Sustained Processing Research Articles

Exploring the Impact of Math Anxiety and Task Difficulty on Pupil Dilation in Adults and Young Children.

We investigated the relations between self-reported math anxiety, task difficulty, and pupil dilation in adults and very young children during math tasks of varying difficulty levels. While task difficulty significantly influenced pupillary responses in both groups, the association between self-reported math anxiety and pupil dilation differed across age cohorts. The children exhibited resilience to the effects of math anxiety, hinting at additional influential factors such as formal math education experiences shaping their relations to mathematics and their impact on cognitive processes over time. Contrary to expectations, no significant association between self-reported math anxiety and pupil dilation during task anticipation was found in either group. In adults, math anxiety influenced pupil dilation exclusively during the initial phase of task processing indicating heightened cognitive load, but this influence diminished during sustained task processing. Theoretical implications emphasize the need for exploring individual differences, cognitive strategies, and the developmental trajectory of math anxiety in very young children.

Academic Skills Used by College Students Without Brain Injury: A Validation Study

Purpose: The purpose of this study was to develop a brief, ecologically valid measure of academic-related skills used by students in both in-person and online higher education. Method: Twelve undergraduate ( n = 7) and graduate ( n = 5) college students without brain injury participated in a pilot study followed by focus group semistructured interviews. Next, preliminary normative data were collected from a larger sample of undergraduate ( n = 152) and graduate ( n = 73) students without brain injury, ages 18–35 years. Participants were asked to rate the cognitive, communicative, and academic skills they used for in-person and online instruction. The students completed a 27-item scale (Likert, 1 = strongly disagree to 6 = strongly agree ). Results: Following an exploratory factor analysis, seven distinct factors were retained creating the final instrument in the population without brain injury. These included sustained attention, metacognition, working memory, problem solving, reading comprehension, selective attention, and processing speed. Conclusions: Responses from college students without brain injury helped to validate items on the College Readiness After Mild Traumatic Brain Injury scale. Undergraduate and graduate students identified the skills they used in both online and in-person academic learning environments. Future plans include the recruitment of students with mild traumatic brain injury returning to higher education to investigate the sensitivity of the scale.

Adversity and error-monitoring: Effects of emotional context.

This study tested whether self-reports of childhood adversity would predict altered error processing under emotional versus non-emotional task conditions. N = 99 undergraduates completed two selective attention tasks, a traditional color-word Stroop task and a modified task using emotional words, while EEG was recorded. Participants also completed self-report measures of adverse and positive childhood experiences, executive functioning, depression, current stress, and emotion regulation. Reports of adversity were robustly correlated with self-reported challenges in executive functioning, even when controlling for self-reported depression and stress, but adversity was not correlated with task performance. With regard to neural markers of error processing, adversity predicted an enhanced error-related negativity and blunted error-positivity, but only during the emotion-word blocks of the task. Moreover, error-related changes in alpha oscillations were predicted by adversity, in a pattern that suggested less error responsiveness in alpha patterns during the emotion block, compared to the color block, among participants with higher adversity. Overall, results indicate alterations in error monitoring associated with adversity, such that in an emotional context, initial error detection is enhanced and sustained error processing is blunted, even in the absence of overt performance changes.

Can irony regulate negative emotion? Evidence from behaviour and ERPs

ABSTRACT This study used ratings and event-related potentials (ERPs) to compare the mechanisms through which verbal irony and cognitive reappraisal mitigate negative emotion. Verbal irony is when the literal meaning of words contrasts with their intended meaning. Cognitive reappraisal is when we reconsider emotional stimuli to make them less intense. Our hypothesis was that cognitive reappraisal is a potential mechanism through which irony reduces negative emotion. Participants viewed mildly negative pictures first, then read an ironic or literal statement about it in one block, and used cognitive reappraisal of or attending to the picture in the other block. Participants then viewed the picture for a second time, before rating how negative they felt. Behaviourally, irony reduced negative feelings more than literal statements, and reappraisal reduced negative feelings more than attending, with a larger reduction from reappraisal than from irony. In ERPs, irony elicited a prolonged N400 compared to literal, indexing an initial contrast between picture and word affect and sustained processing of their combination. Cognitive reappraisal elicited a larger late positivity compared to attending at the instruction screen. No differences were found during second picture presentation. These findings suggest that irony and cognitive reappraisal can reduce negative affect in different ways.

