participants from this cohort also completed the cTBS paradigm. All participants gave informed consent to the study, which was reviewed and approved by the institutional review boards at each participating institution. Participants were recruited through local community advertisement and local Asperger’s Associations and clinics. All AS participants in both cohorts had an IQ > 80 based on the Weschler Abbreviated Scale of Intelligence (WASI) and a formal clinical diagnosis from an independent clinician prior to participation in the study. All met DSM-IV-TR criteria for Asperger’s Syndrome and met criteria for ASD on the Autism Diagnostic Observation Schedule, Module 4 (ADOS) (mean ± SD Social and Communication score, 10.2 ± 4.6). Additionally, the Autism Diagnostic
Interview Revised was completed Trametinib in vivo on 11 participants whose parents were available for interview. For these individuals the mean Social score was 18.2 ± 5.1, Communication score was 20.0 ± 2.6 GSK 3 inhibitor and Repetitive Behavior score was 6.0 ± 2.3. Cognitive and clinical evaluation was identical for the two cohorts, with Spanish-translated versions of the ADOS and WASI used for the participants in cohort two. Participants in the neurotypical group were healthy controls with no neurological or psychiatric disorders. This group was matched with respect to chronological age, gender and full-scale IQ with the AS group. All participants were given a comprehensive neurological exam by a board-certified neurologist to confirm normal gross motor and fine motor functioning. Lastly, all participants were screened following published recommendations (Rossi et al., 2009) to ensure that they did not have any condition that would put them at greater risk of an adverse event related to TMS (e.g. a personal or family history of epilepsy). Study procedures were identical
in the two study locations. The experimenters Fossariinae who collected the data at each location were trained by Dr Pascual-Leone and used the same equipment and procedures described herein. cTBS and iTBS were applied as described in Huang et al., 2005. The cTBS paradigm consisted of three pulses of 50 Hz stimulation repeated at 200-ms intervals for 40 s (for a total of 600 pulses) at an intensity of 80% of active motor threshold (AMT). In the iTBS paradigm participants received a 2-s train of TBS repeated every 10 s for a total of 190 s (600 pulses), also at an intensity of 80% of AMT (Fig. 1). Corticospinal excitability was assessed prior to and following cTBS or iTBS by measuring peak-to-peak amplitude of MEPs induced in the contralateral first dorsal interosseus (FDI) muscle in response to single-pulse TMS at a rate of approximately 0.1 Hz (a random jitter of ± 1 s was introduced to avoid any train effects). Three batches of 10 MEPs were recorded prior to cTBS or iTBS and used as a baseline. Following cTBS or iTBS, batches of 10 MEPs were measured at periodic intervals for a total of 120 min to track changes in MEP amplitude over time.