Neural correlates of joint attention in infants aged 8-24 months: A systematic review.

Joint attention, or the infant's ability to coordinate their attention with a social partner towards an object, emerges around 9 months of age and becomes more frequent during the second year of life. Previous studies, especially with adults, highlight the involvement of several networks of the social brain in the processing of joint attention stimuli. This work aims to systematically review the literature on the neural correlates of joint attention in infants aged 8-24 months of age. Four databases were searched for empirical studies published in English from inception to July 2024 (updated in May 2025). Sixteen studies were included, using electroencephalography (EEG, n = 11), functional near-infrared spectroscopy (fNIRS; n = 3), and functional magnetic resonance imaging (fMRI; n = 2) to assess brain activation mainly in typically developing infants. EEG studies suggest a pattern of cortical activity in frontal, central and parietal regions of the infants' brain, alpha-band desynchronization and larger amplitude of the negative central component in response to joint attention stimuli. fNIRS studies found increased activation in the superior temporal sulcus-temporoparietal junction and prefrontal regions of the brain. One fMRI study showed correlations between initiating joint attention and the functional connectivity in brain networks: visual, dorsal attention and default mode networks. In contrast, another study found no relation between left posterior superior temporal cortex connectivity and infant social communication. Findings highlight the importance of investigating the neural mechanisms underlying joint attention in infancy, and their contribution as early indicators of typical and atypical development.