Objective: To examine the auditory perception of maternal utterances by neonates using near-infrared spectroscopy (NIRS).
Methods: Twenty full-term, healthy neonates were included in this study. The neonates were tested in their cribs while they slept in a silent room. First, two probe holders were placed on the left and right sides of the forehead over the eyebrows using double-sided adhesive tape. The neonates were then exposed to auditory stimuli in the form of infant-directed speech (IDS) or adult-directed speech (ADS), sampled from each of the mothers, through an external auditory speaker.
Results: A 2 (stimulus: IDS and ADS) × 2 (recording site: channel 1 (right side) and channel 2 (left side)) analysis of variance for these relative oxygenated haemoglobin values showed that IDS (Mean = 0.25) increased brain function significantly (F = 3.51) more than ADS (Mean = −0.26).
Conclusions: IDS significantly increased brain function compared with ADS. These results suggest that the emotional tone of maternal utterances could have a role in activating the brains of neonates to attend to the utterances, even while sleeping.
- ADS, adult-directed speech
- F0, fundamental frequency
- IDS, infant-directed speech
- NIRS, near-infrared spectroscopy
- oxy-Hb, oxygenated haemoglobin
- SPL, sound-pressure level
Statistics from Altmetric.com
This work was supported by a Grant-in-Aid for Scientific Research to T Toshima from the Japanese Society for the Promotion of Science (A: 14201012).
Competing interests: None declared.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.