Socioeconomic Status, the Home Language Environment, Noise Exposure, and the Mismatch Response in Infancy.

Socioeconomic resources have long been associated with children's language development. Several proximal factors have been suggested as candidate mechanisms underlying socioeconomic disparities in language development, including differences in the home language environment and home noise levels. These experiences may in part shape auditory discrimination skills, a key component of language comprehension. To index early auditory discrimination, researchers measured brain function in relation to the detection of different sounds with an event-related potential (ERP) called the mismatch response (MMR). The current study aimed to examine associations among socioeconomic circumstances, the home language environment, home noise exposure, and the MMR in a socioeconomically, racially, and ethnically diverse longitudinal sample of 6- and 12-month-old infants. Socioeconomic circumstances were measured prenatally via parent report. The home language environment and home noise levels were measured using digital language processing devices when infants were approximately 6 months of age. The MMR was elicited during a passive auditory oddball task at two timepoints-6 and 12 months of age. Results showed that neither SES, the home language environment, nor home noise levels predicted infant MMR at either age. These findings add to a growing body of literature examining the role of distal and proximal factors in shaping infant brain activity related to language development.