The cognitive neuroscience of sustained attention: where top-down meets bottom-up

Vigilance: discussion of related concepts and proposal for a definition

We reviewed current definitions of vigilance to propose a definition, applicable in sleep medicine. As previous definitions contained terms such as attention, alertness, and arousal, we addressed these concepts too. We defined alertness as a quantitative measure of the mind state governing sensitivity to stimuli. Arousal comprises a stimulus-induced upward change in alertness, irrespective of the subsequent duration of the increased level of alertness. Vigilance is defined as the capability to be sensitive to potential changes in one's environment, ie the capability to reach a level of alertness above a threshold for a certain period of time rather than the state of alertness itself. It has quantitative and temporal dimensions. Attention adds direction towards a stimulus to alertness, requiring cognitive control: it involves being prepared to process stimuli coming from an expected direction. Sustained attention corresponds to a state in which some level of attention is purposefully maintained, adding a time factor to the definition of attention. Vigilance differs from sustained attention in that the latter in addition implies a direction to which attention is cognitively directed as well as a specification of duration. Attempts to measure vigilance, however, are often in fact measurements of sustained attention.

How Processing of Sensory Information From the Internal and External Worlds Shape the Perception and Engagement With the World in the Aftermath of Trauma: Implications for PTSD

Post-traumatic stress disorder (PTSD) is triggered by an individual experiencing or witnessing a traumatic event, often precipitating persistent flashbacks and severe anxiety that are associated with a fearful and hypervigilant presentation. Approximately 14–30% of traumatized individuals present with the dissociative subtype of PTSD, which is often associated with repeated or childhood trauma. This presentation includes symptoms of depersonalization and derealization, where individuals may feel as if the world or self is “dream-like” and not real and/or describe “out-of-body” experiences. Here, we review putative neural alterations that may underlie how sensations are experienced among traumatized individuals with PTSD and its dissociative subtype, including those from the outside world (e.g., touch, auditory, and visual sensations) and the internal world of the body (e.g., visceral sensations, physical sensations associated with feeling states). We postulate that alterations in the neural pathways important for the processing of sensations originating in the outer and inner worlds may have cascading effects on the performance of higher-order cognitive functions, including emotion regulation, social cognition, and goal-oriented action, thereby shaping the perception of and engagement with the world. Finally, we introduce a theoretical neurobiological framework to account for altered sensory processing among traumatized individuals with and without the dissociative subtype of PTSD.

Identifying the Distinct Cognitive Phenotypes in Multiple Sclerosis

Importance

Cognitive impairment is a common and disabling feature of multiple sclerosis (MS), but a precise characterization of cognitive phenotypes in patients with MS is lacking.

Objectives

To identify cognitive phenotypes in a clinical cohort of patients with MS and to characterize their clinical and magnetic resonance imaging (MRI) features.

Design, Setting, and Participants

This multicenter cross-sectional study consecutively screened clinically stable patients with MS and healthy control individuals at 8 MS centers in Italy from January 1, 2010, to October 31, 2019. Patients with MS and healthy control individuals who were not using psychoactive drugs and had no history of other neurological or medical disorders, learning disability, severe head trauma, and alcohol or drug abuse were enrolled.

Main Outcomes and Measures

Participants underwent a neurological examination and a cognitive evaluation with the Rao Brief Repeatable Battery and Stroop Color and Word Test. A subgroup of participants also underwent a brain MRI examination. Latent profile analysis was used on cognitive test z scores to identify cognitive phenotypes. Linear regression and mixed-effects models were used to define clinical and MRI features of each phenotype.

Results

A total of 1212 patients with MS (mean [SD] age, 41.1 [11.1] years; 784 women [64.7%]) and 196 healthy control individuals (mean [SD] age, 40.4 [8.6] years; 130 women [66.3%]) were analyzed in this study. Five cognitive phenotypes were identified: preserved cognition (n = 235 patients [19.4%]), mild-verbal memory/semantic fluency (n = 362 patients [29.9%]), mild-multidomain (n = 236 patients [19.5%]), severe-executive/attention (n = 167 patients [13.8%]), and severe-multidomain (n = 212 patients [17.5%]) involvement. Patients with preserved cognition and mild-verbal memory/semantic fluency were younger (mean [SD] age, 36.5 [9.8] years and 38.2 [11.1] years) and had shorter disease duration (mean [SD] 8.0 [7.3] years and 8.3 [7.6] years) compared with patients with mild-multidomain (mean [SD] age, 42.6 [11.2] years; mean [SD] disease duration, 12.8 [9.6] years; P < .001), severe-executive/attention (mean [SD] age, 42.9 [11.7] years; mean [SD] disease duration, 12.2 [9.5] years; P < .001), and severe-multidomain (mean [SD] age, 44.0 [11.0] years; mean [SD] disease duration, 13.3 [10.2] years; P < .001) phenotypes. Severe cognitive phenotypes prevailed in patients with progressive MS. At MRI evaluation, compared with those with preserved cognition, patients with mild-verbal memory/semantic fluency exhibited decreased mean (SE) hippocampal volume (5.42 [0.68] mL vs 5.13 [0.68] mL; P = .04), patients with the mild-multidomain phenotype had decreased mean (SE) cortical gray matter volume (687.69 [35.40] mL vs 662.59 [35.48] mL; P = .02), patients with severe-executive/attention had higher mean (SE) T2-hyperintense lesion volume (51.33 [31.15] mL vs 99.69 [34.07] mL; P = .04), and patients with the severe-multidomain phenotype had extensive brain damage, with decreased volume in all the brain structures explored, except for nucleus pallidus, amygdala and caudate nucleus.

Conclusions and Relevance

This study found that by defining homogeneous and clinically meaningful phenotypes, the limitations of the traditional dichotomous classification in MS can be overcome. These phenotypes can represent a more meaningful measure of the cognitive status of patients with MS and can help define clinical disability, support clinicians in treatment choices, and tailor cognitive rehabilitation strategies.

Is 10 Better than 1? The Effect of Speaker Variability on Children's Cross-situational Word Learning

The current study examined the effect of speaker variability on children's cross-situational word learning (XSWL). The study also examined the role of bilingual experience and sustained attention. Forty English monolingual children and 40 Spanish-English bilingual children ages 4-7 completed a XSWL task in a Single Speaker Condition and a Multiple Speaker Condition. Results indicated that speaker variability neither facilitated nor hindered XSWL. While monolingual children outperformed bilingual children, speaker-variability effects did not fluctuate across the two language groups. Notably, exposure to multiple speakers facilitated XSWL in children with poorer sustained attention skills, suggesting that variability in the input may be especially useful to children with poorer cognitive processing abilities.

