As a young man, Boris Brott, conductor of the Hamilton Philharmonic Orchestra in Ontario, says he was mystified by the unusual ability he had to automatically "play" certain pieces sight unseen. "I'd be conducting a score for the first time, and suddenly the cello line would jump out at me: I'd know the flow of the piece even before I turned the page of the score.

"One day, I mentioned this to my mother, who is a professional cellist. I thought she would be intrigued because it was always the cello line that was so distinct in my mind. She was, but when she heard what the pieces were, the mystery quickly resolved itself. All of the scores I knew sight unseen were ones she had prepared for a program while she was pregnant with me, but never had occasion to play after that."

Brott's startling prenatal reminiscence is one of many that Dr. Thomas Verny, a Toronto psychiatrist, has collected during a decade-long search he has conducted exploring the mysteries of what he calls The Secret Life of the Unborn Child (by Thomas Verny, M.D., with John Kelly, a Delta Book, published by Dell, $6.95).

From Verny's search a new portrait of the prenatal world emerges that differs dramatically from the traditional pediatric dogma: Instead of a passive, mindless creature, oblivious to its surroundings until birth, Verny says that from the sixth month in utero (in the uterus, before birth) the unborn child is "an aware, reacting, fascinating little person" who leads an active mental and emotional life. Among other things, Verny maintains that an unborn baby can (during the last trimester of pregnancy) see, hear, experience and, on a primitive level, learn; is sensitive to his or her parents' feelings about the pregnancy, and is capable of responding to love.

Parents, claims Verny, need not wait until birth to begin to provide a happy and healthy life for their children. Although many of his findings are controversial, he believes passionately that "whether a child becomes happy or sad, aggressive or meek, secure or anxiety-ridden may depend, in part, on the messages a baby receives in the womb."

In the late 1960s the medical community discovered a post-birth system of mother-child communication--"bonding"--and recognized its vital importance to the newborn. Verny maintains there is bonding before birth, or what he calls "intrauterine" bonding.

"I think it's totally illogical," he writes, "to assume that bonding just miraculously occurs at the time of birth. An unborn child is actually closer to his mother with intrauterine bonding than after birth. I think we really need to expand the whole concept of bonding to include the prenatal period."

Verny says a woman can bond prenatally through:

* The physical connection: proper nutrition, not smoking, not drinking, enough rest, moderate exercise and eliminating as much stress from her life as possible.

* Sympathetic communication: psychological communication between the unborn child and its mother, such as paying attention to intuitive feelings, extrasensory perceptions and dreams during pregnancy.

* Behavorial communication: "Behavorial communication is the kind of things women have been doing naturally for thousands of years, but now we know they should do more of them and not care whether their husband or mother-in-law thinks they are crazy. This is the gentle rubbing or patting of the stomach, the soothing words, singing lullabys, listening to good music--and by that I don't mean every mother has to listen to Vivaldi or Mozart but don't listen to shoddy music like rock 'n' roll.

"Tell stories to the baby, recite a little poetry. Also have your husband talk to the baby. And play with the baby! A lot of people don't know how to do this and yet it is the most incredible experience. For example, a woman or her husband could push a little on the side of the stomach, wait, then begin pushing on the other side, then the first side again. Within a few minutes the baby will pick up the play and start pushing against your fingers. It's fantastic! Once you have that kind of communicative experience you can imagine the effect it has on you."

Besides being rewarding for prospective parents, Verny says behavorial communication helps the unborn child begin to learn about the life he or she will experience outside the womb as a newborn. "Just imagine how you would feel, alone in a room for six, seven or eight months without any emotional or intellectual stimulation."

Arthur Janov (The Primal Scream) declares in his forthcoming book, Imprints: The Lifelong Effects of the Birth Experience, that the time in the womb can have a permanent effect on the newborn's personality, determining whether the child will grow up to be passive, aggressive, compulsive or addictive.

Although there is much skepticism surrounding the question of personality growth in the womb, Verny's recommendations of "behavorial communication" are being paralleled by some American medical professionals who belong to the Infant Stimulation Education Association. This 2-year-old group is comprised primarily of registered nurses and occupational and physical therapists who believe that post-birth physical, mental and emotional development can be enhanced by providing an enriched environment, loving attachment and appropriate sensory experiences, or "infant stimulation."

Recent studies show that infants who are stimulated have a tendency to gain weight faster, roll over, crawl and walk sooner. They are also more likely to be contented babies who smile more frequently, have longer attention spans and, as they grow older, possess greater curiosity.

According to Dr. Lynn Balzer-Martin, assistant professor of pediatrics at Georgetown University Medical Center, the infant stimulation movement, which has developed quite rapidly in the last three to five years, grew out of techniques employed originally in intensive care nurseries to "make up for deficits, or things missed out on by premature infants. We know that certain of the earliest senses babies have, the senses that become the most sophisticated early--things like the touch sense tactile or the balance and movement sense vestibular --are developed as early as 28 weeks in utero.

