A toddler carries the LENA audio recorder in a pocket on the front of a special vest. Photo credit: Dr. Kathryn L. Humphreys
The alternation in the “conversation” with the supervisors relates to the synchronized activation in language areas.
The type and amount of speech a child is exposed to is related to their brain function JNeurosci.
Babies learn their native language by interacting with their caregivers. Instead of just listening to adult words, taking turns in a “conversation” predicts a child’s future language skills. However, it is unclear how speech exposure affects the circuits in the brain. The brain’s language networks can develop in two phases: a bottom-up network for auditory processing begins to develop in pregnancy, and a top-down network for processing more complex syntax and semantics develops in early childhood.
King et al. documented exposure of 5 to 8 month old infants to home language and used fMRI to measure their resting network activity while they slept in the scanner. Regions in each of the two voice networks were activated together, indicating coordinated activity. Attending a larger number of round tables at home was associated with weaker connectivity in the bottom-up subnet.
Brain connections can be weakened as well as strengthened as they are refined throughout development. Future research could show how weaker connectivity associated with more conversation affects the child’s language development.
Independently, the results highlight the importance of environments at a young age in shaping infant brain function and development and the need to support caregivers in providing enriching environments.
Reference: “The input of naturalistic languages is linked to functional connectivity at rest in childhood”, November 30, 2020, Journal of Neuroscience.
DOI: 10.1523 / JNEUROSCI.0779-20.2020
