Exposure to Mom”s Speech Linked to Mature Left Arcuate Microstructure

THURSDAY, Oct. 16, 2025 (HealthDay News) — More mature left arcuate microstructure is seen in preterm neonates with increased maternal speech exposure, according to a study published online Oct. 13 in Frontiers in Human Neuroscience.

Katherine E. Travis, Ph.D., from the Stanford University School of Medicine in California, and colleagues enrolled 46 neonates born preterm (24 to 31 weeks gestational age). The neonates were randomly assigned to receive increased (T) or routine (C) exposure to mother”s speech (21 and 25 neonates, respectively). The T group heard 10-minute audio recordings of their mothers reading two times per hour between 10 p.m. and 6 a.m., resulting in 2.67 hours per day increased exposure, while the C group did not hear recorded speech. Two high-angular resolution diffusion magnetic resonance imaging scans and T1 relaxometry scans were obtained at near-term equivalent age.

The researchers found that the T group demonstrated significantly lower mean diffusivity compared with the C group (scan 1: β = −0.11; scan 2: β = −0.12) in the left but not right arcuate. Significantly higher fractional anisotropy (scan 1: β = 0.02; scan 2: β = 0.03) and relaxation rate (β = 0.02) were also demonstrated in the T group in the left but not right arcuate.

“This is the first causal evidence that a speech experience is contributing to brain development at this very young age,” Travis said in a statement. “This is a potentially transformative way of thinking about how to approach neonatal care for promoting better language outcomes in children born prematurely.”

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