There is no intervention to be administered in this study. Here, this fMRI study used the backwardly masked paradigm to elucidate how perceiving emotional expressions affects amygdala engagement and its related functional connectivity across two participant groups: ASD with and controls. All ASD participants were diagnosed using the Diagnostic and Statistical Manual of Mental Disorders 5th Edition's (DSM-5) diagnostic criteria (APA, 2013) and confirmed by clinical consensus. ASD individuals were recruited from a community autism program and referred to children's health doctors and child psychiatrists. Exclusion criteria for all participants were neurological abnormalities, a history of epilepsy or seizures, head trauma and IQ <75. The subjects did not participate in any intervention or drug programs during the experimental period.

There is no intervention to be administered in this study. Here, this fMRI study used the backwardly masked paradigm to elucidate how perceiving emotional expressions affects amygdala engagement and its related functional connectivity across two participant groups: ASD with and controls. The participants in the age- and sex-matched control group were recruited from the local community, and screened for major psychiatric illnesses by conducting structured interviews.

Age in years

State-Trait Anxiety Inventory (STAI)

Autism-Spectrum Quotient (AQ)

During fMRI scanning, subjects watched emotional faces and performed the color identification task, in which they were asked to judge the color of each face (pseudo-colored in either red, yellow, or blue) and to indicate the answer by a keypad button press.

Immediately after fMRI scanning, participants underwent the detection task, during which they were shown all of the stimuli again and alerted of the presence of fearful faces. The subjects were administered a forced-choice test under the same presentation conditions as those during scanning and asked to indicate whether they observed a fearful face or not.

During fMRI scanning, subjects watched emotional faces and performed the color identification task, in which they were asked to judge the color of each face (pseudo-colored in either red, yellow, or blue) and to indicate the answer by a keypad button press.