifested by more fixations. However, this preference tendency vanished once participants were instructed to convey countermeasures and conceal their familiarity by deploying gaze equally to all faces. This gaze behavior during the visual detection task differed significantly from the one observed during a short-term memory task used in a previous study in which a preference towards unfamiliar faces was evident even when countermeasures were applied. Conclusions: Different tasks elicit different patterns of gaze behavior towards familiar and unfamiliar faces. Moreover, the ability to voluntarily control gaze behavior is tightly related to task demands. Adequate ability to control gaze was observed in the current visual detection task when memorizing the faces was not required for a successful accomplishment of the task. Thus, applied settings would benefit from a short-term memory task which is much more robust to countermeasure efforts. Beyond shedding light on theories of gaze preference, these findings provide a backbone for future research in the field of deception detection via eye movements. [ABSTRACT FROM AUTHOR]