Resting-state functional connectivity of goal-directed and habitual-learning systems: The efficacy of cognitive-behavioral therapy for obsessive-compulsive disorder

BACKGROUND

There is an imbalance between goal-directed and habitual-learning system in patients with obsessive-compulsive disorder (OCD). At present, the relationship between cognitive behavior therapy (CBT) as a first-line therapy and goal-directed and habitual-learning disorder is still unclear. We attempted to discuss the effect of CBT treatment in patients with OCD, using abnormalities in goal-directed and habitual-learning-related brain regions at baseline as predictive factors.

METHODS

A total of 71 subjects, including 35 OCD patients and 36 healthy controls, were recruited. The OCD patients underwent 8 weeks of CBT. These patients were divided into two groups based on treatment response (Nresponders = 18, Nnonresponders = 17). Further subgroup analysis was conducted based on disease duration (Nshort = 17, Nlong = 18) and age of onset (Nearly = 14, Nlate = 21). We collected resting-state ROI-ROI functional connectivity data and apply repeated-measures linear mixed-effects models to investigate the differences of different subgroups.

RESULTS

CBT led to symptom improvement in OCD patients, with varying degrees of effectiveness across subgroups. The orbitofrontal cortex (OFC) and insula, key regions for goal-directed behavior and habitual-learning, respectively, showed significant impacts on CBT efficacy in subgroups with different disease durations and ages of onset.

CONCLUSION

The findings suggest that the goal-directed system may influence the efficacy of CBT through goal selection, maintenance, and emotion regulation. Furthermore, we found that disease duration and age of onset may affect treatment outcomes by modulating functional connectivity between goal-directed and habitual-learning brain regions.

Preschoolers' in-group bias promotes altruistic sharing and reduces second-party punishment: The role of theory of mind

This study examines how in-group bias affects altruistic sharing and second-party punishment in preschoolers and the role of theory of mind (ToM) in in-group bias. Preschoolers aged 4 to 7 years (N = 309; 160 girls) were asked to share resources with an in-group member and an out-group member (Dictator Game) and to reject or accept an unequal allocation proposed by an in-group member and an out-group member (Ultimatum Game). The results showed that preschoolers shared more resources with, and tolerated more unfair behaviors from, in-group members. ToM influenced the in-group bias in both altruistic sharing and second-party punishment. Notably, children's degree of in-group favoritism in altruistic sharing was positively related to the second-party punishment children imposed on out-group members. However, this pattern was found only among children who had acquired first-order ToM. This study reveals the developmental patterns of preschoolers' in-group bias in altruistic sharing and second-party punishment and the effects of ToM on in-group bias.

ClassIIb histone deacetylase participates in perioperative neurocognitive disorders in elderly mice via HSP90/GR signaling pathway

OBJECTIVE

Multiple factors contribute to the development of perioperative neurocognitive disorders (PND). This study was designed to investigate whether Histone Deacetylase 6 (HDAC6) was involved in the formation of postoperative cognitive dysfunction in elderly mice by regulating the degree of acetylation of heat shock protein (HSP90) and related protein functions and quantities.

METHODS

C57BL/6 J male mice were randomly divided into six groups: control naive (group Control), anesthesia (group Anesthesia), splenectomy surgery (group Surgery), splenectomy surgery plus dissolvent (group Vehicles), splenectomy surgery plus the inhibitor ACY-1215 (group Ricolinostat), and splenectomy surgery plus the inhibitor RU-486(group Mifepristone). After the mice were trained for Morris Water Maze (MWM) test for five days, anesthesia and operational surgery were carried out the following day. Cognitive function was assessed on the 1st, 3rd and 7th days post-surgery. The hippocampi were harvested on days 1, 3, and 7 post-surgeries for Western blots and ELISA assays.

RESULTS

Mice with the splenectomy surgery displayed the activation of the hypothalamic-pituitary-adrenal axis (HPA-axis), marked an increase in adrenocorticotropic hormone (ACTH), glucocorticoid, mineralocorticoid at the molecular level and impaired spatial memory in the MWM test. The hippocampus of surgical groups showed a decrease in acetylated HSP90, a rise in glucocorticoid receptor (GR)-HSP90 association, and an increase in GR phosphorylation and translocation. HDAC6 was increased after the surgical treated. Using two specific inhibitors, HDAC6 inhibitor Ricolinostat (ACY-1215) and GR inhibitor Mifepristone (RU-486), can partially mitigate the effects caused by surgical operation.

CONCLUSIONS

Abdominal surgery may impair hippocampal spatial memory, possibly through the HDAC6-triggered increase in the function of HSP90, consequently strengthening the negative role of steroids in cognitive function. Targeting HDAC6- HSP90/GR signaling may provide a potential avenue for the treatment of the impairment of cognitive function after surgery.

Sparking creativity: Encouraging creative idea generation through automatically generated word recommendations

Creative block is a familiar foe to any who attempt to create and is especially related to "writers block". While significant effort has been focused on developing methods to break such blocks, it remains an active challenge. Here, we focus on the role of semantic memory structure in driving creative block, by having people get "stuck" in a certain part of their semantic memory network. We directly examine whether we can "pull out" a participant from where they got "stuck" in their semantic memory, breaking their creative impasse. Our Associative Creativity Sparker (ACS) is a cognitive network science-based online tool that aims to spark creative ideas and break creative impasse: Once a participant runs out of ideas in a creative idea generation task, word recommendations are suggested to prime new ideas. These word recommendations are either towards or away from previous ideas, as well as close or far from the target object, based on a conceptual space extracted from the participants responses using online text analysis. In Study 1, 121 participants use the ACS to generate creative alternative uses for five different objects and completed creativity and Gf tasks. In Study 2, we repeat the design of Study 1, but further examine the impact of writing experience on the ACS, by examining 120 novice and 120 experienced writers. Across both studies, our results indicate that the location of word recommendations affects the fluency and originality of one's ideas, and that novice and experienced writers differently benefit from these word recommendations.

Statistical learning ability at 17 months relates to early reading skills via oral language

Statistical learning ability has been found to relate to children's reading skills. Yet, statistical learning is also known to be vital for developing oral language skills, and oral language and reading skills relate strongly. These connections raise the question of whether statistical learning ability affects reading via oral language or directly. Statistical learning is multifaceted, and so different aspects of statistical learning might influence oral language and reading skills distinctly. In a longitudinal study, we determined how two aspects of statistical learning from an artificial language tested on 70 17-month-old infants-segmenting sequences from speech and generalizing the sequence structure-related to oral language skills measured at 54 months and reading skills measured at approximately 75 months. Statistical learning segmentation did not relate significantly to oral language or reading, whereas statistical learning generalization related to oral language, but only indirectly related to reading. Our results showed that children's early statistical learning ability was associated with learning to read via the children's oral language skills.

Meta-analysis of structural and functional abnormalities in behavioral addictions

BACKGROUND

The incidence of behavioral addictions (BAs) associated with scientific and technological advances has been increasing steadily. Unfortunately, a large number of studies on the structural and functional abnormalities have shown poor reproducibility, and it remains unclear whether different addictive behaviors share common underlying abnormalities. Therefore, our objective was to conduct a quantitative meta-analysis of different behavioral addictions to provide evidence-based evidence of common structural and functional changes.

METHODS

We conducted systematic searches in PubMed, Web of Science and Scopus from January 2010 to December 2023, supplementing reference lists of high-quality relevant meta-analyses and reviews, to identify eligible voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI) studies. Using anisotropic seed-based D-Mapping (AES-SDM) meta-analysis methods, we compared brain abnormalities between BAs and healthy controls (HCs).

RESULTS

There were 11 GMV studies (287 BAs and 292 HCs) and 26 fMRI studies (577 BAs and 545 HCs) that met inclusion criteria. Compared with HCs, BAs demonstrated significant reductions in gray matter volume (GMV) in (1) right anterior cingulate gyri extending into the adjacent superior frontal gyrus, as well as in the left inferior frontal gyrus and right striatum. (2) the bilateral precuneus, right supramarginal gyrus, and right fusiform gyrus were hyperfunction; (3) the left medial cingulate gyrus extended to the superior frontal gyrus, the left inferior frontal gyrus, and right middle temporal gyrus had hypofunction.

CONCLUSIONS

Our study identified structural and functional impairments in brain regions involved in executive control, cognitive function, visual memory, and reward-driven behavior in BAs. Notably, fronto-cingulate regions may serve as common biomarkers of BAs.