Interaction between image and text during the process of biblical art reception

In our exploratory study, we ask how naive observers, without a distinct religious background, approach biblical art that combines image and text. For this purpose, we choose the book ‘New biblical figures of the Old and New Testament’ published in 1569 as source of the stimuli. This book belongs to the genre of illustrated Bibles, which were very popular during the Reformation. Since there is no empirical knowledge regarding the interaction between image and text during the process of such biblical art reception, we selected four relevant images from the book and measured the eye movements of participants in order to characterize and quantify their scanning behavior related to such stimuli in terms of i) looking at text (text usage), ii) text vs. image interaction measures (semantic or contextual relevance of text), and iii) narration. We show that texts capture attention early in the process of inspection and that text and image interact. Moreover, semantics of texts are used to guide eye movements later through the image, supporting the formation of the narrative.

Altered frontal connectivity after sleep deprivation predicts sustained attentional impairment: A resting-state functional magnetic resonance imaging study

A series of studies have shown that sleep loss impairs one's capability for sustained attention. However, the underlying neurobiological mechanism linking sleep loss with sustained attention has not been elucidated. The present study aimed to investigate the effect of sleep deprivation on the resting-state brain and explored whether the magnitude of vigilance impairment after acute sleep deprivation can be predicted by measures of spontaneous fluctuations and functional connectivity. We implemented resting-state functional magnetic resonance imaging with 42 participants under both normal sleep and 24-hr sleep-deprivation conditions. The amplitude of low-frequency fluctuations (ALFF) and functional connectivity was used to investigate the neurobiological change caused by sleep deprivation, and the psychomotor vigilance task (PVT) was used to measure sustained attention in each state. Correlation analysis was used to investigate the relationship between the change in ALFF/functional connectivity and vigilance performance. Sleep deprivation induced significant reductions in ALFF in default mode network nodes and frontal-parietal network nodes, while inducing significant increments of ALFF in the bilateral thalamus, motor cortex, and visual cortex. The increased ALFF in the visual cortex was correlated with increased PVT lapses. Critically, decreased frontal-thalamus connectivity was correlated with increased PVT lapses, while increased frontal-visual connectivity was correlated with increased PVT lapses. The findings indicated that acute sleep deprivation induced a robust alteration in the resting brain, and sustained attentional impairment after sleep deprivation could be predicted by altered frontal connectivity with crucial neural nodes of stimulus input, such as the thalamus and visual cortex.

Longitudinal course of depressive symptom severity among youths with bipolar disorders: Moderating influences of sustained attention and history of child maltreatment

BACKGROUND

Pediatric bipolar disorders are often characterized by disruptions in cognitive functioning, and exposure to child maltreatment (e.g., physical and sexual abuse) is associated with a significantly poorer course of illness. Although clinical and developmental research has shown maltreatment to be robustly associated with poorer cognitive functioning, it is unclear whether maltreatment and cognitive function jointly influence the clinical course of bipolar symptoms.

METHODS

This secondary analysis examined moderating effects of lifetime childhood physical and sexual abuse, and cognitive disruptions (sustained attention, affective information processing), on longitudinal ratings of depression symptom severity in youths from the Course and Outcome of Bipolar Youth (COBY) study, examined from intake (M = 12.24 years) through age 22 (N = 198; 43.9% female; Mean age of bipolar onset = 8.85 years).

RESULTS

A significant moderating effect was detected for sustained attention and maltreatment history. In the context of lower sustained attention, maltreatment exposure was associated with higher depression symptom severity during childhood, but not late adolescence. There was no association between maltreatment and symptom severity in the context of higher sustained attention, and no association between attention and depression symptom severity for non-maltreated youths.

LIMITATIONS

Depression symptom ratings at each assessment were subject to retrospective recall bias despite the longitudinal design. Cognitive assessments were administered at different ages across youths.

CONCLUSIONS

Depressive symptoms in pediatric bipolar may be jointly moderated by impairments in attention and exposure to maltreatment. Assessment of these risks, particularly in childhood, may be beneficial for considering risk of recurrence or chronicity of depressive symptoms.

Central auditory processing and listening effort in normal-hearing children: a pilot study

OBJECTIVES

The current study aims to assess the link between central auditory processes and listening effort in a group of normal-hearing children. This will provide information over and beyond the standard central auditory processes and might have practical implications for listening situations which often require speech understanding in noisy environments.

METHOD

The current study included 35 normal-hearing children from six to eleven years old. Tympanometry, tonal audiometry, and speech audiometry was performed. Different auditory processing skills were assessed using the Frequency Pattern Test, the Staggered Spondaic Word Test, and the Dichotic Digits Test. Finally, a dual-task paradigm was used to evaluate listening effort. This paradigm consisted of the simultaneous performance of a speech-recognition task in different conditions of background noise and a visuospatial memory task using a digital Corsi Block test.

RESULTS

Significant correlations between listening effort and several components of the auditory processing tests were established. Specifically, listening effort correlated significantly with some components of the SSWT as well as the DDT. Additionally, the listening effort test showed a significant age effect for the listening condition with the highest Signal-To-Noise Ratio.

CONCLUSIONS

Based on the current results, inclusion of listening effort in the test battery for auditory processing disorders would be valuable.

Longitudinal touchscreen use across early development is associated with faster exogenous and reduced endogenous attention control

Childhood screen time is associated with both attentional difficulties (for television viewing) and benefits (in action video gamers), but few studies have investigated today’s pervasive touchscreen devices (e.g. smartphones and tablets), which combine salient features, interactive content, and accessibility from toddlerhood (a peak period of cognitive development). We tested exogenous and endogenous attention, following forty children who were stable high (HU) or low (LU) touchscreen users from toddlerhood to pre-school. HUs were slower to disengage attention, relative to their faster baseline orienting ability. In an infant anti-saccade task, HUs displayed more of a corrective strategy of orienting faster to distractors before anticipating the target. Results suggest that long-term high exposure to touchscreen devices is associated with faster exogenous attention and concomitant decreases in endogenous attention control. Future work is required to demonstrate causality, dissociate variants of use, and investigate how attention behaviours found in screen-based contexts translate to real-world settings.

Executive functions in agenesis of the corpus callosum: Working memory and sustained attention in the BTBR inbred mouse strain

INTRODUCTION

Agenesis of the corpus callosum (AgCC) is characterized by the congenital partial or complete absence of the corpus callosum. Several strains of mice have been reported to carry AgCC, with the BTBR T⁺ Itpr3^tf /J (BTBR) inbred mouse strain consistently showing a complete absence of the corpus callosum, as well as a variable reduction in the size of the hippocampal commissure. While much research has focused on the social deficits of the BTBR strain, little research on its cognitive behavior has been conducted. The goal of our study was to compare two facets of executive functioning, spatial working memory, and sustained attention between the BTBR and C57BL/6J (B6) strains.

