A systematic review and meta-analysis of altered electrophysiological markers of performance monitoring in Obsessive-Compulsive Disorder (OCD), Gilles de la Tourette Syndrome (GTS), Attention-Deficit/Hyperactivity disorder (ADHD) and Autism

Psychometric, pre-processing, and trial-type considerations in individual differences studies of EEG mid-frontal theta power and latency

EEG mid-frontal theta-band activity (MFT; 4-8 Hz) is of considerable interest as a possible biomarker in translational research on cognitive control. However, because most of the MFT literature has focused on experimental within-subjects effects, the impact of particular data processing choices on individual difference analyses is not well understood. This study aimed to reduce that gap by examining the psychometric properties of different pipelines for measuring individual differences in MFT power and latency. Ninety-three adults aged 60 or older completed a flanker task during EEG recording. Stimulus-locked MFT was extracted in three primary pipelines via the fast Fourier transform (FFT), linear- and log-spaced wavelet, and filter-Hilbert analyses. The effects of frequency resolution, electrode choice, overall versus peak power, and trial type (overall, congruent, incongruent, and subtraction- and regression-based residual scores contrasting congruent and incongruent activity) were examined, as was the degree of overlap among related variables. Internal consistency reliabilities and associations with reaction times (RT) during the Flanker were assessed for select measures. Results indicated no benefit of higher frequency resolutions or region of interest over single-electrode measurements from FCz. Two-part coefficient alpha reliabilities ranged from 0.63 to 1.00 for MFT power variables, and from 0.02 to 0.83 for latency variables. Contrary to hypotheses and common criticisms of derived scores, correlations with RT were generally strongest for the difference and residual scores, with an additional benefit of time-frequency-based peak power relative to FFT-based overall power (r ~ = 0.30 vs. 0.45). These findings add to the growing literature on psychometric properties of EEG biomarkers, and help clarify measurement strategies that may enhance detection of behavioral and clinical correlates of MFT power and latency.

Event-related potential in juvenile obsessive-compulsive disorder: a systematic review and meta-analysis of error- and correct-related negativity

The error-related negativity (ERN) is a negative wave observed in electroencephalography (EEG) following errors in certain neurocognitive tasks, such as the Flanker task. This wave has been found to be heightened in individuals suffering from obsessive-compulsive disorder (OCD) in several adult studies and meta-analyses. Therefore, the ERN may serve as a relevant neurobiological marker for OCD. However, the ERN exhibits some developmental aspects. Considering this, we conducted a meta-analysis of studies examining the ERN in children and adolescents with OCD. We identified nine studies that compared ERN amplitude during a Flanker task between youth with OCD and matched controls. Our meta-analysis revealed that ERN amplitude was elevated in juvenile OCD patients compared to controls. We did not find that age, task accuracy, or sex moderated the difference between patients and controls. In conclusion, our meta-analysis confirmed that the ERN observed during the Flanker task may be a relevant biological marker for OCD in children and adolescents.

Enhanced Performance Monitoring as a Transdiagnostic Risk Marker of the Anxiety and Obsessive-Compulsive Spectrum: The Role of Disorder Category, Clinical Status, Family Risk, and Anxiety Dimensions

In this preregistered study, we investigated the relationship between neural correlates of performance monitoring and disorders of the anxiety and obsessive-compulsive spectrum. Specifically, we aimed at understanding the role of disorder category, clinical status, family risk, and the transdiagnostic symptom dimensions of anxious apprehension and anxious arousal. To this end, we measured event-related potentials (ERPs) of performance monitoring (i.e., error-related negativity, ERN, and correct-response negativity, CRN) in a large sample of 156 participants, including groups of patients with obsessive-compulsive disorder, social anxiety disorder, and specific phobia, as well as a naturalistic control group. Contrary to our initial expectations, we did not observe significant differences in ERPs among the clinical groups, nor in comparison to the naturalistic control group. However, after creating a more strictly defined healthy control group, we found larger ERN amplitudes in the specific phobia compared with the healthy control group. In addition, when comparing participants with and without a lifetime clinical diagnosis of any internalizing disorder, regardless of their main diagnosis, as well as when comparing those with or without a family risk for internalizing psychopathology, we observed larger amplitudes for both ERN and CRN. Subsequently, we combined data from this study and a previously published subclinical study to examine the role of transdiagnostic symptom dimensions (i.e., anxious apprehension and anxious arousal) across a wider severity spectrum. In this joint sample of 246 participants, gender emerged as a moderator of the link between anxious apprehension and enhanced performance monitoring. Specifically, women with increasing anxious apprehension exhibited elevated ERN and CRN amplitudes. In conclusion, our study challenges the notion of a disorder-specific link to performance monitoring. Instead, our findings suggest that enhanced performance monitoring is associated with a higher propensity for anxious apprehension and acts as a broad risk marker for internalizing psychopathology, reflecting vulnerability beyond diagnostic borders within the anxiety- and obsessive-compulsive spectrum.

