Do developmental prosopagnosics with high vs. low levels of autism traits differ in how they process faces?

Abstract

Developmental prosopagnosia (DP) studies have routinely excluded individuals with high autism traits, assuming that DPs with high levels of autism traits have qualitatively different mechanisms of face recognition impairment, e.g., caused by social motivational factors. Indeed, autism spectrum disorders (ASD) are associated with face recognition memory and face emotion processing deficits but largely unimpaired face perception and holistic face processing abilities, whereas DPs without ASD have shown face perception and holistic processing deficits in addition to face memory deficits. To investigate the relationship between autism traits and face processing in DP, we administered a large behavioral battery and a face/scene/object/body fMRI localizer to 43 DPs with a wide range of Autism Quotient (AQ) scores as well as 27 healthy controls. When comparing the high (n=15; met broader autism phenotype classification) and low (n=28) AQ DP groups (AQ: 28.33 vs. 14.50; p<.001), we found a similar pattern across face processing tasks, with no differences in face matching (Cambridge Face Perception Test; p=.617), holistic face processing (Inversion effect: p=.644; Part-whole effect: p=.170), featural processing (Eyes: p=.643; Mouth: p=.984), or face memory (Cambridge Face Memory Test; p=.598). Both DP groups performed significantly worse on the face processing tasks compared to the control group (p’s<.05), with the exception of the mouth composite. As expected, the higher AQ group showed significantly decreased face emotion recognition compared to the low AQ group (p=.028). During the fMRI localizer task, both DP groups showed similarly reduced face selectivity in the left occipital and fusiform face areas compared to controls. Notably, the higher AQ DPs also showed decreased face selectivity in the bilateral posterior superior temporal sulcus compared to the lower AQ DPs. These results suggest that high autism traits do not result in qualitatively different face processing in DPs, but are associated with greater face emotion recognition impairments.