; range, 20 to 40). All subjects had normal or corrected-to-normal vision, provided written informed consent, and were paid for their participation in the study. The Institutional Review Board at Carnegie Mellon University

and the University of Pittsburgh KU-57788 nmr approved the experimental procedures, which were in compliance with the safety guidelines for MRI research. Autism diagnosis was established using the Autism Diagnostic Observation Schedule (ADOS) (Lord et al., 2000) and expert clinical evaluation. Full clinical details and inclusion/exclusion criteria are available in the supplementary materials (Table S1). Imaging was performed using a Siemens (Erlangen, Germany) 3T Verio MRI scanner located at the Carnegie Mellon Scientific Imaging & Brain Research Center in Pittsburgh. The scanner was equipped with a Siemens 12 channel birdcage head coil, which was used for RF transmit and receive. Blood oxygenation level-dependent (BOLD) contrast was obtained using a T2∗-sensitive echo planar imaging pulse sequence (repetition time of 1,500 ms, echo time = 30 ms, flip angle = 75°, 24 slices, 3 × 3 × 3 mm voxels, field of view = 192 mm). Anatomical volumes were acquired with a T1-weighted 3D-MPRAGE pulse sequence (1 × 1 × 1 mm). Each session included 1 or 2 runs of each sensory experiment, one resting-state Selisistat mouse experiment, and one

anatomical scan. The entire scanning session lasted between 1 and 1.5 hr. fMRI data were processed with Brain Voyager (R. Goebel, Brain Innovation, Maastricht, The Netherlands) and with custom software written in Matlab (Mathworks, Natick, MA). Preprocessing of fMRI data included 3D motion correction, temporal high-pass filtering with

a cutoff frequency of 6 cycles per run, spatial smoothing using a Gaussian kernel with 8 mm width at half height, alignment with the anatomical volume using trilinear interpolation, and transformation to the Talairach coordinate system (Talairach and Tournoux, 1988). The cortical Terminal deoxynucleotidyl transferase surface was reconstructed from the anatomical scans, separately for each subject; the procedure included segmenting the gray and white matter and inflating/flattening the gray matter for visualization. Subjects participated in three independent sensory experiments in the visual, auditory, and somatosensory domains as well as one resting-state experiment, which did not contain any stimulus or task. All three sensory experiments followed the same rapid event-related temporal structure (Figure S1), which was designed to enable assessment of response amplitude, variability, and adaptation (although adaptation results are not reported in the current paper). Each trial contained an adaptor followed by a test stimulus (Figure S1). Each run contained 12 adapted trials, 12 unadapted trials, and 12 trials of the adaptor without a test condition. Most subjects participated in two runs of each experiment.