Atypical Pattern of Frontal EEG Asymmetry for Direct Gaze in Young Children with Autism Spectrum Disorder

Music therapy improves engagement and initiation for autistic children with mild intellectual disabilities: A randomized controlled study

This study aimed to evaluate the effectiveness of music therapy (MT) for children with co-occurring autism spectrum disorder (ASD) and intellectual disabilities (ID) and explore whether pre-intervention quantitative electroencephalogram (qEEG) responses can predict outcomes. A randomized controlled trial was conducted with 33 children receiving MT and 34 receiving an active control therapy. Participants received either MT or a non-musical social skills intervention for 45 min weekly over 12 weeks. Primary outcomes were measured using the Childhood Autism Rating Scale (CARS-2), along with the parent-rated Social Responsiveness Scale (SRS-2) and video coding of social behaviors. Both conditions significantly improved in CARS-2 scores at 2 weeks and 4 months post-intervention, with no differences between MT and control conditions. No changes were found in SRS-2 scores. While both conditions showed reduced disengagement after intervention, only the MT condition showed increased engagement and initiation. Strong qEEG responses to social scenes and music predicted increased initiation, indicating its potential to help tailor interventions. These results support incorporating MT into standard services and further research on qEEG predictors.

Neurological Validation of ASD Diagnostic Criteria Using Frontal Alpha and Theta Asymmetry

Background/Objectives: Diagnosis of Autism Spectrum Disorder (ASD) relies on the observation of difficulties in social communication and interaction, plus the presence of repetitive and restrictive behaviors. The identification of neurological correlates of these symptoms remains a high priority for clinical research, and has the potential to increase the validity of diagnosis of ASD as well as provide greater understanding of how the autistic brain functions. This study focused on two neurological phenomena that have been previously associated with psychiatric disorders (alpha- and theta-wave asymmetry across the frontal region of the brain), and tested for their association with the major diagnostic criteria for ASD. Methods: A total of 41 male autistic youth underwent assessment with the Autism Diagnostic Observation Schedule (ADOS-2) and 3 min of eyes-closed resting EEG to collect alpha- and theta-wave data from right and left frontal brain sites. Results: Different associations were found for theta versus alpha asymmetry and the ADOS-2 subscales, across different brain regions responsible for a varying range of cognitive functions. In general, theta asymmetry was associated with conversation with others, sharing of enjoyment, and making social overtures, whereas alpha asymmetry was linked with making eye contact, reporting events to others, and engaging in reciprocal social communication. Specific brain regions involved are identified, as well as implications for clinical practice. Conclusions: Specific autism symptoms may be associated with selected brain region activity, providing a neurological basis for diagnosis and treatment.

The Timing of Gaze Direction Perception: ERP Decoding and Task Modulation

Distinguishing the direction of another person's eye gaze is extremely important in everyday social interaction, as it provides critical information about people's attention and, therefore, intentions. The temporal dynamics of gaze processing have been investigated using event-related potentials (ERPs) recorded with electroencephalography (EEG). However, the moment at which our brain distinguishes the gaze direction (GD), irrespectively of other facial cues, remains unclear. To solve this question, the present study aimed to investigate the time course of gaze direction processing, using an ERP decoding approach, based on the combination of a support vector machine and error-correcting output codes. We recorded EEG in young healthy subjects, 32 of them performing GD detection and 34 conducting face orientation tasks. Both tasks presented 3D realistic faces with five different head and gaze orientations each: 30°, 15° to the left or right, and 0°. While the classical ERP analyses did not show clear GD effects, ERP decoding analyses revealed that discrimination of GD, irrespective of head orientation, started at 140 ms in the GD task and at 120 ms in the face orientation task. GD decoding accuracy was higher in the GD task than in the face orientation task and was the highest for the direct gaze in both tasks. These findings suggest that the decoding of brain patterns is modified by task relevance, which changes the latency and the accuracy of GD decoding.

