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Prenatal Learning and Memory

Learning is defined as the modification of behavior by experience (12.). For learning to take place, both the ability to experience the outside world through the senses, and the ability to record these experiences through memory, are necessary.

Development of the senses and of the brain are prerequisites to prenatal learning. Without the physical equipment necessary to interact with the environment, and the neural equipment necessary to process the information acquired, no learning can take place. The development of the senses is a gradual process, and it is difficult to determine precisely when the embryo actually begins to receive information in the form of sensation and respond to it deliberately, and when a response is purely reflexive. The pattern of development of the embryonic heart may be indicative of how the development and use of other organs progresses. The heart begins pumping blood as soon as a single chamber is able. The organ begins to function long before its completion, with the rest of the circulatory system added as it is needed ( 3.). It is reasonable to assume that the development of the central nervous system and the senses follow this pattern.

The embryonic brain, like the heart, develops in a pattern of increasing complexity. The first neurons are formed out of the Overhead View of Early Embryonic Brainectoderm, one of the three cell layers present in the very early embryo. These cells fold inward and form a nerve cord. These cells differentiate into central and peripheral nerve cells ( 8. ). Those cells that become the central nervous system form the neural tube, the beginning of the brain and spinal cord, during the fourth week ( 13.). Most of the neural tube forms the spinal cord, but the anterior end of the neural tube folds forward and begins to form the brain.

The embryonic brain then proceeds to develop into three regions: the prosencephalon, or forebrain, the mesencephalon, or midbrain, and the rhombencephalon, or hindbrain ( 8. ). The forebrain forms two major divisions, the telencephalon and the diencephalon. This division occurs at five weeks gestational age. The telecephalon becomes the cerebrum, and the diencephalon becomes the thalamus, the hypothalamus, and the pituitary. The midbrain becomes the parts of the brain that process visual and auditory information, as well as connecting other brain regions and coordinating reflexes. The hindbrain forms the cerebellum, pons, and medula -- known collectively as the brain stem. These brain regions control basic bodily functions; the cerebellum also serves to coordinate brain impulses and physical behavior ( 12. ). By eight weeks, all the basic parts of the brain are in place( 1. ), as are all other organs as the unborn child leaves the embryonic stage of development and becomes a fetus ( 6. ). However, the brain is by no means complete; brain cells continue to be formed into the fifth month of gestation ( 11. ).

6 Week Old EmbryoWith the use of an electroencephalogram, or EEG, activity in the brain can be detected as early as five or six weeks gestational age ( 6. ). Whether brain activity begins at this time or merely becomes detectable at this time is uncertain; it is known that neural connections begin forming as soon as neurons begin forming, as early as fourteen days gestation ( 9. ).

The embryo develops reflexes ( 13. ) and is capable of motion ( 3.) as early as five weeks gestational age, and by six weeks the Association for Pre- and Peri-Natal Psychology and Health states that these movements show evidence of being voluntary rather than reflexive. These movements, early in gestation, are spontaneous and endogenous. The embryo is capable of responding to stimulation, but more frequently moves for no outwardly apparent reason ( 3. ). Dr. Harley Smyth, a neurologist, testified before the Canadian Supreme Court that "at six weeks [gestational age - eight weeks gestation or LMP] there is the possibility of recording electrical activity from the nervous system already so highly organized that it can subserve . . . purposeful and even co-ordinated movements." (5.) At six weeks development, the motor cortex has not yet been formed out of the rest of the forebrain, the cerebellum has not been differentiated from the rest of the hindbrain, and the spinal cord is incomplete. Yet motion occurs, and thought may also be beginning. This gives evidence to the theory that, rather than forming and then beginning to function, embryonic organs function as they form. Learning, therefore, may begin to take place far before the brain structures traditionally thought to be necessary for conscious thought are present.