Knowledge by omission: the significance of omissions in the 5-choice serial reaction time task.

The 5-choice serial reaction time task (5-CSRTT) is commonly used to assess attention in rodents. Manipulation of this task by decreasing the light stimulus duration is often used to probe attentional capacity and causes a decrease in accuracy and an increase in omissions. However, although a decrease in response accuracy is commonly interpreted as a decrease in attention, it is more difficult to interpret an increase in omissions in terms of attentional performance. Here we present a series of experiments in rats that seeks to investigate the origins of these key behavioral measures of attention in the 5-CSRTT. After an initial training in the 5-CSRTT, rats were tested in a variable stimulus duration procedure to increase task difficulty and probe visual attentional capacity under several specific controlled conditions. We found that response accuracy reflects visuospatial sustained attentional processing, as commonly interpreted, while response omission reflects rats' ignorance about the stimulus location, presumably due to failure to pay attention to the curved wall during its presentation. Moreover, when rats lack of relevant information, they choose not to respond instead of responding randomly. Finally, pretreatment with nicotine selectively decreased response omissions, without affecting response accuracy, particularly when the attentional demand was high. Overall, our results indicate that response accuracy and response omission thus correspond to two distinct attentional states.

Individual differences in processing speed and curiosity explain infant habituation and dishabituation performance.

Habituation and dishabituation are the most prevalent measures of infant cognitive functioning, and they have reliably been shown to predict later cognitive outcomes. Yet, the exact mechanisms underlying infant habituation and dishabituation are still unclear. To investigate them, we tested 106 8-month-old infants on a classic habituation task and a novel visual learning task. We used a hierarchical Bayesian model to identify individual differences in sustained attention, learning performance, processing speed and curiosity from the visual learning task. These factors were then related to habituation and dishabituation. We found that habituation time was related to individual differences in processing speed, while dishabituation was related to curiosity, but only for infants who did not habituate. These results offer novel insights in the mechanisms underlying habituation and serve as proof of concept for hierarchical models as an effective tool to measure individual differences in infant cognitive functioning. RESEARCH HIGHLIGHTS: We used a hierarchical Bayesian model to measure individual differences in infants' processing speed, learning performance, sustained attention, and curiosity. Faster processing speed was related to shorter habituation time. High curiosity was related to stronger dishabituation responses, but only for infants who did not habituate.

A meta-analysis on the therapeutic efficacy of repetitive transcranial magnetic stimulation for cognitive functions in attention-deficit/hyperactivity disorders

BackgroundTherapeutic efficacies of repetitive transcranial magnetic stimulation (rTMS) for improving cognitive functions in patients with deficit/hyperactivity disorder (ADHD) remained unclear. The aim of this meta-analysis was to investigate the therapeutic efficacy of rTMS focusing on different cognitive performances.MethodsMajor databases were searched electronically from inception to February 2023 by using keywords mainly “rTMS” and “ADHD” to identify randomized controlled trials (RCTs) that investigated the therapeutic efficacy of rTMS for improving cognitive functions assessed by standardized tasks in patients with ADHD. The overall effect size (ES) was calculated as standardized mean difference (SMD) based on a random effects model.ResultsMeta-analysis of five RCTs with 189 participants (mean age of 32.78 and 8.53 years in adult and child/adolescent populations, respectively) demonstrated that rTMS was more effective for improving sustained attention in patients with ADHD compared with the control groups (SMD = 0.54, p = 0.001).Our secondary analysis also showed that rTMS was more effective for improving processing speed than the control groups (SMD = 0.59, p = 0.002) but not for enhancing memory or executive function.ConclusionsOur results supported the therapeutic efficacy of rTMS for improving sustained attention and processing speed. However, the limitation of available data warrants further studies to verify these findings.

