Search

Flexible problem solving, the ability to deal with currently goal-irrelevant information that may have been goal-relevant in previous, similar situations, plays a prominent role in cognitive development and has been repeatedly investigated in developmental research. However, this research, spanning from infancy to the school years, lacks a unifying framework, obscuring the developmental timing of flexible problem solving. Therefore, in this review paper, previous findings are gathered, organized, and integrated under a common framework to unveil how and when flexible problem solving develops. It is showed that the development of flexible problem solving coincides with increases in executive functions, that is, inhibition, working memory and task switching. The analysis of previous findings shows that dealing with goal-irrelevant, non-salient information received far more attention than generalizing in the presence of goal-irrelevant, salient information. The developmental timing of the latter can only be inferred from few transfer studies, as well as executive functions, planning and theory of mind research, to highlight gaps in knowledge and sketch out future research directions. Understanding how transfer in the presence of seemingly relevant but truly irrelevant information develops has implications for well-balanced participation in information societies, early and lifespan education, and investigating the evolutionary trajectory of flexible problem solving.

A growing number of studies suggest that aging is associated with a decrease in efficacy of cognitive pain modulation. Resting state functional connectivity (rsFC) analysis of the brain offers one way of investigating the potential neural mechanisms that may underly this age-related decline. In this study, 32 young (26.7 ± 4.3 years) and 32 healthy older (68.3 ± 7.1 years) adults underwent a 6-minute resting state fMRI scan, as well as a pain distraction paradigm. In the latter, participants received painful heat stimuli while performing either an easy or a difficult working memory task. We performed region-of-interest (ROI) to ROI rsFC analysis of the imaging data, focusing on regions implicated in pain processing and descending pain control. We then examined the relationship between rsFC parameters and the magnitude of the distraction effect (the reduction in perceived pain intensity during the difficult vs the easy task). Older adults showed reduced connectivity compared to young adults between several descending pain modulatory regions, including the ACC and PAG, the right secondary somatosensory cortex (SII) and right dorsolateral prefrontal cortex and between the ACC and left amygdala. Importantly, rsFC in older adults correlated positively with the distraction effect, between several regions including the right SI and right amygdala, the left SI and right insula and between the ACC and left amygdala. Our findings thus demonstrate, for the first time, that reduced cognitive pain modulation in older age is directly associated with decreased rsFC within key nodes of the descending pain control network.

Previous research has shown that cognitive modulation of pain through psychological strategies can contribute to pain relief and that distraction from pain through cognitive engagement represents an efficient method of these strategies. However, little is known about the impacts of stress and age on pain modulation, although previous findings suggest a negative effect of stress and that the efficacy may be impaired due to age-related cognitive decline. The present study therefore investigated the impact of acute stress on the efficacy of pain modulation through distraction in aging. Before and after an acute stress induction using the Trier Social Stress Test (TSST) or a control condition, healthy younger (18-30 years) and older (60+ years) adults performed a n-back working memory task with low (0-back) and high (2-back) working memory load serving as the distraction paradigm, during which participants received individual adjusted non-painful and moderately painful electrical stimuli transmitted transdermal to the left inner forearm and rated them regarding intensity and unpleasantness on a visual analogue scale. Stress response was measured using heart rate and pulse and mood questionnaires about the stress experience. Preliminary results suggest more effective pain distraction under low working memory load for older adults, while in younger adults, pain reduction was higher under high load condition. So far, acute stress did not affect pain distraction in both age groups. The final results may contribute to a deeper understanding of pain modulation in aging and the impact of stress for a helpful optimization of pain therapy in older age.

Older people, suffering from pain and its consequences more often than younger people, would benefit significantly from non-pharmacological pain treatment. So far, little is known about how age affects psychological pain modulation strategies. Preliminary findings hint towards a less efficient pain inhibition through cognition-based pain modulation strategies, as cognitive distraction from pain. Here, executive functions (EFs) have been considered a key factor in the age – pain relationship, with age-related cognitive decline in EFs being associated with reduced pain relief through distraction in older adults. We investigated influence of four core EFs on distraction from pain in aging. In a two-session design, healthy young (18-30 years) and older participants (60+ years) performed a Go-Nogo task, the Stroop-Color-Word-Task, the Sternberg-Task, and the Attentional Network Task. Afterwards, participants performed a pain distraction task, namely a n-Back working memory task with low and high cognitive load, during which participants received individually adjusted transdermal electrical pulse trains in non-painful and moderately painful intensities to the inner forearm. Ratings of intensity and unpleasantness were collected and stimulus-related (EF tasks) and pain-related evoked potentials were recorded with a 64-channel EEG. Unexpectedly, first analyses on the currently small sample suggest a more efficient pain relief through distraction under low relative to high cognitive load in older adults. The distraction effect was related to EFs, some of which showed age-related cognitive impairment. Our findings could lead to a better understanding how to adapt pain treatments in this population by including selective cognitive trainings and optimizing distraction task difficulty.

Real time electroencephalogram (EEG) based neurofeedback has been shown to be effective in regulating brain activity, thereby modifying cognitive performance and behavior. Nevertheless, individual variations in neurofeedback learning rates limit the overall efficacy of EEG based neurofeedback. In the present study we investigated the effects of learning rate and control over training realized by self-pacing on cognitive performance and electrocortical activity. Using a double-blind design, we randomly allocated 60 participants to either individual upper alpha (IUA) or sham neurofeedback and subsequently to self- or externally paced training. Participants receiving IUA neurofeedback improved their IUA activity more than participants receiving sham neurofeedback. Furthermore, the learning rate predicted enhancements in resting-state activity and mental rotation ability. The direction of this linear relationship depended on the neurofeedback condition being positive for IUA and negative for sham neurofeedback. Finally, self-paced training increased higher-level cognitive skills more than externally paced training. These results underpin the important role of learning rate in enhancing both resting-state activity and cognitive performance. Our design allowed us to differentiate the effect of learning rate between neurofeedback conditions, and to demonstrate the positive effect of self-paced training on cognitive performance in IUA neurofeedback.

The experience of adversity in childhood has been associated with poor health outcomes in adulthood. In search of the biological mechanisms underlying these effects, research so far focused on alterations of DNA methylation or shifts in transcriptomic profiles. The level of protein, however, has been largely neglected. We utilized mass spectrometry to investigate the proteome of CD14+ monocytes in healthy adults reporting childhood adversity and a control group before and after psychosocial stress exposure. Particular proteins involved in (i) immune processes, such as neutrophil-related proteins, (ii) protein metabolism, or (iii) proteins related to mitochondrial biology, such as those involved in energy production processes, were upregulated in participants reporting exposure to adversity in childhood. This functional triad was further corroborated by protein interaction- and co-expression analyses, was independent of stress exposure, i.e. observed at both pre- and post-stress time points, and became evident especially in females. In line with the mitochondrial allostatic load model, our findings provide evidence for the long-term effects of childhood adversity on mitochondrial biology.

Considering the importance of mathematical knowledge for STEM careers, we aimed to better understand the cognitive mechanisms underlying the commonly observed relation between number line estimations (NLEs) and arithmetics. We used a within-subject design to model NLEs in an unbounded and bounded task and to assess their relations to arithmetics in second to fourth grades. Our results mostly agree with previous findings, indicating that unbounded and bounded NLEs likely index different cognitive constructs at this age. Bounded NLEs were best described by cyclic power models including the subtraction bias model, likely indicating proportional reasoning. Conversely, mixed log-linear and single scalloped power models provided better fits for unbounded NLEs, suggesting direct estimation. Moreover, only bounded but not unbounded NLEs related to addition and subtraction skills. This thus suggests that proportional reasoning probably accounts for the relation between NLEs and arithmetics, at least in second to fourth graders. This was further confirmed by moderation analysis, showing that relations between bounded NLEs and subtraction skills were only observed in children whose estimates were best described by the cyclic power models. Depending on the aim of future studies, our results suggest measuring estimations on unbounded number lines if one is interested in directly assessing numerical magnitude representations. Conversely, if one aims to predict arithmetic skills, one should assess bounded NLEs, probably indexing proportional reasoning, at least in second to fourth graders. The present outcomes also further highlight the potential usefulness of training the positioning of target numbers on bounded number lines for arithmetic development.