Prediction of behavioral performance by alpha-band phase synchronization in working memory

Working memory (WM) is a cognitive system with limited capacity that can temporarily store and process information. The purpose of this study was to investigate functional connectivity based on phase synchronization during WM and its relationship with the behavioral response. In this regard, we recorded EEG/Eye tracking data of seventeen healthy subjects while performing a memory-guided saccade (MGS) task with two different positions (near eccentricity and far eccentricity). We computed saccade error as memory performance and measured functional connectivity using Phase Locking Value (PLV) in the alpha frequency band (8-12 Hz). The results showed that PLV is negatively correlated with saccade error. Our finding indicated that during the maintenance period, PLV between the frontal and visual area in trials with low saccade error increased significantly compared to trials with high saccade error. Furthermore, we observed a significant difference between PLV for near and far conditions in the delay period. The results suggest that PLV in memory maintenance, in addition to predicting saccade error as behavioral performance, can be related to the coding of spatial information in WM.

Investigating functional connectivity related to stroke recovery: A systematic review

INTRODUCTION

Stroke recovery is a complex process influenced by various factors, including specific neural reorganization. The objective of this systematic review was to identify important functional connectivity (FC) changes in resting-state fMRI data that were often correlated with motor, emotional, and cognitive outcome improvement.

METHOD

A systematic search using PubMed and SCOPUS databases was conducted to identify relevant studies published between 2010 and 2023.

RESULTS

A total of 766 studies were identified, of which 20 studies (602 S individuals) met the inclusion criteria. Fourteen studies focussed on motor recovery while six on cognitive recovery. All studies reported interhemispheric FC to be strongly associated with motor and cognitive recovery. The preservation and changes of M1-M1 (eight incidences) and M1-SMA (nine incidences) FC were found to be strongly correlated with motor function improvement. For cognitive recovery, restoration and preservation of FC with and between default mode network (DMN)-related regions were important for the process.

CONCLUSIONS

This review identified specific patterns of FC that were consistently reported with recovery of motor and cognitive function. The findings may serve in refining future management strategies to enhance patient outcomes.

The influence of multiple cognitive workload levels of an exergame on dorsal attention network connectivity at the source level

This study investigates how adding a cognitive task on a balance board (exergame) affects connectivity in the dorsal attention network (DAN) during an exergame task. Healthy young adults performed a soccer ball-moving task by tilting a balance board with their feet while their brain activity was measured using electroencephalography (EEG). In this exergame, the speed of obstacles in front of the goal manipulated the cognitive workload. Higher speed means a higher cognitive workload. The study found significant changes in functional connectivity within DAN regions, specifically in the alpha band. During the shift from easy to medium cognitive task, we observed a significant increase in connectivity (p= 0.0436) between the right inferior temporal (ITG R) and the Left middle temporal (MTG L). During the transition from easy to hard cognitive tasks, strengthened interactions (p= 0.0324) between inferior temporal (ITG) and parsopercularis (pOPPER) were found. This suggests that the proposed balanceboard-based exergame enhances the functionality of specific brain regions, such as ITG and MTG regions, and improves connectivity in the frontal cortex. We also found a correlation between brain activity and performance data, highlighting that increased cognitive workload resulted in decreased performance and heightened frontal alpha activity. These findings align with research suggesting that adding cognitive games to physical activity-based tasks in rehabilitation programs can boost brain activity, resulting in improved decision-making and visual processing skills. This information can help clinicians tailor rehabilitation methods that target specific brain regions.

Measuring temporal bias in sequential numerosity comparison

While several methods have been proposed to assess the influence of continuous visual cues in parallel numerosity estimation, the impact of temporal magnitudes on sequential numerosity judgments has been largely ignored. To overcome this issue, we extend a recently proposed framework that makes it possible to separate the contribution of numerical and non-numerical information in numerosity comparison by introducing a novel stimulus space designed for sequential tasks. Our method systematically varies the temporal magnitudes embedded into event sequences through the orthogonal manipulation of numerosity and two latent factors, which we designate as "duration" and "temporal spacing". This allows us to measure the contribution of finer-grained temporal features on numerosity judgments in several sensory modalities. We validate the proposed method on two different experiments in both visual and auditory modalities: results show that adult participants discriminated sequences primarily by relying on numerosity, with similar acuity in the visual and auditory modality. However, participants were similarly influenced by non-numerical cues, such as the total duration of the stimuli, suggesting that temporal cues can significantly bias numerical processing. Our findings highlight the need to carefully consider the continuous properties of numerical stimuli in a sequential mode of presentation as well, with particular relevance in multimodal and cross-modal investigations. We provide the complete code for creating sequential stimuli and analyzing participants' responses.

Consistency within change: Evaluating the psychometric properties of a widely used predictive-inference task

Rapid adaptation to sudden changes in the environment is a hallmark of flexible human behaviour. Many computational, neuroimaging, and even clinical investigations studying this cognitive process have relied on a behavioural paradigm known as the predictive-inference task. However, the psychometric quality of this task has never been examined, leaving unanswered whether it is indeed suited to capture behavioural variation on a within- and between-subject level. Using a large-scale test-retest design (T1: N = 330; T2: N = 219), we assessed the internal (internal consistency) and temporal (test-retest reliability) stability of the task's most used measures. We show that the main measures capturing flexible belief and behavioural adaptation yield good internal consistency and overall satisfying test-retest reliability. However, some more complex markers of flexible behaviour show lower psychometric quality. Our findings have implications for the large corpus of previous studies using this task and provide clear guidance as to which measures should and should not be used in future studies.

Does Mindfulness Improve Intergroup Bias, Internalized Bias, and Anti-Bias Outcomes?: A Meta-Analysis of the Evidence and Agenda for Future Research

Whereas mindfulness has been shown to enhance personal well-being, studies suggest it may also benefit intergroup dynamics. Using an integrative conceptual model, this meta-analysis examined associations between mindfulness and (a) different manifestations of bias (implicit/explicit attitudes, affect, behavior) directed toward (b) different bias targets (outgroup or ingroup, e.g., internalized bias), by (c) intergroup orientation (toward bias or anti-bias). Of 70 samples, 42 (N = 3,229) assessed mindfulness-based interventions (MBIs) and 30 (N = 6,002) were correlational studies. Results showed a medium-sized negative effect of MBIs on bias outcomes, g = -0.56, 95% confidence interval [-0.72, -0.40]; I(2;3)2: 0.39; 0.48, and a small-to-medium negative effect between mindfulness and bias for correlational studies, r = -0.17 [-0.27, -0.03]; I(2;3)2: 0.11; 0.83. Effects were comparable for intergroup bias and internalized bias. We conclude by identifying gaps in the evidence base to guide future research.

Switching between task control modes incurs greater reprogramming costs than programming the response de novo

When performing synchronous hand and foot movements, the way the limbs are synchronized differs depending on the mode of control. When performed in a reaction time (RT) paradigm (reactive control), EMG onsets become synchronized resulting in asynchronous displacement onset. However, when the same movement is performed as an anticipation-timing task (predictive control), displacement onset is synchronized by unconsciously introducing a small delay between EMG onsets. The present experiment investigated the reprogramming costs associated with switching between predictive and reaction control modes. Participants (N = 12, 6F) were asked to simultaneously lift their right heel and right hand in an anticipation-timing task when a rotating clock hand reached a specified target. On some trials, an auditory stimulus was presented either 250 ms or 500 ms before the target and participants were instructed to execute the synchronous movement as quickly as possible after the signal (i.e., switch to reactive mode). Results showed that when the auditory stimulus was delivered 250 ms before the target, participants were unable to switch to a reactive control mode but did switch when the auditory stimulus was presented 500 ms before the target. As expected, the RT on switch trials was substantially longer (∼230 ms) than a simple RT control condition but was also significantly longer (∼130 ms) than a choice RT control condition. These results indicate that switching between control modes for a task involving the same musculature incurs reprogramming costs that are even greater than the time required to program the response de novo.

