scholarly journals Altered Temporal Structure of Neural Phase Synchrony in Patients With Autism Spectrum Disorder

2021 ◽  
Vol 12 ◽  
Author(s):  
Huibin Jia ◽  
Fei Gao ◽  
Dongchuan Yu
Keyword(s):  
Autism Spectrum Disorder ◽  
Time Series ◽  
Temporal Structure ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Fluctuation Analysis ◽  
Phase Synchrony ◽  
Temporal Correlations

Functional connectivity, quantified by phase synchrony, between brain regions is known to be aberrant in patients with autism spectrum disorder (ASD). Here, we evaluated the long-range temporal correlations of time-varying phase synchrony (TV-PS) of electrocortical oscillations in patients with ASD as well as typically developing people using detrended fluctuation analysis (DFA) after validating the scale-invariance of the TV-PS time series. By comparing the DFA exponents between the two groups, we found that those of the TV-PS time series of high-gamma oscillations were significantly attenuated in patients with ASD. Furthermore, the regions involved in aberrant TV-PS time series were mainly within the social ability and cognition-related cortical networks. These results support the notion that abnormal social functions observed in patients with ASD may be caused by the highly volatile phase synchrony states of electrocortical oscillations.

scholarly journals Edge-centric analysis of time-varying functional brain networks with applications in autism spectrum disorder

2021 ◽  
Author(s):  
Farnaz Zamani Esfahlani ◽  
Lisa Byrge ◽  
Jacob Tanner ◽  
Olaf Sporns ◽  
Daniel Kennedy ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Time Series ◽  
High Amplitude ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Time Varying ◽  
Dynamic Features ◽  
Sliding Windows ◽  
Functional Brain

The interaction between brain regions changes over time, which can be characterized using time-varying functional connectivity (tvFC). The common approach to estimate tvFC uses sliding windows and offers limited temporal resolution. An alternative method is to use the recently proposed edge-centric approach, which enables the tracking of moment-to-moment changes in co-fluctuation patterns between pairs of brain regions. Here, we first examined the dynamic features of edge time series and compared them to those in the sliding window tvFC (sw-tvFC). Then, we used edge time series to compare subjects with autism spectrum disorder (ASD) and healthy controls (CN). Our results indicate that relative to sw-tvFC, edge time series captured rapid and bursty network-level fluctuations that synchronize across subjects during movie-watching. The results from the second part of the study suggested that the magnitude of peak amplitude in the collective co-fluctuations of brain regions (estimated as root sum square (RSS) of edge time series) is similar in CN and ASD. However, the trough-to-trough duration in RSS signal is greater in ASD, compared to CN. Furthermore, an edge-wise comparison of high-amplitude co-fluctuations showed that the within-network edges exhibited greater magnitude fluctuations in CN. Our findings suggest that high-amplitude co-fluctuations captured by edge time series provide details about the disruption of functional brain dynamics that could potentially be used in developing new biomarkers of mental disorders.

scholarly journals Graph Ricci Curvatures Reveal Disease-related Changes in Autism Spectrum Disorder

2021 ◽  
Author(s):  
Pavithra Elumalai ◽  
Yasharth Yadav ◽  
Nitin Williams ◽  
Emil Saucan ◽  
Jürgen Jost ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Resting State ◽  
Neurodevelopmental Disorders ◽  
Data Exchange ◽  
Meta Analysis ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
The Brain

Autism Spectrum Disorder (ASD) is a set of neurodevelopmental disorders that pose a significant global health burden. Measures from graph theory have been used to characterise ASD-related changes in resting-state fMRI functional connectivity networks (FCNs), but recently developed geometry-inspired measures have not been applied so far. In this study, we applied geometry-inspired graph Ricci curvatures to investigate ASD-related changes in resting-state fMRI FCNs. To do this, we applied Forman-Ricci and Ollivier-Ricci curvatures to compare networks of ASD and healthy controls (N = 1112) from the Autism Brain Imaging Data Exchange I (ABIDE-I) dataset. We performed these comparisons at the brain-wide level as well as at the level of individual brain regions, and further, determined the behavioral relevance of region-specific differences with Neurosynth meta-analysis decoding. We found brain-wide ASD-related differences for both Forman-Ricci and Ollivier-Ricci curvatures. For Forman-Ricci curvature, these differences were distributed across 83 of the 200 brain regions studied, and concentrated within the Default Mode, Somatomotor and Ventral Attention Network. Meta-analysis decoding identified the brain regions showing curvature differences as involved in social cognition, memory, language and movement. Notably, comparison with results from previous non-invasive stimulation (TMS/tDCS) experiments revealed that the set of brain regions showing curvature differences overlapped with the set of brain regions whose stimulation resulted in positive cognitive or behavioural outcomes in ASD patients. These results underscore the utility of geometry-inspired graph Ricci curvatures in characterising disease-related changes in ASD, and possibly, other neurodevelopmental disorders.

