3.4 Infant Cognition

The rapid physical growth of the human infant, just described, is impressive, but intellectual growth during infancy is even more awesome. Concepts and sentences—non-existent in newborns—are evident by age 1 and consolidated by age 2. We begin with Jean Piaget, who many consider to be the most influential researcher of all time in the area of cognitive developmental psychology (Birney et al., 2005).

Sensorimotor Intelligence

Piaget called cognition in the first two years sensorimotor intelligence because infants learn through their senses and motor skills. He subdivided this period into six stages (see TABLE 3.3).

Stages One and Two: Simple Reflexes and Primary Circular ReactionsFor the first two stages, infants focus primarily on themselves. Stage one, called the stage of simple reflexes, includes the neonatal reflexes that infants use during their first month of life, the foundations of infant thought. During this stage, the newborn’s motor reflexes evoke certain brain reactions.

Soon sensation leads to perception, which ushers in stage two, first acquired adaptations or primary circular reactions (also called the stage of first habits). This stage lasts from one month to four months. It is a primary circular reaction because this is when infants begin to put together two separate actions or sensations, such as looking and touching or listening and touching, to form a habit. For example, the infant places her thumb in her mouth, finds it soothing, and begins to suck. Over time, the two separate actions become one combined action, repeated over and over (circular).

Newborns reflexively suck anything that touches their lips. By about 1 month, they have adapted this reflex to bottles or breasts, pacifiers or fingers, each requiring specific types of tongue-pushing. This adaptation is a sign that infants have begun to interpret their perceptions; as they accommodate to pacifiers, they are thinking.

Time for Adaptation Sucking is a reflex at first, but adaptation begins as soon as an infant differentiates a pacifier from her mother’s breast, or realizes that her hand has grown too big to fit into her mouth. This infant’s expression of concentration suggests that she is about to make that adaptation and suck just her thumb from now on.

FSTOP/PUNCHSTOCK

Stages Three and Four: Secondary Circular Reactions and Coordination of Secondary Circular ReactionsIn stages three and four, reactions are no longer confined to the infant’s body; they are an interaction between the baby and something else in the external world. During stage three (4 to 8 months), infants attempt to produce exciting experiences, making interesting events last. Infants will continue to repeat those actions over and over because of their consequences. For example, realizing that rattles make noise, they wave their arms and laugh whenever someone puts a rattle in their hand. The sight of something delightful—a favourite book, a smiling parent—can trigger active efforts for interaction.

Next comes stage four (8 months to 1 year), coordination of secondary circular reactions or new adaptation and anticipation, also called the means to the end because babies have goals that they try to reach. At this stage, infants begin to show intentionality. Often they ask for help (fussing, pointing, gesturing) to accomplish what they want. Thinking is more innovative because adaptation is more complex. For instance, instead of always smiling at Daddy, an infant might first assess Daddy’s mood and then try to engage. Stage-three babies know how to continue an experience; stage-four babies initiate and anticipate.

That initiation is goal-directed, not random. For instance, babies who are breastfed indicate that they are hungry, lifting up their mothers’ shirts. They also inform caregivers when they do not want to eat, keeping their mouths firmly shut if they are full or if the food on the spoon is not what they want. If the caregivers have been using sign language, among the first signs learned before age 1 are “eat” and “all done.”

Object PermanencePiaget thought that, at about 8 months, babies first understand object permanence—the concept that objects or people continue to exist when they are no longer in sight. As Piaget predicted, beginning at about 8 months, infants search for toys that have fallen from the crib, rolled under a couch, or disappeared under a blanket. Babies who are blind also acquire object permanence toward the end of their first year, reaching for an object that they hear nearby (Fazzi et al., 2011).

Piaget developed a basic experiment to measure object permanence: An adult shows an infant an interesting toy and then covers it with a lightweight cloth. The results are as follows:

• Infants younger than 8 months do not search for the object (by removing the cloth).
• At about 8 months, if infants are given the opportunity to search immediately (by removing the cloth), they do so; however, if they have to wait a few seconds before beginning to search, they forget that the object was there.
• By 2 years, children fully comprehend object permanence, progressing through several stages of ever-advanced cognition (Piaget, 1954).

Piaget believed that an infant’s failure to search before 8 months of age was evidence that the baby had no concept of object permanence—that “out of sight” literally means “out of mind.” However, researchers who track infants’ eye movements and brain activity believe that Piaget was mistaken because even infants younger than 8 months do look longer at the correct spot (the cloth covering the toy). Indeed, some scientists believe that infants as young as 2 and 3 months of age can represent fully hidden objects (Cohen & Cashon, 2006). Other scientists are not convinced (Kagan, 2008), arguing that looking and reaching are two different and non-interchangeable tasks.

Exploration at 15 Months Taste and smell are primary senses for adults when eating, but for Jonathan, and other 15-month-olds, the best way to investigate food is to squish it in his hands, observe any changes in colour and texture, and listen for any sounds.