Rewilding psychology

Some commentators have recently argued that scientific psychology is overly reliant on artificial laboratory-based activities and that it undervalues field-based investigations. However, it remains unclear how a field-based programme of psychological research might be organized in a scalable way. We examine and compare two existing field-based approaches: Roger Barker's behaviour settings programme and Edwin Hutchins's distributed cognition programme. Both programmes prioritize observational work, and both reject the individual as the unit of analysis in favour of a community-scale unit. However, whereas the behaviour settings programme is concerned with structural properties of community life, distributed cognition is concerned more narrowly with the functional analysis of expert team performance. We discuss how these programmes can inform a future community-scale approach to studying psychology in the wild. We conclude that the two programmes are proof of concept of the possibility of a scientific psychology that rejects methodological individualism. This article is part of the theme issue 'People, places, things and communities: expanding behaviour settings theory in the twenty-first century'.

Discriminative analysis of schizophrenia and major depressive disorder using fNIRS

BACKGROUND

Research into the shared and distinct brain dysfunctions in patients with schizophrenia (SCZ) and major depressive disorder (MDD) has been increasing. However, few studies have explored the application of functional near-infrared spectroscopy (fNIRS) in investigating brain dysfunction and enhancing diagnostic methodologies in these two conditions.

METHODS

A general linear model was used for analysis of brain activation following task-state fNIRS from 131 patients with SCZ, 132 patients with MDD and 130 healthy controls (HCs). Subsequently, seventy-seven time-frequency analysis methods were used to construct new features of fNIRS, followed by the implementation of five machine learning algorithms to develop a differential diagnosis model for the three groups. This model was evaluated by comparing it to both a diagnostic model relying on traditional fNIRS features and assessments made by two psychiatrists.

RESULTS

Brain activation analysis revealed significantly lower activation in Broca's area, the dorsolateral prefrontal cortex, and the middle temporal gyrus for both the SCZ and MDD groups compared to HCs. Additionally, the SCZ group exhibited notably lower activation in the superior temporal gyrus and the subcentral gyrus compared to the MDD group. When distinguishing among the three groups using independent validation datasets, the models utilizing new fNIRS features achieved an accuracy of 85.90 % (AUC = 0.95). In contrast, models based on traditional fNIRS features reached an accuracy of 52.56 % (AUC = 0.66). The accuracies of the two psychiatrists were 42.00 % (AUC = 0.60) and 38.00 % (AUC = 0.50), respectively.

CONCLUSION

This investigation brings to light the shared and distinct neurobiological abnormalities present in SCZ and MDD, offering potential enhancements for extant diagnostic systems.

Sleep, event appraisal, and affect: An ecological momentary assessment study

BACKGROUND

Appraisal theory posits that emotions result from cognitive appraisals of events and situations. Experimental work suggests that sleep influences cognitive processes and event appraisal, which the present study examines in real life. Poor sleep influences brain regions involved in the appraisal-to-emotion process, and tired participants showed more conservative appraisal and reported less positive and more negative affect. In the present study, we tested whether sleep duration and/or quality predicted more pleasant event appraisal and whether sleep moderated the association between event appraisal and affect.

METHODS

Participants (N = 892) from the general Dutch population reported thrice daily on event appraisal and various emotions for 30 days and once daily on sleep duration and quality. We constructed multilevel models to account for the nested structure of our data (observations within participants).

RESULTS

Multilevel regression analyses showed that on days when participants reported having slept longer and better than their average, their event appraisal was more positive. Subjective sleep duration and quality did not influence the relationship between event appraisal and affect. Hence, poor sleep predicted changes in cognitive functioning, as people appraised situations as more unpleasant.

LIMITATIONS

We measured subjective sleep duration and quality with two single items and focused on only pleasantness dimension of event appraisal.

CONCLUSIONS

Results match perspectives on emotions as multicomponent systems involving appraisal processes. Understanding the elements of event appraisal may help unravel the detrimental effects of poor sleep on mental health and well-being.

Transcutaneous auricular vagus nerve stimulation improves anxiety symptoms and cortical activity during verbal fluency task in Parkinson's disease with anxiety

OBJECTIVE

To investigate the effect of 20/4Hz transcutaneous auricular vagus nerve stimulation (taVNS) on anxiety symptoms in Parkinson's disease (PD) and the potential neural mechanism.

METHODS

In the current randomized, double-blind, sham-controlled trial, 30 PD patients with anxiety (PD-A), 30 PD patients without anxiety (PD-nA), and 30 healthy controls (HCs) were enrolled. PD-A patients were randomly (1:1) allotted to real taVNS stimulation group (RS) or sham stimulation group (SS) to explore the efficacy of a two-week treatment of taVNS to promote anxiety recovery. Simultaneously, all participants were measured activation in the bilateral prefrontal cortex during verbal fluency task (VFT) using functional near-infrared spectroscopy.

RESULTS

PD-A patients showed significantly decreased oxyhemoglobin in the left triangle part of the inferior frontal gyrus (IFG) during VFT, which was negatively related to the severity of anxiety symptoms. After two-week treatment of taVNS, the interaction of group and time had significant effect on HAMA scores (F = 18.476, p < 0.001, η2 = 0.398). In RS group, compared with baseline, HAMA scores decreased significantly in the post-treatment and follow-up condition (both p < 0.001). Meanwhile, in RS group, HAMA scores were lower than those in SS group in the post-treatment and follow-up condition (p = 0.006, <0.001, respectively). Furthermore, the 20/4Hz taVNS remarkably ameliorated anxiety symptoms in PD patients, directly correlated with the increased activation of the left triangle part of the IFG during VFT in RS group.

CONCLUSION

Our results depicted that taVNS could ameliorate the anxiety symptoms of PD-A patients and regulated the function of the left triangle part of the IFG.

Spelling principles matter: An ERP study investigating the processing of different types of pseudohomophones

Spelling in any writing system is governed by fundamental principles. We examined the processing of two types of pseudohomophones constructed from words whose spellings are based on different principles - on the traditional principle of writing, requiring memorization of their spelling, and on the morphological principle, allowing the determination of their spelling from another word with the same morpheme (root) to examine the dependence of the occurrence of orthography-phonology conflict on spelling principles. Event-related potentials were recorded from 22 volunteers during silent reading. Pseudohomophones based on the morphological principle increased the N400 amplitude, emphasizing semantic and morphological processing importance. The P600 component showed significant effects for differentiating words and pseudohomophones based on the traditional principle, predominantly indicating the involvement of memory and reanalysis processes. Source reconstruction demonstrates that both pseudohomophones activate the left inferior frontal gyrus. However, pseudohomophones based on the traditional principle additionally activate the right and left postcentral gyrus, indicating the involvement of additional areas in the differentiation process. The earlier differences for stimuli based on the morphological principle indicate access to smaller units (morphemes), whereas stimuli based on the traditional principle require whole word processing. Our findings underscore the significant role of spelling principles in orthographic processing.

The temporal mismatch across listening sides affects cortical auditory evoked responses in normal hearing listeners and cochlear implant users with contralateral acoustic hearing

Combining a cochlear implant with contralateral acoustic hearing typically enhances speech understanding, although this improvement varies among CI users and can lead to an interference effect. This variability may be associated with the effectiveness of the integration between electric and acoustic stimulation, which might be affected by the temporal mismatch between the two listening sides. Finding methods to compensate for the temporal mismatch might contribute to the optimal adjustment of bimodal devices and to improve hearing in CI users with contralateral acoustic hearing. The current study investigates cortical auditory evoked potentials (CAEPs) in normal hearing listeners (NH) and CI users with contralateral acoustic hearing. In NH, the amplitude of the N1 peak and the maximum phase locking value (PLV) were analyzed under monaural, binaural, and binaural temporally mismatched conditions. In CI users, CAEPs were measured when listening with CI only (CIS_only), acoustically only (AS_only) and with both sides together (CIS+AS). When listening with CIS+AS, various interaural delays were introduced between the electric and acoustic stimuli. In NH listeners, interaural temporal mismatch resulted in decreased N1 amplitude and PLV. Moreover, PLV is suggested as a more sensitive measure to investigate the integration of information between the two listening sides. CI users showed varied N1 latencies between the AS_only and CIS_only listening conditions, with increased N1 amplitude when the temporal mismatch was compensated. A tendency towards increased PLV was also observed, however, to a lesser extent than in NH listeners, suggesting a limited integration between electric and acoustic stimulation. This work highlights the potential of CAEPs measurement to investigate cortical processing of the information between two listening sides in NH and bimodal CI users.

Transcriptional Patterns of Brain Structural Covariance Network Abnormalities Associated With Suicidal Thoughts and Behaviors in Major Depressive Disorder

BACKGROUND

Although brain structural covariance network (SCN) abnormalities have been associated with suicidal thoughts and behaviors (STBs) in individuals with major depressive disorder (MDD), previous studies have reported inconsistent findings based on small sample sizes, and underlying transcriptional patterns remain poorly understood.

