Inference With Interference Between Units in an fMRI Experiment of Motor Inhibition

• 成果类型: Article
• 署名作者: Luo, Xi; Small, Dylan S.; Li, Chiang-Shan R.; Rosenbaum, Paul R.
• 署名单位: Brown University; Brown University; University of Pennsylvania; Yale University
• 刊物名称: JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION
• ISSN/ISSBN: 0162-1459
• DOI: 10.1080/01621459.2012.655954
• 发表日期: 2012
• 页码: 530-541
• 关键词: inferior frontal-cortex; response-inhibition; Causal Inference; randomized experiments; general-class; tests; hypotheses; statistics; task

摘要

An experimental unit is an opportunity to randomly apply or withhold a treatment. There is interference between units if the application of the treatment to one unit may also affect other units. In cognitive neuroscience, a common form of experiment presents a sequence of stimuli or requests for cognitive activity at random to each experimental subject and measures biological aspects of brain activity that follow these requests. Each subject is then many experimental units, and interference between units within an experimental subject is, likely, in part because the stimuli follow one another quickly and in part because human subjects learn or become experienced or primed or bored as the experiment proceeds. We use a recent functional magnetic resonance imaging (fMRI) experiment concerned with the inhibition of motor activity to illustrate and further develop recently proposed methodology for inference in the presence of interference. A simulation evaluates the power of competing procedures.