ARIEL SKELLEY/AGE FOTOSTOCK

Piaget further tested this ability by conducting the following type of experiment. A research assistant (RA) shows an infant an attractive toy and places it under one of two cloths, cloth A. The infant looks, and reaches for the toy under cloth A. The RA places the toy under cloth A several more times, allowing the infant to reach for it each time. Then, the RA changes the hiding spot and places the toy under cloth B, right in front of the infant. Which cloth will the infant lift up? Cloth A. This is called A-not-B error.

Stages Five and Six: Tertiary Circular Reactions and Mental RepresentationIn their second year, infants start experimenting in thought and deed—or, rather, in the opposite sequence: deed and thought. They act first (stage five) and think later (stage six).

Stage five (12 to 18 months) is called tertiary circular reactions or new means through active experimentation, when goal-directed anticipation (stage four) becomes more expansive and creative. This is when infants become intentional and purposive, knowing what they are going to do before they actually do it. Toddlers delight in squeezing all the toothpaste out of the tube, taking apart an electronic device, or uncovering an anthill, activities they have never seen an adult do. Piaget referred to stage-five toddlers as little scientists who “experiment in order to see.” Their devotion to discovery is familiar to every adult scientist—and to every parent.

Finally, in the sixth stage (ages 18 to 24 months), toddlers enter the stage of new means through mental combinations. Thankfully, stage-six infants use thought and memory, which deter the little scientists somewhat. Stage-six infants can even pretend. They can also think through a problem to discover a solution and then act upon it. For instance, a toddler sitting on the floor may want to play with his toy that is at the end of his blanket. The toddler realizes that if he pulls the blanket, the toy will come closer and closer until he can reach it.

Imitation This 14-month-old toddler demonstrates deferred imitation, copying her parents who she has seen using their tablet.

TOOGA PRODUCTIONS, INC./GETTY IMAGES

Piaget also described deferred imitation, another stage-six intellectual accomplishment, when mental combinations allow children to copy behaviour they noticed hours or even days earlier (Piaget, 1945/1962). He wrote about his daughter, Jacqueline, who observed another child

Piaget Re-EvaluatedAs detailed by hundreds of developmentalists, many infants reach the stages of sensorimotor intelligence earlier than Piaget predicted (Oakes, 2011). Not only do 5-month-olds show surprise when objects seem to disappear (evidence of object permanence before 8 months, as described earlier), but some babies younger than 1 year also pretend and defer imitation (both stage-six abilities, according to Piaget).

A major limitation of Piaget’s method for determining what infants could think is that it relied only on direct observation of behaviour, such as noticing whether or not a baby pulled away a cloth to search for a hidden object. Scientists now have many ways of measuring brain activity long before any observable evidence is apparent (see TABLE 3.4) (Johnson, 2010).

TABLE 3.4: Some Techniques Used by Neuroscientists to Understand Brain Function

Some require millisecond video analysis, such as whether an infant stares at a disappearing object for 20 or 30 milliseconds. Before any conclusions are drawn, data from dozens of infants need to be analyzed statistically. Other techniques involve brain scans. For example, in functional magnetic resonance imaging (fMRI), a burst of electrical activity measured by blood flow within the brain is recorded, indicating that neurons are firing. This leads researchers to conclude that a particular stimulus has been noticed and processed, even if the infant takes no action.

Brain scans are one way to investigate mirror neurons, an astonishing discovery that arose from careful research on monkeys—something not done in Piaget’s day. About two decades ago, scientists were surprised to discover that a particular region of a macaque monkey’s brain responded to actions the monkey had merely observed, as if it had actually performed those actions itself (Gallese et al., 1996).

For example, when one macaque saw another reach for a banana, the same brain areas were activated (lit up in brain scans) in both monkeys. Mirror neurons in the F5 area of the observing macaque’s premotor cortex responded to what was observed. Using increasingly advanced technology, neuroscientists have now found mirror neurons in several parts of the human brain (Keysers & Gazzola, 2010).

Many scientists are particularly interested in the implications for infant cognition. Perhaps the avid watching and listening that babies do enable them to learn long before Piaget realized. Because of mirror neurons, their understanding of objects, language, or human intentions might be far more advanced than researchers have demonstrated (Diamond & Amso, 2008; Rossi et al., 2011; Virji-Babul et al., 2012).

Scientists are now convinced that infants have memories, goals, deferred imitation, and mental combinations well in advance of the timing that Piaget proposed for his stages (Bauer et al., 2010; Morasch & Bell, 2009). Piaget was correct to describe babies as eager learners. He simply underestimated how rapidly that learning occurs.

Information Processing

Piaget’s four periods of cognition contrast with information-processing theory, a perspective originally modelled after computer functioning, including input, memory, programs, calculation, and output.

Information-processing research has found that many concepts and categories develop in very young brains. Even math concepts may begin as early as 3 months, advancing throughout the first year (Libertus & Brannon, 2009). For instance, 6-month-olds can detect the difference between a display of 8 dots and one of 16 dots, but not until 9 months of age can they distinguish between 8 and 12 dots (Lipton & Spelke, 2003).