METHODS

Spatial working memory was measured utilizing a delayed matching-to-position (DMTP) task and sustained attention was measured utilizing an operant task in which mice were trained to distinguish signal and nonsignal events.

RESULTS

Both the BTBR and B6 mice demonstrated a predictable decline in performance on the DMTP task as the delay interval increased and predictable increase in performance on the sustained attention task as the duration of the signal event increased. Although no significant differences were found between strains on the performance of these tasks, there was a significant difference in learning the association between lever pressing and food reward. Histological investigation confirmed the complete absence of commissural fibers from the corpus callosum, but also the hippocampal commissure, counter to a previous study.

CONCLUSION

The results suggest spatial working memory and sustained attention are unaffected by the absence of these commissural fibers alone.

The Effect of Martial Arts Training on Cognitive and Psychological Functions in At-Risk Youths

The current study assessed whether an extended program of martial arts training was a viable intervention for at-risk youths in improving cognitive and psychological functions. Adolescent boys attending specialized education facilities for at-risk youths took part in regular sport lessons or martial arts practice twice a week for 6 months. Hormonal reactivity was assessed during initial training, and measures of psychological (aggression, self-esteem) and cognitive (inhibition, flexibility, speed of processing, and attention) functions were assessed before and immediately following the intervention. Participants in the martial arts training demonstrated significant improvement in the domains of inhibition and shifting and speed of processing. Additionally, initial hormonal reactivity (oxytocin and cortisol) to the intervention predicted significant post-intervention change on several measures of cognitive and psychological functioning. Specifically, oxytocin reactivity predicted improvement in processing speed, as well as reduction of aggression, whereas cortisol reactivity predicted increases in self-esteem. This pioneering, ecologically valid study demonstrates the initial efficacy of this enjoyable, readily available, group intervention for at-risk boys and suggests potential mechanisms that may mediate the process of change.

Comparative analysis of sleep patterns and attention components in high school and college adolescents

Adolescence is a phase with physiological and behavioral changes. One of them occurs in the sleep-wake cycle pattern, manifested by a phase delay. However, morning school start time can decrease sleep duration during weekdays, impairing adolescent cognitive performance and well-being. Adolescents of different ages and educational level might suffer the impact of academic demand on sleep-wake cycle and cognition differently. Thus, the aim of this study is to compare the sleep habits and quality, sleepiness upon awakening and attention components among adolescents in the first years of high school and college. 71 adolescents participated in the study (45 girls and 26 boys), 44 enrolled in high school morning classes (G1 - 15.5±0.7 years), from a private school, and 27 college students enrolled in morning classes (G2 - 18.8±1.04 years), from biosciences courses from a public institution. The groups did not differ in bedtime, get up time, time in bed and sleep irregularity. However, both groups showed differences according to the day of the week, bedtime and get up time became later and time in bed extended on weekends. G1 presented worse sleep quality and regarding attention, showed higher percentage of omissions in all components and worse performance in sustained attention (ANOVA, p<0.05). The poorer sleep quality of high school adolescents and reduced attention may have a negative effect on school performance. Additional studies are needed to investigate the causes of these differences between these two educational levels.

Mindfulness training preserves sustained attention and resting state anticorrelation between default-mode network and dorsolateral prefrontal cortex: A randomized controlled trial

Mindfulness training can enhance cognitive control, but the neural mechanisms underlying such enhancement in children are unknown. Here, we conducted a randomized controlled trial (RCT) with sixth graders (mean age 11.76 years) to examine the impact of 8 weeks of school-based mindfulness training, relative to coding training as an active control, on sustained attention and associated resting-state functional brain connectivity. At baseline, better performance on a sustained-attention task correlated with greater anticorrelation between the default mode network (DMN) and right dorsolateral prefrontal cortex (DLPFC), a key node of the central executive network. Following the interventions, children in the mindfulness group preserved their sustained-attention performance (i.e., fewer lapses of attention) and preserved DMN-DLPFC anticorrelation compared to children in the active control group, who exhibited declines in both sustained attention and DMN-DLPFC anticorrelation. Further, change in sustained-attention performance correlated with change in DMN-DLPFC anticorrelation only within the mindfulness group. These findings provide the first causal link between mindfulness training and both sustained attention and associated neural plasticity. Administered as a part of sixth graders' school schedule, this RCT supports the beneficial effects of school-based mindfulness training on cognitive control.

White matter abnormalities and cognitive function in euthymic patients with bipolar disorder and major depressive disorder

OBJECTIVES

In recent years, a growing number of diffusion tensor imaging (DTI) studies have compared white matter integrity between patients with major depressive disorder (MDD) and bipolar disorder (BD). However, few studies have examined the pathophysiological significance of different degrees of white matter abnormalities between the two disorders. The present study comprehensively assessed white matter integrity among healthy controls (HC) and euthymic patients with MDD and BD using whole-brain tractography and examined associations between white matter integrity and cognitive functioning.

METHODS

We performed neurocognitive examinations and DTI with 30 HCs, 30 patients with MDD, and 30 patients with BD. We statistically evaluated white matter integrity and cognitive function differences across the three groups, assessing associations between white matter integrities and cognitive function.

RESULTS

The BD group showed lower fractional anisotropy (FA) for the corpus callosum body, as well as lower, sustained attention and set-shifting scores compared to the other groups. FA for the left body of the corpus callosum was correlated with sustained attention in patients with BD.

CONCLUSIONS

The significant reduction of white matter integrity in the corpus callosum in BD, compared to MDD, was associated with an impairment of sustained attention. This result promotes the understanding of the significance of white matter integrity in mood disorders.

Differential effects of different antipsychotic drugs on cognitive function in patients with chronic schizophrenia

BACKGROUND

Cognitive impairment is core feature of schizophrenia. The impact of antipsychotics on cognition remains controversial. This study aimed to examine the effects of long-term use of different types of antipsychotics on cognitive impairment in schizophrenia patients.

METHODS

We used the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to assess the cognition of three groups of schizophrenia patients (318 on clozapine, 125 on risperidone, and 166 on typical antipsychotic drugs) and 399 healthy controls, and used the Positive and Negative Syndrome Scale to assess schizophrenia symptoms of patients.

RESULTS

Patients taking typical antipsychotics scored higher on the immediate memory and delayed memory index than those taking clozapine or risperidone (all p < 0.01). Patients taking clozapine scored higher on the language subscale than those taking risperidone (p < 0.05). Multiple regression analysis showed that the drug type was identified as an independent contributor to the immediate memory, language, and delayed memory index of RBANS (all p < 0.05).