"So if a baby is born at say, 31 weeks (nine weeks early), then besides all the other medical problems that can occur from being premature, they have missed out on a lot of the maturing of the nervous system which--had they remained in the uterus responding to the natural stimulation of touch and movement--they would have received as the mother went about her daily activities.

"We would work with these infants to try and make sure that while they are in the hospital getting their medical needs taken care of, they would also be getting the appropriate stimulation to help their movement-sense and touch-sense and those other things that are important for the development of motor skills later."

It was simply a natural progression, says Balzer-Martin, to adapt the techniques used for helping premature babies to normal infants--making use of all our recent knowledge about infants: their styles of paying attention and learning; what things they prefer, the color, and the shapes they readily respond to and at what ages, and when they best respond to stimulation."

Infant stimulation basically is a "more deliberate or considered approach to helping your baby grow and develop," she says, rather than "just playing symphonies and assuming that because you are a bright person and there is a lot going on around your house, your baby will be exposed to it."

Expecting my first baby in a few weeks,I decided to attend an infant stimulation class offered by the Washington Adventist Hospital. I was intrigued and fascinated by the idea that my child-within could respond to lullabies and poetry now and I wanted to learn how I could best stimulate "Michael/Kate" before and after birth. At the very least, I told us, the class should be fun. What I had not expected was for infant-stimulation to be revolutionary.

The first thing you learn in "infant stim" is to forget that passive nature nonsense you've been led to believe about newborn babies. They have very definite likes and dislikes, even just hours after birth. Color for one. So you've painted the nursery blue, pink or yellow? Fashioned that beautiful bassinet out of white eyelet and pale silk ribbons? Fine. Now get out the black and white.

"A big part of infant stimulation," explains Balzer-Martin, "has to do with knowing the preferences of newborns, the colors they like and at what age, the type of designs that appeal to them, the complexities of the design. Too simple bores them and too complex overwhelms them.

"You know historically, people have thought newborns were pretty boring, that they had so few capabilities and that there wasn't much satisfaction or reward you could get from interacting with them other than attending to the basic needs--to be fed, to be changed, to feel secure--and being very loving.

"But it didn't matter, for instance, what colors you had around an infant for the first few months because some people thought their eyes were closed like puppies. Those who realized they newborns could see just couldn't have imagined newborns had preferences for certain shapes--like the checkerboard, bull's-eye, triangle, and especially the human face--and for colors, black and white for the first six months.

"This doesn't mean you should only show your baby black and white things, but I think most people wouldn't show their baby black and white objects at all because the logic would suggest that it would be the least interesting. It might not appeal to us, but it is what appeals to baby."

Among other preferences of newborns:

* Auditory stimulation: classical music, their parents' voices and for the first two weeks of life, the sound of their mother's heartbeat. They respond to being talked to in a high-pitched voice, the alternating of baby sounds with adult speech patterns and the repetition of their own name.

* Tactile stimulation: slow skin-to-skin stroking in a head-to-toe direction; cuddling and rocking; gentle exercise, such as rolling the baby from side-to-side, lying the baby on her back so that she can push her feet against your hands, and the feel of different textures such as cotton, satin, wool, fake fur (a favorite) gently rubbed on their skin.

* Olfactory stimulation: mother's breast milk, sweet smells such as cherry juice, strawberry extract, nutmeg and cinnamon and their mother's eau de cologne (but go easy on the perfume, nothing musky or heavy). A drop or two dabbed on baby's sheet will comfort a fussy newborn fighting sleep.

And so now, newly sensitive to my child-within's preferences, black and white sheep graze on the crib's yellow-flowered bumper pads and curtain windows. At least for now, dainty pink and blue florals have given way to black and white teddys--striped, checked and dotted--all dancing in a row, face down, so that baby can see them. A black and white checkerboard and simple happy face wait propped along the sides of the white eyelet-lined rocking cradle.

Mindful of sensitive ears already capable of hearing, every day "Michael/Kate" and I listen to Massenet's soothing "Meditation from Thais" and Bach's "Air on G String"; this we have decided is the music we will soon nurse by, so it's best to practice our relaxation techniques. Gentle rhythmic kicking generally accompanies my singing of "Sleep Baby Sleep" and sympathetic communication has told me that already Yeats' "Cradle Song" has become a favorite.

I sigh as I kiss you

For I must own

That I shall miss you

When you are grown

Contentedly we wait these last days together, already friends instead of anxious strangers.

I do not know what infant stimulation may do for "Michael/Kate's" development in the future. It doesn't, after all, guarantee a genius or even a gifted child. A happy child and mother doing and exploring things together will be enough.

I do know, however, that before birth a partnership has already begun.