One-year regional brain volume changes as potential predictors of cognitive function in multiple sclerosis: a pilot study

BackgroundThe most reliable magnetic resonance imaging (MRI) marker of cognitive dysfunction in multiple sclerosis (MS) is brain atrophy. However, 1-year volumetric changes prior to cognitive assessment were never studied as potential predictors of cognition, which we aim to assess with this pilot work.MethodsTwenty-two MS patients were submitted to a baseline measure of 83 regional brain volumes with MRI and re-evaluated 1 year later; they were also tested with the Brief International Cognitive Assessment for MS (BICAMS): sustained attention and processing speed were examined with the Symbol Digit Modalities Test (SDMT), verbal and visuo-spatial learning and memory with the learning trials from the California Verbal Learning Test-II (CVLT) and the Brief Visuo-spatial Memory Test-revised (BVMT), respectively. Controlling for age, sex, and years of education, a multivariate linear regression model was created for each cognitive score at 1-year follow-up in a backward elimination manner, considering cross-sectional regional volumes and 1-year volume changes as potential predictors.ResultsDecreases in the volumes of the left amygdala and the right lateral orbitofrontal cortex in the year prior to assessment were identified as possible predictors of worse performance in verbal memory (P = 0.009) and visuo-spatial memory (P = 0.001), respectively, independently of cross-sectional brain regional volumes at time of testing.ConclusionOur work reveals novel 1-year regional brain volume changes as potential predictors of cognitive deficits in MS. This suggests a possible role of these regions in such deficits and might contribute to uncover cognitively deteriorating patients, whose detection is still unsatisfying in clinical practice.

Subjective and neural reactivity during savoring and rumination

Repetitive thinking about negative emotions or events is strongly associated with worse mental health, whereas repetitive positive thought is generally believed to be beneficial. This observation is at odds with the idea that all forms of repetitive thinking share underlying neural mechanisms. To resolve this apparent discrepancy, the present study examined relationships between subjective affect and neural mechanisms during periods of sustained processing of positive (savoring) and negative (rumination) emotion. We also examined potential common moderators of savoring and rumination including memory specificity and sleep quality. Results indicated that individuals who experience high positive affect during savoring also are likely to experience more intense negative affect during rumination. fMRI-derived brain activity revealed common mechanisms of rumination and savoring. Memory specificity had common effects on neural correlates of rumination and savoring; sleep quality was not associated with mechanisms of savoring or rumination. These results suggest that repetitive engagement with positive and negative affect is similar both subjectively and mechanistically. Clinical interventions for rumination may benefit from capitalizing on preserved capacity for savoring.

Comparison of basic neurocognitive violations in patients with residual schizophrenia with and without history of ischemic stroke

Relevance. The cognitive symptoms associated with schizophrenia have been a subject of controversy and are often viewed through a dualistic lens. According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), these cognitive symptoms can be further elucidated within specific neurocognitive domains.
 Many of the symptoms of schizophrenia manifest behaviorally and can be challenging to differentiate from the consequences of organic brain impairment, especially when these symptoms involve the frontal and temporal cortex or have a diffuse presentation.
 Aim – to evaluate neurocognitive deficit in patients with residual schizophrenia with history of ischemic stroke.
 Materials and methods. A comprehensive study was conducted involving 100 patients diagnosed with recurrent schizophrenia (ICD-10: F20.5) at the Communal Non-Profit Enterprise "Regional Clinical Institution for the Provision of Psychiatric Care". We selected 59 patients: 32 patients with residual schizophrenia without history of stroke (Group 1, G1) and 27 patients with residual schizophrenia with history of stroke (Group 2, G2). Neuropsychological testing was used to evaluate neurocognitive violations. Due to massive distortions that brought to testing results by schizophrenia negative symptoms, only general evaluation was made to reflect critical or non-critical to no violations in separate functions. Statistical method of chi-square test was used to compare results in groups. 
 Study results. To compare neurocognitive violations in G1 and G2 we performed neuropsychological testing in basic neurocognitive domains. G2 patients, diagnosed with both schizophrenia and a stroke, generally exhibit heightened cognitive impairments compared to G1 patients with only schizophrenia. Notably, deficits in Sustained Attention, Divided Attention, Processing Speed, Working Memory, Mental Flexibility, immediate memory, implicit learning, and both expressive and receptive language are more pronounced in G2 patients. However, for functions like Selective Attention, Planning, Decision-Making, recent and very-long-term memory, and interpersonal understanding, the added influence of a stroke in G2 doesn't drastically differentiate them from G1. In essence, while schizophrenia inherently poses cognitive challenges, the co-occurrence of a stroke amplifies certain deficits but not others. This data suggests a complex interplay between schizophrenia and stroke in influencing cognitive function.
 Conclusions. The coexistence of schizophrenia and a history of stroke in G2 patients frequently exacerbates certain cognitive impairments when compared to those diagnosed solely with schizophrenia. This underlines the compounded cognitive challenges faced by patients with comorbid conditions. However, for some cognitive domains, the severity of impairments is primarily governed by schizophrenia, irrespective of the presence of an additional stroke history. This comprehensive analysis underscores the complex interplay of multiple conditions on cognitive function and emphasizes the importance of individualized care and intervention strategies tailored to the specific cognitive challenges faced by each patient group.

