Abnormal Static And Co-activation Patterns Of Spontaneous Brain Activity In Autism Spectrum Disorder

Autism spectrum disorder(ASD) is a prevalent neurodevelopmental condition characterized by defcits in social communication.Recently,abnormal activities in "social brain",such as salience network(SN)and default mode network(DMN),have become the focus of research on the pathogenesis of ASD.Resting state functional magnetic resonance(rsf MRI)technique is widely used to search for brain biomarkers of ASD.However,the findings of rs FC were inconsistent.The reasons may be as follows: 1)small sample size,different sample selection and the heterogeneity of the disease;2)rs FC studies ignore the non-stationarity of spontaneous brain activity.In order to reveal the stable characteristics of abnormal spontaneous activity in ASD,based on the importance of DMN in ASD and resting state,we conducted the following three studies in this paper:First,meta-analysis technique is used to integrate the 10 ASD DMN rs FC studies.It was found that the rs FC of the DMN in ASD was increased with that of other network systems,while decreased within DMN.Second,co-activation patterns(CAPs)were used for analysis.Rather than relying on sliding windows,CAPs take a single f MRI frame rather than a fixed window length,to identify critical co-activating patterns that recur over time.Our result shows that ASD manifests as recurring CAPs which are similar to healthy subjects.Third,based on the importance of whole-brain activity in psychiatric disorders,we used the CAPs to explore whole-brain transient patterns.Both universal activation and universal deactivated CAPs in ASD had the least total time which was negatively correlated with ADOS social scores.In addition,ASD in adolescents had abnormal time metrics in universal deactivated CAPs,while ASD in adults had abnormal time metrics in positive activation of DMN.In summary,this paper quantitatively shows the abnormal static connection pattern of DMN in ASD.In the key nodes of DMN,ASD shows the ability to dynamically reorganize the brain similar to that of healthy people.At the whole brain level,ASD tended to be more transient,possibly reflecting a deficiency in the arousal level of ASD patients.This helps to deepen our cognition of abnormal brain spontaneous activity in ASD,and provides ideas and basis for further research on the pathological mechanism of ASD.