CONCLUSIONS

Patients taking typical antipsychotics have better memory than those taking clozapine or risperidone. Patients taking clozapine have better language function than those taking risperidone.

Intraindividual reaction time variability as an index of attentional control acts as a moderator of the longitudinal relationships between marital quality and children's externalizing problems

The current study investigated whether trial-to-trial intraindividual reaction time variability (IIRTV), which serves as an index of attentional control fluctuations, moderates the effect of marital quality at 7 years of age on the development of children's externalizing problems from 7 to 9 years of age (N = 197). At the first assessment (T1), a flanker task was administered to children for assessing their IIRTV. The Chinese version of a marital quality questionnaire (Evaluating and Nurturing Relationship Issues, Communication, and Happiness [ENRICH]) and the Chinese version of the Child Behavior Checklist (CBCL) were completed by children's mothers to assess marital quality and children's externalizing problems. At the second and third assessments (T2 and T3), children's externalizing problems were reassessed by their mothers. Growth curve analyses showed that boys' externalizing problems were relatively high and significantly decreased over time, whereas girls' externalizing problems were relatively low and stable. Importantly, the results indicated that boys' IIRTV (but not girls' IIRTV) and parental marital quality interactively predict the concurrent and developmental trajectories of externalizing problems. Specifically, boys with greater IIRTV were found to exhibit a relatively persistent high level of externalizing problems in the context of poor parental marital quality, whereas boys with lower IIRTV were found to exhibit a relatively low level of externalizing problems over time regardless of their parental marital quality. The findings suggest that poorer attentional control indexed by greater IIRTV is a robust predictor of boys' externalizing problems and that better attentional control indexed by lower IIRTV may buffer the negative impact of adverse family environment on the development of boys' externalizing problems.

Pupillometry as an Objective Measure of Sustained Attention in Young and Older Listeners

The ability to sustain attention on a task-relevant sound source while avoiding distraction from concurrent sounds is fundamental to listening in crowded environments. We aimed to (a) devise an experimental paradigm with which this aspect of listening can be isolated and (b) evaluate the applicability of pupillometry as an objective measure of sustained attention in young and older populations. We designed a paradigm that continuously measured behavioral responses and pupillometry during 25-s trials. Stimuli contained a number of concurrent, spectrally distinct tone streams. On each trial, participants detected gaps in one of the streams while resisting distraction from the others. Behavior demonstrated increasing difficulty with time-on-task and with number/proximity of distractor streams. In young listeners (N = 20; aged 18 to 35 years), pupil diameter (on the group and individual level) was dynamically modulated by instantaneous task difficulty: Periods where behavioral performance revealed a strain on sustained attention were accompanied by increased pupil diameter. Only trials on which participants performed successfully were included in the pupillometry analysis so that the observed effects reflect task demands as opposed to failure to attend. In line with existing reports, we observed global changes to pupil dynamics in the older group (N = 19; aged 63 to 79 years) including decreased pupil diameter, limited dilation range, and reduced temporal variability. However, despite these changes, older listeners showed similar effects of attentive tracking to those observed in the young listeners. Overall, our results demonstrate that pupillometry can be a reliable and time-sensitive measure of attentive tracking over long durations in both young and (with caveats) older listeners.

Stress Regulation of Sustained Attention and the Cholinergic Attention System

BACKGROUND

Stress exacerbates symptoms of schizophrenia and attention-deficit/hyperactivity disorder, which are characterized by impairments in sustained attention. Yet how stress regulates attention remains largely unexplored. We investigated whether a 6-day variable stressor altered sustained attention and the cholinergic attention system in male and female rats.

METHODS

Sustained attention was tested with the sustained attention task. Successful performance on the sustained attention task relies on the release of acetylcholine (ACh) into the cortex from cholinergic neurons in the nucleus basalis of Meynert (NBM). Thus, we evaluated whether variable stress (VS) altered the morphology of these neurons with a novel approach using a Cre-dependent virus in genetically modified ChAT::Cre rats, a species used for this manipulation only. Next, electrochemical recordings measured cortical ACh following VS. Finally, we used RNA sequencing to identify VS-induced transcriptional changes in the NBM.

RESULTS

VS impaired attentional performance in the sustained attention task and increased the dendritic complexity of NBM cholinergic neurons in both sexes. NBM cholinergic neurons are mainly under inhibitory control, so this morphological change could increase inhibition on these neurons, reducing downstream ACh release to impair attention. Indeed, VS decreased ACh release in the prefrontal cortex of male rats. Quantification of global transcriptional changes revealed that although VS induced many sex-specific changes in gene expression, it increased several signaling molecules in both sexes.

CONCLUSIONS

These studies suggest that VS impairs attention by inducing molecular and morphological changes in the NBM. Identifying mechanisms by which stress regulates attention may guide the development of novel treatments for psychiatric disorders with attention deficits.

Controlling Brain State Prior to Stimulation of Parietal Cortex Prevents Deterioration of Sustained Attention

Sustained attention is a limited resource which declines during daily tasks. Such decay is exacerbated in clinical and aging populations. Inhibition of the intraparietal sulcus (IPS), using low-frequency repetitive transcranial magnetic stimulation (LF-rTMS), can lead to an upregulation of functional communication within the attention network. Attributed to functional compensation for the inhibited node, this boost lasts for tens of minutes poststimulation. Despite the neural change, no behavioral correlate has been found in healthy subjects, a necessary direct evidence of functional compensation. To understand the functional significance of neuromodulatory induced fluctuations on attention, we sought to boost the impact of LF-rTMS to impact behavior. We controlled brain state prior to LF-rTMS using high-frequency transcranial random noise stimulation (HF-tRNS), shown to increase and stabilize neuronal excitability. Using fMRI-guided stimulation protocols combining HF-tRNS and LF-rTMS, we tested the poststimulation impact on sustained attention with multiple object tracking (MOT). While attention deteriorated across time in control conditions, HF-tRNS followed by LF-rTMS doubled sustained attention capacity to 94 min. Multimethod stimulation was more effective when targeting right IPS, supporting specialized attention processing in the right hemisphere. Used in cognitive domains dependent on network-wide neural activity, this tool may cause lasting neural compensation useful for clinical rehabilitation.

Astrocytes-The Ultimate Effectors of Long-Range Neuromodulatory Networks?