The information-processing perspective has uncovered many notable aspects of infant cognition. Babies are thought to be little scientists in the first year of life. As one scientist summarizes, “Rather than bumbling babies, they are individuals who…can learn surprisingly fast about the patterns of nature” (Keil, 2011).

The term infant (or childhood) amnesia refers to the belief that adults and older children can remember almost nothing that took place before the age of 2 years. Information processing has revealed otherwise. We now focus on one specific aspect of the information-processing perspective—memory.

Goals and Cognition Much of infant intellectual development is about goal-directed behaviour. This Ottawa toddler has already learned that opening his mouth for his father will encourage his father to keep feeding him ice cream.

DANIELLE DONDERS - MOTHERSHIP PHOTOGRAPHY/GETTY IMAGES

MemoryEvidence for infant memory comes from innovative experiments in which 3-month-olds were taught to make a mobile move by kicking their legs (Rovee-Collier, 1987, 1990). The infants lay on their backs, in their own cribs, connected to a mobile by means of a ribbon tied to one foot.

Virtually all the infants began making some occasional kicks (as well as random arm movements and noises) and realized, after a while, that kicking made the mobile move. They then kicked more vigorously and frequently, sometimes laughing at their accomplishment. So far, this is no surprise—self-activated movement is highly reinforcing to infants, a part of dynamic perception.

When some infants had the mobile-and-ribbon apparatus reinstalled in their cribs one week later, most started to kick immediately. Their reaction indicated that they remembered their previous experience. But when other 3-month-old infants were retested two weeks later, they began with only random kicks. Apparently they had forgotten.

Then the lead researcher, Carolyn Rovee-Collier, developed another experiment. Two weeks after the initial training, the infants watched the mobile move but were not tied to it and were positioned so that they could not kick. This experience of looking, but not kicking, was a reminder session. The next day, when they were again connected to the mobile and positioned so that they could move their legs, they kicked as they had learned to do two weeks earlier. Apparently, watching the mobile move on the previous day had revived their faded memory. The information about making the mobile move was stored in their brains, but they needed processing time to retrieve it. The reminder session provided that time.

Selective Amnesia As we grow older, we forget about spitting up, nursing, crying, and almost everything else from our early years. However, strong emotions (love, fear, mistrust) may leave lifelong traces.

CALVIN AND HOBBES © 1989 WATTERSON. DIST. BY UNIVERSAL UCLICK

Other research finds that repeated reminders are more powerful than single reminders, and that context is crucial, especially for infants younger than 9 months old: Being tested with the same mobile in the same room as the initial experience aids memory (Rovee-Collier & Cuevas, 2009).

Scientists now believe that an infant’s memory begins to develop prenatally, when the baby is still in the womb. For example, one Canadian study used technologies such as ultrasound and image processing to measure a fetus’s heart rate while listening to its mother and a female stranger reading passages in English and Mandarin. The fetuses showed an increase in heart rate when they heard their mother’s voice and their native language, indicating they had developed memories of the voices and languages to which they were repeatedly exposed (Kisilevsky et al., 2009).

So, very young infants can remember, even if they cannot later put memories into words. Memories are particularly evident when

• experimental conditions are similar to those of real life
• motivation is high
• retrieval is strengthened by reminders and repetition.

The Active BrainThe crucial insight from information processing is that the brain is a very active organ, even in infancy, so that the particulars of experiences and memory are critically important in determining what a child knows or does not know. Soon generalization is possible. In another study, after 6-month-olds had had only two half-hour sessions with a novel puppet, a month later they remembered the experience—an amazing feat of memory for babies who could not talk or even stand up (Giles & Rovee-Collier, 2011).

Active Learning The objects and people that these infants experience influence their brain development and memory.

MARINA RAITH/GETTY IMAGES

Other research finds that toddlers transfer learning from one object or experience to another. They learn from many people and events—from parents and strangers, from other babies and older siblings, from picture books and family photographs (Hayne & Simcock, 2009). The dendrites and neurons of the brain change to reflect early experiences and memories. Infants do not simply copy what they have seen, they think about it. For example, 15-month-old infants were shown an adult playing with a toy in a particular way. A day later, they were given another toy, one they had never seen. They tried to play with it as they remembered from the day before. This was especially true if, on the previous day, the toddler had also been allowed to play with the toy (Yang et al., 2010). Action strengthens memory.

Memory Aid Personal motivation and action are crucial to early memory, which is why Noel has no trouble remembering which shape covers the photograph of herself as a baby.

LUCAS OLENIUK/TORONTO STAR VIA GETTY IMAGES

Many studies show that infants remember not only specific events and objects, but also patterns and general goals (Keil, 2011). Some examples come from research, such as infants’ memory of syllables and rhythms that they have heard, or their understanding of how objects move in relation to others; additional examples arise from close observations of babies at home, such as their understanding of what they expect from Mommy as compared to Daddy, or what details indicate bedtime. Every day of their young lives, infants are processing information and storing conclusions.