Introduction
autism spectrum disorder, ASD, repetition suppression
DISORDERS
Altered sensory reactivity, interests, and/or responses in autism spectrum disorder (ASD) are now recognized as core to this diagnosis (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) [Nevertheless, there is an accumulation of evidence that ASD is associated with an alteration in excitation–inhibition ratio (E-I imbalance) in the central neural systems [The importance of the GABA system in ASD and related conditions led to the development of arbaclofen, a selective GABA type B (GABAThe brain continually adapts to sensory inputs, filtering out irrelevant stimuli and prioritizing deviant stimuli that may be meaningful (signaling danger or reward) [Though the molecular and circuit mechanisms supporting MMN remain uncertain, there is consensus that at least two mechanisms are essential for its generation: 1) Stimulus-specific adaptation (SSA) in animals or repetition suppression in humans allows neural responses to adapt (reduce) to repeated sounds while maintaining responsiveness to deviants [In humans, neurodevelopmental conditions such as ASD alter brain function across the subcortical and cortical systems known to be involved in sensory processing from birth [Inconsistent results from the oddball paradigm in ASD could also be a consequence of the multi-source distribution of MMN generators and the metric used. Both repetition suppression and deviance detection have been observed in neurons along the hierarchical auditory pathway, including cortical (auditory and medial prefrontal) and subcortical (inferior colliculus and medial geniculate body) regions [In contrast, time-frequency analysis, namely Event-Related Spectral Perturbation (ERSP) [Here we investigated how altering GABA function modulates auditory processing in individuals with and without ASD. Scalp EEG was used to record neurophysiological responses induced in an auditory oddball paradigm—a stream of regular repeating standard sounds was occasionally interrupted by sounds deviating in frequency, duration, or frequency-duration combination [Given the evidence for weaker suppression of repetitive stimuli in ASD [