4 Blocks were presented in one of four orders, counterbalanced across participants. Each order consisted of four “super-blocks” containing four word blocks each (two emotion, two neutral), and
between every “super-block” participants either viewed a fixation cross or were told to rest. Each super-block contained the same order of word blocks, and emotion and neutral blocks always alternated within super-blocks. Inhibitors,research,lifescience,medical Counterbalancing orders varied whether an emotion or neutral block was presented first within the super-blocks (e.g., neg, neu, pos, neu vs. neu, neg, neu, pos) and whether the negative condition was presented before the positive condition across super-blocks (e.g., neg, neu, pos, neu vs. pos, neu, neg, neu). In summary, each half of the task contained two super-blocks, and the halves contained an equal number of word blocks per condition (two negative, two positive, four neutral blocks). Thus, the first and second halves Inhibitors,research,lifescience,medical of the task were identical in form, although the actual words used as stimuli differed in each block (no words were repeated). Behavioral analysis Behavioral data were analyzed by computing average RT for correct trials and number
of errors for each participant in the negative and neutral conditions separately for each half of the task. A Time (first Inhibitors,research,lifescience,medical half of the task vs. second half of the task) × Emotion (negative words vs. neutral words) repeated-measures general linear model (GLM) was conducted (using SPSS v19), with PSWQ, MASQ-AA, Inhibitors,research,lifescience,medical and MASQ-AD-LI entered as continuous predictors. The effects of particular interest were the Time × Emotion × PSWQ and Time × Emotion ×MASQ-AA interactions, which tested whether habituation
in the response to negative words was moderated by the anxiety types. fMRI data collection MRI data were collected using a 3T Siemens Allegra (Siemens Medical Solutions USA, Inc., Malvern, PA). The fMRI data were 370 three-dimensional images acquired using a Siemens Inhibitors,research,lifescience,medical gradient-echo echo-planar imaging sequence (TR 2000 msec, TE 25 msec, flip angle 80°, FOV = 220 mm). Each image consisted of 38 oblique axial slices (slice thickness 3 mm, 0.3 mm gap, in-plane resolution 3.4375 mm by 3.4375 mm). After the fMRI acquisition, a 160-slice MPRAGE structural sequence was acquired (Trichostatin A cost spatial resolution 1 mm, isometric), which was used to warp the participant’s functional data into standard space. fMRI data reduction and preprocessing FEAT (FMRI Expert already Analysis Tool, http://www.fmrib.ox.ac.uk/analysis/research/feat/), part of the FSL (FMRIB Software Library, http://www.fmrib.ox.ac.uk/fsl) analysis package, was used to process each participant’s functional brain images and carry out group analyses. A high-pass filter was used to remove drift in MRI signal intensity, and functional data were motion-corrected and spatially smoothed using a 5 mm (full-width half-max) 3D Gaussian kernel.