It was long thought that astrocytes, given their lack of electrical signaling, were not involved in communication with neurons. However, we now know that one astrocyte on average maintains and regulates the extracellular neurotransmitter and potassium levels of more than 140,000 synapses, both excitatory and inhibitory, within their individual domains, and form a syncytium that can propagate calcium waves to affect distant cells via release of “gliotransmitters” such as glutamate, ATP, or adenosine. Neuromodulators can affect signal-to-noise and frequency transmission within cortical circuits by effects on inhibition, allowing for the filtering of relevant vs. irrelevant stimuli. Moreover, synchronized “resting” and desynchronized “activated” brain states are gated by short bursts of high-frequency neuromodulatory activity, highlighting the need for neuromodulation that is robust, rapid, and far-reaching. As many neuromodulators are released in a volume manner where degradation/uptake and the confines of the complex CNS limit diffusion distance, we ask the question—are astrocytes responsible for rapidly extending neuromodulator actions to every synapse? Neuromodulators are known to influence transitions between brain states, leading to control over plasticity, responses to salient stimuli, wakefulness, and sleep. These rapid and wide-spread state transitions demand that neuromodulators can simultaneously influence large and diverse regions in a manner that should be impossible given the limitations of simple diffusion. Intriguingly, astrocytes are ideally situated to amplify/extend neuromodulator effects over large populations of synapses given that each astrocyte can: (1) ensheath a large number of synapses; (2) release gliotransmitters (glutamate/ATP/adenosine) known to affect inhibition; (3) regulate extracellular potassium that can affect excitability and excitation/inhibition balance; and (4) express receptors for all neuromodulators. In this review article, we explore the hypothesis that astrocytes extend and amplify neuromodulatory influences on neuronal networks via alterations in calcium dynamics, the release of gliotransmitters, and potassium homeostasis. Given that neuromodulatory networks are at the core of our sleep-wake cycle and behavioral states, and determine how we interact with our environment, this review article highlights the importance of basic astrocyte function in homeostasis, general cognition, and psychiatric disorders.

Cholinergic Modulation of the Default Mode Like Network in Rats

The discovery of the default mode network (DMN), a large-scale brain network that is suppressed during attention-demanding tasks, had major impact in neuroscience. This network exhibits an antagonistic relationship with attention-related networks. A better understanding of the processes underlying modulation of DMN is imperative, as this network is compromised in several neurological diseases. Cholinergic neuromodulation is one of the major regulatory networks for attention, and studies suggest a role in regulation of the DMN. In this study, we unilaterally activated the right basal forebrain cholinergic neurons and observed decreased right intra-hemispheric and interhemispheric FC in the default mode like network (DMLN). Our findings provide critical insights into the interplay between cholinergic neuromodulation and DMLN, demonstrate that differential effects can be exerted between the two hemispheres by unilateral stimulation, and open windows for further studies involving directed modulations of DMN in treatments for diseases demonstrating compromised DMN activity.

A Review on the Role of the Neuroscience of Flow States in the Modern World

Flow states have been shown to help people reach peak performance, yet this elusive state is not easily attained. The review describes the current state of literature on flow by addressing the environmental influences as well as the cognitive and neurocognitive elements that underlie the experience. In particular, the research focusses on the transition of cognitive control from an explicit to an implicit process. This is further expanded upon to look at the current, yet related neurocognitive research of high performance associated with the implicit process of automaticity. Finally, the review focusses on transcranial direct current stimulation (tDCS) as a novel method to facilitates an induction of flow states. Implications are aimed at a general technique to improve on skill acquisition and overall performance.

Relationship Between Task-Based and Parent Report-Based Measures of Attention and Executive Function in Children with Fetal Alcohol Spectrum Disorders (FASD)

A majority of children with fetal alcohol spectrum disorders (FASD) have demonstrated attention and executive function deficits as measured by both parent report measures and performance on tasks requiring sustained levels of attention. However, prior studies have consistently reported a lack of association between parental report-based and task-based performance measures. The current study investigated whether changes in performance over time within-task (i.e., first-half versus second-half) better correspond to parental reports of executive function and temperament in children with FASD. Greater differences in split-half performance during a continuous performance task were found to be associated with higher parent-reported levels of behavioral regulation and inhibitory control. These findings suggest that within-task performance differences may more accurately reflect individual differences in executive function and temperament as measured by parental report and help to further inform the way in which cognitive processes are measured in children with FASD.

Nicotinic Receptor Subunit Distribution in Auditory Cortex: Impact of Aging on Receptor Number and Function

The presence of novel or degraded communication sounds likely results in activation of basal forebrain cholinergic neurons increasing release of ACh onto presynaptic and postsynaptic nAChRs in primary auditory cortex (A1). nAChR subtypes include high-affinity heteromeric nAChRs commonly composed of α4 and β2 subunits and low-affinity homomeric nAChRs composed of α7 subunits. In young male FBN rats, we detail the following: (1) the distribution/expression of nAChR subunit transcripts in excitatory (VGluT1) and inhibitory (VGAT) neurons across A1 layers; (2) heteromeric nAChR binding across A1 layers; and (3) nAChR excitability in A1 layer (L) 5 cells. In aged rats, we detailed the impact of aging on A1 nAChR subunit expression across layers, heteromeric nAChR receptor binding, and nAChR excitability of A1 L5 cells. A majority of A1 cells coexpressed transcripts for β2 and α4 with or without α7, while dispersed subpopulations expressed β2 and α7 or α7 alone. nAChR subunit transcripts were expressed in young excitatory and inhibitory neurons across L2-L6. Transcript abundance varied across layers, and was highest for β2 and α4. Significant age-related decreases in nAChR subunit transcript expression (message) and receptor binding (protein) were observed in L2-6, most pronounced in infragranular layers. In vitro patch-clamp recordings from L5B pyramidal output neurons showed age-related nAChR subunit-selective reductions in postsynaptic responses to ACh. Age-related losses of nAChR subunits likely impact ways in which A1 neurons respond to ACh release. While the elderly require additional resources to disambiguate degraded speech codes, resources mediated by nAChRs may be compromised with aging.SIGNIFICANCE STATEMENT When attention is required, cholinergic basal forebrain neurons may trigger increased release of ACh onto auditory neurons in primary auditory cortex (A1). Laminar and phenotypic differences in neuronal nAChR expression determine ways in which A1 neurons respond to release of ACh in challenging acoustic environments. This study detailed the distribution and expression of nAChR subunit transcript and protein across A1 layers in young and aged rats. Results showed a differential distribution of nAChR subunits across A1 layers. Age-related decreases in transcript/protein expression were reflected in age-related subunit specific functional loss of nAChR signaling to ACh application in A1 layer 5. Together, these findings could reflect the age-related decline in selective attention observed in the elderly.

