Title
Hippocampus-specific fMRI group activation analysis using the continuous medial representation
Abstract
We present a new shape-based approach for regional group activation analysis in fMRI studies. The method restricts anatomical normalization, spatial smoothing and random effects statistical analysis to the space inside and around a structure of interest. Normalization involves finding intersubject correspondences between manually outlined masks, and it leverages the continuous medial representation, which makes it possible to extend surface-based shape correspondences to the space inside and outside of structures. Our approach is an alternative to whole-brain normalization in cases where the latter may fail due to anatomical variability or pathology. It also provides an opportunity to analyze the shape and thickness of structures concurrently with functional activation. We apply the technique to the hippocampus and evaluate it using data from a visual scene encoding fMRI study, where activation in the hippocampus is expected. We produce detailed statistical maps of hippocampal activation, as well as maps comparing activation inside and outside of the hippocampus. We find that random effects statistics computed by the new approach are more significant than those produced using the Statistical Parametric Mapping framework (Friston, K.J., Holmes, A.P., Worsley, K.J., Poline, J.-P., Firth, C.D., Frackowiak, R.S.J. 1994, Statistical parametric maps in functional imaging: a general linear approach. Human Brain Mapping, 2(4): 189–210) at low levels of smoothing, suggesting that greater specificity can be achieved by the new method without a severe tradeoff in sensitivity.
Year
DOI
Venue
2007
10.1016/j.neuroimage.2007.01.029
NeuroImage
Keywords
Field
DocType
Functional neuroimaging,Hippocampus,Random effects,Normalization,Statistical Parametric Mapping
Normalization (statistics),Functional neuroimaging,Computer science,Image processing,Cognitive psychology,Statistical parametric mapping,Artificial intelligence,Computer vision,Random effects model,Pattern recognition,Functional imaging,Parametric statistics,Smoothing
Journal
Volume
Issue
ISSN
35
4
1053-8119
Citations 
PageRank 
References 
9
0.70
28
Authors
9
Name
Order
Citations
PageRank
Paul A. Yushkevich12442140.69
John A. Detre222125.13
Dawn Mechanic-Hamilton3545.35
María A. Fernández-Seara4475.88
Kathy Z. Tang5232.27
Angela Hoang6101.18
Marc Korczykowski71589.51
Hui Zhang837623.01
James C. Gee94558321.75