Hippocampus-specific fMRI group activation analysis with continuous M-Reps.

A new approach to group activation analysis in fMRI studies that test hypotheses focused on specific brain structures is presented and used to analyze hippocampal activation in a visual scene encoding study. The approach leverages the cm-rep method to normalize hippocampal anatomy and project intra-subject hippocampal activation maps into a common reference space, eliminating normalization errors inherent in whole-brain approaches and guaranteeing that peaks detected in the random effects activation map are indeed associated with the hippocampus. When applied to real fMRI data, the method detects more significant hippocampal activation than the established whole-brain method.