Embryonic senses allow interaction with the environment as early as five to six weeks gestational age, when an embryo will respond to a stroking of its cheek ( 3.). The embryo will arch its back and push back its head ( 10. ). Sensitivity to touch spreads gradually through the body. By eight weeks, the embryo shows evidence of sensation in the genital area, in the palms of the hands by nine weeks, and the soles of the feet by ten weeks. By fifteen weeks, the entire torso is sensitive to touch ( 3. ).

The structures needed to experience taste are developed by twelve weeks, and the sense of smell develops gradually between nine and thirteen weeks . Many chemical compounds and products of the mother's diet cross the placenta, providing the fetus with a changing range of tastes and smells. Research shows that a fetus will swallow more amniotic fluid when a sweet taste is present than when a sour taste is introduced to the womb ( 3. ).

Reactive listening has been demonstrated through research at fourteen weeks gestational age, approximately eight weeks before the ear is structurally complete. Researchers in Belfast demonstrated this by beaming a pure pulse sound into the womb at various gestational ages; a visible reaction was first demonstrated by the fetuses and observed by ultrasound at fourteen weeks. Other studies have demonstrated that a five-second auditory stimulus can cause a change in heart rate that lasts up to an hour ( 3.).Fetus sucking his thumb

Vision, while well developed in premature infants, cannot be readily tested in the womb. It has been demonstrated, however, that the fetus reacts to light with an acceleration in heart rate ( 3. ).

There is some evidence that the fetus experiences pain, as well as emotional responses such as anger or pleasure, at least as early as 14 weeks, when amniocentesis is performed. During fetal blood transfusion, a 590% rise in beta endorphin and a 183% rise in cortosol have been documented in the fetus. The presence of both of these hormones in such high levels, as a response to a stimulus, is chemical evidence of pain ( 3. ). Fetuses respond in a variety of ways to amniocentesis, from shying away from the needle to kicking at it ( 4. ). The variety of responses in different fetuses of the same age to the same experience seems to indicate that these responses are not instinctual, but individual responses of fear, curiosity or aggression. A fetus will experience fluctuations in heart rate during and immediately following amniocentesis, and breathing motion patterns may not stabilize for days. Ultrasonographers have observed male fetuses experiencing erections as early as 14 gestational weeks in conjunction with thumb-sucking, which may give evidence to the fetus's ability to experience pleasure ( 3. ). These emotional responses, taking place before the limbic system is fully formed and long before the cerebral cortex, thought to be responsible for conscious thought, is completed, are further evidence that the brain is functioning long before its individual structures are complete.

Anecdotal evidence for prenatal learning abounds. A professional cellist and conductor found to his amazement that he knew the cello part to several pieces perfectly -- despite having never seen the music before. His mother, also a professional cellist, had practiced those pieces while pregnant ( 11. ). Twins appear to learn patterns of interaction that they carry with them throughout their lives. In one case "brother and sister were seen playing cheek-to-cheek on either side of the dividing membrane. At one year of age, their favorite game was to take positions on opposite sides of a curtain, and begin to laugh and giggle as they touched each other and played through the curtain. " ( 2. ). Some parents claim to have taught their unborn children to kick on request, but using verbal association when the baby kicks on his or her own ( 2. ). Research into prenatal learning and other facets of prenatal awareness often simply confirm what many parents believed already, that it is possible to interact with a child before birth.

There is also much clinical evidence for prenatal awareness and learning. Most of the research done into prenatal learning has dealt with auditory learning. Conclusive evidence that newborns recognize their mother's voices has been presented by Anthony DeCasper, a psychologist at the University of North Carolina. Dr. DeCasper had expectant mother read 'The Cat in the Hat' to their fetuses at regular intervals before birth. The results were clearly indicative of learning prior to birth; "At birth, babies were hooked up to recordings which they could select by sucking on a non-nutritive nipple. After a few trials, babies cleverly sucked at whatever speed was necessary to obtain their mother's voice reading "The Cat in the Hat." ( 2. ).

