Brain schematic of facial emotion processing. Image credit: Fan et al. (CC BY 4.0)
Facial expressions are a primary source of social information, allowing humans to infer others’ emotions and intentions. The ability to discriminate basic facial expressions emerges early in life, and infants can distinguish sad from happy faces. The ability to read facial expressions and to recognize emotions continues to improve from childhood through adolescence.
Most developmental evidence comes from behavioral measures or non-invasive imaging methods, with limited insight into the timing and distribution of neurons involved in these processes. This makes it difficult to characterize how neural representations of facial emotions change with age.
A method known as intracranial EEG (iEEG) provides direct, high-spatial and temporal resolution measurements of neural activity. It enables precise comparisons of how different brain regions encode facial emotion information across developmental stages, and how perceptual and cognitive systems mature to support social understanding. However, iEEG is rarely available in both children and adults due to its invasive nature.
Fan, Tripathi and Bijanki wanted to better understand how the brain learns to recognize emotions from facial emotions as children grow older by analyzing an existing, open-access iEEG data set. Specifically, they asked whether young children rely mainly on brain areas that process what a face looks like, while older individuals also use brain areas involved in interpretation and understanding.
Fan et al. found clear age-related differences in how the brain processes facial emotions. In young children, information about facial expressions is mainly processed in brain areas that analyze facial features. In older individuals, additional brain regions involved in interpretation and higher-level understanding also become engaged. The researchers also found that the brain’s ability to distinguish complex emotions increases gradually with age. Together, these findings suggest that as children grow and gain social experience, the brain increasingly relies on higher-level systems to interpret the emotional meaning of faces, not just their visual features.
Understanding how recognizing emotions becomes more accurate and complex with age is important for clinicians, educators, and families concerned with children’s social and emotional development – especially for conditions in which emotion understanding develops atypically. Before these findings can be applied in practice, future studies will need to confirm them in larger and more diverse groups and use non-invasive brain measures suitable for everyday settings. Translating these insights into tools for assessment or intervention will also require close collaboration between researchers, clinicians and educators.