Growing evidence suggests that aging is associated with less efficient endogenous pain modulation as demonstrated by reduced conditioned pain modulation, and that these changes may be mediated by differences in frontal functioning. Yet, little is known about potential age-related changes in cognitive pain modulation, such as distraction from pain. In a first session, 30 healthy young (19–35 years) and 30 healthy older (59–82 years) adults completed a battery of neuropsychological tests. In a second session, we acquired functional brain images while participants completed a working memory task with two levels of cognitive load (high vs. low) and concurrently received individually adjusted heat stimuli (warm vs. painful). In both age groups, completing the high load task was associated with a significant reduction in the perceived intensity and unpleasantness of painful stimuli and a reduction in activation of brain regions involved in pain processing. Group comparisons revealed that young adults showed a stronger de-activation of brain regions involved in pain processing during the high load vs. the low load task, such as the right insula, right mid cingulate cortex and left supramarginal gyrus, compared to older adults. Older adults, on the other hand, showed an increased activation in the anterior cingulate cortex during the high load vs. low load task, when compared to young adults. Covariate analyses indicated that executive functions significantly predicted neural pain modulation in older adults: Better executive functions were associated with a more pronounced de-activation of the insula, thalamus and primary somatosensory cortex and increased activation of prefrontal regions during the high vs. low load task. These findings suggest that cognitive pain modulation is altered in older age and that the preservation of executive functions may have beneficial effects on the efficacy of distraction from pain.

Introduction : La cyberchondrie se caractérise pas des recherches en ligne répétées et compulsives au sujet de la santé, résultant en une détresse et une augmentation de l’anxiété liée à la santé. Ce comportement, considéré comme un problème de santé publique émergeant, pourrait être exacerbé par l’apparition de la pandémie de Covid-19. Cette étude vise à étudier les changements dans la gravité de la cyberchondrie durant la pandémie et d’identifier les prédicteurs de la cyberchondrie à ce moment. Méthode : Des données auto-rapportées sur la gravité de la cyberchondrie (avant et pendant la pandémie), le style d’attachement, les traits d’impulsivité, les symptômes somatiques, les peurs liées au Covid-19, l’anxiété liée à la santé, et l’intolérance à l’incertitude ont été collectées auprès de 725 participants. L’étude en ligne a été distribuée dans les pays européens francophones lors de la première vague de la pandémie. Résultats : Les facettes de détresse et d’interférence avec le fonctionnement de la cyberchondrie ont augmentés durant la pandémie, alors que la facette de réassurance a diminué. Lors des analyses de régression utilisant l’apprentissage automatique supervisé, les peurs liées au Covid-19 ainsi que l’anxiété liée à la santé ont émergés comme étant les prédicteurs les plus importants des facettes de détresse et d’interférence avec le fonctionnement de la cyberchondrie pendant la pandémie. Conclusion : Ces résultats mettent en exergue l’impact de la pandémie sur la cyberchondrie et identifie les facteurs qui devraient être investis pour prévenir et gérer la cyberchondrie lors d’une crise de santé publique.

Theories of number development have traditionally argued that the acquisition and discrimination of symbolic numbers (i.e., number words and digits) are grounded in and are continuously supported by the Approximate Number System (ANS)—an evolutionarily ancient system for number. In the current study, we challenge this claim by investigating whether the ANS continues to support the symbolic number processing throughout development. To this end, we tested 87 first- (Age M = 6.54 years, SD = 0.58), third- (Age M = 8.55 years, SD = 0.60) and fifth-graders (Age M = 10.63 years, SD = 0.67) on four audio-visual comparison tasks (1) Number words–Digits, (2) Tones–Dots, (3) Number words–Dots, (4) Tones–Digits, while varying the Number Range (Small and Large), and the Numerical Ratio (Easy, Medium, and Hard). Results showed that larger and faster developmental growth in the performance was observed in the Number Words–Digits task, while the tasks containing at least one non-symbolic quantity showed smaller and slower developmental change. In addition, the Ratio effect (i.e., the signature of ANS being addressed) was present in the Tones–Dots, Tones–Digits, and Number Words–Dots tasks, but was absent in the Number Words–Digits task. These findings suggest that it is unlikely that the ANS continuously underlines the acquisition and the discrimination of the symbolic numbers. Rather, our results indicate that non-symbolic quantities and symbolic numbers follow qualitatively distinct developmental paths, and argue that the latter ones are processed in a semantic network which starts to emerge from an early age. ispartof: Journal of Numerical Cognition vol:6 issue:3 pages:304-321 status: published

Rationale Severe alcohol use disorder (SAUD) is a psychiatric condition linked to cerebral and cognitive consequences. SAUD is notably characterized by an overactivation of the reflexive/reward system when confronted with alcohol-related cues. Such overreactivity generates a preferential allocation of attentional resources toward these cues, labeled as attentional biases (AB). Theoretical assumptions have been made regarding the characteristics of AB and their underlying processes. While often considered as granted, these assumptions remain to be experimentally validated. Aims We first identify the theoretical assumptions made by previous studies exploring the nature and role of AB. We then discuss the current evidence available to establish their validity. We finally propose research avenues to experimentally test them. Methods Capitalizing on a narrative review of studies exploring AB in SAUD, the current limits of the behavioral measures used for their evaluation are highlighted as well as the benefits derived from the use of eye-tracking measures to obtain a deeper understanding of their underlying processes. We describe the issues related to the theoretical proposals on AB and propose research avenues to test them. Four experimental axes are proposed, respectively, related to the determination of (a) the genuine nature of the mechanisms underlying AB; (b) their stability over the disease course; (c) their specificity to alcohol-related stimuli and (d) their reflexive or controlled nature. Conclusions This in-depth exploration of the available knowledge related to AB in SAUD, and of its key limitations, highlights the theoretical and clinical interest of our innovative experimental perspectives capitalizing on eye-tracking measures.

The burgeoning scientific interest in the clinical benefits of mindfulness has resulted in an extensive body of research linking mindfulness-based practices to improvements across a wide range of pain-related outcomes. Yet, a clear understanding of the mechanisms via which mindfulness conveys its purported effects is still lacking. Novel insights from neuroimaging studies suggest that mindfulness may alleviate pain via unique neural mechanisms characterised by increased pain-related sensory processing and abatement of evaluative and memory-related processes. In light of these observations, recently formulated predictive processing accounts posit that the non-elaborative sustained attention to present-centred experience during mindfulness practice may lead to a weighing of incoming sensory information over prior information during the perceptual process. This interpretation hence raises the intriguing possibility that mindfulness may mitigate the well-documented biasing influence of prior expectations and information on pain perception. We tested this hypothesis across three separate pain expectancy-manipulation paradigms. Study 1 investigated whether the instructed use of a mindfulness strategy vs. an vsernative cognitive regulatory strategy (i.e., suppression) differentially modulates susceptibility to conditioned hypoalgesic and hyperalgesic effects during an implicit classical pain conditioning paradigm. The results revealed that while participants assigned to the suppression condition exhibited preserved cue-induced hypoalgesic effects, no such effects were observed for the mindfulness condition. In Study 2, we employed a recently developed pain categorization paradigm to test whether trait mindfulness level modulates the influence of prior categorical information on pain perception and pain-related decision-making. Although the paradigm successfully elicited categorization-induced perceptual biases, modulation of these effects did not differ across individuals with high and low trait mindfulness. Finally, in Study 3, we used an explicit pain-cueing paradigm in which we aimed to address some of the methodological limitations of Study 1. The analyses revealed that high trait mindfulness scorers reported smaller cue-induced hyperalgesic effects for pain unpleasantness ratings compared to low trait mindfulness scorers. There were, however, no group differences in cue-induced hypoalgesia. Results from the pain conditioning studies provide partial support for the notion that mindfulness may mitigate the influence of prior expectations and information on pain perception. These findings add to growing evidence suggesting that mindfulness may alleviate pain via neuropsychological mechanisms opposite to those typically involved in conditioning/placebo-induced hypoalgesia. The discussion section explores potential methodological and mechanistic explanations for the asymmetric pattern of results observed across the three studies and considers the potential clinical implications of those findings.