METHODS

Using a multicenter magnetic resonance imaging dataset including 218 MDD patients with STBs, 230 MDD patients without STBs, and 263 healthy control participants, we established individualized SCNs based on regional morphometric measures and assessed network topological metrics using graph theoretical analysis. Machine learning methods were applied to explore and compare the diagnostic value of morphometric and topological features in identifying MDD and STBs at the individual level. Brainwide relationships between STBs-related connectomic alterations and gene expression were examined using partial least squares regression.

RESULTS

Group comparisons revealed that SCN topological deficits associated with STBs were identified in the prefrontal, anterior cingulate, and lateral temporal cortices. Combining morphometric and topological features allowed for individual-level characterization of MDD and STBs. Topological features made a greater contribution to distinguishing between patients with and without STBs. STBs-related connectomic alterations were spatially correlated with the expression of genes enriched for cellular metabolism and synaptic signaling.

CONCLUSIONS

These findings revealed robust brain structural deficits at the network level, highlighting the importance of SCN topological measures in characterizing individual suicidality and demonstrating its linkage to molecular function and cell types, providing novel insights into the neurobiological underpinnings and potential markers for prediction and prevention of suicide.

Prefrontal-Limbic Circuitry Is Associated With Reward Sensitivity in Nonhuman Primates

BACKGROUND

Abnormal reward sensitivity is a risk factor for psychiatric disorders, including eating disorders such as overeating and binge-eating disorder, but the brain structural mechanisms that underlie it are not completely understood. Here, we sought to investigate the relationship between multimodal whole-brain structural features and reward sensitivity in nonhuman primates.

METHODS

Reward sensitivity was evaluated through behavioral economic analysis in which monkeys (adult rhesus macaques; 7 female, 5 male) responded for sweetened condensed milk (10%, 30%, 56%), Gatorade, or water using an operant procedure in which the response requirement increased incrementally across sessions (i.e., fixed ratio 1, 3, 10). Animals were divided into high (n = 6) or low (n = 6) reward sensitivity groups based on essential value for 30% milk. Multimodal magnetic resonance imaging was used to measure gray matter volume and white matter microstructure. Brain structural features were compared between groups, and their correlations with reward sensitivity for various stimuli was investigated.

RESULTS

Animals in the high sensitivity group had greater dorsolateral prefrontal cortex, centromedial amygdaloid complex, and middle cingulate cortex volumes than animals in the low sensitivity group. Furthermore, compared with monkeys in the low sensitivity group, high sensitivity monkeys had lower fractional anisotropy in the left dorsal cingulate bundle connecting the centromedial amygdaloid complex and middle cingulate cortex to the dorsolateral prefrontal cortex, and in the left superior longitudinal fasciculus 1 connecting the middle cingulate cortex to the dorsolateral prefrontal cortex.

CONCLUSIONS

These results suggest that neuroanatomical variation in prefrontal-limbic circuitry is associated with reward sensitivity. These brain structural features may serve as predictive biomarkers for vulnerability to food-based and other reward-related disorders.

Biomarkers of neural integrity and immunoglobulin genes influence neurodegeneration in Alzheimer's disease

Compelling evidence has been presented in favor of herpes simplex virus type 1 (HSV1) being one of the causative agents of Alzheimer's disease (AD). The success of HSV1 as a pathogen relates to its sophisticated strategies to evade host immunosurveillance. One strategy involves encoding a decoy Fcγ receptor (FcγR) that thwarts the Fcγ-mediated effector functions, such as antibody-dependent cellular cytotoxicity (ADCC), a potent host immunosurveillance mechanism against virally infected cells. The decoy FcγR binds to antibodies of all IgG subclasses, except IgG3; therefore, IgG3 would be expected to play an important role in viral clearance by neutralization and ADCC, and thus contribute to protection from HSV1-spurred diseases. Previous studies have shown significant association between anti-HSV1 IgG3 antibodies and cortical thinning of the areas of the brain typically altered in AD and also targeted by HSV1. The aim of the present investigation was to determine whether GM (γ marker) 5 and GM 21 allotypes, hereditary allelic determinants expressed on IgG3, together with brain biomarkers of neural integrity, contributed to neurodegeneration-as measured by mini-mental state examination (MMSE) score-in patients with AD. Multiple regression analyses showed that the homozygous GM 5/5 genotype, preserved right hippocampus, and right insula thickness were associated with higher MMSE scores (p < 0.001), whereas the opposite pattern and GM 5/21 genotype were associated with worse clinical profiles. Influence of GM 5/21-expressing IgG3 antibodies on the ADCC of HSV1-infected neurons could, at least partially, explain these results.

Sleep quality predicts future mood symptoms in adolescents with bipolar disorder

BACKGROUND

Poor sleep is prevalent in adolescents with bipolar disorder, precedes illness onset, and is associated with worse mood symptoms. We examined interrelationships between sleep quality and mood symptoms in adolescents with bipolar disorder, particularly effects of sleep quality on emergent mood symptoms.

METHODS

Adolescents with bipolar disorder participated in a two-year longitudinal treatment study. Sleep quality (Pittsburgh Sleep Quality Index, PSQI) was assessed quarterly during treatment (baseline, 3-, 6-, 9-, 12-month visits) and twice during follow-up (18-, 24-month visits). Mood symptoms (ALIFE Psychiatric Status Ratings) were retrospectively rated weekly by an independent clinician. Lag models tested whether sleep quality predicted next month's mood symptoms and whether mood symptoms predicted future sleep quality.

RESULTS

Adolescents with bipolar disorder had poor sleep quality. Sleep quality initially improved but remained stable thereafter. Worse sleep quality at 6-months predicted worse depression, hypomania, and suicidal ideation the following month. Sleep quality was worse for adolescents who had a suicide attempt during the study compared to those who did not and was worse preceding months with a suicide attempt compared to months without attempts. Alternatively, worse depression predicted worse future sleep quality at baseline, 3-, and 18-months and worse suicidal ideation predicted worse future sleep quality at baseline, 12-, and 18-months.

LIMITATIONS

Mood symptoms were rated retrospectively and the PSQI may not capture all dimensions of sleep important for mood symptoms.

CONCLUSIONS

Targeted evidence-based sleep treatment in adolescents with bipolar disorder may alleviate sleep problems and have additional benefits on mood symptoms and suicidality risk.

Mothers' and their children's emotional and behavioral symptom trajectories and subsequent maternal adjustment: Twenty-seven years of motherhood

BACKGROUND

This study aims to describe maternal depressive symptoms (MDS) trajectories in a longitudinal study extending from pregnancy to 27 years after the birth of the firstborn child. We also explored the associations of both MDS trajectories and child internalizing and externalizing problem trajectories with maternal adjustment (adaptive functioning, emotional and behavioral problems).

METHODS

The population-based study was conducted in Tampere, Finland, and the sample comprised 356 first-time mothers. MDS were screened with the Edinburgh Postnatal Depression Scale during pregnancy, first week after delivery, 2 and 6 months postnatally, and when the child was 4-5, 8-9, 16-17, and 26-27 years of age. The internalizing and externalizing problems of the children were assessed with the Child Behavior Checklist when the child was 4-5, 8-9, and 16-17 years of age. Maternal adaptive functioning and internalizing and externalizing problems were assessed with the Adult Self Report at 26-27 years after the birth of the first child. Complete follow-up data were available for 168 mothers.

RESULTS

We describe a three-group trajectory model of MDS (High Stable, Low Stable, Very Low). Elevated depressive symptom patterns were associated with less optimal maternal outcomes regarding both adaptive and problem dimensions. The child's internalizing and externalizing problem trajectories were associated with maternal internalizing and externalizing problems but not with maternal adaptive functioning.

LIMITATIONS

Maternal and child measures were based on maternal reports only.

CONCLUSIONS

The interconnectedness of the well-being of the mother and child should be noted in health and mental health services for adults and children.

Functional connectivity of the default mode network in first-episode drug-naïve patients with major depressive disorder

BACKGROUND

Alterations in the default mode network (DMN) have been reported in major depressive disorder (MDD), well-replicated robust alterations of functional connectivity (FC) of DMN remain to be established. Investigating the functional connections of DMN at the overall and subsystem level in early MDD patients has the potential to advance our understanding of the physiopathology of this disorder.