Reappraisal is less effective than distraction in downregulation of neural responses to physical threats-An event-related potential investigation.

Evolutionary threats (ETs), such as predatory animals and heights, elicit stronger fear responses and are more often the subject of specific phobias, as compared to modern threats (MTs, such as guns and motorcycles). Since processing of ET depends on lower-order, phylogenetically conserved neural fear circuits, it may be less susceptible to higher-order (vs. simpler) cognitive emotion regulation. Given the relevance for treatment of specific phobias, we tested this hypothesis in an ERP study. Sixty-one female participants passively watched high- and low-threat pictures of evolutionary (snakes, lizards) and modern (guns, water-guns) origin, and downregulated responses to the high-threat pictures (snakes and guns) using either cognitive reappraisal or a simpler cognitive distraction strategy. ET elicited stronger early (EPN) and sustained (LPP) attention processing compared to MT. Both strategies successfully downregulated subjective and LPP (but not EPN) responses compared to passive watching. Although reappraisal was more effective subjectively, distraction downregulated the LPP earlier and stronger than reappraisal, irrespective of the threat type. These findings provide novel evidence that neural responses to physical threat might be less susceptible to cognitive emotion regulation via higher-order (reappraisal) versus simpler (distraction) strategies, irrespective of the evolutionary or modern relevance of threat. Combining both strategies could be beneficial for the emotion regulation-enhancing interventions for specific phobias. Distraction could be used during initial exposure, to reduce immediate emotion responding and help endure the contact with the feared stimulus, whereas reappraisal could be used subsequently, when emotions are less intense, to change maladaptive thoughts about the stimulus for future encounters.

Rhythmic Information Sampling in the Brain during Visual Recognition.

When we fixate an object, visual information is continuously received on the retina. Several studies observed behavioral oscillations in perceptual sensitivity across such stimulus time, and these fluctuations have been linked to brain oscillations. However, whether specific brain areas show oscillations across stimulus time (i.e., different time points of the stimulus being more or less processed, in a rhythmic fashion) has not been investigated. Here, we revealed random areas of face images at random moments across time and recorded the brain activity of male and female human participants using MEG while they performed two recognition tasks. This allowed us to quantify how each snapshot of visual information coming from the stimulus is processed across time and across the brain. Oscillations across stimulus time (rhythmic sampling) were mostly visible in early visual areas, at theta, alpha, and low beta frequencies. We also found that they contributed to brain activity more than previously investigated rhythmic processing (oscillations in the processing of a single snapshot of visual information). Nonrhythmic sampling was also visible at later latencies across the visual cortex, either in the form of a transient processing of early stimulus time points or of a sustained processing of the whole stimulus. Our results suggest that successive cycles of ongoing brain oscillations process stimulus information incoming at successive moments. Together, these results advance our understanding of the oscillatory neural dynamics associated with visual processing and show the importance of considering the temporal dimension of stimuli when studying visual recognition.SIGNIFICANCE STATEMENT Several behavioral studies have observed oscillations in perceptual sensitivity over the duration of stimulus presentation, and these fluctuations have been linked to brain oscillations. However, oscillations across stimulus time in the brain have not been studied. Here, we developed an MEG paradigm to quantify how visual information received at each moment during fixation is processed through time and across the brain. We showed that different snapshots of a stimulus are distinctly processed in many brain areas and that these fluctuations are oscillatory in early visual areas. Oscillations across stimulus time were more prevalent than previously studied oscillations across processing time. These results increase our understanding of how neural oscillations interact with the visual processing of temporal stimuli.