Frontal EEG alpha asymmetry in youth with autism: Sex differences and social-emotional correlates

In youth broadly, EEG frontal alpha asymmetry (FAA) associates with affective style and vulnerability to psychopathology, with relatively stronger right activity predicting risk for internalizing and externalizing behaviors. In autistic youth, FAA has been related to ASD diagnostic features and to internalizing symptoms. Among our large, rigorously characterized, sex-balanced participant group, we attempted to replicate findings suggestive of altered FAA in youth with an ASD diagnosis, examining group differences and impact of sex assigned at birth. Second, we examined relations between FAA and behavioral variables (ASD features, internalizing, and externalizing) within autistic youth, examining effects by sex. Third, we explored whether the relation between FAA, autism features, and mental health was informed by maternal depression history. In our sample, FAA did not differ by diagnosis, age, or sex. However, youth with ASD had lower total frontal alpha power than youth without ASD. For autistic females, FAA and bilateral frontal alpha power correlated with social communication features, but not with internalizing or externalizing symptoms. For autistic males, EEG markers correlated with social communication features, and with externalizing behaviors. Exploratory analyses by sex revealed further associations between youth FAA, behavioral indices, and maternal depression history. In summary, findings suggest that individual differences in FAA may correspond to social-emotional and mental health behaviors, with different patterns of association for females and males with ASD. Longitudinal consideration of individual differences across levels of analysis (e.g., biomarkers, family factors, and environmental influences) will be essential to parsing out models of risk and resilience among autistic youth.

Comparison of comprehensive quantitative EEG metrics between typically developing boys and girls in resting state eyes-open and eyes-closed conditions

Introduction

A majority of published studies comparing quantitative EEG (qEEG) in typically developing (TD) children and children with neurodevelopmental or psychiatric disorders have used a control group (e.g., TD children) that combines boys and girls. This suggests a widespread supposition that typically developing boys and girls have similar brain activity at all locations and frequencies, allowing the data from TD boys and girls to be aggregated in a single group.

Methods

In this study, we have rigorously challenged this assumption by performing a comprehensive qEEG analysis on EEG recoding of TD boys (n = 84) and girls (n = 62), during resting state eyes-open and eyes-closed conditions (EEG recordings from Child Mind Institute's Healthy Brain Network (HBN) initiative). Our qEEG analysis was performed over narrow-band frequencies (e.g., separating low α from high α, etc.), included sex, age, and head size as covariates in the analysis, and encompassed computation of a wide range of qEEG metrics that included both absolute and relative spectral power levels, regional hemispheric asymmetry, and inter- and intra-hemispheric magnitude coherences as well as phase coherency among cortical regions. We have also introduced a novel compact yet comprehensive visual presentation of the results that allows comparison of the qEEG metrics of boys and girls for the entire EEG locations, pairs, and frequencies in a single graph.

Results

Our results show there are wide-spread EEG locations and frequencies where TD boys and girls exhibit differences in their absolute and relative spectral powers, hemispheric power asymmetry, and magnitude coherence and phase synchrony.

Discussion

These findings strongly support the necessity of including sex, age, and head size as covariates in the analysis of qEEG of children, and argue against combining data from boys and girls. Our analysis also supports the utility of narrow-band frequencies, e.g., dividing α, β, and γ band into finer sub-scales. The results of this study can serve as a comprehensive normative qEEG database for resting state studies in children containing both eyes open and eyes closed paradigms.

Impairment in reading negative social cues extends beyond the face in autism

Nonverbal expressions are essential to regulating social communication and interaction. Impaired emotion recognition from facial expressions has been linked to various psychiatric conditions characterized by severe social deficits such as autism. As body expressions as an additional source of social-emotional information have attracted little research attention, little is known about whether emotion recognition impairments are specific to faces, or extend to body expressions. This study explored and compared emotion recognition from face versus body expressions in autism spectrum disorder. We compared 30 men with autism spectrum disorder to 30 male age- and IQ-matched control participants in their ability to recognize angry, happy, and neutral expressions from dynamic face and body expressions. Participants with autism spectrum disorder showed impaired recognition of angry expressions from both faces and bodies, while there were no group differences in recognizing happy and neutral expressions. In autism spectrum disorder, recognizing angry face expressions was inversely predicted by gaze avoidance, while recognizing angry body expressions was inversely predicted by impairments in social interaction and autistic traits. These findings suggest that distinct mechanisms may underlie the impaired emotion recognition from face and body expressions in autism spectrum disorder, respectively. Overall, our study demonstrates that emotion-specific recognition difficulties in autism spectrum disorder are not limited to face expressions but extend to emotional body expressions.