Virtual reality (VR) is a powerful method of redirecting attention away from pain. Yet, little is known about which factors modulate the size of this distraction effect. The aim of this study was to investigate the role of cognitive load and inter-individual differences in the cognitive and affective domain on heat pain thresholds during a VR game. Ninety healthy participants (mean age ± SD: 23.46 ± 3.28; 50% identified as male and 50% as female) played a low and high load version of a VR game while heat pain thresholds and heart rate were recorded. The effects of cognitive load were assessed by computing the difference in pain thresholds between the high and low load condition for each participant. In addition, we computed the difference in heart rate variability (HRV) measures between both conditions to explore whether these would be correlated with the difference in heat pain thresholds. Prior to the VR session, participants completed questionnaires about their emotional distress, pain-related cognitions, and different executive functioning tasks. Contrary to our expectations, not all participants benefitted from a higher load in terms of distraction from pain. Logistic regression analysis revealed that participants who reported more emotional distress were more likely to exhibit higher pain thresholds in the low relative to the high load condition. Accordingly, these participants tended to show marginally higher HRV in the low compared to the high load condition. Our study demonstrates that the potential benefits of an increased cognitive load in VR on pain sensitivity depends on individual differences in affective state.

The Care4PD study examined the impact of the COVID-19 pandemic on the care situation of people (PwP) with Parkinson’s disease in Germany. A comprehensive, nationwide, anonymous questionnaire for PwP was distributed by the members’ journal of the German Parkinson’s Disease Association and in several PD specialized in- and outpatient institutions. PwP subjectively evaluated their general care situation and individual impairments during the pandemic. We analyzed 1269 eligible out of 1437 returned questionnaires (88.3%) and compared PwP with (p-LTC) and without (np-LTC) professional long-term care. Both groups rated the general pandemic-related consequences as being rather mild to moderate (e.g., worsening of symptom or concerns). However, familial/social contact restrictions were indicated as most compromising, whereas access to outpatient professional health care providers was less affected. PwP with professional LTC reported more impairment than those without. COVID-19 vaccination rates and acceptance were generally high (p-LTC: 64.3%, np-LTC: 52.3%) at the time of the study, but realization of sanitary measures—especially wearing masks as a patient during care sessions—still needs to be improved. Technical options for telemedicine were principally available but only rarely used. Altogether, during the COVID-19 pandemic, PwP in Germany seemed to have a relatively stable health care access, at least in outpatient settings, while mainly social isolation compromised them. The p-LTC group was more impaired in everyday live compared with the np-LTC group.

Background: Self-stigma in people with Parkinson's disease (PD) can substantially impact quality of life and possibilities for social participation. An integrative analysis of determinants of self-stigma has been lacking. Objective: We sought to explore which complementary insights from qualitative and quantitative studies, as well as from expert consultation, could be gained. Methods: An established mixed methods study design was employed to first conduct a mixed methods scoping review of published qualitative and quantitative literature, and then consult with experts to arrive at an exhaustive list of determinants of self-stigma after a thematic synthesis. Results: A total of 87 unique determinants of self-stigma were identified. Quantitative studies and expert consultations mainly identified personal determinants of people with self-stigma (e.g., age, anxiety, or apathy). In contrast, qualitative studies identified social situations associated with self-stigma (e.g., joint meals of people with typical PD with others). Notably, self-stigma of people with PD was found to be particularly salient in unfamiliar places, at the working place or in contact with people without PD. Across methods, cognitive impairment, tremor, and abnormal walk and unsteady gait, respectively, were associated with self-stigma. Conclusion: The mixed method study design yielded complementary insights, but also factors commonly associated with self-stigma across methods. Future prioritization exercises may gain further insights into self-stigma of people with PD. Facilitating social encounters by both addressing needs of affected people and raising knowledge and public awareness may improve quality of life in people with PD

How humans integrate and abstract numerical information across different formats is one of the most debated questions in human cognition. We addressed the neuronal signatures of the numerical integration using an EEG technique tagged at the frequency of visual stimulation. In an oddball design, participants were stimulated with standard sequences of numbers ( 5) was inserted at 1.25 Hz. We observed significant oddball amplitudes for all single notations, showing for the first time using this EEG technique, that the magnitude information is spontaneously and unintentionally abstracted, irrespectively of the numerical format. Significant amplitudes were also observed for digits-number words and number words-dots, but not for digits-dots, suggesting an automatic integration across some numerical formats. These results imply that direct and indirect neuro-cognitive links exist across the different numerical formats. ispartof: SCIENTIFIC REPORTS vol:11 issue:1 ispartof: location:England status: published

The right hemispheric lateralization of face recognition, which is well documented and appears to be specific to the human species, remains a scientific mystery. According to a long-standing view, the evolution of language, which is typically substantiated in the left hemisphere, competes with the cortical space in that hemisphere available for visuospatial processes, including face recognition. Over the last decade, a specific hypothesis derived from this view according to which neural competition in the left ventral occipito-temporal cortex with selective representations of letter strings causes right hemispheric lateralization of face recognition, has generated considerable interest and research in the scientific community. Here, a systematic review of studies performed in various populations (infants, children, literate and illiterate adults, left-handed adults) and methodologies (behavior, lesion studies, (intra)electroencephalography, neuroimaging) offers little if any support for this reading lateralized neural competition hypothesis. Specifically, right-lateralized face-selective neural activity already emerges at a few months of age, well before reading acquisition. Moreover, consistent evidence of face recognition performance and its right hemispheric lateralization being modulated by literacy level during development or at adulthood is lacking. Given the absence of solid alternative hypotheses and the key role of neural competition in the sensory-motor cortices for selectivity of representations, learning, and plasticity, a revised language-related neural competition hypothesis for the right hemispheric lateralization of face recognition should be further explored in future research, albeit with substantial conceptual clarification and advances in methodological rigor.

