Project summary Autism spectrum disorder (ASD) is usually diagnosed early in childhood. Understanding the developmental curves of brain functions in typically developing children and children with ASD will help to understand the brain correlates of ASD. In this project, we will analyze functional MRI (fMRI) data of more than 1,000 children and adults to portrait brain developmental curves. FMRI has been commonly used to study brain functions in action. Usually, participants are asked to do some strictly designed tasks on a computer, or simply lay in the scanner without thinking a thing in particular. A more natural way to perform scanning has been proposed, where the participants are asked to watch short movie clips during the scanning. However, data analysis for movie watching data becomes complicated. We have developed a novel method to examine functional communications between brain regions during movie watching. In this project, we will compare our new method with existing methods. The project is divided into two parts. In the first part, we will study brain developments in hundreds of typically developing children. We will compare data from movie watching and resting-state, and compare different analysis methods. The results will help us find better methods to chart the developing brain. In the second part, we will compare the developing curves between individuals with ASD and those in typically developing individuals. The data may help us to establish a better way to scan individuals of ASD, and a better way to characterize brain functions in ASD.