Sensory Memory: Learning from the Five Senses

As you look at a newborn, have you wondered when babies start learning, or pondered the purpose of the early days and weeks when a baby spends most of their waking hours in search of a bottle or breast for feeding? The answers may surprise you.

Their tiny brain is ready to learn immediately—even before birth. Despite the seemingly vacant look, uncontrolled eye movements, and flailing body parts, an infant is building a memory system that will control the child’s actions for their entire life. Parents, families, caregivers, and teachers take notice: everything that is happening to and around a baby has an impact on their developing brain systems.

The first memory system to begin development is sensory memory.

Memory Starts With a Newborn

You would have nothing to think about if your five senses were blocked. Memory from the senses begins before birth. For instance, an infant’s sense of smell is completely developed at the time of a full-term birth. During the third trimester of pregnancy, the fetus can smell almost everything the mother inhales or eats. This sense is needed for baby’s survival. Very early in life, an infant will turn toward their mother’s breast, as the smell of breast milk is quickly learned. The ability to suck has been practiced in utero for this very purpose.

At birth, the infant sees a world that is relatively dark, with only a tunnel of sight. Most likely it is a black and white world, while the tiny brain receives signals of light and shapes from the environment. The baby can resolve visual input that is about 1/40 of that of an adult’s. Although limiting, the baby can recognize a familiar face when being held. Around two months of age, an adult and a child can be caught in a “gaze fest” as they fixate on one another. Fixation engagement can be emotionally charged with love fostered between the child and the parent or caregiver. Due to rapid development of the visual system, a one-year-old can see nearly as well as an adult.

A third part of the sensory memory system, one tightly linked with smell, is the development of taste. Scientists believe that flavors from food eaten by the expectant mother are passed to the fetus through the amniotic fluid that nourishes the fetus.  Chemical detectors are located on the tongue, roof of the mouth, soft palate, and upper throat area. Babies are able to decipher four categories—sweet, salty, bitter, and sour.  Taste stimulation to systems at the base of the brain cause automatic responses of salivation, swallowing, and tongue movements. Good tastes motivate the very young child to drink and, ultimately, to eat.

The sense of sound is also developing in utero, beginning about 12 weeks prior to birth. Pregnant women notice that the fetus may kick or jump as a response to a loud or unusual noise. The little one is settled by soft voices, humming, or hearing calm music.  After birth, very young children will show interest in words spoken with elongated high-pitched words and intonation. The sentence, “Oh, look at the baby,” might sound like, “O-h-h-h, l-l-l-o-o-o-k  a-a-a-t th-a-a-a  b-a-a-a-be-e.” This type of talk happens naturally when speaking to infants (Eckart, 2020) in all languages and is often referred to as “parentese”.

The developing sense of hearing is particularly aware of language with interesting sounds in words. Parents promote the sense of hearing with rhyming words, nursery rhymes, silly sayings with alliteration, singing, and music. The sensory memory area of the brain is stimulated for learning, cognition, and emotional growth as well.

Finally, let’s consider the sense of touch. This important sensation runs from all the body parts through the spinal cord to the base of the child’s brain. An instantaneous relay system allows baby to feel pressure, pain, heat, or cold. Interestingly, there are many more sensory receptors for human babies (and adults) around the mouth, hands, and fingers than there are in other parts of the body.

Parents provide natural loving activities which promote health and normal growth through stimulation to the baby’s body. How often do you see an adult or older sibling rocking and swaying when holding a small child? Babies are comforted with a hand placed on their belly or as they are wrapped in a blanket. Babies are generally calm when they are placed in a sling or tight-fitting carrier, as they feel closeness with another person.

When someone is looking at the baby and their lips are moving, the child receives sound in addition to the visual image of the person. Thus, the baby realizes the mouth can be moved and vocal cords be activated. Babbling that will eventually form words begins. Music is heard, siblings are singing and dancing, and the baby responds by moving hands and legs and making noises. The family is sitting around the table and enjoying a meal, and the baby reaches for the food.

Baby is observing, problem-solving, and developing thoughts for the next memory system that develops: working memory.

A More Complex Method for Thought: Working Memory

This brief introduction to the senses and their development is just the beginning of human memory: remembering, recognizing, and seeking familiarity in a child’s ever-expansive environment. With stimulation from the five senses, networks of understanding at birth continue well into the first and second year. The sensory memory system is the primary way infants and toddlers learn about the environment in which they live. As the senses complete their development, everything is interesting and the young child will spend nearly 100% of their waking time seeking information from the senses and trying to make meaning from stimuli they receive.

Somewhere between the end of the first and second year (or possibly year three) the second memory system—working memory—kicks in, as the child spends brief periods of time in what appears to be contemplating, thinking about, and producing an action.  Working memory is a major developmental cognitive step and overtakes sensory memory for learning and other cognitive actions. It is a major accomplishment and critical memory system for all thinking and problem-solving for the child’s quickly developing brain.

Does the need for sensory memory go away? Certainly not! It is the primary input to begin the thinking process. The five senses—hearing, seeing, touch, smell, and taste—are the keys to learning as the sensory memory system is the first stop for all the incoming stimulation from the senses for the years to come. As a two- or three-year old receives constant input from the environment, the child gradually learns what information is important to capture and then, with and sometimes without conscious thought, learns to pay attention.

References

Coby, B. (2021). Black and white baby book. Independently published.

duopress labs & Mora (Illustrator). (2016). Hello, baby animals:  A durable high-contrast black-and-white board book for newborns and babies.

Forestell, C.A., & Mennella,J.A. (2017, June 6).  The relationship between infant facial expressions and food acceptance, Current Nutrition Reports, 6,141-147.

Nevills, P. (2023). Building the Young Reader’s Brain, Birth through Age 8. Third Edition. Corwin.

Eckart, K. (2020, February 3).  Not just “baby talk”:  Parentese helps parents, babies make “conversation” and boosts language development. UW NEWS.