CH 5 NOTES- Intro to Dev. Psych
Physical and Cognitive Development in Infancy
VOCAB:
prefrontal cortex: the part of the cortex that is located directly behind the forehead and is important to the development of voluntary movements
Early-life adversity: profound and pervasive deprivation experienced during infancy, often resulting in severe developmental delays
Sleeper effects: the detrimental effects of early-life adversity that occur only later in development
Fine motor skills: motor skills related to the development and coordination of small muscles, such as those that move the fingers and eyes
Gross motor skills: motor skills related to the development and coordination of large muscles; important for locomotion
Locomotion: the ability to move around on one’s own
Visual proprioception: the visual feedback that one gets from moving around, linked to the development of wariness of heights in infancy
Social referencing: infants’ tendency to look to their caregiver for an indication of how to feel and act in unfamiliar circumstances
Piaget’s Sensorimotor Substages:
Exercising reflexive schemas- involuntary rooting, sucking, grasping, looking
Primary circular reactions- repetition of actions that are pleasurable in themselves
Secondary circular reactions- dawning awareness of the relationship of own actions to the environment; extended actions that produce interesting changes in the environment
Basically babies repeat actions to produce interesting changes in their environment
Coordination of secondary circular reactions- combining schemas to achieve a desired effect; earliest form of problem solving
tertiary circular reactions- deliberate variation of problem-solving means; experimentation to see what the consequences will be
Basically deliberate variation of action sequences to solve problems and explore the world
Beginning of symbolic representation- images and words come to stand for familiar objects; invention of new means of problem solving through symbolic combinations
Intentionality: the ability to engage in behaviors directed toward achieving a goal
Object permanence: the understanding that objects have substance, maintain their identity when their location is changed, and ordinarily continue to exist when out of sight
Representations: internal, mental symbols of experience; according to Piaget, the ability to form mental symbols emerges during sensorimotor substage 6
Symbolic play: play in which one object stands for, or represents, another (pretend play)
deferred imitation: the imitation of an action observed in the past
A-not-B error: a pattern of reacting in the object permanence task, in which the infant looks for the hidden object in location A, where the infant had previously found the object, instead of location B, where the infant has just observed it being hidden
Violation-of-expectations method: a test of mental representation in which the child is habituated to an event and then presented with possible and impossible variants of the event
Developing attention:
Phase I: Stimulus-detection reflex. The stimulus-detection reflex signals the baby’s initial awareness of some change in the environment. In this phase (not labeled in the figure), there is a very brief slowing and then quickening of the heart rate.
Phase II: Stimulus orienting. During the second phase, the baby’s attention becomes fixed on the stimulus. As you can see in the figure, the heart rate slows considerably during this period.
Phase III: Sustained attention. In the third phase, the heart rate remains slow as the baby cognitively processes the stimulus. The baby’s entire body may become still, and it is relatively more difficult to distract the baby with a new stimulus. Sustained attention is believed to be a voluntary state; that is, the baby purposefully controls and focuses his or her attention on the stimulus. At this point, the baby is truly paying attention.
Phase IV: Attention termination. In this phase, the baby is still looking at the object but is no longer processing its information. (It takes a moment to break contact with the stimulus.) The heart rate begins to return to prestimulus levels.
SUMMARY:
Physical Growth
Height and weight increase rapidly throughout infancy, especially during the 1st year. Body proportions shift; the head accounts for relatively less of the infant’s length and the legs for relatively more. Soft bones gradually ossify, and muscle mass increases. Girls tend to develop more quickly than boys.
Significantly slower growth rates, known as infant growth restriction or stunting, are associated with developmental delay, infections, and poor nutrition, whereas significantly faster growth rates are associated with the risk of obesity in later childhood.
