Beta and mu-ERD were observed prior to movement onset and during movement execution, whereas a strong PMBR response emerged following movement termination.
Similarly, while PMBR is thought to reflect an age-dependent inhibitory process [33,72], our data showing increased PMBR are not explained by a greater age range in the ASD group.
PMBR is proposed to be associated with motor deactivation or inhibition of the motor cortex by somatosensory afferents , or a "resetting" of the underlying cortical networks .
In typically developing participants, Gaetz and colleagues  reported a correlation between motor cortical GABA concentration and PMBR power.
Since we were focused on response-locked beta-band ERD and PMBR, we could not analyze trials on which the subjects did not respond to the stimuli, limiting our understanding of whether such trials were associated with additional differences in beta-band activity.
In contrast, the reduced PMBR may be related to reduced inhibition in the motor cortices.
Abbreviations ASD: Autism spectrum disorders MEG: Magnetoencephalography ERD: Event-related desynchronization PMBR: Postmovement beta rebound EEG: Electroencephalography GABA: Gamma-aminobutyric acid DSM: Diagnostic and statistical manual of mental disorders ADOS: Autism diagnostic observation schedule MR(I): Magnetic resonance (imaging).
Cortical oscillations in the mu- (8-13Hz) and beta- (15-30Hz) bands showing event-related desynchronization (ERD, blue) at movement onset and postmovement beta rebound (PMBR, yellow-red) time regions are characterized.