METHODS

We recruited 115 first-episode drug-naïve patients with MDD and 137 demographic-matched healthy controls (HCs). We first compared FC within the DMN, within/between the DMN subsystems, and from DMN subsystems to the whole brain between groups. Subsequently, we explored correlations between clinical features and identified alterations in FC.

RESULTS

First-episode drug-naïve patients with MDD showed significantly increased FC within the DMN, dorsal DMN and medial DMN. Each subsystem showed a distinct FC pattern with other brain networks. Increased FC between the subsystems (core DMN, dorsal DMN) and other networks was associated with more severe depressive symptoms, while medial DMN-related connectivity correlated with memory performance.

LIMITATIONS

The relatively large "pure" MDD sample could only be generalized to a limited population. And, atypical asymmetric FCs in the DMN related to MDD might be missed for only left-lateralized ROIs were used to avoid strong correlations between mirrored (right/left) seed regions.

CONCLUSION

These findings suggest patients with early MDD showed distinct patterns of FC alterations throughout DMN and its subsystems, which were related to illness severity and illness-associated cognitive impairment, highlighting their clinical significance.

Adaptive Strategies of Single-Sided Deaf Cochlear-Implant Users Revealed Through Resting State Activity: an Auditory PET Brain Imaging Study

Brain plasticity refers to the brain's ability to reorganize its structure or function in response to experiences, learning, and environmental influences. This phenomenon is particularly significant in individuals with deafness, as the brain adapts to compensate for the lack of auditory stimulation. The aim of this study is to investigate whether cochlear implantation can restore a normal pattern of brain activation following auditory stimulation in cases of asymmetric hearing loss. We used a PET-scan technique to assess brain activity after cochlear implantation, specifically during an auditory voice/non-voice discrimination task. The results indicated a nearly normal pattern of brain activity during the auditory discrimination task, except for increased activation in areas related to attentional processes compared to controls. Additionally, brain activity at rest showed significant changes in implanted participants, including cross modal visuo-auditory processing. Therefore, cochlear implants can restore the brain's activation pattern through long-term adaptive adjustments in intrinsic brain activity.

Neurocognitive outcomes in young adults with cochlear implants: The role of early language access and crossmodal plasticity

Many children with profound hearing loss have received cochlear implants (CI) to help restore some sense of hearing. There is, however, limited research on long-term neurocognitive outcomes in young adults who have grown up hearing through a CI. This study compared the cognitive outcomes of early-implanted (n = 20) and late-implanted (n = 21) young adult CI users, and typically hearing (TH) controls (n=56), all of whom were enrolled in college. Cognitive fluidity, nonverbal intelligence, and American Sign Language (ASL) comprehension were assessed, revealing no significant differences in cognition and nonverbal intelligence between the early and late-implanted groups. However, there was a difference in ASL comprehension, with the late-implanted group having significantly higher ASL comprehension. Although young adult CI users showed significantly lower scores in a working memory and processing speed task than TH age-matched controls, there were no significant differences in tasks involving executive function shifting, inhibitory control, and episodic memory between young adult CI and young adult TH participants. In an exploratory analysis of a subset of CI participants (n = 17) in whom we were able to examine crossmodal plasticity, we saw greater evidence of crossmodal recruitment from the visual system in late-implanted compared with early-implanted CI young adults. However, cortical visual evoked potential latency biomarkers of crossmodal plasticity were not correlated with cognitive measures or ASL comprehension. The results suggest that in the late-implanted CI users, early access to sign language may have served as a scaffold for appropriate cognitive development, while in the early-implanted group early access to oral language benefited cognitive development. Furthermore, our results suggest that the persistence of crossmodal neuroplasticity into adulthood does not necessarily impact cognitive development. In conclusion, early access to language - spoken or signed - may be important for cognitive development, with no observable effect of crossmodal plasticity on cognitive outcomes.

EEG emotion recognition based on data-driven signal auto-segmentation and feature fusion

Pattern recognition based on network connections has recently been applied to the brain-computer interface (BCI) research, offering new ideas for emotion recognition using Electroencephalogram (EEG) signal. However unified standards are currently lacking for selecting emotional signals in emotion recognition research, and potential associations between activation differences in brain regions and network connectivity pattern are often being overlooked. To bridge this technical gap, a data-driven signal auto-segmentation and feature fusion algorithm (DASF) is proposed in this paper. First, the Phase Locking Value (PLV) method was used to construct the brain functional adjacency matrix of each subject, and the dynamic brain functional network across subjects was then constructed. Next, tucker decomposition was performed and the Grassmann distance of the connectivity submatrix was calculated. Subsequently, different brain network states were distinguished and signal segments under emotional states were automatically extract using data-driven methods. Then, tensor sparse representation was adopted on the intercepted EEG signals to effectively extract functional connections under different emotional states. Finally, power-distribution related features (differential entropy and energy feature) and brain functional connection features were effectively combined for classification using the support vector machines (SVM) classifier. The proposed method was validated on ERN and DEAP datasets. The single-feature emotion classification accuracy of 86.57 % and 87.74 % were achieved on valence and arousal dimensions, respectively. The accuracy of the proposed feature fusion method was achieved at 89.14 % and 89.65 %, accordingly, demonstrating an improvement in emotion recognition accuracy. The results demonstrated the superior classification performance of the proposed data-driven signal auto-segmentation and feature fusion algorithm in emotion recognition compared to state-of-the-art classification methods.

The Causal Relationships Between Gut Microbiota, Brain Volume, and Intelligence: A Two-Step Mendelian Randomization Analysis

BACKGROUND

Growing evidence indicates that dynamic changes in gut microbiome can affect intelligence; however, whether these relationships are causal remains elusive. We aimed to disentangle the poorly understood causal relationship between gut microbiota and intelligence.

METHODS

We performed a 2-sample Mendelian randomization (MR) analysis using genetic variants from the largest available genome-wide association studies of gut microbiota (N = 18,340) and intelligence (N = 269,867). The inverse-variance weighted method was used to conduct the MR analyses complemented by a range of sensitivity analyses to validate the robustness of the results. Considering the close relationship between brain volume and intelligence, we applied 2-step MR to evaluate whether the identified effect was mediated by regulating brain volume (N = 47,316).

RESULTS

We found a risk effect of the genus Oxalobacter on intelligence (odds ratio = 0.968 change in intelligence per standard deviation increase in taxa; 95% CI, 0.952-0.985; p = 1.88 × 10-4) and a protective effect of the genus Fusicatenibacter on intelligence (odds ratio = 1.053; 95% CI, 1.024-1.082; p = 3.03 × 10-4). The 2-step MR analysis further showed that the effect of genus Fusicatenibacter on intelligence was partially mediated by regulating brain volume, with a mediated proportion of 33.6% (95% CI, 6.8%-60.4%; p = .014).

CONCLUSIONS

Our results provide causal evidence indicating the role of the microbiome in intelligence. Our findings may help reshape our understanding of the microbiota-gut-brain axis and development of novel intervention approaches for preventing cognitive impairment.

Transcranial alternating current stimulation barely enhances working memory in healthy adults: A meta-analysis

Working memory (WM) is a pivotal neural mechanism for cognitive function and ability. Transcranial alternating current stimulation (tACS) was used to improve WM by entraining key brain rhythms. We submitted to meta-analysis 143 effects of tACS on WM performance, found in 42 reports published between 2014 and 2023, encompassing a total of 1386 healthy adults stimulated. The overall effect size of 134 interventions intended to improve WM equaled Hedges' g = 0.076 [0.039, 0.113]. However, after correcting for a significant publication bias this effect size dropped to zero. By contrast, 9 interventions distorting the brain synchronization using antiphase tACS reliably decreased WM performance, with Hedges' g = -0.266, [-0.458, -0.074]. Individuating the targeted frequency band was the only reliable moderator. The disparity between our null outcome and moderately positive tACS effects estimated by previous meta-analyses resulted from our inclusion of the most recent studies mostly reporting negligible effects. Our results suggest that current tACS protocols barely enhance WM in healthy adults. More research is needed to develop effective methods for WM stimulation.

