Exploratory case study of monozygotic twins with 22q11.2DS provides further clues to circumscribe neurocognitive markers of psychotic symptoms

Abstract

Variation in facial emotion processing abilities may contribute to variability in penetrance for psychotic symptoms in 22q11.2DS. However, the precise nature of the social cognitive dysfunction (i.e., facial expression perception vs. emotion recognition), the potential additional roles of genetic and environmental variabilities, and consequently the possibility of using this neurocognitive marker in clinical monitoring remain unclear. The present case study aimed at testing the hypothesis that when confounding factors are controlled, the presence of psychotic symptoms in 22q11.2DS is associated, at the individual level, with a neural marker of facial expression perception rather than explicit emotional face recognition. Two monozygotic twins with 22q11.2DS discordant for psychiatric manifestations performed (1) a classical facial emotion labelling task and (2) an implicit neural measurement of facial expression perception using a frequency-tagging approach in electroencephalography (EEG). Analysis of the periodic brain response elicited by a change of facial expression from neutrality indicated that the twin with psychotic symptoms did not detect emotion among neutral faces while the twin without the symptoms did. In contrast, both encountered difficulties labelling facial emotion. The results from this exploratory twin study support the idea that impaired facial expression perception rather than explicit recognition of the emotion expressed might be a neurocognitive endophenotype of psychotic symptoms that could be reliable at a clinical level. Although confirmatory studies should be required, it facilitates further discussion on the etiology of the clinical phenotype in 22q11.2DS.

Odor-evoked hedonic contexts influence the discrimination of facial expressions in the human brain

“…Frequency-domain analysis of such periodic brain activity allows quantifying an objective signature of the automatic processes elicited by the stimulation with high SNR (Norcia et al, 2015 for review). This approach has been recently adapted to investigate perceptual abilities for faces (e.g., Liu-Shuang et al, 2014;Rossion et al, 2015;Zimmermann et al, 2019), including facial expression processing in healthy (Dzhelyova et al, 2017;Leleu et al, 2018;Poncet et al, 2019) and clinical populations (Leleu et al, 2019;Favre et al, 2019;Van der Donck et al, 2019).…”