Infant attention and frontal EEG neuromarkers of childhood ADHD

Numerous electroencephalogram (EEG) studies have sought to elucidate the neural mechanisms of attention deficit hyperactivity disorder (ADHD), with most of the existing literature focused on children, adolescents, and adults. In this retrospective study, measures of frontal EEG power and behavioral attention of 40 5-month-old infants later diagnosed with ADHD in childhood were compared to 40 systematically matched-control infants. Compared to the control group, infants in the ADHD group exhibited longer looking fixations during an attention task. Frontal EEG power in the 6-9 Hz infant alpha band was lower in the ADHD group compared to the control group. Mean frontal EEG power was associated with visual fixations, underscoring specific attention behavior corresponding to frontal brain development in infancy. Infants later diagnosed with ADHD exhibited higher attention problems in childhood at ages 4 and 9 compared to the control group, and longer looking fixations in infancy were associated with higher childhood ADHD-related symptomatology. These findings suggest that decreased infant frontal EEG power and looking fixations as early as 5-months of age may serve as important early markers of later ADHD and can aid in building a more comprehensive model of ADHD from a developmental neuroscience approach.

Role and related mechanisms of non-invasive brain stimulation in the treatment of Tourette syndrome

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by impaired or delayed functional development. Although the pathology of TS remains to be determined, the continuous development of science and technology has provided new perspectives to understand its pathological mechanism. Research into non-invasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation and direct current stimulation, have shown promising therapeutic potential in clinical studies. Furthermore, NIBS has been shown to affect the brain of patients with TS, including synaptic transmission, release of neurotransmitters, in addition to the activation of microglial cells and astrocytes. However, an exploration of the innate mechanisms is still lacking. This review aims to summarize the pathogenesis of TS and intervention with NIBS in clinical patients with TS. It aims to provide a theoretical basis for more in-depth investigations of innovative therapies for TS in the future.

Clinical Characteristics of Cognitive Subgroups of Obsessive Compulsive Disorder

INTRODUCTION

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous disorder. The results of symptom-based classification studies are inconsistent in resolving this heterogeneity. The aim of this study was to investigate clinical differences between clusters created according to neurocognitive performance.

METHODS

This study combined data sets from three previously published studies. A total of 135 outpatients diagnosed with OCD, and 106 healthy controls (HCs) were evaluated using the 17-Item Hamilton Depression Rating Scale (HDRS-17) and a comprehensive neuropsychological battery. Patients were also administered the Yale-Brown Obsessive Compulsive Scale (Y-BOCS).

RESULTS

Two neurocognitive subgroups were identified by k-means cluster analysis: globally impaired (GI, n = 42) and cognitively intact (CI, n = 93). The GI subgroup performed worse than the HC and CI groups on all neurocognitive tests. There was no difference between the CI group and HC in any cognitive domains. Compulsive symptom severity [t(133) = -2.45, p = 0.015], Y-BOCS total score [t(133) = -2.09, p = 0.038], and age of onset were higher in the GI group than in the CI group [t(132) = -4.24, p < 0.001]. Years of education were higher in the CI and HC groups than in the GI group [F(238) = 35.27, p < 0.001]. There was no difference in symptom profile between the CI and GI groups.

CONCLUSION

The identified cognitive clusters may indicate subtypes with different neurobiological bases. A better dissection of the cognitive structure of OCD could potentially facilitate genetic and neuroimaging studies.

Brain Wave Oscillations as an Objective Neurophysiological Biomarker of Homeopathic Subjective Well-Being

BACKGROUND

 Homeopathy uses the "similitude principle" to arouse a therapeutic reaction in the body against its own disorders. For this to occur optimally, the medicinal pathogenetic effects must present similarity with the totality of the individual's symptoms. To assess if this similarity has been successfully achieved, Hahnemann states that "improvement in the disposition and mind"-i.e., subjective well-being-is the most important parameter to consider.

AIM

 Our aim was to perform a narrative review of the literature, exploring what is known about subjective well-being as a marker of therapeutic action, and to formulate ways in which subjective well-being might be quantifiable and applied in future homeopathy research.