Easy to process, hard to control: Transient and sustained processing fluency impairs cognitive control adjustments to conflict.

Recent research suggests that the cognitive monitoring system of control could be using negative affective cues intrinsic to changes in information processing to initiate top-down regulatory mechanisms. Here, we propose that positive feelings of ease-of-processing could be picked up by the monitoring system as a cue indicating that control is not necessary, leading to maladaptive control adjustments. We simultaneously target control adjustments driven by task context and on a trial-by-trial level, macro-, and micro-adjustments. This hypothesis was tested using a Stroop-like task comprised trials varying in congruence and perceptual fluency. A pseudo randomisation procedure within different proportion of congruence conditions was used to maximise discrepancy and fluency effects. Results suggest that in a mostly congruent context participants committed more fast errors when incongruent trials were easy-to-read. Moreover, within the mostly incongruent condition, we also found more errors on incongruent trials after experiencing the facilitation effect of repeated congruent trials. These results suggest that transient and sustained feelings of processing fluency can downregulate control mechanisms, leading to failed adaptive adjustments to conflict.

Abnormal structural and functional network topological properties associated with left prefrontal, parietal, and occipital cortices significantly predict childhood TBI-related attention deficits: A semi-supervised deep learning study.

Traumatic brain injury (TBI) is a major public health concern in children. Children with TBI have elevated risk in developing attention deficits. Existing studies have found that structural and functional alterations in multiple brain regions were linked to TBI-related attention deficits in children. Most of these existing studies have utilized conventional parametric models for group comparisons, which have limited capacity in dealing with large-scale and high dimensional neuroimaging measures that have unknown nonlinear relationships. Nevertheless, none of these existing findings have been successfully implemented to clinical practice for guiding diagnoses and interventions of TBI-related attention problems. Machine learning techniques, especially deep learning techniques, are able to handle the multi-dimensional and nonlinear information to generate more robust predictions. Therefore, the current research proposed to construct a deep learning model, semi-supervised autoencoder, to investigate the topological alterations in both structural and functional brain networks in children with TBI and their predictive power for post-TBI attention deficits. Functional magnetic resonance imaging data during sustained attention processing task and diffusion tensor imaging data from 110 subjects (55 children with TBI and 55 group-matched controls) were used to construct the functional and structural brain networks, respectively. A total of 60 topological properties were selected as brain features for building the model. The model was able to differentiate children with TBI and controls with an average accuracy of 82.86%. Functional and structural nodal topological properties associated with left frontal, inferior temporal, postcentral, and medial occipitotemporal regions served as the most important brain features for accurate classification of the two subject groups. Post hoc regression-based machine learning analyses in the whole study sample showed that among these most important neuroimaging features, those associated with left postcentral area, superior frontal region, and medial occipitotemporal regions had significant value for predicting the elevated inattentive and hyperactive/impulsive symptoms. Findings of this study suggested that deep learning techniques may have the potential to help identifying robust neurobiological markers for post-TBI attention deficits; and the left superior frontal, postcentral, and medial occipitotemporal regions may serve as reliable targets for diagnosis and interventions of TBI-related attention problems in children.

The Gateway from Centaurs to Jupiter-family Comets: Thermal and Dynamical Evolution

It was recently proposed that there exists a “gateway” in the orbital parameter space through which Centaurs transition to Jupiter-family comets (JFCs). Further studies have implied that the majority of objects that eventually evolve into JFCs should leave the Centaur population through this gateway. This may be naively interpreted as gateway Centaurs being pristine progenitors of JFCs. This is the point we want to address in this work. We show that the opposite is true: gateway Centaurs are, on average, more thermally processed than the rest of the population of Centaurs crossing Jupiter’s orbit. Using a dynamically validated JFC population, we find that only ∼20% of Centaurs pass through the gateway prior to becoming JFCs, in accordance with previous studies. We show that more than half of JFC dynamical clones entering the gateway for the first time have already been JFCs—they simply avoided the gateway on their first pass into the inner solar system. By coupling a thermal evolution model to the orbital evolution of JFC dynamical clones, we find a higher than 50% chance that the layer currently contributing to the observed activity of gateway objects has been physically and chemically altered, due to previously sustained thermal processing. We further illustrate this effect by examining dynamical clones that match the present-day orbits of 29P/Schwassmann-Wachmann 1, P/2019 LD2 (ATLAS), and P/2008 CL94 (Lemmon).