The emergence of visual cortex specialization for culturally acquired characters like letters and digits, both arbitrary shapes related to specific cognitive domains, is yet unclear. Here, 20 young children (6.12 years old) were tested with a frequency-tagging paradigm coupled with electroencephalogram recordings to assess discrimination responses of letters from digits and vice-versa. One category of stimuli (e.g., letters) was periodically inserted (1/5) in streams of the other category (e.g., digits) presented at a fast rate (6 Hz). Results show clear right-lateralized discrimination responses at 6 Hz/5 for digits within letters, and a trend for left-lateralization for letters. These results support an early developmental emergence of ventral occipito-temporal cortex specialization for visual recognition of digits and letters, potentially in relation with relevant coactivated brain networks. [ABSTRACT FROM AUTHOR]

Spatial biases associated with subtraction or addition problem solving are generally considered as reflecting leftward or rightward attention shifts along a mental numerical continuum, but an alternative hypothesis not implying spatial attention proposes that the operator (plus or minus sign) may favour a response to one side of space (left or right) because of semantic associations. We tested these two accounts in a series of temporal order judgement experiments that consisted in the auditory presentation of addition or subtraction problems followed 200 ms (Experiments 1-2) or 800 ms (Experiment 3) later by the display of two lateralized targets in close temporal succession. To dissociate the side where the operation first brought their attention from the side they had to respond to, we asked participants to report which of the left or right target appeared first or last on screen. Under the attention-orienting account, addition should elicit more rightward responses than subtraction when participants have to focus on the first target, but more leftward responses when they have to focus on the last target, because the latter is opposite to the side where the operation first brought their attention. Under the semantic account, addition should elicit more rightward responses than subtraction, no matter the focus is on the first or last target, because participants should systematically favour the side conceptually linked to the operator. The results of the three experiments converge to indicate that, in lateralized target detection tasks, the spatial biases induced by arithmetic operations stem from semantic associations.

The developmental origins of human adults’ right hemispheric specialization for face perception remain unclear. On the one hand, infant studies have shown a right hemispheric advantage for face perception. On the other hand, it has been proposed that the adult right hemispheric lateralization for face perception slowly emerges during childhood due to reading acquisition, which increases left lateralized posterior responses to competing written material (e.g., visual letters and words). Since methodological approaches used in infant and children typically differ when their face capabilities are explored, resolving this issue has been difficult. Here we tested 5-year-old preschoolers varying in their level of visual letter knowledge with the same fast periodic visual stimulation (FPVS) paradigm leading to strongly right lateralized electrophysiological occipito-temporal face-selective responses in 4- to 6-month-old infants (de Heering and Rossion, 2015). Children's face-selective response was quantitatively larger and differed in scalp topography from infants’, but did not differ across hemispheres. There was a small positive correlation between preschoolers’ letter knowledge and a non-normalized index of right hemispheric specialization for faces. These observations show that previous discrepant results in the literature reflect a genuine nonlinear development of the neural processes underlying face perception and are not merely due to methodological differences across age groups. We discuss several factors that could contribute to the adult right hemispheric lateralization for faces, such as myelination of the corpus callosum and reading acquisition. Our findings point to the value of FPVS coupled with electroencephalography to assess specialized face perception processes throughout development with the same methodology.

Establishing consistent relationships between neural activity and behavior is a challenge in human cognitive neuroscience research. We addressed this issue using variable time constraints in an oddball frequency-sweep design for visual discrimination of complex images (face exemplars). Sixteen participants viewed sequences of ascending presentation durations, from 25 to 333 ms (40 to 3 Hz stimulation rate) while their electroencephalogram (EEG) was recorded. Throughout each sequence, the same unfamiliar face picture was repeated with variable size and luminance changes while different unfamiliar facial identities appeared every 1 s (1 Hz). A neural face individuation response, tagged at 1 Hz and its unique harmonics, emerged over the occipito-temporal cortex at 50 ms stimulus duration (25 to 100 ms across individuals), with an optimal response reached at 170 ms stimulus duration. In a subsequent experiment, identity changes appeared non-periodically within fixed-frequency sequences while the same participants performed an explicit face individuation task. The behavioral face individuation response also emerged at 50 ms presentation time, and behavioral accuracy correlated with individual participants’ neural response amplitude in a weighted middle stimulus duration range (50 to 125 ms). Moreover, the latency of the neural response peaking between 180 to 200 ms correlated strongly with individuals’ behavioral accuracy in this middle duration range, as measured independently. These observations point to the minimal (50 ms) and optimal (170 ms) stimulus durations for human face individuation and provide novel evidence that inter-individual differences in the magnitude and latency of early, high-level neural responses are predictive of behavioral differences in performance at this function.

In the approach of frequency tagging, stimuli that are presented periodically generate periodic responses of the brain. Following a transformation into the frequency domain, the brain's response is often evident at the frequency of stimulation, F, and its higher harmonics (2F, 3F, etc.). This approach is increasingly used in neuroscience, as it affords objective measures to characterize brain function. However, whether these specific harmonic frequency responses should be combined for analysis—and if so, how—remains an outstanding issue. In most studies, higher harmonic responses have not been described or were described only individually; in other studies, harmonics have been combined with various approaches, for example, averaging and root-mean-square summation. A rationale for these approaches in the context of frequency-based analysis principles and an understanding of how they relate to the brain's response amplitudes in the time domain have been missing. Here, with these elements addressed, the summation of (baseline-corrected) harmonic amplitude is recommended.

Alterations in the affective component of pain perception are related to the development of chronic pain and may contribute to the increased vulnerability to pain observed in aging. The present study analyzed age-related changes in resting-state brain activity and their possible relation to an increased pain perception in older adults. For this purpose, we compared EEG current source density and fMRI functional-connectivity at rest in older (n = 20, 66.21 ± 3.08 years) and younger adults (n = 21, 20.71 ± 2.30 years) and correlated those brain activity parameters with pain intensity and unpleasantness ratings elicited by painful stimulation. We found an age-related increase in beta2 and beta3 activity in temporal, frontal, and limbic areas, and a decrease in alpha activity in frontal areas. Moreover, older participants displayed increased functional connectivity in the anterior cingulate cortex (ACC) and the insula with precentral and postcentral gyrus. Finally, ACC beta3 activity was positively correlated with pain intensity and unpleasantness ratings in older, and ACC-precentral/postcentral gyrus connectivity was positively correlated with unpleasantness ratings in older and younger participants. These results reveal that ACC resting-state hyperactivity is a stable trait of brain aging and may underlie their characteristic altered pain perception.

Number transcoding is the cognitive task of converting between different numerical codes (i.e. visual “42”, verbal “forty-two”). Visual symbolic to verbal transcoding and vice versa strongly relies on language proficiency. We evaluated transcoding of German-French bilinguals from Luxembourg in 5th, 8th, 11th graders and adults. In the Luxembourgish educational system, children acquire mathematics in German (LM1) until the 7th grade, and then the language of learning mathematic switches to French (LM2). French `70s `80s `90s are less transparent than `30s `40s `50s numbers, since they have a base-20 structure, which is not the case in German. Transcoding was evaluated with a reading aloud and a verbal-visual number matching task. Results of both tasks show a cognitive cost for transcoding numbers having a base-20 structure (i.e. `70s, `80s and `90s), such that response times were slower in all age groups. Furthermore, considering only base-10 numbers (i.e. `30s `40s `50s), it appeared that transcoding in LM2 (French) also entailed a cost. While participants across age groups tended to read numbers slower in LM2, this effect was limited to the youngest age group in the matching task. In addition, participants made more errors when reading LM2 numbers. In conclusion, we observed an age-independent language effect with numbers having a base-20 structure in French, reflecting their reduced transparency with respect to the decimal system. Moreover, we find an effect of language of math acquisition such that transcoding is less well mastered in LM2. This effect tended to persist until adulthood in the reading aloud task, while in the matching task performance both languages become similar in older adolescents and young adults. This study supports the link between numbers and language, especially highlighting the impact of language on reading numbers aloud from childhood to adulthood.