RESULTS

 The concept of subjective well-being has been extensively studied in the complementary and conventional medical literature. Improved well-being has been observed in clinical trials, including those in the fields of positive psychology and meditation. Positive subjective outcomes of this nature are supported by objective evidence through associated changes in brain oscillatory activity using electroencephalography and/or "brain mapping" by functional magnetic resonance imaging. Neurophysiological responses in the brain have been identified in subjects after they ingested a homeopathic medicine.

CONCLUSIONS

 The concept of subjective well-being is supported by a body of literature and is a measurable entity. When viewed from the perspective of electrophysiological changes, brain activity is an objective neurophysiological biomarker with a potential to quantify individual well-being in the context of homeopathy research.

Schizophrenia Following Early Adolescence Prodrome: A Neurodevelopmental Subtype With Autism-like Sensorimotor and Social Cognition Deficits

BACKGROUND AND HYPOTHESIS

While age at onset in schizophrenia (SCZ) is usually defined by age at onset of psychosis, the illness actually occurs earlier, with a prodrome often starting in childhood or adolescence. We postulated that SCZ with early-adolescence prodromes (SCZ-eaP) presents with social cognition deficits and sensorimotor impairments more similar to autism spectrum disorders (ASD) than SCZ with late-adolescence prodromes (SCZ-laP).

STUDY DESIGN

The movie for the assessment of social cognition and neurological soft signs (NSS) were compared between four groups, ASD, SCZ-eaP (<15 years), SCZ-laP (>15 years), and controls (N = 119), while accounting for age, sex, intelligence quotient, education level, and medication effect. Mediation analyses tested the effect of NSS on social cognition, across groups, and local gyrification indices were used to test whether NSS reflected deviations in early neurodevelopmental trajectories.

STUDY RESULTS

For social cognition and NSS, subjects with ASD were not different from SCZ-eaP, while they differed from SCZ-laP. Age at onset of prodrome correlated with NSS (r = -0.34, P = .018), and social cognition (r = 0.28, P = .048). Neurological soft signs mediated social cognition impairment across diagnoses (β = -1.24, P < 1e-6), and was explained by hypergyrification in the right fusiform gyrus, right frontal pole gyrus, and left postcentral gyrus.

CONCLUSIONS

Earlier age of prodrome in SCZ is associated with impaired social cognition, mediated by neurodevelopmentally-related sensorimotor impairments along the ASD-SCZ spectrum. It suggests age of prodrome, rather than the age at psychosis onset, should be considered to define more homogeneous subgroups in SCZ.

Coping with emotional dysregulation among young adults with ADHD: A mixed-method study of self-awareness and strategies in daily life

BACKGROUND

Emotional dysregulation (ED) impacts functional outcomes among individuals with attention-deficit hyperactivity disorder (ADHD). Self-awareness and strategies may enhance coping with ED yet are rarely studied in ADHD.

OBJECTIVES

To explore ED-related self-awareness and strategies in daily life of adults with ADHD, and to examine the interrelations between them and their association with symptoms.

METHODS

Sixty young adults with ADHD participated in a mixed-method study. At baseline, self-awareness and strategies were assessed using the Self-Regulation Skills Interview (SRSI); ADHD symptoms were self-rated using the ASRS symptom checklist. Then, symptoms were rated over 5-days using ecological momentary assessment (EMA).

RESULTS

Significant challenges in self-awareness and strategies were demonstrated quantitatively and qualitatively. Awareness of ED was associated with variability of ADHD symptoms on EMA yet not with symptom severity. Qualitative content analysis revealed a range of self-awareness levels, which were related to noticing ED-related cues and understanding contextual factors predictive of ED. Self-awareness and strategies were significantly associated. Strategies varied regarding effort, individual preference and temporality.

CONCLUSIONS

Variability of ADHD symptoms was negatively associated with self-awareness of ED. Strategy selection in daily-life among adults with ADHD may be affected by self-awareness and by a possible trade-off between short-term effort and long-term effectiveness.

Leg stereotypy syndrome: phenomenological and quantitative analysis

BACKGROUND

Leg stereotypy syndrome (LSS) is a very common, yet underrecognized condition. The pathophysiology of the condition is not well understood.

OBJECTIVE

To evaluate and describe the visual kinematic characteristics of the repetitive leg movements in individuals with LSS.

METHODS

In this study, we identified and videotaped individuals diagnosed with LSS at the Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, Texas between 2000 and 2023. Only patients with LSS and without any co-morbidities were included in the study. Their medical records were carefully reviewed, and the demographic and clinical data were entered into a database. Video recordings of the repetitive leg movements were then analyzed using TremAn software.

