Attentional Set Research Articles

Voluntary wheel running exercise rescues behaviorally-evoked acetylcholine efflux in the medial prefrontal cortex and epigenetic changes in ChAT genes following adolescent intermittent ethanol exposure.

Adolescent intermittent ethanol (AIE) exposure, which models heavy binge ethanol intake in adolescence, leads to a variety of deficits that persist into adulthood-including suppression of the cholinergic neuron phenotype within the basal forebrain. This is accompanied by a reduction in acetylcholine (ACh) tone in the medial prefrontal cortex (mPFC). Voluntary wheel running exercise (VEx) has been shown to rescue AIE-induced suppression of the cholinergic phenotype. Therefore, the goal of the current study is to determine if VEx will also rescue ACh efflux in the mPFC during spontaneous alternation, attention set shifting performance, and epigenetic silencing of the cholinergic phenotype following AIE. Male and female rats were subjected to 16 intragastric gavages of 20% ethanol or tap water on a two-day on/two-day off schedule from postnatal day (PD) 25-54, before being assigned to either VEx or stationary control groups. In Experiment 1, rats were tested on a four-arm spontaneous alternation maze with concurrent in vivo microdialysis for ACh in the mPFC. An operant attention set-shifting task was used to measure changes in cognitive and behavioral flexibility. In Experiment 2, a ChIP analysis of choline acetyltransferase (ChAT) genes was performed on basal forebrain tissue. It was found that VEx increased ACh efflux in the mPFC in both AIE and control male and female rats, as well as rescued the AIE-induced epigenetic methylation changes selectively at the Chat promoter CpG island across sexes. Overall, these data support the restorative effects of exercise on damage to the cholinergic projections to the mPFC and demonstrate the plasticity of cholinergic system for recovery after alcohol induced brain damage.

Trial history contributes to the optimal tuning of attention.

In visual search tasks, targets are difficult to find when they are similar to the surrounding nontargets. In this scenario, it is optimal to tune attention to target features that maximize the difference between target and nontargets. We investigated whether the optimal tuning of attention is driven by biases arising from previously attended stimuli (i.e., trial history). Consistent with the effects of trial history, we found that optimal tuning was stronger when a single target-nontarget relation was repeated than when two target-nontarget relations alternated randomly. Detailed analysis of blocks with random alternation showed that optimal tuning was stronger when the target-nontarget relation probed in the current trial matched the relation in the previous trial. We evaluated several mechanisms that may underlie the effects of trial history, such as priming of attentional set, switch costs, and sensory adaptation. However, none of the accounts was able to fully account for the pattern of results. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A hierarchical reinforcement learning model explains individual differences in attentional set shifting.

Attentional set shifting refers to the ease with which the focus of attention is directed and switched. Cognitive tasks, such as the widely used CANTAB IED, reveal great variation in set shifting ability in the general population, with notable impairments in those with psychiatric diagnoses. The attentional and learning processes underlying this cognitive ability and how they lead to the observed variation remain unknown. To directly test this, we used a modelling approach on two independent large-scale online general-population samples performing CANTAB IED, with one including additional psychiatric symptom assessment. We found a hierarchical model that learnt both feature values and dimension attention best explained the data and that compulsive symptoms were associated with slower learning and higher attentional bias to the first relevant stimulus dimension. These data showcase a new methodology to analyse data from the CANTAB IED task, as well as suggest a possible mechanistic explanation for the variation in set shifting performance, and its relationship to compulsive symptoms.

No signs of interference between learned attentional sets

No signs of interference between learned attentional sets

Intentional learning establishes multiple attentional sets that simultaneously guide attention.