Brain Development
Increased myelination of axons, along with other changes, such as the formation of neural networks that allow different parts of the brain to communicate and work together, leads to substantial development of the cerebral cortex, including the prefrontal and language-related areas, and to greater synchrony among the brain areas. These changes appear to be vital to the emergence in late infancy of more systematic problem solving, voluntary control of behavior, and the acquisition of language. By late infancy, most of the brain structures that will support adult behavior are present
As shown by studies of orphans who experienced early life adversity, prolonged deprivation in infancy leads to ongoing impairments in intellectual functioning. Because the brain undergoes considerable development between 6 and 24 months of age, lack of experiences during this sensitive period appears to affect both experience-expectant and experience-dependent brain development
Motor Development
As the movements of their hands and fingers become better coordinated during the 1st year, infant perfect their reaching and grasping.With continuing increases in coordination of fine motor movements, by age 2 infants can do much in the way of feeding and dressing themselves and can turn book pages, cut paper, string beads, and stack blocks.
Progress in locomotion leads to the emergence of crawling by 8 to 9 months of age, at which time wariness of heights appears. Walking begins at around 1 year and is made possible by the development of component motor skills and by practice.
Cognitive development
For some developmentalists, including Piaget, young infants are limited to sensorimotor intelligence until about 18 months of age, when they become capable of representational thinking — thinking that is truly conceptual.
For other developmentalists, very early in development, if not from birth, infants are capable of representing and understanding the world conceptually. A rudimentary conceptual system develops separately from, although in close association with, the sensorimotor system.
In Piaget’s stage of sensorimotor development, infants acquire knowledge exclusively through motor actions directed at their immediate environment and guided by their senses.
Following the first two of Piaget’s substages, in which infants learn to control reflexes and then to modify and repeat actions involving their bodies, infants move through four additional sensorimotor substages:
In substage 3, infants 4 to 8 months of age become capable of secondary circular reactions, repeating actions that involve objects, not simply those that involve their own body.
In substage 4, at 8 to 12 months of age, infants begin to display intentionality, engaging in goal-directed behavior.
In substage 5, the stage of tertiary circular reactions, infants 12 to 18 months of age deliberately vary their actions, thus experimenting in order to explore the world.
In substage 6, which occurs between 18 and 24 months of age, infants begin to base their actions on representations. The ability to represent mentally is crucial to problem solving, symbolic play, deferred imitation, and the use of language.
The sequence and timing of the behaviors associated with Piaget’s sensorimotor stages have been replicated with infants in a wide range of societies. However, critics of Piaget argue that young infants have representational competence that traditional Piagetian tests do not enable them to reveal.
Conceptual Development:
For Piaget, object permanence emerges only gradually, beginning at about 8 months. Thus 8- to 12-month-olds continue to search for an object in a location where they discovered it even when they have seen it hidden again in a different location. Other developmentalists have argued that the infants’ behavior reflects not a lack of representational competence but performance problems — specifically, memory limitations or a tendency to perseverate, repeating the same movement or the same successful strategy.
Using the violation-of-expectations method researchers have obtained results suggesting that infants as young as 2½ months are capable of representations
According to the dynamic systems approach, cognitive development in infancy involves not a shift from sensorimotor to conceptual intelligence, but the growing abilities to coordinate all the various systems involved in sensorimotor and conceptual intelligence
The formation of representations may depend heavily on experience. In experiments, infants’ typical preference for a novel object over a familiar object is reversed when the room is darkened, perhaps because experience with an object leads to a stronger representation of it
Experiments using the violation-of-expectations method suggest that infants as young as 3 months of age have an initial grasp of various physical laws concerning the behavior of objects, such as the law of gravity.
Other experiments using simplified tests suggest that, contrary to Piaget’s view, young infants may be capable of understanding basic numbers and cause–effect relationships. Of particular interest is infants’ abilities to categorize, evident as early as 3 months of age. Developmentalists are uncertain whether changes in categorization abilities during infancy simply reflect improved perceptual abilities or signal a change from categorization based only on perceptual features to categorization that is also conceptually based.
The Growth of Attention and Memory
Developments in attention and memory are crucial to all the other cognitive changes of infancy
Infants are increasingly able to sustain their attention; in addition, they are increasingly fast at processing information about the targets of their attention. These changes are reflected in experiments showing that attention to simple visual displays decreases after the first few months but attention to complex stimuli increases
Memory increases rapidly during the 1st year, as shown by the increase in the length of time over which infants are able to remember procedures such as how to make a mobile move