RESULTS

We identified 14 individuals with LSS who were videotaped at our center. The videos of the 5 cases were too brief and therefore not suitable for TremAn quantitative analysis. The remaining 9 individuals exhibited regular rhythmic oscillations of the legs. Among these, two individuals displayed rhythmic movements only in video segments where their legs were in crossed positions. The other 7 individuals had regular rhythmic oscillations, always with the toes resting on the floor with the heels raised. Frequency analysis showed values between 4.5 and 6.5 Hz, fairly consistent with a variance below 0.5 Hz in individual cases. The oscillation frequency changed from 5.7 Hz to 2.7 Hz while standing.

CONCLUSION

In this study, 6 of 9 individuals with LSS showed 4.5-6.5 Hz regular rhythmic leg movements. Studies involving a larger LSS population with additional electrophysiological evaluations are needed to obtain further insights into this common movement disorder.

Transdiagnostic psychopathology in the light of robust single-trial event-related potentials

Recent evidence indicates that event-related potentials (ERPs) as measured on the electroencephalogram (EEG) are more closely related to transdiagnostic, dimensional measures of psychopathology (TDP) than to diagnostic categories. A comprehensive examination of correlations between well-studied ERPs and measures of TDP is called for. In this study, we recruited 50 patients with emotional disorders undergoing 14 weeks of transdiagnostic group psychotherapy as well as 37 healthy comparison subjects (HC) matched in age and sex. HCs were assessed once and patients three times throughout treatment (N = 172 data sets) with a battery of well-studied ERPs and psychopathology measures consistent with the TDP framework The Hierarchical Taxonomy of Psychopathology (HiTOP). ERPs were quantified using robust single-trial analysis (RSTA) methods and TDP correlations with linear regression models as implemented in the EEGLAB toolbox LIMO EEG. We found correlations at several levels of the HiTOP hierarchy. Among these, a reduced P3b was associated with the general p-factor. A reduced error-related negativity correlated strongly with worse symptomatology across the Internalizing spectrum. Increases in the correct-related negativity correlated with symptoms loading unto the Distress subfactor in the HiTOP. The Flanker N2 was related to specific symptoms of Intrusive Cognitions and Traumatic Re-experiencing and the mismatch negativity to maladaptive personality traits at the lowest levels of the HiTOP hierarchy. Our study highlights the advantages of RSTA methods and of using validated TDP constructs within a consistent framework. Future studies could utilize machine learning methods to predict TDP from a set of ERP features at the subject level.

Disentangling associations between impulsivity, compulsivity, and performance monitoring

Disorders marked by high levels of impulsivity and compulsivity have been linked to changes in performance monitoring, specifically the error-related negativity (ERN). We investigated the relationship between performance monitoring and individual differences in impulsivity and compulsivity. A total of 142 participants were recruited into four groups, each with different combinations of impulsivity and compulsivity, and they performed a flanker task to assess error-related brain activity. We defined error-related brain activity as ERN amplitude and theta power. Single-trial regression was employed to analyze the amplitude differences between incorrect and correct trials within the ERN time window. The findings revealed that impulsivity, compulsivity, and different measures of response processing exhibited distinct interactions, which were influenced by the configuration of impulsivity and compulsivity, but also depended on the measure of response processing. Specifically, high compulsivity predicted larger ERN amplitudes in individuals with low impulsivity, whereas high impulsivity had no significant effect on ERN amplitude in individuals with low compulsivity. Furthermore, when both impulsivity and compulsivity were high, no significant increase in ERN amplitude was observed; instead, there was a reduced difference between incorrect and correct trials. No significant differences were found for theta power. While the association between error-related brain activity and transdiagnostic markers or psychopathology may be smaller than generally assumed, considering the interaction between different transdiagnostic markers and their facets can enhance our understanding of the complex associations that arise during the investigation of neural correlates of performance monitoring, specifically the ERN.

Altered Error Monitoring and Decreased Flanker Task Accuracy in Pediatric Obsessive-Compulsive Disorder

The error-related negativity (ERN) and error positivity (Pe) are components of the event-related potential following an error that are potential mechanistic biomarkers of obsessive-compulsive disorder (OCD). The study examined the ERN, Pe, flanker task accuracy, and clinical measures in 105 OCD cases and 105 matched healthy controls (HC) ages 8-18 years. Higher flanker task accuracy in all participants was associated with an increased ERN amplitude and increased difference between Pe and correct positivity amplitudes (ΔPe). Compared to HC, OCD cases had an increased ERN but decreased ΔPe and flanker task accuracy. Those differences were also significant in tic-related and non-tic-related OCD cases compared to HC. A lower ΔPe was associated in cases with an earlier age at OCD symptom onset. The results support the hypothesis that OCD involves defects in an error monitoring system and suggest a reduced ΔPe may compromise error signaling and cause uncertainty about the correctness of a response.

