I have always wondered if babies can count discrete quantities like one, two or three apples in their mind even before they can talk. Do they have pre-verbal concept of quantity? These are some questions that researchers are working on in their laboratories. I have done several case studies of some of my patients on early counting.

Since Alex was 1 month old, her mother and her siblings demonstrated to her the concept of “one” and “two.” Mom showed her index finger pointing up from 10 inches of her face and said “one.” Then she would bring her index finger horizontally pointing to the left and say again “one” and one second later point it downward and say “one” again. After these three different positioning of the index finger, her mother would make one stroke downward touching Alex’s left cheek and say, “one.” This game is played at least four times a day for three days.

On the fourth day, the mother would demonstrate the concept of two with the index finger and the middle finger using the left hand following the same sequence of pointing up, horizontal and down. Then making two downward strokes on Alex’s right cheek. On the seventh day the mother would bring up both of her hands from about 10 inches of Alex’s face. She would say, “Show me one” and wait for a response. Then she would say, “Show me two.”

When Alex was 7 months olds she consistently reach for the “one” index finger when told, “Show me one” and reach for the two fingers when her mother or siblings says, “Show me two.”

When you show your baby one Lego block and you say, “one,” she will look at it and at the same time hear the word, “one.” Her brain is recording in her memory center, the hippocampus, the concept of “one” and in her visual center at the back of the head the appearance of “one block.” The sound “one” is also registered at the auditory center.

While these three brain centers are recording “one,” there is group of brain cells doing another task simultaneously, taking notice the emotional content, facial expression, and tone of voice of the speaker. This part of the brain is called amygdala, the center of emotion. Each time you show one block to your baby the three brain centers: memory, visual, and the auditory centers are stimulated and the word “one” plus the appearance of a “block” is embedded. The amygdala allows the other brain centers to perform their jobs effectively.

Depending on the emotion and expression of the parent, the word “one” and the visual appearance of “one block” is embedded lightly or strongly in the other cortical centers. If the mother is animated while showing the “one block” the hippocampus will record it more permanently. And the visual and auditory centers will see and hear the word “one” clearly.

If the mother is depressed and not smiling when she says the word “one” the hippocampus might not register it at all. The visual center and the auditory centers might not even recognize that there is “one” block in front of her because the negative neural influence of the amygdala is overpowering the visual and auditory effect coming from the “one block” stimuli. The end result is memory failure. And in computer parlance “hard-drive crashes.”

Babies whose parents are not in sync emotionally, abusive, or depressed promote their baby’s brain to have frequent hard-drive crashes of the hippocampus. These daily hard- drive crashes of the brain can lead to mental, language and behavioral problems.

When Mario was 18 months old his language development was advanced compared to his peers. He could combine two or three words together and can even count in Spanish. When he was two years old, Mario’s parents had marital discord and ultimately they separated. During that time Mario had frequent hard-drive crashes of his brain. Now Mario is 6 years old with school difficulties, hyperactivity, and other behavioral problems. He is now taking stimulant medications.

On the other hand, Maria had parents who did not have any marital problems at all. At 18 months Maria knew her address and full name. She knew where mommy and daddy worked and what kind of job they do. Maria also knew where five other relatives worked. She said ABCDE and spoke in four-word sentences.

Maria counted up to 10 at 18 months old. At 20 months Maria reads her name. Maria is now 6 years old. She is in the top of her class. She is a happy, well-behaved child. Maria did not have any hard-drive crashes of her brain.

Leo Leonidas, MD, FAAP, is assistant clinical professor in pediatrics at

Tufts University.