Overwhelmed by the man in the moon? Pareidolic objects provoke increased amygdala activation in autism

An interesting feature of the primate face detection system results in the perception of illusory faces in objects, or pareidolia. These illusory faces do not per se contain social information, such as eye-gaze or specific identities, yet they activate the cortical brain face -processing network, possibly via the subcortical route, including the amygdala. In autism spectrum disorder (ASD), aversion to eye-contact is commonly reported, and so are alter-ations in face processing more generally, yet the underlying reasons are not clear. Here we show that in autistic participants (N=37), but not in non-autistic controls (N=34), pareidolic objects increase amygdala activation bilaterally (right amygdala peak: X = 26, Y =-6, Z =-16; left amygdala peak X =-24, Y =-6, Z =-20). In addition, illusory faces engage the face-processing cortical network significantly more in ASD than in controls. An early imbalance in the excitatory and inhibitory systems in autism, affecting typical brain maturation, may be at the basis of an overresponsive reaction to face configuration and to eye contact. Our data add to the evidence of an oversensitive subcortical face processing system in ASD.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

An interesting phenomenon in the primate face detection system is the perception of illusory faces in objects, known as pareidolia. In autistic individuals, pareidolic objects increase amygdala activation and engage the face-processing cortical network significantly more compared to non-autistic individuals. This suggests an oversensitive subcortical face processing system in autism, possibly due to early imbalances in the excitatory and inhibitory systems.