Altered Error Monitoring and Decreased Flanker Task Accuracy in Pediatric Obsessive-Compulsive Disorder

The error-related negativity (ERN) and error positivity (Pe) are components of the event-related potential following an error that are potential mechanistic biomarkers of obsessive-compulsive disorder (OCD). The study examined the ERN, Pe, flanker task accuracy, and clinical measures in 105 OCD cases and 105 matched healthy controls (HC), ages 8 to 18 years, with 21 cases having a tic disorder history. Higher flanker task accuracy in all participants was associated with an increased ERN amplitude and increased difference between Pe and correct positivity amplitudes (ΔPe). Compared to HC, OCD cases had an increased ERN but decreased flanker task accuracy and ΔPe. Those differences were also significant in tic-related and non-tic-related OCD cases compared to HC. A lower ΔPe was associated in OCD cases with an earlier age at OCD symptom onset. The results support the hypothesis that OCD involves defects in an error monitoring system and suggest a reduced ΔPe may compromise error signaling and cause uncertainty about the correctness of a response.

Error-related cardiac deceleration: Functional interplay between error-related brain activity and autonomic nervous system in performance monitoring

Coordinated interactions between the central and autonomic nervous systems are crucial for survival due to the inherent propensity for human behavior to make errors. In our ever-changing environment, when individuals make mistakes, these errors can have life-threatening consequences. In response to errors, specific reactions occur in both brain activity and heart rate to detect and correct errors. Specifically, there are two brain-related indicators of error detection and awareness known as error-related negativity and error positivity. Conversely, error-related cardiac deceleration denotes a momentary slowing of heart rate following an error, signaling an autonomic response. However, what is the connection between the brain and the heart during error processing? In this review, we discuss the functional and neuroanatomical connections between the brain and heart markers of error processing, exploring the experimental conditions in which they covary. Given the current limitations of available data, future research will continue to investigate the neurobiological factors governing the brain-heart interaction, aiming to utilize them as combined markers for assessing cognitive control in healthy and pathological conditions.

Neurophysiological explorations across the spectrum of psychosis, autism, and depression, during wakefulness and sleep: protocol of a prospective case-control transdiagnostic multimodal study (DEMETER)

BACKGROUND

Quantitative electroencephalography (EEG) analysis offers the opportunity to study high-level cognitive processes across psychiatric disorders. In particular, EEG microstates translate the temporal dynamics of neuronal networks throughout the brain. Their alteration may reflect transdiagnostic anomalies in neurophysiological functions that are impaired in mood, psychosis, and autism spectrum disorders, such as sensorimotor integration, speech, sleep, and sense of self. The main questions this study aims to answer are as follows: 1) Are EEG microstate anomalies associated with clinical and functional prognosis, both in resting conditions and during sleep, across psychiatric disorders? 2) Are EEG microstate anomalies associated with differences in sensorimotor integration, speech, sense of self, and sleep? 3) Can the dynamic of EEG microstates be modulated by a non-drug intervention such as light hypnosis?

METHODS

This prospective cohort will include a population of adolescents and young adults, aged 15 to 30 years old, with ultra-high-risk of psychosis (UHR), first-episode psychosis (FEP), schizophrenia (SCZ), autism spectrum disorder (ASD), and major depressive disorder (MDD), as well as healthy controls (CTRL) (N = 21 × 6), who will be assessed at baseline and after one year of follow-up. Participants will undergo deep phenotyping based on psychopathology, neuropsychological assessments, 64-channel EEG recordings, and biological sampling at the two timepoints. At baseline, the EEG recording will also be coupled to a sensorimotor task and a recording of the characteristics of their speech (prosody and turn-taking), a one-night polysomnography, a self-reference effect task in virtual reality (only in UHR, FEP, and CTRL). An interventional ancillary study will involve only healthy controls, in order to assess whether light hypnosis can modify the EEG microstate architecture in a direction opposite to what is seen in disease.

DISCUSSION

This transdiagnostic longitudinal case-control study will provide a multimodal neurophysiological assessment of clinical dimensions (sensorimotor integration, speech, sleep, and sense of self) that are disrupted across mood, psychosis, and autism spectrum disorders. It will further test the relevance of EEG microstates as dimensional functional biomarkers.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT06045897.