Intracranial EEGs evidenced visual object processing in the human medial temporal lobe subregions

The perirhinal cortex (PRC) and parahippocampal cortex (PHC) are core regions along the visual dual-stream. The specific functional roles of the PRC and PHC and their interactions with the downstream hippocampus cortex (HPC) are crucial for understanding visual memory. Our research used human intracranial EEGs to study the neural mechanism of the PRC, PHC, and HPC in visual object encoding. Single-regional function analyses found evidence that the PRC, PHC, and HPC are activated ∼100 ms within the broad-gamma band and that the PRC was more strongly activated than either the PHC or the HPC after an object stimulus. Inter-regional analyses showed strong bidirectional interactions of the PRC with both the PHC and HPC in the low-frequency band, whereas the interactions between the PHC and HPC were not significant. These findings demonstrated the core role of the PRC in encoding visual object information and supported the hypothesis of PRC-HPC-ventral object pathway. The recruitment of the PHC and its interaction with the PRC in visual object encoding also provide new insights beyond the traditional dorsal-stream hypothesis.

Moderate-intensity aerobic exercise enhanced dopamine signaling in diet-induced obese female mice without preventing body weight gain

Obesity continues to rise in prevalence and financial burden despite strong evidence linking it to an increased risk of developing several chronic diseases. Dopamine response and receptor density are shown to decrease under conditions of obesity. However, it is unclear if this could be a potential mechanism for treatment without drugs that have a potential for abuse. Therefore, the aim of this study was to investigate whether moderate-intensity exercise could reduce body weight gain and the associated decreases in dopamine signaling observed with high-fat diet-induced adiposity. We hypothesized that exercise would attenuate body weight gain and diet-induced inflammation in high-fat (HF)-fed mice, resulting in dopamine signaling (release and reuptake rate) comparable to sedentary, low-fat (LF)-fed counterparts. This hypothesis was tested using a mouse model of diet-induced obesity (DIO) and fast-scan cyclic voltammetry to measure evoked dopamine release and reuptake rates. Although the exercise protocol employed in this study was not sufficient to prevent significant body weight gain, there was an enhancement of dopamine signaling observed in female mice fed a HF diet that underwent treadmill running. Additionally, aerobic treadmill exercise enhanced the sensitivity to amphetamine (AMPH) in this same group of exercised, HF-fed females. The estrous cycle might influence the ability of exercise to enhance dopamine signaling in females, an effect not observed in male groups. Further research into females by estrous cycle phase, in addition to determining the optimal intensity and duration of aerobic exercise, are logical next steps.

Shared representations of human actions across vision and language

Humans can recognize and communicate about many actions performed by others. How are actions organized in the mind, and is this organization shared across vision and language? We collected similarity judgments of human actions depicted through naturalistic videos and sentences, and tested four models of action categorization, defining actions at different levels of abstraction ranging from specific (action verb) to broad (action target: whether an action is directed towards an object, another person, or the self). The similarity judgments reflected a shared organization of action representations across videos and sentences, determined mainly by the target of actions, even after accounting for other semantic features. Furthermore, language model embeddings predicted the behavioral similarity of action videos and sentences, and captured information about the target of actions alongside unique semantic information. Together, our results show that action concepts are similarly organized in the mind across vision and language, and that this organization reflects socially relevant goals.

Multivariate pattern analysis of cooperation and competition in constructive action

The neural underpinning of cooperative and competitive constructive activity has been investigated using mass-univariate approaches. In this study, we sought to compare the results of these approaches with the results of multivariate pattern analysis (MVPA). In particular, we wanted to test whether MVPA supports the claim made in previous studies that cooperation is associated with the activity of reward-related brain circuits. Participants were required to construct a pattern on the screen either individually or in cooperation or competition with another person during an fMRI scan. Both the MVPA classification methods and the representational similarity analysis indicated the involvement of orbitofrontal and ventromedial prefrontal areas in processes that distinguish between cooperation and competition, and activation analysis showed that these areas are more active during cooperation than during competition. However, a single trial analysis showed that the effect was reversed when only winning trials were considered. In these trials, activation of reward-related areas was higher during competition than during cooperation. Moreover, the contrast between won and lost trials in terms of reward circuits involvement was sharper under competition than under cooperation. Thus, although cooperation can be generally more rewarding than competition, it is associated with smaller difference between trials lost and trials won in terms of reward circuits activation. One may speculate that in cooperation, victory and defeat are shared with the partner and, contrary to competition, are not experienced as personal achievement or failure.

Functional connectivity during facial and vocal emotion recognition: Preliminary evidence for dissociations in developmental change by nonverbal modality

The developmental trajectory of emotion recognition (ER) skills is thought to vary by nonverbal modality, with vocal ER becoming mature later than facial ER. To investigate potential neural mechanisms contributing to this dissociation at a behavioural level, the current study examined whether youth's neural functional connectivity during vocal and facial ER tasks showed differential developmental change across time. Youth ages 8-19 (n = 41) completed facial and vocal ER tasks while undergoing functional magnetic resonance imaging, at two timepoints (1 year apart; n = 36 for behavioural data, n = 28 for neural data). Partial least squares analyses revealed that functional connectivity during ER is both distinguishable by modality (with different patterns of connectivity for facial vs. vocal ER) and across time-with changes in connectivity being particularly pronounced for vocal ER. ER accuracy was greater for faces than voices, and positively associated with age; although task performance did not change appreciably across a 1-year period, changes in latent functional connectivity patterns across time predicted participants' ER accuracy at Time 2. Taken together, these results suggest that vocal and facial ER are supported by distinguishable neural correlates that may undergo different developmental trajectories. Our findings are also preliminary evidence that changes in network integration may support the development of ER skills in childhood and adolescence.

From long-term to short-term: Distinct neural networks underlying semantic knowledge and its recruitment in working memory

Although numerous studies suggest that working memory (WM) and semantic long-term knowledge interact, the nature and underlying neural mechanisms of this intervention remain poorly understood. Using functional magnetic resonance imaging (fMRI), this study investigated the extent to which neural markers of semantic knowledge in long-term memory (LTM) are activated during the WM maintenance stage in 32 young adults. First, the multivariate neural patterns associated with four semantic categories were determined via an implicit semantic activation task. Next, the participants maintained words - the names of the four semantic categories implicitly activated in the first task - in a verbal WM task. Multi-voxel pattern analyses showed reliable neural decoding of the four semantic categories in the implicit semantic activation and the verbal WM tasks. Critically, however, no between-task classification of semantic categories was observed. Searchlight analyses showed that for the WM task, semantic category information could be decoded in anterior temporal areas associated with abstract semantic category knowledge. In the implicit semantic activation task, semantic category information was decoded in superior temporal, occipital and frontal cortices associated with domain-specific semantic feature representations. These results indicate that item-level semantic activation during verbal WM involves shallow rather than deep semantic information.

Investigating the impact of early deafness on learned action-effect contingency for action linked to peripheral sensory effects

Investigating peripheral visual processing in individuals with early auditory deprivation is a critical research area in the field of neuroscience, since it helps understanding the phenomenon of sensory adaptation and brain plasticity after sensory loss. Prior research has already demonstrated that the absence of auditory input, which is crucial to detect events occurring out of the central egocentric visual space, leads to an improved processing of visual and tactile stimuli occurring in peripheral regions of the sensory space. Nevertheless, no prior studies have explored whether such enhanced processing also takes place within the domain of action, particularly when individuals are required to perform actions that produce peripheral sensory outcomes. To test this hypothesis, we recruited 15 hearing (31 ± 3.3 years) and 15 early deaf adults (42 ± 2.6 years) for a neuro-behavioral experiment involving: 1) a behavioral task where participants executed a simple motor action (i.e., a button press) and received a visual feedback either in the center or in a peripheral region of the visual field, and 2) the electrophysiological recording of brain electrical potentials (EEG). We measured and compared neural activity preceding the motor action (the readiness potentials) and visual evoked responses (the N1 and P2 ERP components) and found that deaf individuals did not exhibit more pronounced modulation of neural responses when their motor actions resulted in peripheral visual stimuli compared to their hearing counterparts. Instead they showed a reduced modulation when visual stimuli were presented in the center. Our results suggest a redistribution of attentional resources from center to periphery in deaf individuals during sensorimotor coupling.