Even though aging is associated with increased and prolonged episodes of pain, little is known about potential age-related changes in the "top-down" modulation of pain, such as cognitive distraction from pain. The hypoalgesic effect of distraction results from a competition for attentional and executive resources mediated by the prefrontal cortex (PFC). Given that age-related grey matter atrophy is particularly prominent in the PFC, older adults may benefit less from distraction to reduce pain than young adults. The aim of this study was to investigate the influence of aging on task-related hypoalgesia and its neural mechanisms, with a focus on the role of executive functions in distraction from pain. 64 participants (32 young adults: 26.69 ± 4.14 years; 32 older adults: 68.28 ± 7.00 years) first completed a battery of neuropsychological tests. In a second session, we administered a pain distraction paradigm while functional brain images were acquired. In this paradigm, participants completed a low (0-back) and a high (2-back) load condition of a working memory task while receiving either innocuous or painful heat stimuli to their lower arm. To control for age-related differences in sensitivity to pain and perceived task difficulty, stimulus intensity and task speed were individually calibrated. Both age groups showed significantly reduced activity in a network of regions involved in pain processing when performing the high compared to the low load distraction task; however, young adults showed a larger neural distraction effect in several of these regions, including the insula, caudate and midcingulate cortex. Moreover, in older adults, better executive functions – in particular inhibitory control abilities – were associated with a larger neural distraction effect in the insula, thalamus and primary somatosensory cortex, and with more activation in several prefrontal cortex regions during the high load task. These findings clearly demonstrate that the top-down control of pain is altered by age and could explain the higher vulnerability of older adults to developing chronic pain. Moreover, our findings suggest that the assessment of executive functions may be a useful tool for predicting the efficacy of cognitive pain modulation strategies in older adults.

Aging is known to affect neurobiological and physiological aspects of pain perception and has been associated with reduced pain sensitivity and a deterioration of descending pain inhibitory mechanisms. To investigate age differences in neural electrophysiological correlates of pain processing, we induced acute pain in healthy older (60 yrs+) and younger adults (18 to 35 yrs), using short transdermal electrical pulses administered to the inner forearm, with individually adjusted stimulation intensities. Participants received alternating blocks of painful and non-painful control stimulation and rated the intensity and unpleasantness of each stimulus on two visual analog scales. Pain-related evoked potentials were recorded with a 64-channel EEG. Preliminary results indicate that younger and older participants rated painful stimuli more intensive and unpleasant compared to the control stimulation, with older adults showing a slight habituation over time. In younger adults, ERP amplitudes (N2, P2 P3) of painful stimulation were enhanced compared to non- painful stimulation. In contrast, older participants showed generally reduced ERPs, no difference between pain and non-painful stimulation and by tendency longer latencies for painful stimulation. This suggests that nociceptive neural processing is altered in aging, while the reported pain perception is unaffected. Given that aging is also associated with a decline of cognitive functions and PFC volume and activity changes, this could have implications for the efficacy of cognitive pain modulation. Altogether, our results highlight the need for a deeper understanding of the mechanisms underlying pain processing in older adults, and how these age-related changes affect (cognitive) pain treatments in this population.

Asymptomatic individuals, called “silent spreaders” spread SARS-CoV-2 efficiently and have complicated control of the ongoing COVID-19 pandemic. As seen in previous influenza pandemics, socioeconomic and life-trajectory factors are important in disease progression and outcome. The demographics of the asymptomatic SARS-CoV-2 carriers are unknown. We used the CON-VINCE cohort of healthy, asymptomatic, and oligosymptomatic individuals that is statistically representative of the overall population of Luxembourg for age, gender, and residency to characterise this population. Gender (male), not smoking, and exposure to early-life or adult traumatic experiences increased the risk of IgA seropositivity, and the risk associated with early-life exposure was a dose-dependent metric, while some other known comorbidities of active COVID-19 do not impact it. As prior exposure to adversity is associated with negative psychobiological reactions to external stressors, we recorded psychological wellbeing during the study period. Exposure to traumatic events or concurrent autoimmune or rheumatic disease were associated with a worse evolution of anxiety and depressive symptoms throughout the lockdown period. The unique demographic profile of the “silent spreaders” highlights the role that the early-life period plays in determining our lifelong health trajectory and provides evidence that the developmental origins of health and disease is applicable to infectious diseases.

Introduction: Virtual reality (VR) has been shown to be a powerful method of redirecting attention away from pain and is increasingly used in clinical settings as a therapeutic tool for pain treatment. Yet, little is known about the underlying factors that modulate the size of the hypoalgesic response to a VR game, such as cognitive load and inter-individual differences in self-reported pain-related cognitions, emotion regulation habits, gaming skills, and executive functions. Methods: 90 healthy participants played two versions of the VR game 'Subnautica', differing in cognitive load (low load vs. high load). In the low load condition, participants navigated along a predefined route. In the high load condition, participants additionally memorized a series of single digits presented along the route. Pain heat thresholds as well as psychophysiological measures (ECG, EDA) were recorded during a passive control condition (in VR) prior to, as well as during, the two interactive sessions. In addition, participants completed several psychological questionnaires and different executive functioning tasks prior to the VR sessions. Results: Pain thresholds were significantly higher in the two interactive VR sessions when compared to the passive control condition, whereas the cognitive load of the game had no effect on pain thresholds. Individual differences in pain-related cognitions, prepotent response inhibition abilities and the level of emotional awareness reported by female participants, but not the level of gaming skills, influenced the size of the hypoalgesic effect. Discussion: In line with a growing body of studies, we observed a robust hypoalgesic response to playing a VR game, highlighting once more the potential of VR as a tool for pain reduction. Importantly, the hypoalgesic effect was not dependent on the participants’ level of gaming skills or the cognitive load of the game, suggesting that the sensory properties of the VR game were sufficient to change the processing of pain.

Objective Cognitive-driven activity of daily living (ADL) impairment in Parkinson’s disease (PD) is increasingly discussed as prodromal marker for dementia. Diagnostic properties of assessments for this specific ADL impairment are sparsely investigated in PD. The ability of the Functional Activities Questionnaire (FAQ) for differentiating between PD patients with normal cognition and with mild cognitive impairment (PD-MCI), according to informant and self-reports, was examined. Global cognitive function in groups with and without mild ADL impairment was compared according to different cut-offs. Methods Multicenter data of 589 patients of an international cohort (CENTRE-PD) were analyzed. Analyses were run separately for informant-rated and self-rated FAQ. Receiver operating characteristic (ROC) analysis was conducted to define the optimal FAQ cut-off for PD-MCI (≥ 1), and groups were additionally split according to reported FAQ cut-offs for PD-MCI in the literature (≥ 3, ≥ 5). Binary logistic regressions examined the effect of the Montreal Cognitive Assessment (MoCA) score in PD patients with and without mild ADL impairment. Results Two hundred and twenty-five (38.2%) patients were classified as PD-MCI. For all three cut-off values, sensitivity was moderate to low ( 0.54) with a tendency of higher values for self-reported deficits. For the self-report, the cut-off ≥ 3 showed a significant effect of the MoCA (B = − 0.31, p = 0.003), where FAQ ≥ 3 patients had worse cognition. No effect for group differences based on informant ratings was detected. Conclusion Our data argue that self-reported ADL impairments assessed by the FAQ show a relation to the severity of cognitive impairment in PD.