Fetuses also learn the beginnings of languages from their mothers while in the womb. Research using acoustic spectroscopy has shown that, at twenty-seven weeks, a baby's cry already contains some features of his or her mother's speech, such as rhythms and voice characteristics. Newborns show a preference for their mother's language; French babies prefer to watch someone speak French, while Russian babies show a preference for Russian. A French experiment conducted on fetuses thirty-three to thirty-seven weeks gestation demonstrated memory of a children's rhyme, while still in the womb. During the course of the experiment, the mothers read a certain rhyme to their unborn children daily; at the end of this time, the fetuses displayed recognition of this rhyme over other rhymes they had not heard ( 2. ).

A study by Donald Shelter, professor of education at the University of Rochester's Eastman School of Music, shows that fetuses are also capable of remembering a wordless tune. This study also gives evidence to the positive effects of prenatal exposure to complex rhythms. In this study a stereo earphone system was placed directly on the mother's abdomen, allowing the fetuses to list to orchestral music with a single dominant melody. After two years, most of the thirty participants were able to recognize that melody. In addition, these children showed very advanced speech ability ( 11. ). The positive effect of this experiment on its subjects suggests that prenatal teaching is not only possible but beneficial.

This research provides conclusive evidence to prenatal learning taking place in the second and third trimesters. However, little research appears to have been done on the possibility of learning earlier than fourteen weeks and the onset of hearing. This is most likely due to the difficulty in providing other sorts of stimuli, and also of measuring the very young fetus's response. However, the developmental pattern present in the senses and other organs indicates that the brain may be functioning very early in pregnancy. Voluntary motion and emotional responses to stimuli indicate that the fetus is to some degree conscious. It seems likely that learning can and does take place from very early in gestation.

Works Cited: Text

1. Chamberlain, David, ed.. "Early and very early parenting: parents ask about life inthe womb." Life before birth. (17 Nov. 1998).

2. Chamberlain, David, ed.. "Prenatal memory and learning." Life before birth. (8 Nov. 1998).

3. Chamberlain, David, ed.. "The fetal senses." Life before birth. (8 Nov. 1998).

4. "Communication before language." Life before birth. (15 Nov. 1998).

5.) Evidence of Dr. Harley Smyth (Position), Borowski v. The Attorney General of Canada 8C.C.C. (3d) 1983; See Trial for Life, Vol. 1, Alliance Against Abortion, Winnipeg, 1984, Testimony of Dr. Harley Smyth, p. 492.

6. Houp, Katherine H. "Embryology." Piotrowski, Nancy A., ed. v. 4 Magill's medical guide: health and illness suppliment. Salem Press; 1996. pp. 1069-1073.

7. "Milestones in fetal development." Human development. (24 Nov. 1995). (15 Nov. 1998).

8. "Neurology." Piotrowski, Nancy A., ed. v. 4 Magill's medical guide: health and illness suppliment. Salem Press, 1996. pp. 1397 - 1400

9. Nilsson, Lennart. A Child is Born. New York: Dell Publishing, 1993.

10. Papalia, Diane E.; Olds, Sally Wendkos. A child's world: infancy through adolescense. New York: McGraw Hill, 1990.

11. "Prenatal learning and development." (11 Nov. 1998).

12. Purves, William K.; Gordon, H. Orians, H; Heller, Craig H.; Sadava, David. Life: the science of biology. Salt Lake City, UT: Sinauer Associates, 1998.

13. Ross, Anna E. "Summary of prenatal fevelopment." Dr. Ross' Vertebrate Embryology Course (Bio 211): Contents of Unit 2 Embryology Lecture Notes. (Fall 1996). (5 Nov. 1998).

Works Cited: Photographs

1. Nilsson, Lennart. A Child is Born. New York: Dell Publishing, 1990. pp.78.

2. Petit Format/Nestle/Science Source/Photo Researchers. Published in:

Papalia, Diane E. and Olds, Sally Wendkos. A Child's World: Infancy Through Adolescence: Fifth Editon. University of Pennsylvania: McGraw-Hill Publishing Company, 1990. pp. 96

3. Oxford Scientific Films: D.Bromhall. Published in:

Flanagan, Geraldine Lux. Beginning Life. New York: DK Publishing, 1996. pp. 79.