A systematic meta-review of systematic reviews on attention deficit hyperactivity disorder

BACKGROUND

There are now hundreds of systematic reviews on attention deficit hyperactivity disorder (ADHD) of variable quality. To help navigate this literature, we have reviewed systematic reviews on any topic on ADHD.

METHODS

We searched MEDLINE, PubMed, PsycINFO, Cochrane Library, and Web of Science and performed quality assessment according to the Joanna Briggs Institute Manual for Evidence Synthesis. A total of 231 systematic reviews and meta-analyses met the eligibility criteria.

RESULTS

The prevalence of ADHD was 7.2% for children and adolescents and 2.5% for adults, though with major uncertainty due to methodological variation in the existing literature. There is evidence for both biological and social risk factors for ADHD, but this evidence is mostly correlational rather than causal due to confounding and reverse causality. There is strong evidence for the efficacy of pharmacological treatment on symptom reduction in the short-term, particularly for stimulants. However, there is limited evidence for the efficacy of pharmacotherapy in mitigating adverse life trajectories such as educational attainment, employment, substance abuse, injuries, suicides, crime, and comorbid mental and somatic conditions. Pharmacotherapy is linked with side effects like disturbed sleep, reduced appetite, and increased blood pressure, but less is known about potential adverse effects after long-term use. Evidence of the efficacy of nonpharmacological treatments is mixed.

CONCLUSIONS

Despite hundreds of systematic reviews on ADHD, key questions are still unanswered. Evidence gaps remain as to a more accurate prevalence of ADHD, whether documented risk factors are causal, the efficacy of nonpharmacological treatments on any outcomes, and pharmacotherapy in mitigating the adverse outcomes associated with ADHD.

In Context: A Developmental Model of Reward Processing, With Implications for Autism and Sensitive Periods

OBJECTIVE

Differences in reward processing have been associated with numerous psychiatric disorders, including autism and attention-deficit/hyperactivity disorder (ADHD). Many attempts to understand reward processing characterize differences in clinical populations after disorder onset; however, divergence may begin much earlier. In fact, the typical developmental progression of reward processing in infancy and early childhood is poorly understood. We re-conceptualize classic infant developmental constructs such as preferential looking into a Six-Component Developmental Model of Reward Processing: an infant- and young child-focused framework to guide research and assessment of reward processing across development.

METHOD

The extant developmental literature including recent textbooks, systematic reviews, and meta-analyses was reviewed to build a conceptual framework. We describe experimental paradigms to assess each developmental component of reward processing longitudinally from infancy. A timeline of each component's emergence was estimated.

RESULTS

Six components of reward processing were identified-association, discrimination, preference/valuation, effort, anticipation, and response. Selected evidence suggests emergence between birth and 6 months. Application of this model to autism led to a reinterpretation of existing disparate results, and illuminated a path to study the developmental processes underlying a popular hypothesis of autism, the motivation hypothesis. Current evidence further suggests that a sensitive period may exist for the emergence of reward processing.

CONCLUSION

The proposed framework offers a useful reconceptualization of the extant literature. Future longitudinal work using the suggested experimental paradigms with high-risk populations could elucidate the developmental trajectory of the components and timing of potential sensitive period(s) for each component.

Cognitive control in adults with high-functioning autism spectrum disorder: a study with event-related potentials

Introduction

Little is known about cognitive control in adults with high-functioning forms of autism spectrum disorder because previous research focused on children and adolescents. Cognitive control is crucial to monitor and readjust behavior after errors to select contextually appropriate reactions. The congruency effect and conflict adaptation are measures of cognitive control. Post-error slowing, error-related negativity and error positivity provide insight into behavioral and electrophysiological correlates of error processing. In children and adolescent with autism spectrum disorder deficits in cognitive control and error processing have been shown by changes in post-error slowing, error-related negativity and error positivity in the flanker task.

Methods

We performed a modified Eriksen flanker task in 17 adults with high-functioning autism spectrum disorder and 17 healthy controls. As behavioral measures of cognitive control and error processing, we included reaction times and error rates to calculate congruency effects, conflict adaptation, and post-error slowing. Event-related potentials namely error-related negativity and error positivity were measured to assess error-related brain activity.

Results

Both groups of participants showed the expected congruency effects demonstrated by faster and more accurate responses in congruent compared to incongruent trials. Healthy controls exhibited conflict adaptation as they obtained performance benefits after incongruent trials whereas patients with autism spectrum disorder did not. The expected slowing in reaction times after errors was observed in both groups of participants. Individuals with autism spectrum disorder demonstrated enhanced electrophysiological error-processing compared to healthy controls indicated by increased error-related negativity and error positivity difference amplitudes.

