背景：注意力缺陷多动障碍（ADHD）是一种在儿童和青少年期发病率较高的神经发育性疾病。以往大多数关于ADHD的研究只关注其大脑活动的静态特征，但目前有越来越多的研究证明了动态性是大脑活动的重要内在特质。
目的：为了探究ADHD患者大脑活动的动态特征，本文重点分析了ADHD组和正常组被试分别在静息态fMRI和电影fMRI条件中的动态大脑功能连接差异模式，并进一步分析了两组人在自由观看动画电影时被试间功能大脑活动相关性的差异模式。
被试：30名ADHD患者和30名健康被试的磁共振成像数据均来自于Child Mind Institute Healthy Brain Network公开数据库，主要包括T1结构像、静息态fMRI功能像和电影fMRI功能像（自由观看时长为3分钟21秒的动画电影短片《礼物》）。
方法：首先，根据自动解剖标记（AAL）图谱，被试的大脑被划分为90个感兴趣区（ROI）。结合滑动时间窗技术，所有被试的全脑ROI时间序列被划分为若干个长为40秒，步长为1个TR的重叠的时间窗，然后计算出每个时间窗的全脑功能连接矩阵（90 x 90）。在分别对静息态fMRI和电影fMRI条件中的所有被试的全脑功能连接矩阵进行了k均值聚类后，本研究对两种条件中的动态功能连接状态进行了网络分析，计算并比较了各个状态中七大功能网络的网络内和网络间平均功能连接及其差异。然后，本研究分别计算了ADHD组和正常组在两种条件中的动态功能连接状态特征并比较了其组间差异，其中包括状态停留时间、状态转换次数和状态一致性（SC）。 随后，根据SC分别选取了组间差异显著的两个电影片段（片段1和片段2）。最后，本研究分别计算了两组人在观看整个动画电影、片段1和片段2这三种条件中的被试间相关（ISC）和被试间功能相关（ISFC）并比较了其组间差异。
结果：1）电影fMRI条件中的动态功能连接状态种类比静息态fMRI条件中的更为丰富；2）电影fMRI条件中的状态4、状态6和状态7分别与静息态fMRI条件中的状态3、状态2和状态1最为相似；3）在静息态fMRI条件中，ADHD组与正常组的状态停留时间在状态2差异显著，而在电影fMRI条件中，状态停留时间的组间差异在状态1和状态5中最显著；4）ADHD组与正常组在静息态fMRI条件中的状态转换次数存在显著差异，而在电影fMRI条件中并无显著差异；5）在所有SC组间差异显著的片段中均表现为ADHD组显著小于正常组，并未发现ADHD组的SC显著大于正常组的片段；6）不管是在观看整个电影还是在观看特定电影片段时，ADHD组在视觉网络和听觉网络相关脑区的ISC都显著大于正常组；7）在三种条件中，ADHD组与正常组在视觉网络内的ISFC差异都较显著，此外，众多涉及情绪、注意、运动控制等高级认知活动的脑区之间的ISFC也存在显著差异。
结论：本文发现，除了视觉网络、听觉网络、感觉运动网络等初级认知网络以外，ADHD组在诸多高级认知网络中也存在异常的动态大脑活动模式。总之，本文证实了电影fMRI这一研究方式能够有效地探究ADHD患者与正常人之间不同的动态大脑活动模式，这不仅丰富了对ADHD异常的动态大脑活动模式研究，而且对其他神经性发育疾病的动态大脑活动模式研究也起到了一定的促进作用。
 

Background: Attention deficit hyperactivity disorder (ADHD) is a neuro-developmental disorder with a high incidence during childhood and adolescence. Most studies on ADHD simply focus on the static characteristics of brain activity, but there are increasing studies have proved that dynamics is a critical intrinsic characteristic of brain activity.
Aim: To explore the dynamic characteristics of brain activity in ADHD patients, this paper concentrates on dynamic functional connectivity differences between ADHD group and typically developing (TD) group in resting-state fMRI and movie-watching fMRI respectively, and further analyzes the functional brain activity differences between the two groups during watching animated movies freely.
Subjects: The data of 30 ADHD subjects and 30 TD subjects were obtained from the database named Child Mind Institute Healthy Brain Network, including T1 image, the functional image with resting-state and the functional image with movie-watching (watching the animated movie called The Present freely).
Methods: Firstly, the whole brain was divided into 90 regions of interest (ROI) according to the automatic anatomical labeling (AAL) atlas. The average time series of each ROI in all subjects were divided into several overlapping windows with the length of 40 seconds and the step of 1 TR using sliding windows technique. Then, the functional connectivity (FC) matrix (90 x 90) of each window was calculated. After performing k-means clustering algorithm on the FC matrices of all subjects in resting-state fMRI and movie-watching fMRI conditions, we compared the characteristics of dynamic FC states between ADHD group and TD group in the two conditions, including the dwell time of states, the number of state transition and the state consistency (SC). Subsequently, we selected two film clips (P1 and P2) that showed significant differences in SC between ADHD group and TD group. Finally, we calculated the inter-subject correlation (ISC) and the inter-subject functional correlation (ISFC) of ADHD group and TD group, and compared the differences between the two groups in the three conditions including watching the whole movie, watching P1 and watching P2.
Results: 1) the types of dynamic FC   states in movie-watching fMRI were more diverse than those in resting-state fMRI; 2) state 4, state 6 and state7 in movie-watching fMRI are most similar to state 3, state 2 and state1 in resting-state fMRI respectively; 3) the dwell time of state 2 in ADHD group is obviously different from that of TD group in resting-state fMRI, while the difference of dwell time of states between the two groups was most significant in state 1 and state 5 in movie-watching fMRI. 4) There were significant differences in the number of state transition between the ADHD group and the TD group in resting-state fMRI but not in movie-watching fMRI. 5) In the time windows with the significant intergroup difference in SC, the SC of ADHD group was significantly smaller than that of TD group. 6) The ISFC between regions within the audio-visual network in the ADHD group was significantly higher than that in the TD group. 7) The most significant intergroup difference in ISFC appeared in the visual network. In addition, there were significant differences of ISFC between regions involved in advanced cognitive functions such as emotion, attention and motor control between ADHD group and TD group.
Conclusion: Except for the primary cognitive networks such as audio-visual and sensorimotor network, ADHD group also showed abnormal dynamic brain activity patterns in many advanced cognitive networks. In conclusion, this study has proven that movie-watching fMRI can be applied to explore effectively the different dynamic brain activity patterns between ADHD patients and healthy people, which not only enriches the study on dynamic brain activity patterns of ADHD but also promotes the study on the dynamic brain activity patterns of other neurodevelopmental disorders.