Exposure to a face can produce biases in the perception of subsequent faces. Typically, these face aftereffects are studied by adapting to an individual face or category (e.g., faces of a given gender) and can result in renormalization of perceptions such that the adapting face appears more neutral. These shifts are analogous to chromatic adaptation, where a renormalization for the average adapting color occurs. However, in color vision, adaptation can also adjust to the variance or range of colors in the distribution. We examined whether this variance or contrast adaptation also occurs for faces, using an objective EEG measure to assess response changes following adaptation. An average female face was contracted or expanded along the horizontal or vertical axis to form four images. Observers viewed a 20 s sequence of the four images presented in a fixed order at a rate of 6 Hz, while responses to the faces were recorded with EEG. A 6 Hz signal was observed over right occipito-temporal channels, indicating symmetric responses to the four images. This test sequence was repeated after 20 s adaptation to alternations between two of the faces (e.g., horizontal contracted and expanded). This adaptation resulted in an additional signal at 3 Hz, consistent with asymmetric responses to adapted and non-adapted test faces. Adapting pairs have the same mean (undistorted) as the test sequence and thus should not bias responses driven only by the mean. Instead, the results are consistent with selective adaptation to the distortion axis. A 3 Hz signal was also observed after adapting to face pairs selected to induce a mean bias (e.g., expanded vertical and expanded horizontal), and this signal was not significantly different from that observed following adaption to a single image that did not form part of the test sequence (e.g., a single image expanded both vertically and horizontally). In a further experiment, we found that this variance adaptation can also be observed behaviorally. Our results suggest that adaptation calibrates face perception not only for the average characteristics of the faces we experience but also for the gamut of faces to which we are exposed.

The developmental course of neural tuning to visual letter strings is unclear. Here we tested 39 children longitudinally, at the beginning of grade 1 (6.45 ± 0.33 years old) and 1 year after, with fast periodic visual stimulation in electroencephalography to assess the evolution of selective neural responses to letter strings and their relationship with emerging reading abilities. At both grades, frequency-tagged letter strings were discriminated from pseudofont strings (i.e. letter-selectivity) over the left occipito-temporal cortex, with effects observed at the individual level in 62% of children. However, visual words were not discriminated from pseudowords (lexical access) at either grade. Following 1 year of schooling, letter-selective responses showed a specific increase in amplitude, a more complex pattern of harmonics, and were located more anteriorly over the left occipito-temporal cortex. Remarkably, at both grades, neural responses were highly significant at the individual level and correlated with individual reading scores. The amplitude increase in letter-selective responses between grades was not found for discrimination responses of familiar keyboard symbols from pseudosymbols, and was not related to a general increase in visual stimulation responses. These findings demonstrate a rapid onset of left hemispheric letter selectivity, with 1 year of reading instruction resulting in increased emerging reading abilities and a clear quantitative and qualitative evolution within left hemispheric neural circuits for reading.

Animal-fMRI is a powerful method to understand neural mechanisms of cognition, but it remains a major challenge to scan actively participating small animals under low-stress conditions. Here, we present an event-related functional MRI platform in awake pigeons using single-shot RARE fMRI to investigate the neural fundaments for visually-guided decision making. We established a head-fixated Go/NoGo paradigm, which the animals quickly learned under low-stress conditions. The animals were motivated by water reward and behavior was assessed by logging mandibulations during the fMRI experiment with close to zero motion artifacts over hundreds of repeats. To achieve optimal results, we characterized the species-specific hemodynamic response function. As a proof-of-principle, we run a color discrimination task and discovered differential neural networks for Go-, NoGo-, and response execution-phases. Our findings open the door to visualize the neural fundaments of perceptual and cognitive functions in birds—a vertebrate class of which some clades are cognitively on par with primates., Functional magnetic resonance imaging (fMRI) is a powerful method to understand neural mechanisms of cognition but imaging of small animals can be challenging. The authors present an event-related fMRI platform to visualize the neural fundaments of perceptual and cognitive functions in awake birds.

The developmental origin of human adults’ right hemispheric dominance in response to face stimuli remains unclear, in particular because young infants’ right hemispheric advantage in face-selective response is no longer present in preschool children, before written language acquisition. Here we used fast periodic visual stimulation (FPVS) with scalp electroencephalography (EEG) to test 52 preschool children (5.5 years old) at two different levels of face discrimination: discrimination of faces against objects, measuring face-selectivity, or discrimination between individual faces. While the contrast between faces and nonface objects elicits strictly bilateral occipital responses in children, strengthening previous observations, discrimination of individual faces in the same children reveals a strong right hemispheric lateralization over the occipitotemporal cortex. Picture-plane inversion of the face stimuli significantly decreases the individual discrimination response, although to a much smaller extent than in older children and adults tested with the same paradigm. However, there is only a nonsignificant trend for a decrease in right hemispheric lateralization with inversion. There is no relationship between the right hemispheric lateralization in individual face discrimination and preschool levels of readings abilities. The observed difference in the right hemispheric lateralization obtained in the same population of children with two different paradigms measuring neural responses to faces indicates that the level of visual discrimination is a key factor to consider when making inferences about the development of hemispheric lateralization of face perception in the human brain.

Significance Approximating large quantities has been identified as a building block of mathematical cognition. Despite its importance from both a fundamental and an educational perspective, the mechanism behind this ability is still not fully understood. The remaining gap comes from the fact that a set is not only characterized by its number of objects but additionally by nonnumerical features naturally correlating with numerosity (e.g., a more numerous set occupies a larger surface). The current frequency-tagging EEG paradigm isolates specific responses to number and to nonnumerical dimensions. We demonstrate that when numerosity and the other dimensions are totally decorrelated in stimulus sequences, changes of each are automatically discriminated in early visual cortex, highlighting the status of numerosity as a primary visual feature., The ability to handle approximate quantities, or number sense, has been recurrently linked to mathematical skills, although the nature of the mechanism allowing to extract numerical information (i.e., numerosity) from environmental stimuli is still debated. A set of objects is indeed not only characterized by its numerosity but also by other features, such as the summed area occupied by the elements, which often covary with numerosity. These intrinsic relations between numerosity and nonnumerical magnitudes led some authors to argue that numerosity is not independently processed but extracted through a weighting of continuous magnitudes. This view cannot be properly tested through classic behavioral and neuroimaging approaches due to these intrinsic correlations. The current study used a frequency-tagging EEG approach to separately measure responses to numerosity as well as to continuous magnitudes. We recorded occipital responses to numerosity, total area, and convex hull changes but not to density and dot size. We additionally applied a model predicting primary visual cortex responses to the set of stimuli. The model output was closely aligned with our electrophysiological data, since it predicted discrimination only for numerosity, total area, and convex hull. Our findings thus demonstrate that numerosity can be independently processed at an early stage in the visual cortex, even when completely isolated from other magnitude changes. The similar implicit discrimination for numerosity as for some continuous magnitudes, which correspond to basic visual percepts, shows that both can be extracted independently, hence substantiating the nature of numerosity as a primary feature of the visual scene.

To investigate face individuation (FI), a critical brain function in the human species, an oddball fast periodic visual stimulation (FPVS) approach was recently introduced (Liu-Shuang et al., Neuropsychologia, 2014, 52, 57). In this paradigm, an image of an unfamiliar "base" facial identity is repeated at a rapid rate F (e.g., 6 Hz) and different unfamiliar "oddball" facial identities are inserted every nth item, at a F/n rate (e.g., every 5th item, 1.2 Hz). This stimulation elicits FI responses at F/n and its harmonics (2F/n, 3F/n, etc.), reflecting neural discrimination between oddball versus base facial identities, which is quantified in the frequency domain of the electroencephalogram (EEG). This paradigm, used in 20 published studies, demonstrates substantial advantages for measuring FI in terms of validity, objectivity, reliability, and sensitivity. Human intracerebral recordings suggest that this FI response originates from neural populations in the lateral inferior occipital and fusiform gyri, with a right hemispheric dominance consistent with the localization of brain lesions specifically affecting facial identity recognition (prosopagnosia). Here, we summarize the contributions of the oddball FPVS framework toward understanding FI, including its (a)typical development, with early studies supporting the application of this technique to clinical testing (e.g., autism spectrum disorder). This review also includes an in-depth analysis of the paradigm's methodology, with guidelines for designing future studies. A large-scale group analysis compiling data across 130 observers provides insights into the oddball FPVS FI response properties. Overall, we recommend the oddball FPVS paradigm as an alternative approach to behavioral or traditional event-related potential EEG measures of face individuation.

