Functional maturation in visual pathways predicts attention to the eyes in infant rhesus macaques: Effects of social status.

Scientists studied baby monkeys to understand how brain development affects looking at eyes - an important early social skill. They found that babies whose visual brain areas connected better looked at eyes earlier. This was especially true for babies with lower social status in their group. Since looking at eyes is often different in autism, this research helps us understand how early brain development affects social attention.

This longitudinal study examined brain-behavior relationships in infant rhesus macaques from birth to 6 months, focusing on visual pathway development and eye-looking behavior. Using eye-tracking and resting-state fMRI, researchers found that increased functional connectivity between left V1 to V3 visual areas was associated with earlier increases in eye-looking before 2 months of age. Importantly, this relationship was moderated by social status - infants with low social status showed stronger associations between visual connectivity and eye-looking than high-status infants. The findings suggest that maturation of the visual object pathway may support adaptive transitions in social visual attention during early development, with implications for understanding early markers of social difficulties in neurodevelopmental conditions.

Findings suggest early visual pathway connectivity may serve as a biomarker for social attention development. Social environmental factors appear to influence these brain-behavior relationships, highlighting the importance of considering both neural and social factors in early development assessment and intervention planning.

Sample size not reported. Study conducted in rhesus macaques, requiring caution in generalizing to humans. Exploratory findings require replication. Limited detail on methodology and statistical approaches in abstract.

Differences in looking at the eyes of others are one of the earliest behavioral markers for social difficulties in neurodevelopmental disabilities, including autism. However, it is unknown how early visuo-social experiences relate to the maturation of infant brain networks that process visual social stimuli. We investigated functional connectivity (FC) within the ventral visual object pathway as a contributing neural system. Densely sampled, longitudinal eye-tracking and resting state fMRI (rs-fMRI) data were collected from infant rhesus macaques, an important model of human social development, from birth through 6 months of age.

Mean trajectories were fit for both datasets and individual trajectories from subjects with both eye-tracking and rs-fMRI data were used to test for brain-behavior relationships. Exploratory findings showed infants with greater increases in FC between left V1 to V3 visual areas have an earlier increase in eye-looking before 2 months. This relationship was moderated by social status such that infants with low social status had a stronger association between left V1 to V3 connectivity and eye-looking than high status infants. Results indicated that maturation of the visual object pathway may provide an important neural substrate supporting adaptive transitions in social visual attention during infancy.