To demonstrate and compare various modeling approaches at the group level, we adopt the same experimental data used in our previous paper (Chen et al., 2014), with a typical group design that accounts for a confounding effect: varying age across subjects. Briefly, the experiment involved one between-subjects factor, group (two levels: 21 children and 29 adults) and one within-subject factor (two levels: congruent and incongruent conditions). Stimuli were large letters (either “H” or “S”) composed of smaller letters (“H” or “S”). For half of the stimuli, the large letter and the component letters were congruent (e.g., “H” composed of “H”s) and for half they were incongruent (e.g., “H” composed of “S”s). Parameters for the whole brain BOLD data on a 3.0 T scanner were: voxel size of 3.75 × 3.75 × 5.0 mm3, 24 contiguously interleaved axial slices, and TR of 1250 ms (TE = 25 ms, FOV = 240 mm, flip angle = 35°). Six runs of EPI data were acquired from each subject, and each run lasted for 380 s with 304 data points. The task followed an event-related design with 96 trials in each run, with three runs of congruent stimuli interleaved with three runs of incongruent stimuli (order counterbalanced across subjects). Subjects used a two button box to identify the large letter during global runs and the component letter during local runs. Each trial lasted 2500 ms: the stimulus was presented for 200 ms, followed by a fixation point for 2300 ms. Inter-trial intervals were jittered with a varying number of TRs, allowing for a trial-by-trial analysis of how the subject's BOLD response varied with changes in reaction time (RT). The experiment protocol was approved by the Combined Neuroscience Institutional Review Board at the NIMH, and the National Clinical Trials Identifier is NCT00006177.