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Very large fMRI study using the IMAGEN database: sensitivity - specificity and population effect modelling in relation to the underlying anatomy

Creator:

WHELAN, ROBERT;

Institution: Elsevier
Subject Keywords: Neuroscience; Brain Mapping; Likelihood Functions; Linear Models; Magnetic Resonance Imaging; MRI;
Region:
Description:

In this paper we investigate the use of classical fMRI Random Effect (RFX) group statistics when analysing a very large cohort and the possible improvement brought from anatomical information. Using 1326 subjects from the IMAGEN study, we first give a global picture of the evolution of the group effect t-value from a simple face-watching contrast with increasing cohort size. We obtain a wide äctivated" pattern, far from being limited to the reasonably expected brain areas, illustrating the difference between statistical significance and practical significance. This motivates us to inject tissue-probability information into the group estimation, we model the BOLD contrast using a matter-weighted mixture of Gaussians and compare it to the common, single-Gaussian model. In both cases, the models parameters are estimated per-voxel for one subgroup, and the likelihood of both models is computed on a second, separate subgroup to reflect models generalization capacity. Various group sizes are tested, and significance is asserted using a 10-fold cross-validation scheme. We conclude that adding matter information consistently improves the quantitative analysis of BOLD responses in some areas of the brain, particularly those where accurate inter-subject registration remains challenging.

Related: http://dx.doi.org/10.1016/j.neuroimage.2012.02.083
Suggested citation:

WHELAN, ROBERT; . () Very large fMRI study using the IMAGEN database: sensitivity - specificity and population effect modelling in relation to the underlying anatomy [Online]. Available from: http://publichealthwell.ie/node/660019 [Accessed: 24th February 2019].

  

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