One of the key human cognitive capabilities is to extract regularities from the environment to guide behavior. An attentional set for a target feature can be established through statistical learning of probabilistic target associations; however, whether an array of attentional sets of predictive target features can be established during intentional learning, and how they might guide attention, is not known yet. To address these questions, we had human observers perform a visual search task where we instructed them to try to use color to find their target shape. We structured the task with a fine-grained statistical regularity such that the target shapes appeared in different colors with five unique probabilities (i.e., 33%, 26%, 19%, 12%, and 5%) while we recorded their electroencephalogram. Observers rapidly learned these regularities, evidenced by being faster to report targets that appeared in higher probability colors. These effects were not due to unequal sample sizes or simple feature priming. More importantly, equivalent speeding across a set of high-probability colors suggests that the brain was driving attention to multiple targets simultaneously. Our electrophysiological results showed larger amplitude N2 posterior contralateral component, indexing perceptual attention, and late positive complex (LPC) component, indexing postperceptual processes, for targets paired with high-probability colors. These electrophysiological data suggest that the learned attentional sets change both perceptual selection and how postperceptual decisions are made. In sum, we show that multiple attentional sets can be established during intentional learning that accompanies general task acquisition and that these attentional sets can simultaneously guide attention by enhancing both perceptual attention and postperceptual processes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Different spectrum of space radiation induced cognitive impairments in radiation-naïve and adapted rats

NASA's decision to resume manned deep space mission, first to the Moon and then Mars, necessitated a detailed assessment of the potential health effects that astronauts may experience on long-duration missions. Multiple studies suggest that there may be significant space radiation (SR)-induced impairment of neurocognitive processes, including advanced executive functions. However, given the multitude of SR-induced changes in the CNS, it is possible that completely different SR-induced sequelae will be induced in previously exposed individuals. Thus, current risk estimates are likely to be pertinent only for the early stages of a deep space mission, and even then only for astronauts that have no previous experience in space.In this study, rats that maintained high attentional set shifting (ATSET) performance after an initial exposure to 10 cGy of SR (either 250 MeV/n He or GCRsim), were exposed to an additional dose of 10 cGy GCRsim and their ATSET performance reassessed. The re-irradiated rats exhibited significant impairment of ATSET performance, however, the performance decrements differed in two important aspects from those typically observed after single exposures. First, the decrements were manifested when the rats were required to perform set shifting, specifically in the IDR and EDS stages of the ATSET test. Secondly, the main performance decrement was in a loss of processing speed, which in the IDR stage resulted in the re-irradiated rats taking 2-fold more time to solve the problem than did Sham rats. The functional consequence of this decrement was that compared to Sham rats, 20 % fewer SR-exposed rats solved the IDS and EDR problems within 20 s.These data suggests that prior SR exposure alters nature of ATSET impairments from that observed in radiation-naïve individuals. Risk estimates derived from studies that use radiation naïve rats may thus not fully reflect the incidence and nature of ATSET performance deficits that could occur over the entire duration of a mission to Mars, or in astronauts who return to deep space on multiple occasions. It would thus be germane to conduct in-flight monitoring for cognitive performance decrements observed in both radiation naïve and exposed rats during the mission, and ensure that the crew has sufficient overlapping skill sets to minimize the operational impact of these additional cognitive impairments.

Effects of Memantine on Cognitive Flexibility in a Valproic Acid Rat Model of Autism

Abstract Autistic children frequently struggle with cognitive flexibility. The potential molecular mechanism underlying cognitive inflexibility remains unclear. Decreased level of brain-derived neurotrophic factor (BDNF), which plays a vital role in neural development and synaptic plasticity may have a role. This study aimed to investigate the effects of memantine on (BDNF) expression in hippocampus of prenatal VPA exposed rats, and its consequent effects on cognitive flexibility. Pregnant female rats received a single intraperitoneal injection of VPA (600 mg/kg) on gestational day 12.5 to induce autistic-like behaviors in their offspring. Afterwards, the 23-day-old male Wistar rat pups received daily intraperitoneal injections of memantine (20 mg/kg) for 4 weeks. The prenatal VPA-exposed rats exhibited reduced cognitive flexibility in the attentional set- shifting task (ASST) reflecting ASD-associated cognitive flexibility deficits, a common ASD- associated problem with accompanied reduction in hippocampal BDNF. The defective performance in ASST was more prominent in the reversal stages. Memantine associated increased hippocampal BDNF could alleviate cognitive inflexibility in ASD. This study draws attention to the potential favorable effect of memantine on cognitive performance in autistic subjects.

Attentional set and explicit expectations of perceptual load determine flanker interference.

