Trait positive affect is associated with hippocampal volume and change in caudate volume across adolescence
Cognitive Affective & Behavioral Neuroscience (2015) - Comment
pubmed: 25231241  doi: 10.3758/s13415-014-0319-2  issn: 1531-135x  issn: 1530-7026 

Meg Dennison, Sarah Whittle, Murat Yücel, Michelle L. Byrne, Orli Schwartz, Julian G. Simmons, Nicholas B. Allen