Discussion

Our findings show that adults with high-functioning autism spectrum disorder do not show the expected upregulation of cognitive control in response to conflicts. This finding implies that previous experiences may have a reduced influence on current behavior in these patients which possibly contributes to less flexible behavior. Nevertheless, we observed intact behavioral reactions after errors indicating that adults with high-functioning autism spectrum disorder can flexibly adjust behavior in response to changed environmental demands when necessary. The enhancement of electrophysiological error-processing indicates that adults with high-functioning autism spectrum disorder demonstrate an extraordinary reactivity toward errors reflecting increased performance monitoring in this subpopulation of autism spectrum disorder patients.

Prefrontal-cerebellar dynamics during post-success and post-error cognitive controls in major psychiatric disorders

BACKGROUND

Difficulty in cognitive adjustment after a conflict or error is a hallmark for many psychiatric disorders, yet the underlying neural correlates are not fully understood. We have previously shown that post-success and post-error cognitive controls are associated with distinct mechanisms particularly related to the prefrontal-cerebellar circuit, raising the possibility that altered dynamic interactions in this circuit may underlie mental illness.

METHODS

This study included 136 patients with three diagnosed disorders [48 schizophrenia (SZ), 49 bipolar disorder (BD), 39 attention deficit hyperactivity disorder (ADHD)] and 89 healthy controls who completed a stop-signal task during fMRI scans. Brain activations for concurrent, post-success, and post-error cognitive controls were analyzed and compared between groups. Dynamic causal modeling was applied to investigate prefrontal-cerebellar effective connectivity patterns during post-success and post-error processing.

RESULTS

No significant group differences were observed for brain activations and overall effective connectivity structures during post-success and post-error conditions. However, significant group differences were shown for the modulational effect on top-down connectivity from the prefrontal cortex to the cerebellum during post-error trials (pFWE = 0.02), which was driven by reduced modulations in both SZ and ADHD. During post-success trials, there were significantly decreased modulational effect on bottom-up connectivity from the cerebellum to the prefrontal cortex in ADHD (pFWE = 0.04) and decreased driving input to the cerebellum in SZ (pFWE = 0.04).

CONCLUSIONS

These findings suggest that patients with SZ and ADHD are associated with insufficient neural modulation on the prefrontal-cerebellar circuit during post-success and post-error cognitive processing, a phenomenon that may underlie cognitive deficits in these disorders.

Candidate diagnostic biomarkers for neurodevelopmental disorders in children and adolescents: a systematic review

Neurodevelopmental disorders - including attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, communication disorders, intellectual disability, motor disorders, specific learning disorders, and tic disorders - manifest themselves early in development. Valid, reliable and broadly usable biomarkers supporting a timely diagnosis of these disorders would be highly relevant from a clinical and public health standpoint. We conducted the first systematic review of studies on candidate diagnostic biomarkers for these disorders in children and adolescents. We searched Medline and Embase + Embase Classic with terms relating to biomarkers until April 6, 2022, and conducted additional targeted searches for genome-wide association studies (GWAS) and neuroimaging or neurophysiological studies carried out by international consortia. We considered a candidate biomarker as promising if it was reported in at least two independent studies providing evidence of sensitivity and specificity of at least 80%. After screening 10,625 references, we retained 780 studies (374 biochemical, 203 neuroimaging, 133 neurophysiological and 65 neuropsychological studies, and five GWAS), including a total of approximately 120,000 cases and 176,000 controls. While the majority of the studies focused simply on associations, we could not find any biomarker for which there was evidence - from two or more studies from independent research groups, with results going into the same direction - of specificity and sensitivity of at least 80%. Other important metrics to assess the validity of a candidate biomarker, such as positive predictive value and negative predictive value, were infrequently reported. Limitations of the currently available studies include mostly small sample size, heterogeneous approaches and candidate biomarker targets, undue focus on single instead of joint biomarker signatures, and incomplete accounting for potential confounding factors. Future multivariable and multi-level approaches may be best suited to find valid candidate biomarkers, which will then need to be validated in external, independent samples and then, importantly, tested in terms of feasibility and cost-effectiveness, before they can be implemented in daily clinical practice.

Defining brain-based OCD patient profiles using task-based fMRI and unsupervised machine learning

While much research has highlighted phenotypic heterogeneity in obsessive compulsive disorder (OCD), less work has focused on heterogeneity in neural activity. Conventional neuroimaging approaches rely on group averages that assume homogenous patient populations. If subgroups are present, these approaches can increase variability and can lead to discrepancies in the literature. They can also obscure differences between various subgroups. To address this issue, we used unsupervised machine learning to identify subgroup clusters of patients with OCD who were assessed by task-based fMRI. We predominantly focused on activation of cognitive control and performance monitoring neurocircuits, including three large-scale brain networks that have been implicated in OCD (the frontoparietal network, cingulo-opercular network, and default mode network). Participants were patients with OCD (n = 128) that included both adults (ages 24-45) and adolescents (ages 12-17), as well as unaffected controls (n = 64). Neural assessments included tests of cognitive interference and error processing. We found three patient clusters, reflecting a "normative" cluster that shared a brain activation pattern with unaffected controls (65.9% of clinical participants), as well as an "interference hyperactivity" cluster (15.2% of clinical participants) and an "error hyperactivity" cluster (18.9% of clinical participants). We also related these clusters to demographic and clinical correlates. After post-hoc correction for false discovery rates, the interference hyperactivity cluster showed significantly longer reaction times than the other patient clusters, but no other between-cluster differences in covariates were detected. These findings increase precision in patient characterization, reframe prior neurobehavioral research in OCD, and provide a starting point for neuroimaging-guided treatment selection.

Trends of Tourette Syndrome in children from 2011 to 2021: A bibliometric analysis

Objective

Analyze the research status of Tourette Syndrome (TS) in children by CiteSpace and determine the current research hotspots and frontiers.

Materials and methods

We chose publications indexed in the Web of Science Core Collection (WoSCC) database for studies related to TS in children from 2011 to 2021. We built online cooperation maps of countries/regions, institutions, authors, journals, references, and keywords by CiteSpace, and identified hotspots and frontiers of study for children’s TS.

Results

A total of 1,232 publications about TS in children were downloaded from the WoSCC. The USA (414) was the country with the highest rate of production, and University College London (87) was the institution that had the highest publication rate. Andrea Eugenio Cavanna was the most prolific author (39 papers). There was inactive cooperation between institutions, countries/regions, and authors. The Journal of European Child &amp; Adolescent Psychiatry was the most active journal. Hot topics focused on epidemiology, comorbidities, deep brain stimulation, behavioral therapy, basal ganglia, pharmacological treatment, and risk factors of TS in children.

Conclusion

According to the CiteSpace results, this study found that authors, countries/regions, and institutions were not actively working together. Current research hotspots mainly consist of epidemiology, comorbidities, deep brain stimulation, behavior therapy, and basal ganglia. The main research trends include comorbidities, pharmacological treatment, and risk factors. Therefore, international cooperation should be strengthened in the future, and it should be mindful of the psychiatric comorbidities of TS, the choice of intervention measures, and early warning of risk factors.

Tourette syndrome research highlights from 2021

We summarize selected research reports from 2021 relevant to Tourette syndrome that the authors consider most important or interesting. The authors welcome article suggestions and thoughtful feedback from readers.

Aversive anticipations modulate electrocortical correlates of decision-making and reward reversal learning, but not behavioral performance

Predicting the consequences of one's own decisions is crucial for organizing future behavior. However, when reward contingencies vary frequently, flexible adaptation of decisions is likely to depend on the situation. We examined the effects of an instructed threat context on choice behavior (i.e., reversal learning) and its electrocortical correlates. In a probabilistic decision-making task, 30 participants had to choose between two options that were either contingent on monetary gains or losses. Reward contingencies were reversed after reaching a probabilistic threshold. Decision-making and reversal learning were examined with two contextual background colors, which were instructed as signals for threat-of-shock or safety. Self-report data confirmed the threat context as more unpleasant, arousing, and threatening relative to safety condition. However, against our expectations, behavioral performance was comparable during the threat and safety conditions (i.e., errors-to-criterion, number of reversal, error rates, and choice times). Regarding electrocortical activity, feedback processing changed throughout the visual processing stream. The feedback-related negativity (FRN) reflected expectancy-driven processing (unexpected vs. congruent losses and gains), and the threat-selective P3 component revealed non-specific discrimination of gains vs. losses. Finally, the late positive potentials (LPP) showed strongly valence-specific processing (unexpected and congruent losses vs. gains). Thus, regardless of contextual threat, early and late cortical activity reflects an attentional shift from expectation- to outcome-based feedback processing. Findings are discussed in terms of reward, threat, and reversal-learning mechanisms with implications for emotion regulation and anxiety disorders.