Background: Autism spectrum disorder(ASD)is a neurodevelopment disorder characterized by atypical brain connectivity.The thalamus is a critical “information relay” center that plays a major role in relaying incoming information from the sensory periphery[1].Previous studies have revealed atypical structure and function of the thalamus in individuals with ASD[2,3].We hypothesized that atypical thalamic connectivity could impair information transmission from the thalamus to the cortex and result in noisy information reception from the sensory periphery in ASD.Methods: Here we utilized a large multi-center dataset from the Autism Brain Imaging Data Exchange(ABIDE,312 participants with ASD and 344 age,IQ,head-motion matched healthy controls)[4].Data were preprocessed using SPM8 toolbox including temporal and spatial correction,normalization,regressed out the nuisances and filter.We divided the thalamus into 6 regions in each hemisphere using a “winner-takes-all” algorithm[5].Granger Causality Analysis(GCA)was applied to calculate the effective connectivity from all regions of the thalamus to corresponding regions of cortex.Results: Our results showed reduced effective connectivity from thalamus to left prefrontal,right post parietal and bilateral temporal lobes in ASD compared with control participants.The GCA values of the connections from thalamus to bilateral temporal lobes were negatively correlated with severity of communication deficits in ASD.In the control group,the GCA values of thalamus – bilateral temporal lobe connections increased with age,but this relationship was not observed in the ASD group.Discussion:In the present study,we calculated effective connections from the thalamus to the cortex in a large multi-center dataset from ABIDE.Our results revealed impaired thalamo-temporal connection in ASDs,which may result in altered transmission of auditory information from the sensory periphery to primary auditory cortex and eventually contribute to the communication deficits characteristic of ASD.We also revealed that the connections from the thalamus to the temporal lobe strengthens with age in the HC group,which may be caused by experience-dependent development of thalamic neural circuitry.In ASD,this connection didnt change with age,a finding that warrants further investigation.