Neural bases of reading fluency: A systematic review and meta-analysis

Reading fluency, the ability to read quickly and accurately, is a critical marker of successful reading and is notoriously difficult to improve in reading disabled populations. Despite its importance to functional literacy, fluency is a relatively under-studied aspect of reading, and the neural correlates of reading fluency are not well understood. Here, we review the literature of the neural correlates of reading fluency as well as rapid automatized naming (RAN), a task that is robustly related to reading fluency. In a qualitative review of the neuroimaging literature, we evaluated structural and functional MRI studies of reading fluency in readers from a range of skill levels. This was followed by a quantitative activation likelihood estimate (ALE) meta-analysis of fMRI studies of reading speed and RAN measures. We anticipated that reading speed, relative to untimed reading and reading-related tasks, would harness ventral reading pathways that are thought to enable the fast, visual recognition of words. The qualitative review showed that speeded reading taps the entire canonical reading network. The meta-analysis indicated a stronger role of the ventral reading pathway in rapid reading and rapid naming. Both reviews identified regions outside the canonical reading network that contribute to reading fluency, such as the bilateral insula and superior parietal lobule. We suggest that fluent reading engages both domain-specific reading pathways as well as domain-general regions that support overall task performance and discuss future avenues of research to expand our understanding of the neural bases of fluent reading.

N1 and LNC reveal the differential electrophysiological signatures of functional and hedonic images processing

In the process of creative sentence or phrase utilization, novel and appropriate evaluations cause the different brain responses observed in event-related potentials: the N400 reflects the novelty evaluation, whereas a late negative component marks appropriate processing. Do we have similar brain reactions in image perception when we rapidly browse pictures of objects with different novelty, functional/appropriate, and hedonic value? To explore this question, participants were presented with four novel object images with high or low functional and hedonic properties, as well as the ordinary product images, with the instruction to attentively observe and understand each image. We found a clear dissociation between processing of novelty and functional value: novelty objects produced negative deflections in the N2-N400 time window relative to the ordinary object images, whereas images with high functional value elicited a larger N2 and late negative waves (LNC) resembling the late component found for the appropriate phrases. Object images with high hedonic value, however, were associated with earlier aesthetic preference reflected in smaller N1 amplitudes, but failed to elicit a LNC effect. We therefore conclude that the processing of novelty, functional, and hedonic value are dissociation, and the perception of hedonic value is earlier (N1) than the novelty processing (N400) and the verification of functional value (LNC).

Speech perception following transcranial direct current stimulation (tDCS) over left superior temporal gyrus (STG) (including Wernicke's area) versus inferior frontal gyrus (IFG) (including Broca's area)

Imaging and neurocognitive studies have searched for the brain areas involved in speech perception, specifically when speech is accompanied by noise, attempting to identify the underlying neural mechanism(s). Transcranial direct current stimulation (tDCS), a noninvasive, painless cortical neuromodulation technique, has been used to either excite or inhibit brain activity in order to better understand the neural mechanism underlying speech perception in noise. In the present study, anodal (excitatory) and cathodal (inhibitory) stimulations were performed on 48 participants, either over the left Inferior Frontal Gyrus (IFG), which includes Broca's area (n = 10 anodal, and n = 10 cathodal) or over the left Superior Temporal Gyrus (STG), which includes Wernicke's area (n = 13 anodal, n = 15 cathodal). Speech perception was measured using a sentence recognition task accompanied by white noise with a signal-to-noise ratio of -10 dB. Speech perception performance was measured four times: at baseline, after each of the two sessions of stimulation (one active and one sham session, the order of which was randomized between participants), and at a two-week follow-up session. Groups receiving anodal and cathodal stimulation over the left IFG did not show an effect of stimulation type. For groups receiving left STG stimulation, anodal stimulation resulted in higher scores, regardless of whether it was given before or after sham stimulation. However, cathodal stimulation showed an effect only when active stimulation was applied following sham stimulation. These results showed that tDCS had a direct effect on improving speech perception only over left STG. Furthermore, while anodal stimulation was effective in whatever order it was given, cathodal stimulation was effective only following sham stimulation, thereby allowing some amount of training. These findings carry both theoretical and clinical implications for the relationship between the DMN's left IFG and left STG areas during speech perception accompanied by background noise.

Clinically established early Parkinson's disease patients do not show impaired use of priors in conditions of perceptual uncertainty

The ability to use past learned experiences to guide decisions is an important component of adaptive behavior, especially when decision-making is performed under time pressure or when perceptual information is unreliable. Previous studies using visual discrimination tasks have shown that this prior-informed decision-making ability is impaired in Parkinson's disease (PD), but the mechanisms underlying this deficit and the precise impact of dopaminergic denervation within cortico-basal circuits remain unclear. To shed light on this problem, we evaluated prior-informed decision-making under various conditions of perceptual uncertainty in a sample of 13 clinically established early PD patients, and compared behavioral performance with healthy control (HC) subjects matched in age, sex and education. PD patients and HC subjects performed a random dot motion task in which they had to decide the net direction (leftward vs. rightward) of a field of moving dots and communicate their choices through manual button presses. We manipulated prior knowledge by modulating the probability of occurrence of leftward vs. rightward motion stimuli between blocks of trials, and by explicitly giving these probabilities to subjects at the beginning of each block. We further manipulated stimulus discriminability by varying the proportion of dots moving coherently in the signal direction and speed-accuracy instructions. PD patients used choice probabilities to guide perceptual decisions in both speed and accuracy conditions, and their performance did not significantly differ from that of HC subjects. An additional analysis of the data with the diffusion decision model confirmed this conclusion. These results suggest that the impaired use of priors during visual discrimination observed at more advanced stages of PD is independent of dopaminergic denervation, though additional studies with larger sample sizes are needed to more firmly establish this conclusion.

Deficits in congenital amusia: Pitch, music, speech, and beyond

Congenital amusia is a neurodevelopmental disorder characterized by deficits of music perception and production, which are related to altered pitch processing. The present study used a wide variety of tasks to test potential patterns of processing impairment in individuals with congenital amusia (N = 18) in comparison to matched controls (N = 19), notably classical pitch processing tests (i.e., pitch change detection, pitch direction of change identification, and pitch short-term memory tasks) together with tasks assessing other aspects of pitch-related auditory cognition, such as emotion recognition in speech, sound segregation in tone sequences, and speech-in-noise perception. Additional behavioral measures were also collected, including text reading/copying tests, visual control tasks, and a subjective assessment of hearing abilities. As expected, amusics' performance was impaired for the three pitch-specific tasks compared to controls. This deficit of pitch perception had a self-perceived impact on amusics' quality of hearing. Moreover, participants with amusia were impaired in emotion recognition in vowels compared to controls, but no group difference was observed for emotion recognition in sentences, replicating previous data. Despite pitch processing deficits, participants with amusia did not differ from controls in sound segregation and speech-in-noise perception. Text reading and visual control tests did not reveal any impairments in participants with amusia compared to controls. However, the copying test revealed more numerous eye-movements and a smaller memory span. These results allow us to refine the pattern of pitch processing and memory deficits in congenital amusia, thus contributing further to understand pitch-related auditory cognition. Together with previous reports suggesting a comorbidity between congenital amusia and dyslexia, the findings call for further investigation of language-related abilities in this disorder even in the absence of neurodevelopmental language disorder diagnosis.

Automatic processing of unattended mean emotion: Evidence from visual mismatch responses

The mean emotion from multiple facial expressions can be extracted rapidly and precisely. However, it remains debated whether mean emotion processing is automatic which can occur under no attention. To address this question, we used a passive oddball paradigm and recorded event-related brain potentials when participants discriminated the changes in the central fixation while a set of four faces was presented in the periphery. The face set consisted of one happy and three angry expressions (mean negative) or one angry and three happy expressions (mean positive), and the mean negative and mean positive face sets were shown with a probability of 20% (deviant) and 80% (standard) respectively in the sequence, or the vice versa. The cluster-based permutation analyses showed that the visual mismatch negativity started early at around 92 ms and was also observed in later time windows when the mean emotion was negative, while a mismatch positivity was observed at around 168-266 ms when the mean emotion was positive. The results suggest that there might be different mechanisms underlying the processing of mean negative and mean positive emotions. More importantly, the brain can detect the changes in the mean emotion automatically, and ensemble coding for multiple facial expressions can occur in an automatic fashion without attention.

