The duration of intrauterine development influences discrimination of speech prosody in infants

Abstract

Auditory speech discrimination is essential for normal language development. Children born preterm are at greater risk of language developmental delays. Using functional near‐infrared spectroscopy at term‐equivalent age, the present study investigated early discrimination of speech prosody in 62 neonates born between week 23 and 41 of gestational age (GA). We found a significant positive correlation between GA at birth and neural discrimination of forward versus backward speech at term‐equivalent age. Cluster analysis identified a critical threshold at around week 32 of GA, pointing out the existence of subgroups. Infants born before week 32 of GA exhibited a significantly different pattern of hemodynamic response to speech stimuli compared to infants born at or after week 32 of GA. Thus, children born before the GA of 32 weeks are especially vulnerable to early speech discrimination deficits. To support their early language development, we therefore suggest a close follow‐up and additional speech and language therapy especially in the group of children born before week 32 of GA.

Preterm infants show an atypical processing of the mother's voice

“…Preterm infants born below 32 weeks demonstrated higher peak hemodynamic responses in the backward condition compared to the forward condition in response to speech stimuli in temporal and frontal brain areas. In contrast, term newborns and preterm infants born after 32 weeks exhibited the opposite trend in the same area (Alexopoulos et al, 2021). Not only the GA but also the sex seems to play a fundamental role in the maturation of language-related brain areas, with earlier maturation for girls (Alexopoulos et al, 2022).…”

Fetal temporal sulcus depth asymmetry has prognostic value for language development

“…The fetal auditory system is functional around the 25th weeks of gestational age 26 , and its maturation is subsequently driven by environmental stimuli 27 , 28 . Functional language areas within the left hemisphere develop successively 29 , 30 . While auditory perception is processed in the STS bilaterally, most of the language-sensitive region is located in the depths of the left STS 17 , 25 .…”

Preterm infants show an atypical processing of the mother’s voice

“…A NIRS study performed at term equivalent age in a population of preterm infants born between 23 and 37 weeks further showed a significant positive correlation between gestational age (GA) at birth and neural discrimination of FW versus BW speech, with preterm infants born below 32 weeks, showing a different hemodynamic response to speech sitmuli (Alexopoulos et al, 2021). Not only the GA at birth but also the sex seems to play a fundamental role in the maturation of language-related brain areas, with earlier maturation for girls (Alexopoulos et al, 2022).…”