Face Processing in School-Aged Preterm Children: Assessing Neural Sensitivity to Facial Identity and Expression Using Frequency-Tagging EEG.

Background: Preterm (PT) birth is associated with important social vulnerabilities that can have long-term implications and may result in psychopathology (e.g., autism spectrum disorder). A recurring "preterm behavioral phenotype" has been described, although these difficulties may often be subtle and subclinical. As face processing is crucial for social interactions and several studies reported impaired face processing performance in PT populations, we hypothesize that face processing difficulties may contribute to or be a part of these social difficulties. Here, we investigate the neural sensitivity for crucial socio-communicative facial cues in school-aged PT children.

Methods: Thirty-nine 8-to-12-year-old PT children born between 24 and 32 weeks of gestation and thirty-eight term-born matched controls performed a series of innovative facial identity and expression discrimination frequency-tagging electroencephalography paradigms. More specifically, we evaluated the neural sensitivity to implicitly and automatically discriminate a different facial identity among a stream of identical faces, as well as an expressive face (fearful and happy, in separate sequences) among a stream of neutral faces.

Results: We found intact implicit facial identity and expression processing in both groups. Unexpectedly, PT participants showed a significantly greater neural sensitivity towards these subtle socio-communicative facial cues. Correlations with neonatal measures such as gestational age and birth weight showed that this greater neural sensitivity is uniformly present among the PT group.

Conclusion: Evidence suggests that impaired neural sensitivity for facial cues may not be the primary cause for behavioral face processing and social difficulties often encountered in PT children.