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High vagal tone is associated with more efficient regulation of homeostasis in low‐risk human fetuses
Author(s) -
Groome Lynn J.,
Loizou Philip C.,
Holland Scherri B.,
Smith Lisa A.,
Hoff Charles
Publication year - 1999
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/(sici)1098-2302(199907)35:1<25::aid-dev4>3.0.co;2-q
Subject(s) - vagal tone , homeostasis , fetus , autonomic nervous system , medicine , endocrinology , parasympathetic nervous system , psychology , biology , heart rate , blood pressure , pregnancy , genetics
Homeostasis is maintained primarily by the parasympathetic nervous system and is thought to provide a physiological substrate for the development of complex behaviors. This investigation was undertaken to test the hypothesis that infants with high parasympathetic tone are more efficient regulators of homeostasis than infants with low parasympathetic tone. Respiratory sinus arrhythmia (RSA) was used as a measure of parasympathetic tone, and the efficiency of homeostatic control was quantified, for each infant, by the slope (S RSA ) and correlation coefficient (R RSA ) of the regression line relating fluctuations in heart period and fluctuations in RSA. To test our hypothesis, we examined the relationship between RSA and both S RSA and R RSA in 34 low‐risk human fetuses between 36 and 40 weeks gestation. We found that fetuses who were parasympathetic‐dominated had larger S RSA and R RSA values, and hence were more efficient regulators of homeostasis, than fetuses who were sympathetic‐dominated. The results of our analyses are important because they establish, very early in development, a physiological basis for the relationship between vagal tone and the development of complex behaviors. © 1999 John Wiley & Sons, Inc. Dev Psychobiol 35: 25–34, 1999