Task-irrelevant stimuli often capture our attention despite our best efforts to ignore them. It has been noted that tasks involving perceptually complex displays can lead to reduced interference from distractors. The mechanism behind this effect is debated, with some accounts emphasizing the "perceptual load" of the stimuli themselves and others emphasizing the role of proactive control. Here, in three experiments, we investigated the roles of perceptual load, proactive control, and reward motivation in determining distractor interference. Participants performed a visual search task of high, low, or intermediate load, with flanking task-irrelevant distractors. Each trial was preceded by a cue indicating the level of perceptual load (Experiments 1-3) as well as the potential reward that could be earned (Experiments 2 and 3). In all three experiments, the attentional set induced by the preceding trial and cued proactive expectation of perceptual load interacted to determine flanker interference, which was significant for all trial types except trials cued as high load which were also preceded by high load. These effects were not modulated by reward motivation, although in the final experiment reward did significantly improve performance overall. Thus, successful distractor exclusion does not depend upon motivation or load per se but does require an expectation of high load. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Prenatal tobacco and tobacco-cannabis co-exposure: Relationship with attention and memory in middle childhood

We examined associations between prenatal tobacco exposure (with and without cannabis exposure) and children's performance on laboratory measures of sustained attention, attentional set shifting, and working memory in middle childhood (9–12 years of child age). Participants were recruited in the first trimester of pregnancy and oversampled for prenatal tobacco exposure; with a smaller sample (n = 133; n = 34 non-substance exposed, n = 37 exposed to tobacco only, n = 62 co-exposed) invited (oversampled for co-exposure) to participate in the middle-childhood assessment (M age = 10.6, SD = 0.77; 68% Black, 20% Hispanic). Results for sustained attention indicated lower attention (percent hits) at the first epoch for tobacco only exposed compared to non-exposed and co-exposed; a trend (p = .07) towards increases in impulsive responding across time (a total of 8 epochs) for tobacco exposed (with and without cannabis) compared to non-exposed children; and a significant association between higher number of cigarettes in the first trimester and greater increases in impulsive responding across epochs. However, children prenatally exposed to tobacco (with and without cannabis) demonstrated greater short-term memory compared to children not prenatally exposed, and this difference was driven by higher scores for children prenatally co-exposed to tobacco and cannabis compared to those who were non-exposed. Overall, results suggest that prenatal tobacco exposure, especially in the first trimester, may increase risk for impulsive responding on tasks requiring sustained attention, and that co-use of cannabis did not exacerbate these associations. The higher short-term memory scores among children who were co-exposed compared to non-exposed are perplexing and need replication, particularly in studies with larger sample sizes and samples exposed only to cannabis to examine this more closely.

Postnatal maternal care moderates the effects of prenatal bisphenol exposure on offspring neurodevelopmental, behavioral, and transcriptomic outcomes.

Bisphenols (BP), including BPA and "BPA-free" structural analogs, are commonly used plasticizers that are present in many plastics and are known endocrine disrupting chemicals. Prenatal exposure to BPA has been associated with negative neurodevelopmental and behavioral outcomes in children and in rodent models. Prenatal BPA exposure has also been shown to impair postnatal maternal care provisioning, which can also affect offspring neurodevelopment and behavior. However, there is limited knowledge regarding the biological effects of prenatal exposure to bisphenols other than BPA and the interplay between prenatal bisphenol exposure and postnatal maternal care on adult behavior. The purpose of the current study was to determine the interactive impact of prenatal bisphenol exposure and postnatal maternal care on neurodevelopment and behavior in rats. Our findings suggest that the effects of prenatal bisphenol exposure on eye-opening, adult attentional set shifting and anxiety-like behavior in the open field are dependent on maternal care in the first five days of life. Interestingly, maternal care might also attenuate the effects of prenatal bisphenol exposure on eye opening and adult attentional set shifting. Finally, transcriptomic profiles in male and female medial prefrontal cortex and amygdala suggest that the interactive effects of prenatal bisphenol exposure and postnatal maternal care converge on estrogen receptor signaling and are involved in biological processes related to gene expression and protein translation and synthesis. Overall, these findings indicate that postnatal maternal care plays a critical role in the expression of the effects of prenatal bisphenol exposure on neurodevelopment and adult behavior. Understanding the underlying biological mechanisms involved might allow us to identify potential avenues to mitigate the adverse effects of prenatal bisphenol exposure and improve health and well-being in human populations.