Eye Direction Detection and Perception as Premises of a Social Brain: A Narrative Review of Behavioral and Neural Data

The eyes and the gaze are important stimuli for social interaction in humans. Impaired recognition of facial identity, facial emotions, and inference of the intentions of others may result from difficulties in extracting information relevant to the eye region, mainly the direction of gaze. Therefore, a review of these data is of interest. Behavioral data demonstrating the importance of the eye region and how humans respond to gaze direction are reviewed narratively, and several theoretical models on how visual information on gaze is processed are discussed to propose a unified hypothesis. Several issues that have not yet been investigated are identified. The authors tentatively suggest experiments that might help progress research in this area. The neural aspects are subsequently reviewed to best describe the low-level and higher-level visual information processing stages in the targeted subcortical and cortical areas. A specific neural network is proposed on the basis of the literature. Various gray areas, such as the temporality of the processing of visual information, the question of salience priority, and the coordination between the two hemispheres, remain unclear and require further investigations. Finally, disordered gaze direction detection mechanisms and their consequences on social cognition and behavior are discussed as key deficiencies in several conditions, such as autism spectrum disorder, 22q11.2 deletion, schizophrenia, and social anxiety disorder. This narrative review provides significant additional data showing that the detection and perception of someone's gaze is an essential part of the development of our social brain.

Genetic variation in the oxytocin system and its link to social motivation in human infants

Frontal brain asymmetry has been linked to motivational processes in infants and adults, with left lateralization reflecting motivation to approach and right lateralization reflecting motivation to withdraw. We examined the hypothesis that variability in infants' social motivation may be linked to genetic variation in the oxytocin system. Eleven-month-old infants' brain responses and looking preferences to smiling and frowning individuals were assessed in conjunction with a polymorphism in CD38 (rs3796863) linked to autism spectrum disorder (ASD) and reduced oxytocin. Frontal brain asymmetry and looking preferences differed as a function of CD38 genotype. While non-risk A-allele carriers displayed left lateralization to smiling faces (approach) and a heightened looking preference for the individual who smiled, infants with the CC (ASD risk) genotype displayed withdrawal from smiling faces and a preference for the individual who frowned. Findings demonstrate that the oxytocin system is linked to brain and behavioral markers of social motivation in infancy.

Children ASD Evaluation Through Joint Analysis of EEG and Eye-Tracking Recordings With Graph Convolution Network

Recent advances in neuroscience indicate that analysis of bio-signals such as rest state electroencephalogram (EEG) and eye-tracking data can provide more reliable evaluation of children autism spectrum disorder (ASD) than traditional methods of behavior measurement relying on scales do. However, the effectiveness of the new approaches still lags behind the increasing requirement in clinical or educational practices as the “bio-marker” information carried by the bio-signal of a single-modality is likely insufficient or distorted. This study proposes an approach to joint analysis of EEG and eye-tracking for children ASD evaluation. The approach focuses on deep fusion of the features in two modalities as no explicit correlations between the original bio-signals are available, which also limits the performance of existing methods along this direction. First, the synchronization measures, information entropy, and time-frequency features of the multi-channel EEG are derived. Then a random forest applies to the eye-tracking recordings of the same subjects to single out the most significant features. A graph convolutional network (GCN) model then naturally fuses the two group of features to differentiate the children with ASD from the typically developed (TD) subjects. Experiments have been carried out on the two types of the bio-signals collected from 42 children (21 ASD and 21 TD subjects, 3–6 years old). The results indicate that (1) the proposed approach can achieve an accuracy of 95% in ASD detection, and (2) strong correlations exist between the two bio-signals collected even asynchronously, in particular the EEG synchronization against the face related/joint attentions in terms of covariance.

