VBA: A Probabilistic Treatment of Nonlinear Models for Neurobiological and Behavioural Data
Figure 5
Online design optimization for DCM comparison.
This figure summarizes the simulation of online design optimization, in the aim of best discriminating between two brain network models ( and
) given fMRI data time series. In this case, the problem reduces to deciding whether or not to introduce the second experimental factor (here,
= attentional modulation), on top of the first factor (
= photic stimulation). Upper left: the two network models to be compared given fMRI data (top/bottom: with/without attentional modulation of the V1→V5 connection). Upper middle: block-by-block temporal dynamics of design efficiency of both types of blocks. Green (resp. blue) dots correspond to blocks with (resp. without.) attentional modulation. Upper right: scan-by-scan temporal dynamics of the optimized (on-line) design. Lower left: scan-by-scan temporal dynamics of the simulated fMRI signal (blue: V1, green: V5). Lower middle: block-by-block temporal dynamics of 95% posterior confidence intervals on the estimated modulatory effect (under model
). The green line depicts the strength of the simulated effect. Lower right: block-by-block temporal dynamics of log Bayes factors
.