Does Associative Learning Begin Before Birth?

Funding Round: 2 2014-2016

Research Question: Is there evidence that the late gestation fetus can learn?

Interdisciplinary Approach: This project combines developmental psychophysiology with experimental neuroscience to produce a testable hypothesis regarding associative learning in the human fetus. 

Potential Implications of Research:  The results will inform our understanding of whether fetuses learn in utero and generate new tools for fetal research.

Project Description:  The human fetus undergoes a period of rapid growth and differentiation of the brain and nervous system during pregnancy. As pregnancy progresses, the fetus develops the core neurodevelopmental capabilities that are present in the full-term neonate at birth. Less well understood, however, is the degree to which the fetus exhibits higher order processes related to cognition. Does learning begin prior to birth?  Based on what we currently know about the fetus, there is no reason to believe that it does not. Fetuses can hear and respond to sensory stimulation, emanating either outside the uterus or generated within the maternal environment. The maturing fetus also develops sleep-wake cycles that can allow information processing. Recent technologies have afforded greater insight into the functional connectivity during the prenatal period across brain regions that are requisite for learning. Despite this, we know relatively little about prenatal learning. Unlike the infant or child, the fetus cannot be directly viewed, handled, or heard. This makes such research particularly challenging. The majority of studies on prenatal learning have, in fact, been conducted in the postnatal period by testing neonates to infer recognition of stimuli experienced before birth. Most of this research has been directed at determining whether neonates recognize their mother’s voice and native language. Neonatal research is also difficult to conduct and interpret, resulting in relatively few studies of small samples. However, the answer seems to be “yes” – prenatal exposure to the maternal voice, and to a lesser extent musical passages, elicits recognition at birth. 

There are no published, empirical reports of human fetal associative learning or classical conditioning. Thus there is a tremendous knowledge gap in the basic elements of the origins of human learning. The goal of this project is to evaluate whether the human fetus exhibits the ability to make the association between a stimulus and a response. Specifically, we will explore whether fetuses can learn that a particular musical passage (stimulus) will precede a change in the mother’s body position (response). A training session that pairs a brief musical passage (Melody A) will precede the mother’s postural change (sit-stand-sit movement). A second musical passage (Melody B) will be played randomly and be unrelated to the mother’s behavior. After a series of training trials, we will test fetal associative learning by monitoring changes in fetal heart rate. If the fetus has learned to expect a relation between Melody A and maternal posture change, we would expect to see a different response in fetal heart rate when Melody A is played (even though the mother does not change position), but not when Melody B is played. Several procedural controls for ensuring that the conclusions about fetal learning will be put in place.

There is much to be discovered about the origins of human fetal learning and we hope this project will reveal new horizons for future work. We also hope that this venture will generate new tools for fetal research. That is, if the fetus can learn to exhibit different responses to two sounds, this will enable new methodologies to test the detection, discrimination, and categorization of sounds in utero, which can ultimately be extrapolated to other sensory domains.