As soon as a baby is born, her senses become flooded with the sounds, tastes and smells of her new environment. It often seems to those who work with infants that, like a sponge, babies are born ready to take in all this information. Yet, as scientists develop new techniques to study the fetal environment, they're discovering that the learning process often starts well before birth. The term "early learning" has taken on a whole new meaning.
Did You Know?
The capacity to learn is tied up with the development of sensory organs and brain structures. These structures develop at varying rates, some not coming fully "online" until shortly before birth, or even well into infancy. When are the fetal senses "wired-up" and ready to go?
- Taste - Mature taste buds can be seen at around 13 weeks after conception.
- Smell - In a study of premature infants, some responded to the odor of mint as early as week 29 of pregnancy, and all responded by 36 weeks.
- Hearing - The cochlea, an important part of the human auditory system, may be functional by week 18. Other structures of the ear continue to develop into the fifth month of pregnancy.
- Sight - Around week 20, the fetus's heart rate will increase slightly in response to switching on a bright light bulb in front of the womb.
- Touch - Some parts of the fetus's body are sensitive to touch by week 7. The whole body responds to touch around week 13 or 14.
A Sensory Buffet
The tranquility of a mother's womb seems a far cry from the noisy, smelly outside world. Yet, for the fetus, any sensory data is a rich source of information that can be processed and learned.
Immersed in amniotic fluid (AF) for nine months, the fetus is constantly smelling and tasting through the inhalation and swallowing of AF. Evidence shows that fetuses are able to detect fragrant molecules within the AF; and, indeed, remember these smells. Newborn infants show a preference to their own AF over an unknown AF. They also prefer flavors and odors of foods that their mothers had consumed during pregnancy.
Sound, too, is an important part of the fetal sensory environment. The loudest sounds in the womb come from the mother: her voice, her heartbeat and the sounds of her bodily functions, such as digestion. Sounds originating outside the mother can also reach the fetus, although they may be somewhat distorted.
And the fetus is listening to these sounds. A newborn can recognize a song that was played during pregnancy. Unfortunately, there's no evidence yet that playing Mozart to your unborn child has any short- or long-term benefits.
Touch and sight information is less available to the fetus. The fetus may touch various parts of its own body or the uterine wall with its hand. Some bright light may penetrate the uterine wall, and this may be perceptible to the fetus. However, scientists have yet to discover what the fetus may be learning from these experiences.
The Prenatal Classroom
Special attention is needed to ensure that premature babies have the same learning opportunities as full-term babies. Experts recommend massage, proper visual stimulation and talking often to your baby. Breastfeeding is also an option for many premature infants, exposing the baby not only to the taste of her mother's milk, but the scent and touch of her skin as well. If a baby is too small to nurse, her mother's milk can be pumped and fed to her, thereby exposing her to some of the flavors that she would have tasted in utero with sips of amniotic fluid.
For those still in the womb, variety in the mother's diet can ensure that a fetus is exposed to a full range of flavors. This may promote acceptance of these flavors later in life. So, expectant mothers, eat curry if you want your child to eat curry. Eat garlic if you want your child to eat garlic. But, as many veteran parents know, if you want your child to eat Brussels sprouts, good luck!