Executive Functions in Adolescents with Autism Spectrum Disorder

2017 ◽  
pp. 67-90
Author(s):  
Yael Dai ◽  
Inge-Marie Eigsti
Keyword(s):  
Autism Spectrum Disorder ◽  
Working Memory ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Clinical Implications ◽  
Future Directions ◽  
Adolescents With Autism ◽  
Memory Flexibility ◽  
The Brain

This chapter reviews strengths and weaknesses in executive function (EF) domains, including inhibition, working memory, flexibility, fluency, and planning, in adolescents (age 13–19) with autism spectrum disorder (ASD). Given the dramatic developmental changes in the brain regions that support EF during the period of adolescence, it is critical to evaluate which EF abilities show a distinct profile during this period. As this chapter will demonstrate, youth with ASD show deficits across all domains of EF, particularly in complex tasks that include arbitrary instructions. We describe the fundamental measures for assessing skills in each domain and discuss limitations and future directions for research, as well as clinical implications of these findings for working with youth with ASD.

scholarly journals Neural features of sustained emotional information processing in autism spectrum disorder

Autism ◽  
2020 ◽  
Vol 24 (4) ◽  
pp. 941-953 ◽  
Author(s):  
Carla A Mazefsky ◽  
Amanda Collier ◽  
Josh Golt ◽  
Greg J Siegle
Keyword(s):  
Autism Spectrum Disorder ◽  
Emotion Dysregulation ◽  
Emotional Processing ◽  
Brain Activity ◽  
A Priori ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Typically Developing ◽  
Autism Spectrum Disorder Group

Emotion dysregulation is common in autism spectrum disorder; a better understanding of the underlying neural mechanisms could inform treatment development. The tendency toward repetitive cognition in autism spectrum disorder may also increase susceptibility to perseverate on distressing stimuli, which may then increase emotion dysregulation. Therefore, this study investigated the mechanisms of sustained processing of negative information in brain activity using functional magnetic resonance imaging. We used an event-related task that alternated between emotional processing of personally relevant negative words, neutral words, and a non-emotional task. A priori criteria were developed to define heightened and sustained emotional processing, and feature conjunction analysis was conducted to identify all regions satisfying these criteria. Participants included 25 adolescents with autism spectrum disorder and 23 IQ-, age-, and gender-matched typically developing controls. Regions satisfying all a priori criteria included areas in the salience network and the prefrontal dorsolateral cortex, which are areas implicated in emotion regulation outside of autism spectrum disorder. Collectively, activity in the identified regions accounted for a significant amount of variance in emotion dysregulation in the autism spectrum disorder group. Overall, these results may provide a potential neural mechanism to explain emotion dysregulation in autism spectrum disorder, which is a significant risk factor for poor mental health. Lay abstract Many individuals with autism spectrum disorder struggle with emotions that are intense and interfering, which is referred to as emotion dysregulation. Prior research has established that individuals with autism may be more likely than individuals who are not autistic to have repetitive thoughts. It is possible that persistent thoughts about negative or distressing stimuli may contribute to emotion dysregulation in autism spectrum disorder. This study aimed to identify areas of the brain with evidence of persistent processing of negative information via functional magnetic resonance neuroimaging. We used a task that alternated between emotional processing of personally relevant negative words, neutral words, and a non-emotional task. Criteria were developed to define heightened and persistent emotional processing, and analyses were conducted to identify all brain regions satisfying these criteria. Participants included 25 adolescents with autism spectrum disorder and 23 typically developing adolescents who were similar to the autism spectrum disorder group in IQ, age, and gender ratios. Brain regions identified as having greater and continued processing following negative stimuli in the autism spectrum disorder group as compared with the typically developing group included the salience network and the prefrontal dorsolateral cortex. These areas have been previously implicated in emotion dysregulation outside of autism spectrum disorder. Collectively, brain activity in the identified regions was associated with parent-reported emotion dysregulation in the autism spectrum disorder group. These results help to identify a potential process in the brain associated with emotion dysregulation in autism spectrum disorder. This information may be useful for the development of treatments to decrease emotion dysregulation in autism spectrum disorder.