Probing cognitive flexibility in Shank2-deficient mice: Effects of D-cycloserine and NMDAR signaling hub dynamics

Neurodevelopmental disorders such as autism spectrum disorder (ASD) have a heterogeneous etiology but are largely associated with genetic factors. Robust evidence from recent human genetic studies has linked mutations in the Shank2 gene to idiopathic ASD. Modeling these Shank2 mutations in animal models recapitulates behavioral changes, e.g. impaired social interaction and repetitive behavior of ASD patients. Shank2-deficient mice exhibit NMDA receptor (NMDAR) hypofunction and associated behavioral deficits. Of note, NMDARs are strongly implicated in cognitive flexibility. Their hypofunction, e.g. observed in schizophrenia, or their pharmacological inhibition leads to impaired cognitive flexibility. However, the association between Shank2 mutations and cognitive flexibility is poorly understood. Using Shank2-deficient mice, we explored the role of Shank2 in cognitive flexibility measured by the attentional set shifting task (ASST) and whether ASST performance in Shank2-deficient mice can be modulated by treatment with the partial NMDAR agonist D-cycloserine (DCS). Furthermore, we investigated the effects of Shank2 deficiency, ASST training, and DCS treatment on the expression level of NMDAR signaling hub components in the orbitofrontal cortex (OFC), including NMDAR subunits (GluN2A, GluN2B, GluN2C), phosphoglycerate dehydrogenase and serine racemase. Surprisingly, Shank2 deficiency did not affect ASST performance or alter the expression of the investigated NMDAR signaling hub components. Importantly, however, DCS significantly improved ASST performance, demonstrating that positive NMDAR modulation facilitates cognitive flexibility. Furthermore, DCS increased the expression of GluN2A in the OFC, but not that of other NMDAR signaling hub components. Our findings highlight the potential of DCS as a pharmacological intervention to improve cognitive flexibility impairments downstream of NMDAR modulation and substantiate the key role of NMDAR in cognitive flexibility.

Attentional Control Setting: Type, Quantity and Processing Stage

The attentional control setting is a search template containing target features. Individuals can establish attentional control settings based on the color, size, semantics, joint location-feature of stimulus and even relationships between targets and non-targets. When multiple targets exist, participants may establish multiple attentional control settings or a control setting based on the feature singleton item. However, the processing stage of the attentional control setting is still controversial. Future studies should further analyze the time course of attention control setting in different experimental paradigms to provide solutions to existing controversies, while examining the quantitative limits of attention control setting and the influence of distractor inhibition as a control setting on visual search.

Memory-driven capture during focused visual attention.

Attention can be captured by the presence of distractors that match the current content of working memory in the visual field. This memory-driven capture is well established when observers adopt diffused attentional settings prior to the onset of memory-matching distractors. However, it remains unclear whether memory-driven capture can occur when observers are in a state of focused attention. The present study attempted to address this question by examining whether memory-matching distractors can disrupt performance on a focused attention task. Participants were asked to hold a sample word in working memory and then had to name a central color while ignoring an irrelevant distractor word in the visual display. In Experiments 1 and 2, the distractor word was always presented centrally within the focus of attention. In Experiment 3, the distractor word could be presented either at the center or at the periphery (i.e., outside the focus of attention). The results showed that the irrelevant distractor word within the focus of attention interfered with color-naming performance when it matched the sample word held in working memory. However, no interference effect was observed when the distractor word was presented outside the attentional focus. The present findings indicate that working memory-driven capture during a state of focused visual attention depends crucially on whether or not memory-matching distractors are positioned within the focus of attention.

Preparation and persistence of deploying attention to locations or stimulus structures: Evidence from intermixed probe trials

Attention can be directed to the global or local level of a visual stimulus (i.e., Navon figure). Previous studies yielded reliable trial-to-trial level switch costs (i.e., worse performance when responding to the other level than on a previous trial), even though level cueing effects indicated anticipatory deployment of attention to the upcoming target level. To investigate the interplay of attentional preparation and persistence, we applied a probe trial method assumed to ensure a high degree of preparation for the upcoming target level and minimizing stimulus-specific proactive interference. Mirroring previous findings obtained in the domain of spatial attention, we found evidence for anticipatory attentional focusing on global/local target levels but not for persistence of the attentional set adopted on the previous trial. In a second experiment, we prevented preparation for upcoming attentional demands (in both global-local and spatial attention tasks). This resulted in the modulation of performance (in critical probe trials) by the attentional demands of the predecessor trial. Together, our findings demonstrate sensitivity of the probe trial method for attentional persistence and raise the possibility that such persistence can be completely eliminated by sufficiently strong preparation for the attentional demands of the following trial.

