| 【Objective】Impaired cognitive flexibility has been repeatedly demonstrated in autism spectrum disorder(ASD).While performing cognitive flexibility tasks,ASD individuals show abnormal activation patterns in brain regions associated with flexibility,suggesting impaired cognitive flexibility in ASD patients at the neurological level.Some studies have reported that first-degree relatives of individuals with ASD exhibit difficulties in cognitive flexibility similar to those of probands with ASD.However,there is still a lack of research on cognitive flexibility and its neural mechanism in first-degree relatives of ASD.Therefore,the present study explored the cognitive flexibility and its neuroelectrophysiological mechanisms in first-degree relatives of ASD to better understand the relationship between these brain functional differences and the cognitive flexibility experienced by this population.【Methods】Study 1: Forty-five parents of autism individuals(p ASD)and thirty-one parents of typically developing individuals(p TD)matched with their gender,age and IQ were enrolled.The cognitive flexibility Inventory(CFI)was used to assess impairments in cognitive flexibility in daily life,and the task-switching task was used to evaluate the behavioral flexibility of all participants in a structured assessment situation.Meanwhile,the event-related potentials(ERPs)induced by the task were collected.The Broad Autism Phenotype Questionnaire(BAPQ)was used to quantitatively assess autistic traits in the two groups.Nonparametric test was used to compare the difference of switch cost and repeated measure analysis of variance(RMANOVA)was used to compare differences in N2 and P3 between the two groups.Pearson correlation analysis was used to explore the associations between cognitive flexibility and autistic traits and N2 waves,respectively.Study 2: Forty-five p ASD and thirty-one p TD matched with their gender,age and IQ were enrolled.CFI was used to assess impairments in cognitive flexibility in daily life and BAPQ was used to quantitatively assess autistic traits in the two groups.EEG signals were collected during an eyes-closed rest,and the functional connectivity index-weighted Phase Lag Index(w PLI)of all subjects was calculated.RMANOVA was used to compare differences in functional connectivity in the frontoparietal network between the two groups.Pearson correlation analysis was used to explore the association between functional connectivity in the frontoparietal network and cognitive flexibility.【Results】Study 1: Compared with the p TD group,the p ASD group had lower CFI scores(t=-2.756,P<0.01),while both groups showed an equivalent ‘switch cost’ in this taskswitching task(P>0.05).Compared with the p TD group,p ASD induced greater N2 amplitude at the F3,F4,Fz and C4(F=3.223,P<0.05),while P3 amplitude and latency did not differ between the two groups.In addition,there was a significant negative correlation between the CFI total scores and BAPQ total scores of p ASD(r=-0.734,P<0.01).After controlling for age and IQ,the N2 amplitude in frontal lobe of p ASD was negatively correlated with the CFI total scores under repeatition sequence(r=-0.304,P=0.053).Study 2: The w PLI value of frontoparietal network in the theta band in p ASD was significantly lower than that in p TD group(F=3.700,P<0.05).After controlling for IQ and BAPQ total scores,the w PLI value of intra-frontal lobe(r=0.329,P<0.05)and intra-parietal lobe(r=0.322,P<0.05)in p ASD were significantly positively correlated with the CFI total scores.【Conclusion】Compared with parents of typically developing individuals,parents of ASD individuals experience difficulties in cognitive flexibility at the self-reported and neurological level.The cognitive flexibility difficulties of parents of ASD individuals were related to autistic traits and also to the synchronization of the frontoparietal network in the theta band.These findings suggest that cognitive flexibility is most likely a neurocognitive endophenotype of ASD,which is worthy of further investigation. |
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