Top-down modulation in the infant brain: Learning-induced expectations rapidly affect the sensory cortex at 6 months

Abstract

Although infants are excellent learners, it is unclear whether infants use neural strategies similar to those of adults to track changes in their environment. One adult neural strategy is to use feedback connections to modulate sensory cortices based on their expectations. The current study provides, to our knowledge, the first evidence that the fundamental architecture required for sensory feedback is already in place in infancy. This top-down modulation is especially impressive because the study employs an audiovisual task that requires the flexible use of long-range neural connections, and the infant brain is dominated by short-range neural connections with weak (e.g., unmyelinated) long-range connections. These results suggest that learners can use sophisticated top-down feedback neural strategies from an early age.