Attention for Speaking: Prestimulus Motor-cortical Alpha Power Predicts Picture Naming Latencies

There is a range of variability in the speed with which a single speaker will produce the same word from one instance to another. Individual differences studies have shown that the speed of production and the ability to maintain attention are related. This study investigated whether fluctuations in production latencies can be explained by spontaneous fluctuations in speakers' attention just prior to initiating speech planning. A relationship between individuals' incidental attentional state and response performance is well attested in visual perception, with lower prestimulus alpha power associated with faster manual responses. Alpha is thought to have an inhibitory function: Low alpha power suggests less inhibition of a specific brain region, whereas high alpha power suggests more inhibition. Does the same relationship hold for cognitively demanding tasks such as word production? In this study, participants named pictures while EEG was recorded, with alpha power taken to index an individual's momentary attentional state. Participants' level of alpha power just prior to picture presentation and just prior to speech onset predicted subsequent naming latencies. Specifically, higher alpha power in the motor system resulted in faster speech initiation. Our results suggest that one index of a lapse of attention during speaking is reduced inhibition of motor-cortical regions: Decreased motor-cortical alpha power indicates reduced inhibition of this area while early stages of production planning unfold, which leads to increased interference from motor-cortical signals and longer naming latencies. This study shows that the language production system is not impermeable to the influence of attention.

Manipulating sleep duration perception changes cognitive performance - An exploratory analysis

OBJECTIVES

To test the effect of perceived sleep duration on cognitive performance.

METHODS

Sixteen healthy individuals [8F; mean age (± SD): 24.2 ± 3.0 years)] received an 8-h sleep opportunity followed by a 5-h opportunity on two consecutive nights. Upon waking, they were randomized to being informed that they received either an 8-h or 5-h sleep opportunity, via a clock that ran either fast, slow or normally. Cognitive performance was assessed using 10-min auditory psychomotor vigilance tests and subjective sleepiness ratings. Homeostatic and circadian sleep drive was assessed using waking electroencephalography (EEG).

RESULTS

Reaction time was significantly quicker when individuals thought that they had slept for 8 h but given a 5-h sleep opportunity. Conversely, reaction times were significantly slower when individuals thought they had 5 h of sleep but given an 8-h sleep opportunity. EEG delta power (1.0-4.5 Hz) during wake increased significantly when sleep was restricted to 5 h, and individuals thought they slept for 5 h, but this increase was attenuated with a perceived sleep duration of 8 h following a 5-h opportunity. EEG delta power did not increase, however, with perceived sleep restriction. EEG high-alpha activity (10.5-11.5 Hz) was consistently higher when participants thought that they had an 8-h sleep opportunity, regardless of the actual duration.

CONCLUSIONS

These results suggest that perceived sleep duration may modulate psychosomatic responses. Additional studies with predefined outcomes and analyses are necessary to confirm these findings, which may have important implications for understanding how sleep affects cognition and psychosomatic responses.

Emotion-Cognition Interactions in Attention-Deficit/Hyperactivity Disorder: Increased Early Attention Capture and Weakened Attentional Control in Emotional Contexts

BACKGROUND

Emotion dysregulation is a key dimensional trait in psychopathology. It is of particular interest in attention-deficit/hyperactivity disorder (ADHD) because individual differences in emotion dysregulation predict impairment. Despite growing recognition of its importance, an understanding of emotional functioning in ADHD needs to be better integrated with the well-known nonemotional attentional impairments in the disorder. Here, we assess differences in early, reactive and later, regulatory attention to emotional stimuli, as well as how impairments in attentional control to nonemotional stimuli are affected under different emotional contexts.

METHODS

In all, 130 adolescents (nADHD = 61) completed an emotional go/no-go task while 32-channel electroencephalography data were recorded. Reaction time and accuracy were analyzed using the linear ballistic accumulator model.

RESULTS

The multimethod approach provided convergent evidence of increased early, reactive attention capture and overarousal (faster drift rates, increased P1) by positively valenced stimuli in ADHD, but no differences in later attention to emotional stimuli. Overarousal in positive-valence contexts appeared to exacerbate existing ADHD-related impairments in attentional control to nonemotional stimuli as well (reduced N2 amplitude). In contrast, positive-valence contexts facilitated attentional control to nonemotional stimuli for typically developing adolescents.

CONCLUSIONS

Results highlight the dynamic interaction of emotion with attentional control in ADHD. Distinguishing reactive and regulatory contributions to emotion dysregulation has been informative for clarifying mechanisms and spurring the development of novel interventions in other disorders. It can be informative in ADHD as well.

A diffusion model analysis of sustained attention in children with attention deficit hyperactivity disorder

OBJECTIVE

Whether children with attention deficit hyperactivity disorder (ADHD) have deficits in sustained attention remains unresolved due to the ongoing use of cognitive paradigms that are not optimized for studying vigilance and the fact that relatively few studies report performance over time.

METHOD

In three independent samples of school-age children with (total N = 128) and without ADHD (total N = 59), we manipulated event rate, difficulty of discrimination, and use signal detection (SDT) and diffusion models (DM) to evaluate the cause of the vigilance decrement during a continuous performance task.

RESULTS

For both groups of children, a bias toward "no-go" over time (as indexed by the SDT parameter B″ and the DM parameter z/a) was responsible for generating the vigilance decrement. However, among children with ADHD, the rate at which information accumulated to make a no-go decision (vNoGo) also increased with time on task, representing a possible secondary mechanism that biases children against engagement. At all time points, children with ADHD demonstrated reduced sensitivity to discriminate targets from nontargets.

CONCLUSION

Children with ADHD are particularly sensitive to the cost of task engagement, but nonspecific slower drift rate may ultimately provide a better conceptualization of the cognitive atypicalities commonly observed in that group. Results are interpreted in the context of updated conceptualizations of sustained attention and vigilance. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Frontal cerebral oxygenation asymmetry: intersubject variability and dependence on systemic physiology, season, and time of day

Significance: Our study reveals that frontal cerebral oxygenation asymmetry (FCOA), i.e. a difference in the oxygenation between the right and left prefrontal cortex (PFC), is a real phenomenon in healthy human subjects at rest. Aim: To investigate FCOA, we performed a study with 134 healthy right-handed subjects with the systemic physiology augmented functional near infrared spectroscopy (SPA-fNIRS) approach. Approach: Subjects were measured 2 to 4 times on different days resulting in an unprecedented number of 518 single measurements of the absolute values of tissue oxygen saturation (StO 2 ) and total hemoglobin concentration ([tHb]) of the right and left PFC. Measurements were performed with frequency-domain functional near-infrared spectroscopy. In addition, the cardiorespiratory parameters were measured simultaneously. Results: We found that (i) subjects showed an FCOA (higherStO 2 on the right PFC), but not for tHb; (ii) intrasubject variability was excellent for bothStO 2 and tHb, and fair for FCOA; (iii) StO 2 correlated significantly with bloodCO 2 concentration, [tHb] with heart rate, respiration rate (RR), and the pulse-respiration quotient (PRQ), and FCOA with RR and PRQ; (iv) FCOA andStO 2 were dependent on season and time of day, respectively; (v) FCOA was negatively correlated with the room temperature; and (vi) StO 2 and tHb were not correlated with the subjects mood but with their chronotype, whereas FCOA was not dependent on the chronotype. Conclusion: Our study demonstrates that FCOA is real, and it provides unique insights into this remarkable phenomenon.