Brain fog of post-COVID-19 condition and Chronic Fatigue Syndrome, same medical disorder?

BackgroundMyalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is characterized by persistent physical and mental fatigue. The post-COVID-19 condition patients refer physical fatigue and cognitive impairment sequelae. Given the similarity between both conditions, could it be the same pathology with a different precipitating factor?ObjectiveTo describe the cognitive impairment, neuropsychiatric symptoms, and general symptomatology in both groups, to find out if it is the same pathology. As well as verify if the affectation of smell is related to cognitive deterioration in patients with post-COVID-19 condition.MethodsThe sample included 42 ME/CFS and 73 post-COVID-19 condition patients. Fatigue, sleep quality, anxiety and depressive symptoms, the frequency and severity of different symptoms, olfactory function and a wide range of cognitive domains were evaluated.ResultsBoth syndromes are characterized by excessive physical fatigue, sleep problems and myalgia. Sustained attention and processing speed were impaired in 83.3% and 52.4% of ME/CFS patients while in post-COVID-19 condition were impaired in 56.2% and 41.4% of patients, respectively. Statistically significant differences were found in sustained attention and visuospatial ability, being the ME/CFS group who presented the worst performance. Physical problems and mood issues were the main variables correlating with cognitive performance in post-COVID-19 patients, while in ME/CFS it was anxiety symptoms and physical fatigue.ConclusionsThe symptomatology and cognitive patterns were similar in both groups, with greater impairment in ME/CFS. This disease is characterized by greater physical and neuropsychiatric problems compared to post-COVID-19 condition. Likewise, we also propose the relevance of prolonged hyposmia as a possible marker of cognitive deterioration in patients with post-COVID-19.

Carbon and nitrogen cycling dynamics following permafrost thaw in the Northwest Territories, Canada

Rapid climate warming across northern high latitudes is leading to permafrost thaw and ecosystem carbon release while simultaneously impacting other biogeochemical cycles including nitrogen. We used a two-year laboratory incubation study to quantify concomitant changes in carbon and nitrogen pool quantity and quality as drivers of potential CO2 production in thawed permafrost soils from eight soil cores collected across the southern Northwest Territories (NWT), Canada. These data were contextualized via in situ annual thaw depth measurements from 2015 to 2019 at 40 study sites that varied in burn history. We found with increasing time since experimental thaw the dissolved carbon and nitrogen pool quality significantly declined, indicating sustained microbial processing and selective immobilization across both pools. Piecewise structural equation modeling revealed CO2 trends were predominantly predicted by initial soil carbon content with minimal influence of dissolved phase carbon. Using these results, we provide a first-order estimate of potential near-surface permafrost soil losses of up to 80 g C m−2 over one year in southern NWT, exceeding regional historic mean primary productivity rates in some areas. Taken together, this research provides mechanistic knowledge needed to further constrain the permafrost‑carbon feedback and parameterize Earth system models, while building on empirical evidence that permafrost soils are at high risk of becoming weaker carbon sinks or even significant carbon sources under a changing climate.

The associations of insomnia symptoms with daytime behavior and cognitive functioning in children with attention-deficit/hyperactivity disorder.