Chemogenetic inactivation of the nucleus reuniens and its projections to the orbital cortex produce deficits on discrete measures of behavioral flexibility in the attentional set-shifting task

The nucleus reuniens (RE) of the ventral midline thalamus is a critical node in the communication between the orbitomedial prefrontal cortex (OFC) and the hippocampus (HF). While RE has been shown to directly participate in memory-associated functions through its connections with the medial prefrontal cortex and HF, less is known regarding the role of RE in executive functioning. Here, we examined the involvement of RE and its projections to the orbital cortex (ORB) in attention and behavioral flexibility in male rats using the attentional set shifting task (AST). Rats expressing the hM4Di DREADD receptor in RE were implanted with indwelling cannulas in either RE or the ventromedial ORB to pharmacologically inhibit RE or its projections to the ORB with intracranial infusions of clozapine-N-oxide hydrochloride (CNO). Chemogenetic-induced suppression of RE resulted in impairments in reversal learning and set-shifting. This supports a vital role for RE in behavioral flexibility – or the ability to adapt behavior to changing reward or rule contingencies. Interestingly, CNO suppression of RE projections to the ventromedial ORB produced impairments in rule abstraction – or dissociable effects elicited with direct RE suppression. In summary, the present findings indicate that RE, mediated in part by actions on the ORB, serves a critical role in the flexible use of rules to drive goal directed behavior. The cognitive deficits of various neurological disorders with impaired communication between the HF and OFC, may be partly attributed to alterations of RE -- as an established intermediary between these cortical structures.

Dopaminergic lesions of the anterior cingulate cortex of rats increase vulnerability to salient distractors.

The anterior cingulate cortex (ACC) has been shown to be critical to many aspects of executive function including filtering irrelevant information, updating response contingencies when reinforcement contingencies change and stabilizing task sets. Nonspecific lesions to this region in rats produce a vulnerability to distractors that have gained salience through prior associations with reinforcement. These lesions also exacerbate cognitive fatigue in tests of sustained attention but do not produce global attentional impairments nor do they produce distractibility to novel distractors that do not have a prior association with reinforcement. To determine the neurochemical basis of these cognitive impairments, dopaminergically selective lesions of the ACC were made in both male and female Long-Evans, hooded rats prior to assessment in two attentional tasks. Dopaminergic lesions of the ACC increase the vulnerability of subjects to previously reinforced distractors and impede formation of an attentional set. Lesioned rats were not more susceptible to the effects of novel, irrelevant stimuli in a test of sustained attention as has been previously shown. Additionally, the effects of dopaminergic lesions were found to differ based on sex. Lesioned female, but not male, rats were more vulnerable than sham-lesioned females to the effects of prolonged testing and the removal of reinforcement during a test of sustained attention. Together, these data support the hypothesis that dopamine in the ACC is critical to filtering distractors whose salience has been gained through reinforcement.

Advances in formwork automation, structure and materials in concrete construction

This comprehensive study delves into scientific publications, distinguishing general literature from formwork-specific findings and giving an overview of research methods and formwork systems for concrete construction. A shift towards reusable materials and the widespread use of robotics, particularly in 3D printing is noticeable. Structural research maintains a balanced focus, with little attention set on beams. While automation is attracting interest, full integration into formwork-related publications is still evolving. The need for practical implementation, applicability to mass production and sustainability aspects requires further exploration. Concluding, a list of future challenges is presented, serving as a guidance for subsequent research and developments in research and the concrete industry.

Effects of outcome revaluation on attentional prioritisation of reward-related stimuli.

