Brain functional differences during irony comprehension in adolescents with ASD

Irony comprehension is challenging for both individuals with ASD and poor comprehenders (PCs). We aimed to examine the common and specific mechanisms underlying irony comprehension difficulty in the two populations. Both adolescents with ASD and PC showed lower performance in irony comprehension than an age-matched typical control group (TD). The ASD group also showed deficits in theory of mind (ToM), while the PC group showed impairments in structural language skills. In the brain, the ASD group showed reduced brain activation in the left inferior frontal gyrus (IFG) compared to both the TD and the PC group, suggesting ASD-specific differences, which was further found to be correlated with ToM deficits in ASD. Both the TD and the PC group showed greater activation for the ironic than the literal condition in the bilateral medial prefrontal cortex (mPFC), but the ASD group did not, suggesting ASD-specific difference in irony comprehension. The PC group showed reduced activation in the right cuneus compared to the TD, which was correlated with the language comprehension score, suggesting different mechanisms than ASD. Our findings provide insights about the neurocognitive mechanisms underlying impaired irony comprehension in ASD and PC.