scholarly journals Atypical cortical connectivity in autism spectrum disorder (ASD) as measured by magnetoencephalography (MEG)

2019 ◽  
Author(s):  
Robert A. Seymour ◽  
Paul Sowman ◽  
Klaus Kessler
Keyword(s):  
Autism Spectrum Disorder ◽  
Sensory Processing ◽  
Perspective Taking ◽  
Predictive Coding ◽  
Gamma Oscillations ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Alpha Oscillations ◽  
Oscillatory Power ◽  
Phase Amplitude

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition, characterised by impairments in social interaction and communication, the presence of repetitive behaviours, and multisensory hyper- and hypo-sensitives. This thesis utilised magnetoencephalography, in combination with robust analysis techniques, to investigate the neural basis of ASD. Based on previous research, it was hypothesised that cortical activity in ASD would be associated with disruptions to oscillatory synchronisation during sensory processing, as well as during high-level perspective-taking. More specifically, a novel framework was introduced, based on local gamma-band dysregulation, global hypoconnectivity and deficient predictive-coding. To test this framework, data were collected from adolescents diagnosed with ASD and age-matched controls.Using a visual grating stimulus, it was found that in primary visual cortex, ASD participants had reduced coupling between the phase of alpha oscillations and the amplitude of gamma oscillations (i.e. phase amplitude coupling), suggesting dysregulated visual gamma in ASD. These findings were based on a robust analysis pipeline outlined in Chapter 2. Next, directed connectivity in the visual system was quantified using Granger causality. Compared with controls, ASD participants showed reductions in feedback connectivity, mediated by alpha oscillations, but no differences in inter-regional feedforward connectivity, mediated by gamma oscillations. In the auditory domain, it was found that ASD participants had reduced steady-state responses at 40Hz, in terms of oscillatory power and inter-trial coherence, again suggesting dysregulated gamma. Investigating predictive-coding theories of ASD using an auditory oddball paradigm, it was found that evoked responses to the omission of an expected tone were reduced for ASD participants. Finally, we found reductions in theta-band oscillatory power and connectivity for ASD participants, during embodied perspective-taking. Overall, these findings fit the proposed framework, and demonstrate that cortical activity in ASD is characterised by disruptions to oscillatory synchronisation, at the local and global scales, during both sensory processing and higher-level perspective-taking.Keywords: Autism Spectrum Disorder; Magnetoencephalography; Oscillations; Phase Amplitude Coupling; Connectivity.

scholarly journals Sex-dependent and sex-independent brain resting-state functional connectivity in children with autism spectrum disorder

2016 ◽  
Author(s):  
Xin Di ◽  
Bharat B Biswal
Keyword(s):  
Autism Spectrum Disorder ◽  
Functional Connectivity ◽  
Resting State ◽  
Data Exchange ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Imaging Data ◽  
Resting State Functional Connectivity ◽  
Main Effects

Background: Males are more likely to suffer from autism spectrum disorder (ASD) than females. As to whether females with ASD have similar brain alterations remain an open question. The current study aimed to examine sex-dependent as well as sex-independent alterations in resting-state functional connectivity in individuals with ASD compared with typically developing (TD) individuals. Method: Resting-state functional MRI data were acquired from the Autism Brain Imaging Data Exchange (ABIDE). Subjects between 6 to 20 years of age were included for analysis. After matching the intelligence quotient between groups for each dataset, and removing subjects due to excessive head motion, the resulting effective sample contained 28 females with ASD, 49 TD females, 129 males with ASD, and 141 TD males, with a two (diagnosis) by two (sex) design. Functional connectivity among 153 regions of interest (ROIs) comprising the whole brain was computed. Two by two analysis of variance was used to identify connectivity that showed diagnosis by sex interaction or main effects of diagnosis. Results: The main effects of diagnosis were found mainly between visual cortex and other brain regions, indicating sex-independent connectivity alterations. We also observed two connections whose connectivity showed diagnosis by sex interaction between the precuneus and medial cerebellum as well as the precunes and dorsal frontal cortex. While males with ASD showed higher connectivity in these connections compared with TD males, females with ASD had lower connectivity than their counterparts. Conclusions: Both sex-dependent and sex-independent functional connectivity alterations are present in ASD.

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