Stimuli associated with rewards can acquire the ability to capture our attention independently of our goals and intentions. Here, we examined whether attentional prioritisation of reward-related cues is sensitive to changes in the value of the reward itself. To this end, we incorporated an instructed outcome devaluation (Experiment 1a), "super-valuation" (Experiment 1b), or value switch (Experiment 2) into a visual search task, using eye-tracking to examine attentional prioritisation of stimuli signalling high- and low-value rewards. In Experiments 1a and 1b, we found that prioritisation of high- and low-value stimuli was insensitive to devaluation of a previously high-value outcome, and super-valuation of a previously low-value outcome, even when participants were provided with further experience of receiving that outcome. In Experiment 2, following a value-switch manipulation, we found that prioritisation of a high-value stimulus could not be overcome with knowledge of the new values of outcomes alone. Only when provided with further experience of receiving the outcomes did patterns of attentional prioritisation of high- and low-value stimuli switch, in line with the updated values of the outcomes they signalled. To reconcile these findings, we suggest that participants were motivated to engage in effortful updating of attentional control settings when there was a relative difference between reward values at test (Experiment 2) but that previous settings were allowed to persist when both outcomes had the same value at test (Experiments 1a and 1b). These findings provide a novel framework to further understand the role of cognitive control in driving reward-modulated attention and behaviour.

Meeting the challenges of continuing education online courses: Can we promote self‐regulated learning strategies with adaptive support?

AbstractOnline courses are particularly attractive in continuing education because they offer a high degree of autonomy and flexibility, although this requires learners to take greater responsibility for self‐regulating their learning. That can be challenging for adult learners as they need to handle other obligations in addition to learning. Thus, self‐regulated learning (SRL) support might be needed. In the present study, we aimed to investigate how the specific SRL challenges that adult learners face in online courses can be supported adaptively. Main challenges for adult learners consist in managing learning resources (e.g., time, attention, learning environment). To address these challenges, we developed an adaptive support intervention comprising several features. To assess the effects of the adaptive support on the self‐reported SRL strategy application of adult learners, we analysed data from five iterations of a continuing education online course comparing iterations with adaptive support (with a total of N = 36 participants) to iterations without (with a total of N = 35 participants). Results indicate that the adaptive support significantly improved environmental structuring but did not significantly affect other SRL strategies. Further analyses revealed that learners who did not use the support deteriorated in managing their learning time and in setting specific learning goals during the course. Practitioner notesWhat is already known about this topic Adult learners are likely to face various challenges in self‐regulated online learning, including managing conflicting responsibilities and maintaining focus. Adult learners' successful application of SRL strategies can be challenging, underlining the need for support. Adaptive support interventions have demonstrated positive effects in various educational contexts, indicating potential effectiveness for adult online learners as well. What this paper adds The study provides insights into the positive effects and potential pitfalls of designing an adaptive support intervention to improve adult learners' self‐reported use of the SRL strategies of effort, attention, time management, environmental structuring, and goal setting. Implications for practice and/or policy The findings suggest that providing adaptive support, namely a structured course overview and adaptive recommendations of learning time and relevant content, can positively influence adult learners' environmental structuring. Our findings also highlight the challenge of achieving optimal support design, as evidenced by low support use. This finding highlights the need to explore additional methods to motivate adult learners to use the support provided while carefully respecting their autonomy.

Feature-based attentional control for distractor suppression.

To investigate whether attentional suppression is merely a byproduct of target facilitation or a result of independent mechanisms for distractor suppression, the present study examined whether attentional suppression takes place when target facilitation hardly occurs using a spatial cueing paradigm. Participants searched for target letters that were not red, i.e., a negative color. On each trial, a target color was randomly chosen among 12 colors to prevent establishing attentional control for target colors and to reduce intertrial priming for target colors. Immediately before a target display, a noninformative spatial cue was presented at one of the possible target locations. The cue was rendered in a negative color, which was to be ignored, to detect targets or the reference color, which was never presented for target and non-target letters. Experiment 1showed that negative color cues captured attention less than reference color cues, suggesting feature-based attentional suppression. The suppression effect was replicated when the temporal interval between the onsets of the cue and target displays was reduced in Experiments 2and 3, suggesting proactive suppression. Experiment 3directly confirmed no attentional control settings for target colors and intertrial priming. These findings suggest that distractor features can guide attention at the pre-attentive stage when target features are not used to attend to targets.