A New dispersion entropy and fuzzy logic system methodology for automated classification of dementia stages using electroencephalograms

A new EEG-based methodology is presented for differential diagnosis of the Alzheimer's disease (AD), Mild Cognitive Impairment (MCI), and healthy subjects employing the discrete wavelet transform (DWT), dispersion entropy index (DEI), a recently-proposed nonlinear measurement, and a fuzzy logic-based classification algorithm. The effectiveness and usefulness of the proposed methodology are evaluated by employing a database of measured EEG data acquired from 135 subjects, 45 MCI, 45 AD and 45 healthy subjects. The proposed methodology differentiates MCI and AD patients from HC subjects with an accuracy of 82.6-86.9%, sensitivity of 91 %, and specificity of 87 %.

Intranasal oxytocin enhances approach-related EEG frontal alpha asymmetry during engagement of direct eye contact

The neuropeptide oxytocin is suggested to play a major role in a variety of complex human behaviours, including interpersonal bonding, trust and attachment. Recent theories have suggested that the role oxytocin plays in these complex social behaviours involves a modulation of motivational tendencies of approach-/avoidance-related behaviours. However, to date, direct neurophysiological evidence supporting this notion is limited. In this double-blind, randomized, placebo-controlled study with parallel design, we assessed the effects of administered intranasal oxytocin in 40 adult men on gaze behaviour and a neural marker of approach/avoidance motivational tendencies. Specifically, electroencephalography recordings were performed during the engagement of eye contact with a live model in a naturalistic two-person social context and electroencephalographic frontal alpha asymmetry, an established neurophysiological index of motivational tendencies for approach-/avoidance-related behaviours, was assessed. Compared to placebo, a single dose of oxytocin (24 international units) was shown to increase relative left-sided frontal asymmetry upon direct eye contact with a live model, which is indicative of an increase in approach-related motivational tendencies towards the presented eye contact stimulus. Notably, the treatment effect was most prominently observed in participants with lower self-reported social motivation (higher Motivation subscale scores on the Social Responsiveness Scale), indicating that participants with lower social motivation benefitted the most from the administered oxytocin. No treatment-specific changes were identified in terms of gaze behaviour towards the eye region of the live model. Together, these observations add neurophysiological evidence to the hypothesized role of oxytocin in modulating approach-/avoidance-related tendencies and suggest that inter-subject variability in person-dependent factors need to be considered to evaluate the potential benefit of intranasal oxytocin as a treatment. This notion is of particular relevance to the variety of neuropsychiatric populations such as autism spectrum disorder, social anxiety disorder and depression, for which intranasal oxytocin is increasingly considered a potential treatment.

Eye contact perception in high-functioning adults with autism spectrum disorder

LAY ABSTRACT

The detection of a self-directed gaze is often the starting point for social interactions and a person who feels as if they are being watched can prepare to respond to others' actions irrespective of the real gaze direction because the other person may likely be motivated to approach. Although many studies demonstrated that individuals with autism spectrum disorder have difficulty discriminating gaze direction, it remains unclear how the perception of self-directed gaze by individuals with autism spectrum disorder differs from that of age-, sex-, and IQ-matched typically developing individuals. Participants observed faces with various gaze directions and answered whether the person in the photograph was looking at them or not. Individuals with and without autism spectrum disorder were just as likely to perceive subtle averted gazes as self-directed gazes. The frequency of perceiving a self-directed gaze decreased as gaze aversion increased in both groups and, in general, individuals with autism spectrum disorder showed a comparable ability to perceive a self-directed gaze as that of typically developing individuals. Interestingly, considering face membership of photographs (ingroup or outgroup faces), typically developing individuals, but not individuals with autism spectrum disorder, were more likely to perceive self-directed gazes from ingroup faces than from outgroup faces. However, individuals with autism spectrum disorder had different affective experiences in response to ingroup and outgroup faces. These results suggest that individuals with autism spectrum disorder did not show an ingroup bias for the perception of a self-directed gaze, and raise a possibility that an atypical emotional experience contributes to the diminished ingroup bias.