Muscarinic and Nicotinic Modulation of Memory but not Verbal Problem-solving

Aspects of cognitive flexibility are modulated by the noradrenergic system, which is important in arousal and attention. Acetylcholine also modulates arousal and attention, as well as working memory. Effects of muscarinic and nicotinic antagonism on memory are well established. Our purpose was to test whether muscarinic and nicotinic antagonism affect aspects of cognitive flexibility, specifically verbal problem-solving, as well as memory, given acetylcholine's role in attention and arousal. Eighteen participants attended three testing sessions. Two hours before testing, participants received either 0.6 mg scopolamine, 10 mg mecamylamine, or placebo. Then, participants were tested on three memory tasks (Buschke Selective Reminding Test [BSRT], California Verbal Learning Test [CVLT], Rey Complex Figure Test), two verbal problem-solving/cognitive flexibility tasks (Compound Remote Associates Test, a timed anagram test), and a spatial inductive reasoning task (Raven's Progressive Matrices). Task order and drug order were counterbalanced. Memory impairment was seen on one BSRT measure and multiple CVLT measures with scopolamine, and with one BSRT measure with mecamylamine. There were no effects of either drug on any of the tasks involving cognitive flexibility, including verbal problem-solving. Specific memory impairments were detected using muscarinic, and to a marginal extent, nicotinic antagonists, as expected, but no effect was seen on cognitive flexibility. Therefore, although both the noradrenergic and cholinergic systems play important roles in arousal and cortical signal-to-noise processing, the cholinergic system does not appear to have the same effect as the noradrenergic system on cognitive flexibility, including verbal problem-solving.

Attentional networks functioning and vigilance in expert musicians and non-musicians

Previous literature has shown cognitive improvements related to musical training. Attention is one cognitive aspect in which musicians exhibit improvements compared to non-musicians. However, previous studies show inconsistent results regarding certain attentional processes, suggesting that benefits associated with musical training appear only in some processes. The present study aimed to investigate the attentional and vigilance abilities in expert musicians with a fine-grained measure: the ANTI-Vea (ANT for Interactions and Vigilance-executive and arousal components; Luna et al. in J Neurosci Methods 306:77-87, https://doi.org/10.1016/j.jneumeth.2018.05.011 , 2018). This task allows measuring the functioning of the three Posner and Petersen's networks (alerting, orienting, and executive control) along with two different components of vigilance (executive and arousal vigilance). Using propensity-score matching, 49 adult musicians (18-35 years old) were matched in an extensive set of confounding variables with a control group of 49 non-musicians. Musicians showed advantages in processing speed and in the two components of vigilance, with some specific aspects of musicianship such as years of practice or years of lessons correlating with these measures. Although these results should be taken with caution, given its correlational nature, one possible explanation is that musical training can specifically enhance some aspects of attention. Nevertheless, our correlational design does not allow us to rule out other possibilities such as the presence of cognitive differences prior to the onset of training. Moreover, the advantages were observed in an extra-musical context, which suggests that musical training could transfer its benefits to cognitive processes loosely related to musical skills. The absence of effects in executive control, frequently reported in previous literature, is discussed based on our extensive control of confounds.

Amygdala 5-HTT Gene Network Moderates the Effects of Postnatal Adversity on Attention Problems: Anatomo-Functional Correlation and Epigenetic Changes

Variations in serotoninergic signaling have been related to behavioral outcomes. Alterations in the genome, such as DNA methylation and histone modifications, are affected by serotonin neurotransmission. The amygdala is an important brain region involved in emotional responses and impulsivity, which receives serotoninergic input. In addition, studies suggest that the serotonin transporter gene network may interact with the environment and influence the risk for psychiatric disorders. We propose to investigate whether/how interactions between the exposure to early life adversity and serotonin transporter gene network in the amygdala associate with behavioral disorders. We constructed a co-expression-based polygenic risk score (ePRS) reflecting variations in the function of the serotonin transporter gene network in the amygdala and investigated its interaction with postnatal adversity on attention problems in two independent cohorts from Canada and Singapore. We also described how interactions between ePRS-5-HTT and postnatal adversity exposure predict brain gray matter density and variation in DNA methylation across the genome. We observed that the expression-based polygenic risk score, reflecting the function of the amygdala 5-HTT gene network, interacts with postnatal adversity, to predict attention and hyperactivity problems across both cohorts. Also, both postnatal adversity score and amygdala ePRS-5-HTT score, as well as their interaction, were observed to be associated with variation in DNA methylation across the genome. Variations in gray matter density in brain regions linked to attentional processes were also correlated to our ePRS score. These results confirm that the amygdala 5-HTT gene network is strongly associated with ADHD-related behaviors, brain cortical density, and epigenetic changes in the context of adversity in young children.

Video games as rich environments to foster brain plasticity

This chapter highlights the key role of two main factors, attentional control and reward processing, in unlocking brain plasticity. We first review the evidence for the role that each of these mechanisms plays in neuroplasticity, and then make the case that tools and technologies that combine these two are likely to result in maximal and broad, generalized benefits. In this context, we review the evidence concerning the impact of video game play on brain plasticity, with an eye toward plasticity-driving methods such as the seamless integration of neurofeedback into the video game platforms.

Effects of prebiotics on affect and cognition in human intervention studies

Studies conducted in rodents have highlighted that neurobiological processes underlying cognition and affect are modulated by the gut microbiota. Certain dietary fibers are able to modulate the composition of gut microbiota and are thus considered prebiotics. A review of the impact of the available prebiotic intervention studies in humans on cognition and affect, addressing the potential mediating role of the microbiota, was conducted. PubMed, Scopus, and PsycINFO were selected as sources. Fourteen articles were eligible for narrative synthesis. Data extraction and quality assessment were performed with characteristics established a priori. Some chronic prebiotic interventions (>28 d) improved affect and verbal episodic memory compared with a placebo. Acute prebiotic interventions (<24 h) were more efficient in improving cognitive variables (eg, verbal episodic memory). Future research should measure microbiota using adequate methodologies and recruit patients with dysbiosis, inflammation, or psychopathology. More research is needed to unravel the conditions required to obtain effects on affect and cognition.