Growing up in cities is associated with increased risk for developing mental health problems. Stress exposure and altered stress regulation have been proposed as mechanisms linking urbanicity and psychopathology, with most research conducted in adult populations. Here, we focus on early childhood, and investigate urbanicity, behavior problems and the regulation of the hypothalamus-pituitary-adrenal (HPA) axis, a central circuit of the stress system, in a sample of N = 399 preschoolers aged 45 months. Urbanicity was coded dichotomously distinguishing between residences with more or less than 100,000 inhabitants. Behavior problems were measured using the Child Behavior Checklist (CBCL) 1½ - 5. Cortisol stress reactivity was assessed using an age-appropriated game-like stress task, and cortisol in the first morning urine was measured to assess nocturnal HPA axis activity. Urbanicity was not associated with behavior problems, urinary cortisol or the cortisol stress response. Neither urinary cortisol nor salivary cortisol response after stress exposure were identified as mediators of the relationship between urbanicity and behavior problems. The findings suggest no strong association of urbanicity with behavior problems and HPA axis regulation in preschool age. To our knowledge, this is the youngest sample to date studying the relationship between urbanicity and behavior problems as well as HPA axis regulation. Future research should examine at which age associations can first be identified and which mechanisms contribute to these relationships.

While aging and stress are both known to affect cognitive functions, little is known on whether and how age modulates stress effects on executive functions and their neural correlates. The current study investigated the effect of acute stress on response inhibition and error processing and their underlying cortical processes in younger and older healthy men, using EEG. Forty-nine participants (30 young) were stressed with the Trier Social Stress Test (16 young, 9 older) or underwent a friendly control procedure (14 young, 10 older) and subsequently performed a Go/No-Go task with two levels of task difficulty while performance (reaction time, error rate), stimulus-locked (N2, P3) and response-locked (Ne, Pe) ERPs were measured. Previous results on age-related cognitive deficits were replicated, with slower responses and reduced and delayed N2 and P3 components, as well as reduced Ne and Pe components in older participants. Independent of age, acute stress improved response inhibition, reflected in higher accuracy for compatible trials and enhanced inhibition-related components (N2, P3 and N2d, P3d of the difference waves No-Go minus Go), and improved error processing, reflected in enhanced error-related components (Ne, Pe and Ne_d, Pe_d of the difference waves error minus correct trial). Our findings indicate that acute stress leads to a reallocation of cognitive resources, strengthening inhibition and error processing in young and older healthy men to a similar degree. Neural generators of the analyzed ERPs are mainly part of the salience network, which is upregulated immediately after stress. This offers an explanation as to why response inhibition, in contrast to other executive functions, improves after acute stress.

Placebo analgesia (PA) depends crucially on the prefrontal cortex (PFC), which is assumed to be responsible for initiating the analgesic response. Surprisingly little research has focused on the psychological mechanisms mediated by the PFC and underlying PA. One increasingly accepted theory is that cognitive reappraisal—the reinterpretation of the meaning of adverse events—plays an important role, but no study has yet addressed the possible functional relationship with PA. We studied the influence of individual differences in reappraisal ability on PA and its prefrontal mediation. Participants completed a cognitive reappraisal ability task, which compared negative affect evoked by pictures in a reappraise versus a control condition. In a subsequent fMRI session, PA was induced using thermal noxious stimuli and an inert skin cream. We found a region in the left dorsolateral PFC, which showed a positive correlation between placebo-induced activation and (i) the reduction in participants’ pain intensity ratings; and (ii) cognitive reappraisal ability scores. Moreover, this region showed increased placebo-induced functional connectivity with the periaqueductal grey, indicating its involvement in descending nociceptive control. These initial findings thus suggest that cognitive reappraisal mechanisms mediated by the dorsolateral PFC may play a role in initiating pain inhibition in PA.

Although numeracy, next to literacy, is an essential skill in many knowledge based societies of the 21st century, between 5 and 10 % of the population suffer from more or less severe mathematics learning disorders or dyscalculia. However, mathematical ability is not a pure construct. Instead, mathematical ability maintains a complex relationship with linguistic abilities. This relationship has significant implications for the assessment of a person’s mathematical ability in multilingual contexts. The hereby presented research project addresses the consequences of that relationship in the context of Luxembourg, a highly multilingual country at the center of Europe. The aim of the project was to tackle psychometric issues that arise when the test taker does not master the language of the test sufficiently and to offer an alternative solution to available assessment batteries based on verbal instructions and tasks. In the first study, we demonstrate the role of reading comprehension in the language of instruction on third grader’s performance in mathematics in Luxembourg and show that non-native speaker’s underachievement in mathematics can be largely or entirely explained by their lacking reading comprehension in the language of assessment. In the next study we report on the two first pilot studies with NUMTEST, an assessment battery that aims to measure children’s basic mathematical competence by replacing verbal instructions and task content with video instructions and animated tasks. The findings of these studies show that children’s basic mathematical competence can indeed be reliably assessed using this new paradigm. Opportunities and limitations of the paradigm are discussed. The third and final study of this project addresses the psychometric characteristics of this newly developed assessment battery. Its findings show that the NUMTEST battery provides for good reliability and concurrent validity all while being language neutral. In summary, the presented project provides for an encouraging proof of concept for the video instruction method while offering preliminary evidence for its validity as an early screener for math learning difficulties.

Childhood adversity is related to an increased risk for psychopathology in adulthood. Altered regulation of stress response systems, as well as the changes in stress-immune interplay have been suggested as potential mechanisms underlying these long-term effects. We have previously shown altered transcriptional responses to acute psychosocial stress in adults reporting the experience of childhood adversity. Here, we extend these analyses using a network approach. We performed a co-expression network analysis of genome-wide mRNA data derived from isolated monocytes, sampled 3 h after stress exposure from healthy adults, who experienced childhood adversity and a matched control group without adverse childhood experiences. Thirteen co-expression modules were identified, of which four modules were enriched for genes related to immune system function. Gene set enrichment analysis showed differential module activity between the early adversity and control group. In line with previous findings reporting a pro-inflammatory bias following childhood adversity, one module included genes associated with pro-inflammatory function (hub genes: IL6, TM4SF1, ADAMTS4, CYR61, CCDC3), more strongly expressed in the early adversity group. Another module downregulated in the early adversity group was related to platelet activation and wound healing (hub genes: GP9, CMTM5, TUBB1, GNG11, PF4), and resembled a co-expression module previously found over-expressed in post-traumatic stress disorder resilient soldiers. These discovery analysis results provide a system wide and more holistic understanding of gene expression programs associated with childhood adversity. Furthermore, identified hub genes can be used in directed hypothesis testing in future studies.

