Barreto Edwin D, Morris Brenda H, Philbin M Kathleen, Gray Lincoln C, Lasky Robert E
Department of Pediatrics, Division of Perinatal-Neonatal Medicine, University of Texas Medical School at Houston, TX 77030, USA.
Early Hum Dev. 2006 Nov;82(11):703-7. doi: 10.1016/j.earlhumdev.2006.02.009. Epub 2006 Apr 19.
Previous studies have shown that 4-month-old infants have a decrease in heart rate, a component of the orienting reflex, in response to interesting auditory stimuli and an increase in heart rate to aversive auditory stimuli.
To compare the heart rate responses of former preterm and term infants at 4-5 months corrected age to a recording of NICU noises.
13 former preterm infants and 17 full-term infants were presented NICU noise and another noise of similar level and frequency content in random order. Heart rate 10s prior to the stimulus and for 20s during the stimulus was analyzed. Group differences in second by second heart rate changes in response to the two noise stimuli were compared by analysis of covariance.
Both the preterm and term newborns responded similarly to the NICU noise and the control noise. The preterm infants did not alter their heart rate in response to either stimulus. In contrast, the term infants displayed an orienting response to the second stimulus presented regardless of whether it was the NICU or control noise.
Former preterm infants at 4-5 months corrected age have reduced responsiveness to auditory stimulation in comparison to 4- to 5-month-old term infants. Furthermore, they did not respond to the NICU noise as an aversive stimulus.
先前的研究表明，4个月大的婴儿在面对有趣的听觉刺激时，其定向反射的组成部分心率会下降，而面对厌恶的听觉刺激时心率会增加。
比较4-5个月矫正年龄的早产婴儿和足月儿对新生儿重症监护病房（NICU）噪音录音的心率反应。
对13名早产婴儿和17名足月儿随机播放NICU噪音以及另一种频率和强度相近的噪音。分析刺激前10秒和刺激期间20秒的心率。通过协方差分析比较两组婴儿对两种噪音刺激的逐秒心率变化差异。
早产婴儿和足月儿对NICU噪音和对照噪音的反应相似。早产婴儿对两种刺激均未改变心率。相比之下，足月儿对呈现的第二种刺激表现出定向反应，无论该刺激是NICU噪音还是对照噪音。
与4-5个月大的足月儿相比，4-5个月矫正年龄的早产婴儿对听觉刺激的反应性降低。此外，他们对NICU噪音未表现出厌恶刺激反应。
