The neural development of attentional gain mechanisms in human early visual cortex

Selective attention is an essential cognitive function that helps prioritize the processing of behaviorally relevant sensory information. The disruption of selective attention is thought to be the underlying cause of a wide variety of neurological and neurodevelopmental disorders. A dominant view in the field of attention posits that selective attention operates via modulating gain of neural responses in early visual cortex. Consistent with this idea, multiple past studies in human and non-human adult primates have found that when attention is directed to a certain space on the visual field, it increases the activity of neurons that are tuned to visual stimuli spatially overlapped with the attended location. That said, there is still a paucity of data in younger organisms. Thus, it is poorly understood how selective attention operates throughout human development. Here, we tested this question by measuring spatially selective hemodynamic responses to the attended and unattended visual stimuli from retinotopically organized areas in the early visual cortex of male and female human subjects with ages ranging from 12-34 years old. We used a model-based approach to reconstruct and quantify changes in spatial extent of selective visual attention, and compared them across different age groups. We found that both groups exhibited comparable attentional gain modulations in the spatial representations reconstructed based on neural activity in early visual areas. These results suggest that attentional gain mechanisms in human early visual cortex are developed as early as 12 years of age. Ultimately, this study helps establish the experimental and modeling methods as well as produce baseline data in typically developing individuals that could be compared to future clinical data to study attention deficits in neurodevelopmental disorders.