Older Adults With Smaller and Less Complex Social Networks Show Deficits in Medial Temporal Cerebrovascular Reactivity - Evelyn Chang; Arunima Kapoor; Trevor Lohman; Shubir Dutt; John Paul M. Alitin; Isabel J. Sible; Jean K. Ho; Aimée Gaubert; Anna E. Blanken; Mara Mather; Xingfeng Shao; Danny J.J. Wang; et al. (Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease)