Abnormal functional specialization within medial prefrontal cortex in high-functioning autism: a multi-voxel similarity analysis

Abstract

Multi-voxel pattern analyses have proved successful in ‘decoding’ mental states from fMRI data, but have not been used to examine brain differences associated with atypical populations. We investigated a group of 16 (14 males) high-functioning participants with autism spectrum disorder (ASD) and 16 non-autistic control participants (12 males) performing two tasks (spatial/verbal) previously shown to activate medial rostral prefrontal cortex (mrPFC). Each task manipulated: (i) attention towards perceptual versus self-generated information and (ii) reflection on another person's mental state (‘mentalizing'versus ‘non-mentalizing’) in a 2 × 2 design. Behavioral performance and group-level fMRI results were similar between groups. However, multi-voxel similarity analyses revealed strong differences. In control participants, the spatial distribution of activity generalized significantly between task contexts (spatial/verbal) when examining the same function (attention/mentalizing) but not when comparing different functions. This pattern was disrupted in the ASD group, indicating abnormal functional specialization within mrPFC, and demonstrating the applicability of multi-voxel pattern analysis to investigations of atypical populations.

Neural signatures of autism

“…The identification of state activity extends previous research implicating the right amygdala, right pSTS, bilateral FG, left vlPFC, and vmPFC in adults with ASD, by showing that dysfunction in these regions is already present in school-age children with ASD (25)(26)(27)(28)(29). This is an important advance in the field, given that previous reports of atypical neural response to biological motion included only adult subjects (16,17).…”

A dissociation between social mentalizing and general reasoning

“…Many other executive functions involving memory and attention recruit the lateral or anterior PFC, rather than the mPFC (Van Overwalle, 2009;Gilbert et al, 2006). Direct comparisons (Gilbert et al, 2007) as well as multi-voxel pattern analysis (Gilbert et al, 2009) provide additional evidence that mentalizing and attention show little overlap. Of course, the mPFC is not exclusively involved during social reasoning.…”

Decoding moral judgments from neural representations of intentions

“…Some studies suggest that theory of mind regions are hypoactive [i.e., produce a smaller or less selective response (46,47)], whereas other studies find no difference between ASD and NT individuals (43,48), and still others find the opposite pattern, hyperactivation, in ASD (49)(50)(51). Studies using tasks that elicit spontaneous or implicit social processing may be more likely to find hypoactivation (51)(52)(53).…”