Face processing in the infant brain after pandemic lockdown

Abstract

The role of visual experience in the development of face processing has long been debated. We present a new angle on this question through a serendipitous study that cannot easily be repeated. Infants viewed short blocks of faces during fMRI in a repetition suppression task. The same identity was presented multiple times in half of the blocks (repeat condition) and different identities were presented once each in the other half (novel condition). In adults, the fusiform face area (FFA) tends to show greater neural activity for novel versus repeat blocks in such designs, suggesting that it can distinguish same versus different face identities. As part of an ongoing study, we collected data before the COVID-19 pandemic and after an initial local lockdown was lifted. The resulting sample of 12 infants (9-24 months) divided equally into pre-and post-lockdown groups with matching ages and data quantity/quality. The groups had strikingly different FFA responses: pre-lockdown infants showed repetition suppression (novel > repeat), whereas post-lockdown infants showed the opposite (repeat > novel), often referred to as repetition enhancement. These findings provide speculative evidence that altered visual experience during the lockdown, or other correlated environmental changes, may have affected face processing in the infant brain.

Cortical Face-Selective Responses Emerge Early in Human Infancy

“…However, other fMRI and EEG data challenge that view. Two recent fMRI studies in awake infants observed face-selective responses in FFA, using different stimuli and task procedures (70, 90). For the current paper, we re-analyzed the data reported in one of these papers (70), combining data collected with different coils to more sensitively look for age-related change in face-selective responses.…”

“…One important question for future research will be whether the size or selectivity of FFA in infants correspond to their face recognition abilities. Another interesting question is how the representation of face features, and face identities, in FFA changes during infancy and early childhood (90).…”

Older infants' social learning behavior under uncertainty is modulated by the interaction of face and speech processing

“…It could be that the reduced contacts with various talking faces, especially during the first months of life, slowed down perceptual narrowing processes. Previous studies have already shown specific face processing modes in infants growing up during the Covid‐19 pandemic (e.g., Kim et al., 2022; Yates et al., 2023). Furthermore, we did not study the effect of bilingualism on infants' social learning behavior.…”

Infants’ visual attention to own-race and other-race faces is moderated by experience with people of different races in their daily lives.

“…A related possibility concerns the timing of this research, which took place during the COVID-19 pandemic. It is possible that the social isolation experienced as part of the pandemic changed how infants attend to familiar and novel stimuli (e.g., Yates et al, 2023), although future research will be needed to further bear upon this possibility.…”