The current study aimed to examine the association of insomnia symptoms with daytime behavior and cognitive functioning in children with attention-deficit/hyperactivity disorder (ADHD). Thirty-six children with ADHD and insomnia symptoms, 27 children with ADHD without insomnia symptoms, and 21 age-matched healthy controls were recruited in this study (age range: 6-12 years, 70% male). They were assessed by parent-report questionnaires on insomnia symptoms (Children's Sleep Habits Questionnaire) and ADHD symptoms (Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale [SWAN]), and completed a battery of cognitive tests including the Continuous Performance Test (CPT) for sustained attention, Letter-digit test for processing speed, Digit Span forward test and N-back task for working memory, Tower of London (TOL) test for planning skills and Bergs Card Sorting Test (BCST) for set-shifting ability. Children with ADHD and insomnia symptoms had the highest scores on SWAN total and inattention and hyperactivity subscales, followed by children with ADHD without insomnia and healthy controls (all P < .05). After controlling for potential confounders, children with ADHD and insomnia symptoms showed poorer performance on the CPT and Letter-digit test as compared with children with ADHD without insomnia and healthy controls (all P < .05). Insomnia symptoms are associated with more severe ADHD symptoms and cognitive impairments in children with ADHD, especially deficits in sustained attention and processing speed. Future longitudinal studies are needed to explore the long-term impacts of insomnia symptoms and the effects of sleep-focused intervention on cognitive functioning in children with ADHD. Li X, Shea KSC, Chiu WV, etal. The associations of insomnia symptoms with daytime behavior and cognitive functioning in children with attention-deficit/hyperactivity disorder. J Clin Sleep Med. 2022;18(8):2029-2039.

The effects of prenatal stress on neural responses to infant cries in expectant mothers and fathers.

The perinatal period is characterized by distinct neurobiological and psychological changes initiated prenatally, which may both facilitate postpartum caregiving and increase vulnerability to stress. Parents need to adapt to the high demands of caregiving, which include responding to salient infant cues, such as infant cries. Therefore, assessing the impact of prenatal stress exposure on parents' neural processing of infant cries may elucidate mechanisms conferring early risk for detrimental perinatal outcomes. Using event-related potentials, we examined whether prenatal perceived stress affected neural markers of perceptual (N1, P2) and attentional (LPP) processes elicited by high- and low-distress infant cries in expectant mothers (n=38) and fathers (n=30). Results evidenced that prenatal perceived stress impacted parents' sustained attentional processing (LPP) of infant cries, but not early perceptual responses (N1, P2). Specifically, higher levels of prenatal perceived stress were associated with a greater LPP response to low-distress, but not high-distress, infant cries. There were no parental sex differences in prenatal perceived stress or neural responses to infant cries. Increased attentional processing of low-distress cries in highly stressed parents may reflect uncertainty regarding infant distress level, thereby requiring more attentional resources. Overall, our results suggest that prenatal stress impacts processing of infant cues, even before birth.

Neural correlates of expectations-induced effects of caffeine intake on executive functions

Placebo effects are defined as the beneficial subjective or behavioral outcomes of an intervention that are not attributable to its inherent properties; Placebo effects thus follow from individuals’ expectations about the effects of the intervention. The present study aimed at examining how expectations influence neurocognitive processes.We addressed this question by contrasting three double-blinded within-subjects experimental conditions in which participants were given decaffeinated coffee, while being told they had received caffeinated (condition i) or decaffeinated coffee (ii), and given caffeinated coffee while being told they had received decaffeinated coffee (iii).After each of these three interventions, performance and electroencephalogram was recorded at rest as well as during sustained attention Rapid Visual Information Processing task (RVIP) and a Go/NoGo motor inhibitory control task.We first aimed to confirm previous findings for caffeine-induced enhancement on these executive components and on their associated electrophysiological indexes (The Attention-P3 component, response conflict NoGo-N2 and inhibition NoGo-P3 components (ii vs iii contrast); and then to test the hypotheses that expectations also induce these effects (i vs ii), although with a weaker amplitude (i vs iii).We did not confirm any of our hypotheses for caffeine-induced behavioral improvements and thus did not test the effect of caffeine-related expectations. At the electrophysiological level, however, we confirmed that caffeine increased the Attention-P3 and NoGo-P3 components amplitude but did not confirm an effect on the response-conflict N2 component. We did not confirm that expectations influence any of the investigated electrophysiological indices, but we confirmed that the Attention-P3 Global Field Power values were larger for the caffeine compared to the expectations conditions.We conclude that previously identified behavioral effect size of caffeine and of the related expectations for sustained attention and inhibitory control may have been overestimated, and that caffeine primarily influences the cognitive processes and brain areas supporting attention allocation. Finally, we confirm that caffeine-related expectations induce smaller effects than the substance itself.