Individualized prediction of online shopping addiction from whole-brain functional connectivity

Online shopping addiction (OSA) is defined as a behavioral addiction where an individual exhibits an unhealthy and excessive attachment to shopping on the Internet. Since the OSA shown its adverse impacts on individuals' daily life and social functions, it is important to examine the neurobiological underpinnings of OSA that could be used in clinical practice to identify individuals with OSA. The present study addressed this question by employing a connectome-based prediction model approach to predict the OSA tendency of healthy subjects from whole-brain resting-state functional connectivity. The OSA connectome - a set of connections across multiple brain networks that contributed to predict individuals' OSA tendency was identified, including the functional connectivity between the frontal-parietal network (FPN) and cingulo-opercular network (CON) (i.e., positive network), as well as the functional connectivity within default mode network (DMN) and that between FPN and DMN (i.e., negative network). Key nodes that contributed to the prediction model included the middle frontal gyrus, inferior frontal gyrus, anterior cingulate cortex, and inferior temporal gyrus, which have been associated with impulsivity and emotional processing. Notably, this connectome has shown its specific role in predicting OSA by controlling for the influence of general Internet addiction. Moreover, the strength of the negative network mediated the relationship between OSA and impulsivity, highlighting that the negative network underlies the impulsivity characteristic of OSA. Together, these findings advanced our understanding of the neural correlates of OSA and provided a promising framework for diagnosing OSA.

No evidence for top-down expertise effects on action perception in sprinters using static images

Athletes have been found to demonstrate a superior ability to detect subtle variations in dynamic displays (e.g., point-light displays and videos) depicting expert actions compared to non-athletes. The current study aimed to determine whether this advantage also exists when dynamic information is unavailable (i.e., using static images). Using a staircase procedure, two frames from a video depicting an athlete either walking (everyday action) or performing a sprint start (expert action) were presented, and athletes (sprinters) and non-athletes were asked to indicate whether the images were identical or different. We examined whether presenting the images sequentially (temporal task) or simultaneously (spatial task) influenced participants' discrimination performance. We predicted that the sprinters would outperform the non-sprinters in the spatial task as body postures could be compared directly but not in the temporal task due to larger representational momentum effects for athletes. Contrary to our hypotheses, the sprinters and non-sprinters performed similarly in all tasks and conditions. In line with the prediction that representational momentum may impair performance, participants' thresholds were lower for the spatial than the temporal task. However, post-hoc analysis suggested that this effect is likely to be better explained by a task order effect whereby participants who completed the temporal task first exhibited an advantage in the spatial task, while there were no performance differences for participants who completed the opposite task order. In sum, our results provide no evidence for the idea that motor expertise affects action perception (i.e., perceptual resonance) in a simple psychophysical task employing static images.

Breaking (musical) boundaries by investigating brain dynamics of event segmentation during real-life music-listening

The perception of musical phrase boundaries is a critical aspect of human musical experience: It allows us to organize, understand, derive pleasure from, and remember music. Identifying boundaries is a prerequisite for segmenting music into meaningful chunks, facilitating efficient processing and storage while providing an enjoyable, fulfilling listening experience through the anticipation of upcoming musical events. Expanding on Sridharan et al.'s [Neuron 55, 521-532 (2007)] work on coarse musical boundaries between symphonic movements, we examined finer-grained boundaries. We measured the fMRI responses of 18 musicians and 18 nonmusicians during music listening. Using general linear model, independent component analysis, and Granger causality, we observed heightened auditory integration in anticipation to musical boundaries, and an extensive decrease within the fronto-temporal-parietal network during and immediately following boundaries. Notably, responses were modulated by musicianship. Findings uncover the intricate interplay between musical structure, expertise, and cognitive processing, advancing our knowledge of how the brain makes sense of music.

Functional near-infrared spectroscopy: A novel tool for detecting consciousness after acute severe brain injury

Recent advancements in functional neuroimaging have demonstrated that some unresponsive patients in the intensive care unit retain a level of consciousness that is inconsistent with their behavioral diagnosis of awareness. Functional near-infrared spectroscopy (fNIRS) is a portable optical neuroimaging method that can be used to measure neural activity with good temporal and spatial resolution. However, the reliability of fNIRS for detecting the neural correlates of consciousness remains to be established. In a series of studies, we evaluated whether fNIRS can record sensory, perceptual, and command-driven neural processing in healthy participants and in behaviorally nonresponsive patients. At the individual healthy subject level, we demonstrate that fNIRS can detect commonly studied resting state networks, sensorimotor processing, speech-specific auditory processing, and volitional command-driven brain activity to a motor imagery task. We then tested fNIRS with three acutely brain injured patients and found that one could willfully modulate their brain activity when instructed to imagine playing a game of tennis-providing evidence of preserved consciousness despite no observable behavioral signs of awareness. The successful application of fNIRS for detecting preserved awareness among behaviorally nonresponsive patients highlights its potential as a valuable tool for uncovering hidden cognitive states in critical care settings.

A neural network for religious fundamentalism derived from patients with brain lesions

Religious fundamentalism, characterized by rigid adherence to a set of beliefs putatively revealing inerrant truths, is ubiquitous across cultures and has a global impact on society. Understanding the psychological and neurobiological processes producing religious fundamentalism may inform a variety of scientific, sociological, and cultural questions. Research indicates that brain damage can alter religious fundamentalism. However, the precise brain regions involved with these changes remain unknown. Here, we analyzed brain lesions associated with varying levels of religious fundamentalism in two large datasets from independent laboratories. Lesions associated with greater fundamentalism were connected to a specific brain network with nodes in the right orbitofrontal, dorsolateral prefrontal, and inferior parietal lobe. This fundamentalism network was strongly right hemisphere lateralized and highly reproducible across the independent datasets (r = 0.82) with cross-validations between datasets. To explore the relationship of this network to lesions previously studied by our group, we tested for similarities to twenty-one lesion-associated conditions. Lesions associated with confabulation and criminal behavior showed a similar connectivity pattern as lesions associated with greater fundamentalism. Moreover, lesions associated with poststroke pain showed a similar connectivity pattern as lesions associated with lower fundamentalism. These findings are consistent with the current understanding of hemispheric specializations for reasoning and lend insight into previously observed epidemiological associations with fundamentalism, such as cognitive rigidity and outgroup hostility.

A circuit motif for color in the human foveal retina

The neural pathways that start human color vision begin in the complex synaptic network of the foveal retina where signals originating in long (L), middle (M), and short (S) wavelength-sensitive cone photoreceptor types are compared through antagonistic interactions, referred to as opponency. In nonhuman primates, two cone opponent pathways are well established: an L vs. M cone circuit linked to the midget ganglion cell type, often called the red-green pathway, and an S vs. L + M cone circuit linked to the small bistratified ganglion cell type, often called the blue-yellow pathway. These pathways have been taken to correspond in human vision to cardinal directions in a trichromatic color space, providing the parallel inputs to higher-level color processing. Yet linking cone opponency in the nonhuman primate retina to color mechanisms in human vision has proven particularly difficult. Here, we apply connectomic reconstruction to the human foveal retina to trace parallel excitatory synaptic outputs from the S-ON (or "blue-cone") bipolar cell to the small bistratified cell and two additional ganglion cell types: a large bistratified ganglion cell and a subpopulation of ON-midget ganglion cells, whose synaptic connections suggest a significant and unique role in color vision. These two ganglion cell types are postsynaptic to both S-ON and L vs. M opponent midget bipolar cells and thus define excitatory pathways in the foveal retina that merge the cardinal red-green and blue-yellow circuits, with the potential for trichromatic cone opponency at the first stage of human vision.

Lifespan differences in hippocampal subregion connectivity patterns during movie watching

Age-related episodic memory decline is attributed to functional alternations in the hippocampus. Less clear is how aging affects the functional connections of the hippocampus to the rest of the brain during episodic memory processing. We examined fMRI data from the CamCAN dataset, in which a large cohort of participants watched a movie (N = 643; 18-88 years), a proxy for naturalistic episodic memory encoding. We examined connectivity profiles across the lifespan both within the hippocampus (anterior, posterior), and between the hippocampal subregions and cortical networks. Aging was associated with reductions in contralateral (left, right) but not ipsilateral (anterior, posterior) hippocampal subregion connectivity. Aging was primarily associated with increased coupling between the anterior hippocampus and regions affiliated with Control, Dorsal Attention and Default Mode networks, yet decreased coupling between the posterior hippocampus and a selection of these regions. Differences in age-related hippocampal-cortical, but not within-hippocampus circuitry selectively predicted worse memory performance. Our findings comprehensively characterize hippocampal functional topography in relation to cognition in older age, suggesting that shifts in cortico-hippocampal connectivity may be sensitive markers of age-related episodic memory decline.