International audience; The impact of learning to read in a mixed approach using both the global and phonics teaching methods on the emergence of left hemisphere neural specialization for word recognition is yet unknown in children. Taking advantage of a natural school context with such a mixed approach, we tested 42 first graders behaviorally and with Fast Periodic Visual Stimulation using electroencephalographic recordings (FPVS-EEG) to measure selective neural responses to letter strings. Letter strings were inserted periodically (1/5) in pseudofonts in 40 s sequences displayed at 6 Hz and were either words globally taught at school, that could therefore be processed by visual whole-word form recognition (global method), or control words/pseudowords eliciting grapheme-phoneme (GP) mappings (phonics method). Results show that selective responses (F/5, 1.2 Hz) were left lateralized for control stimuli that triggered GP mappings but bilateral for globally taught words. It implies that neural mechanisms recruited during visual word processing are influenced by the nature of the mapping between written and spoken word forms. GP mappings induce left hemisphere discrimination responses, and visual recognition of whole-word forms induce bilateral responses, probably because the right hemisphere is relatively more involved in holistic visual object recognition. Splitting the group as a function of the mastery of GP mappings into "good" and "poor" readers strongly suggests that good readers actually processed all stimuli (including global words) predominantly with their left hemisphere, while poor readers showed bilateral responses for global words. These results show that in a mixed approach of teaching to read, global method instruction may induce neural processes that differ from those specialized for reading in the left hemisphere. Furthermore, given their difficulties in automatizing GP mappings, poor readers are especially prone to rely on this alternative visual strategy. A preprint of this paper has been released on Biorxiv (van de Walle de Ghelcke et al., 2018).

Acute alcohol intoxication and alcohol use disorders are characterized by a wide range of psychological and cerebral impairments, which have been widely explored using neuropsychological and neuroscientific techniques. Eye tracking has recently emerged as an innovative tool to renew this exploration, as eye movements offer complementary information on the processes underlying perceptive, attentional, memory or executive abilities. Building on this, the present systematic and critical literature review provides a comprehensive overview of eye tracking studies exploring cognitive and affective processes among alcohol drinkers. Using PRISMA guidelines, 36 papers that measured eye movements among alcohol drinkers were extracted from three databases (PsycINFO, PubMed, Scopus). They were assessed for methodological quality using a standardized procedure, and categorized based on the main cognitive function measured, namely perceptive abilities, attentional bias, executive function, emotion and prevention/intervention. Eye tracking indexes showed that alcohol-related disorders are related to: (1) a stable pattern of basic eye movement impairments, particularly during alcohol intoxication; (2) a robust attentional bias, indexed by increased dwell times for alcohol-related stimuli; (3) a reduced inhibitory control on saccadic movements; (4) an increased pupillary reactivity to visual stimuli, regardless of their emotional content; (5) a limited visual attention to prevention messages. Perspectives for future research are proposed, notably encouraging the exploration of eye movements in severe alcohol use disorders and the establishment of methodological gold standards for eye tracking measures in this field.

Objective Transcranial direct current stimulation (tDCS) provides a way to modulate spatial attention by enhancing the ratio of neural activity between the left and right hemispheres, with a potential benefit for the rehabilitation of visual neglect. Methods We tested the effect of bilateral tDCS in healthy individuals performing a visual detection task. This protocol consists in the positioning of the anode and cathode on mirror positions over the left and right parietal areas. The stimulation was repeated over three days to maximize the chance to observe a bias to the hemispace controlateral to the anode. Results Compared to a sham treatment, left anodal – right cathodal stimulation enhanced attention across the full range of space, since the first day with no build-up effect on the next days, and modified the balance of left-right omissions when stimuli appeared at the same time. Conclusion Bilateral tDCS improved detection in both visual fields, with no privileged processing of one side, except when concurrent stimuli were presented. The results provide partial support to the hemispheric rivalry hypothesis. Significance The technique has the potential to boost attention in neglect patients but should be used as an adjuvant rather than as an alternative to functional rehabilitation.

Why people differ in their susceptibility to external events is essential to our understanding of personality, human development, and mental disorders. Genes explain a substantial portion of these differences. Specifically, genes influencing the serotonin system are hypothesized to be differential susceptibility factors, determining a person's reactivity to both positive and negative environments. We tested whether genetic variation in the serotonin transporter (5-HTTLPR) is a differential susceptibility factor for daily events. Participants (N = 326, 77% female, mean age = 25, range = 17-36) completed smartphone questionnaires four times a day over four to five days, measuring stressors, uplifts, positive and negative affect. Affect was predicted from environment valence in the previous hour on a within-person level using three-level autoregressive linear mixed models. The 5-HTTLPR fulfilled all criteria of a differential susceptibility factor: Positive affect in carriers of the short allele (S) was less reactive to both uplifts and stressors, compared to homozygous carriers of the long allele (L/L). This pattern might reflect relative affective inflexibility in S-allele carriers. Our study provides insight into the serotonin system's general role in susceptibility and highlights the need to assess the whole spectrum of naturalistic experiences. (DIPF/Orig.)

International audience; Visual categorization is integral for our interaction with the natural environment. In this process, similar selective responses are produced to a class of variable visual inputs. Whether categorization is supported by partial (graded) or absolute (all-or-none) neural responses in high-level human brain regions is largely unknown. We address this issue with a novel frequency-sweep paradigm probing the evolution of face categorization responses between the minimal and optimal stimulus presentation times. In a first experiment, natural images of variable non-face objects were progressively swept from 120 to 3 ​Hz (8.33-333 ​ms duration) in rapid serial visual presentation sequences. Widely variable face exemplars appeared every 1 ​s, enabling an implicit frequency-tagged face-categorization electroencephalographic (EEG) response at 1 ​Hz. Face-categorization activity emerged with stimulus durations as brief as 17 ​ms (17-83 ​ms across individual participants) but was significant with 33 ​ms durations at the group level. The face categorization response amplitude increased until 83 ​ms stimulus duration (12 ​Hz), implying graded categorization responses. In a second EEG experiment, faces appeared non-periodically throughout such sequences at fixed presentation rates, while participants explicitly categorized faces. A strong correlation between response amplitude and behavioral accuracy across frequency rates suggested that dilution from missed categorizations, rather than a decreased response to each face stimulus, accounted for the graded categorization responses as found in Experiment 1. This was supported by (1) the absence of neural responses to faces that participants failed to categorize explicitly in Experiment 2 and (2) equivalent amplitudes and spatio-temporal signatures of neural responses to behaviorally categorized faces across presentation rates. Overall, these observations provide original evidence that high-level visual categorization of faces, starting at about 100 ​ms following stimulus onset in the human brain, is variable across observers tested under tight temporal constraints, but occurs in an all-or-none fashion.

Attentional bias towards alcohol-related stimuli is a core characteristic of alcohol use disorders (AUD), playing a crucial role in their development and persistence. Many behavioral studies have shown an increased allocation of attentional resources towards alcohol-related stimuli in patients with AUD, but have also revealed a direct link between the bias and key alcohol-related variables like craving, alcohol consumption and relapse. Nevertheless, the extent of the bias in subclinical populations is still poorly documented. The present study used eye-tracking measures to: – investigate the presence of attentional bias in a specific population presenting subclinical excessive alcohol consumption (i.e. binge drinking); – determine the time course of the bias, by disentangling the role played by early and late processing stages; – clarify whether the bias is specifically associated with alcohol-related stimuli or can be generalized towards other appetitive stimulations (i.e. high-caloric food stimuli); – explore the role played by craving in the intensity of the bias. Forty-two binge drinkers and 43 matched controls performed a visual probe task, which required the processing of visual targets preceded by pairs of pictures related to three comparisons (alcohol vs. soft, alcohol vs. high-calories food, salty or sugary food vs. low-calories food). While no difference was observed across conditions for early processing (i.e. first area of interest visited), a group difference for dwell time highlighted the presence of a bias towards soft drinks and healthy food among control participants, without any bias towards alcohol and high-caloric food in binge drinkers. Centrally, complementary analyses indicated that a bias towards alcohol and high-calories food was observed among binge drinkers only in the presence of high craving levels. It thus appears that the attentional bias towards alcohol repeatedly reported in severe AUD is only found in binge drinkers in the presence of elevated craving, and is generalized towards other appetitive cues.