Cognitive Abilities of Dogs with Mucopolysaccharidosis I: Learning and Memory

Mucopolysaccharidosis I (MPS I) results from a deficiency of a lysosomal enzyme, alpha-L-iduronidase (IDUA). IDUA deficiency leads to glycosaminoglycan (GAG) accumulation resulting in cellular degeneration and multi-organ dysfunction. The primary aims of this pilot study were to determine the feasibility of cognitive testing MPS I affected dogs and to determine their non-social cognitive abilities with and without gene therapy. Fourteen dogs were tested: 5 MPS I untreated, 5 MPS I treated, and 4 clinically normal. The treated group received intrathecal gene therapy as neonates to replace the IDUA gene. Cognitive tests included delayed non-match to position (DNMP), two-object visual discrimination (VD), reversal learning (RL), attention oddity (AO), and two-scent discrimination (SD). Responses were recorded as correct, incorrect, or no response, and analyzed using mixed effect logistic regression analysis. Significant differences were not observed among the three groups for DNMP, VD, RL, or AO. The MPS I untreated dogs were excluded from AO testing due to failing to pass acquisition of the task, potentially representing a learning or executive function deficit. The MPS I affected group (treated and untreated) was significantly more likely to discriminate between scents than the normal group, which may be due to an age effect. The normal group was comprised of the oldest dogs, and a mixed effect logistic model indicated that older dogs were more likely to respond incorrectly on scent discrimination. Overall, this study found that cognition testing of MPS I affected dogs to be feasible. This work provides a framework to refine future cognition studies of dogs affected with diseases, including MPS I, in order to assess therapies in a more comprehensive manner.

Gender-specific differences in white matter microstructure in healthy adults exposed to mild stress

Stress is a powerful moderator of brain plasticity and may affect several physiological functions such as the endocrine and the immune system. The impact of stress can be protective or detrimental according to several factors such as level of the stressor and age of occurrence. Also, the impact may differ in males and females. We aim to analyze the effect of mild levels of early and recent stress on white matter microstructure in healthy volunteers. MRI acquisition of diffusion tensor images with a 3.0 T scanner was performed on 130 healthy subjects (71 males and 59 females). Severity of early and recent stress was rated, respectively, on the Risky Families Questionnaire and on the Schedule of Recent Experiences; subjects were divided into low stress and mild stress groups. Mild early stress associated with lower fractional anisotropy (FA) in the cingulate gyrus compared to low early stress. Females reported reduced FA compared to males in the low-stress group in the internal capsule, posterior corona radiata, posterior thalamic radiation, superior longitudinal fasciculus, and sagittal stratum whereas no difference was observed in the mild stress group. An additive effect of early and recent stress was observed in posterior corona radiata, retrolenticular part of the internal capsule, and superior longitudinal fasciculus. The impact of early stress on WM microstructure in healthy subjects is different in males and females. While males seem to be more sensitive to early stress, an additive effect of early and recent stress manifests itself in females.Layman summaryMild levels of early stress associate with lower white matter integrity measured by fractional anisotropy.Females and males show differences in white matter integrity when exposed to low levels of early stress with females showing lower white matter integrity compared to males.No difference in white matter integrity was observed for males and females exposed to mild levels of stress.Mild stress in females is associated with higher white matter integrity.Males seem to be more sensitive to early stress while females are more affected when early stress is followed by stress in adult life.

Psychological Resilience, Mental Health, and Inhibitory Control Among Youth and Young Adults Under Stress

Psychological resilience allows one to cope successfully with adversities occurring during stressful periods, which may otherwise trigger mental illness. Recent models suggest that inhibitory control (IC), the executive control function which supports our goal-directed behavior and regulates our emotional response, may underlie resilience. However, the ways in which this is manifested during stressful situations in real life is still unclear. Here, we examined the relationship between IC, psychological resilience, psychological distress, and anxiety among 138 female and male participants in a stressful situation: during their initial combat training in the military. Using a mobile app, we assessed IC using emotional and non-emotional variations of the Go/No-Go task. Psychological resilience, psychological distress, and anxiety were assessed using mobile versions of self-report questionnaires. We found that psychological resilience is significantly correlated with non-emotional IC (r = 0.24, p < 0.005), but not with emotional IC; whereas, psychological distress and anxiety are correlated with emotional IC (r = -0.253, p < 0.005 and r = -0.224, p < 0.01, for psychological distress and anxiety, respectively), but not with non-emotional IC. A regression model predicting emotional IC confirmed non-emotional IC and distress as unique contributors to the variance, but not psychological distress. In addition, associations between psychological distress and emotional IC were found only for female participants. Collectively, the results clarify the link between IC, resilience, and mental health in real-life stressful situations, showing separate mechanisms of IC involved in resilience on the one hand, and mental health on the other hand. These results have implications for building mobile resilience interventions for youth and young adults facing stressful situations.

Selective Estrogen Receptor β Agonists: a Therapeutic Approach for HIV-1 Associated Neurocognitive Disorders

The persistence of HIV-1 associated neurocognitive disorders (HAND) in the post-cART era, afflicting between 40 and 70% of HIV-1 seropositive individuals, supports a critical need for the development of adjunctive therapeutic treatments. Selective estrogen receptor β agonists, including S-Equol (SE), have been implicated as potential therapeutic targets for the treatment of neurocognitive disorders. In the present study, the therapeutic efficacy of 0.2 mg SE for the treatment of HAND was assessed to address two key questions in the HIV-1 transgenic (Tg) rat. First, does SE exhibit robust therapeutic efficacy when treatment is initiated relatively early (i.e., between 2 and 3 months of age) in the course of viral protein exposure? Second, does the therapeutic utility of SE generalize across multiple neurocognitive domains? Treatment with SE enhanced preattentive processes and stimulus-response learning to the level of controls in all (i.e., 100%) HIV-1 Tg animals. For sustained and selective attention, statistically significant effects were not observed in the overall analyses (Control: Placebo, n = 10, SE, n = 10; HIV-1 Tg: Placebo, n = 10, SE, n = 10). However, given our a priori hypothesis, subsequent analyses were conducted, revealing enhanced sustained and selective attention, approximating controls, in a subset (i.e., 50%, n = 5 and 80%, n = 8, respectively) of HIV-1 Tg animals treated with SE. Thus, the therapeutic efficacy of SE is greater when treatment is initiated relatively early in the course of viral protein exposure and generalizes across neurocognitive domains, supporting an adjunctive therapeutic for HAND in the post-cART era.

Graphical Abstract