Child Development

locomotion

-the ability to move one's self from one place to another--begins with rolling from the supine (back-down) to the prone (front-down) position. By seven months many infants can pull with their arms and push with their legs to drag their bodies forward

childproofing

As your baby grows and begins to crawl, creep, walk, and run around your house, she will be become increasingly susceptible to accidents and injury. To ensure her safety, you must take a collective set of precautions known as

pictorial information

Photographs, though they are flat, give various pictorial cues that create the impression of three-dimensionality; The ability to process pictorial depth cues develops between 5 and 7 months.

Why so many nerve cells and synapses

To provide the potential for adaptation

fovea

a densely packed set of highly sensitive cells at the center of the retina--can discriminate the detail necessary to perceive objects.

SEPARATING FIGURE FROM GROUND

differentiating objects out as separate entities

method of event-related potentials

electrodes are attached to the scalp of the infant to measure changes in electrical activity in the brain in response to changing stimuli presented to the infant. Variations in brain wave patterns to different stimuli are electrodes are attached to the scalp of the infant to measure changes in electrical activity in the brain in response to changing stimuli presented to the infant. Variations in brain wave patterns to different stimuli are interpreted as indications that the infant has perceived the stimuli as different.

Crawling

follows about a month later when the baby is up on all four limbs with the stomach suspended above the floor. Most babies are walking by their first birthday

SCANNING OBJECT CONTOURS

neonates fixate almost exclusively on the external contour of a complex patterned stimulus and tend to ignore interior detail; however, infants switch to scanning mostly internal features

perspective

objects of equal size are judged closer or farther away by their relative size in a picture

superimposition

objects that block out the view of other objects are judged to be closer

creeping

pull with their arms and push with their legs to drag their bodies forward (the stomach is in contact with the floor)

high-amplitude sucking technique

researchers use of a special pacifier with an internal sensing device that indicates when the infant's rate or intensity of sucking increases. An increase sucking activates a device that generates a visual or auditory stimulus. If the infant likes the stimulus, it keeps sucking; if not, it will decrease its sucking.

PERCEPTION OF SPEECH SOUNDS

scientists now believe that newborns possess innate perceptual mechanisms that facilitate the development of language

POSTURAL CONTROL

1. holding the head steady while moving (at 2 months), 2. sitting without support (at 5 months), 3. getting into a sitting position (by seven months), 4. pulling to standing (by 7-8 months) and finally... locomotion

pincer grasp

9-10 months; using the thumb and a single finger. This ability marks the beginning of precise finger control of objects. Between 4 and 6 months, infants grasp most small objects easily

habituation-dishabituation procedure

As a particular stimulus is repeated over and over at the same intensity, infants habituate to the stimulus - the intensity of their responses steadily decrease. When habituation has lowered the response rate to about one half of the original level, the researcher introduces some subtle change in the stimulus and records corresponding changes in the infant's responses. If the infant does not alter his or her behavior to the change in stimulus, the researcher concludes that the change was not perceived. However, if the infant changes response (or dishabituates), the researcher infers that the child has discriminated the change in the stimulus.

THE FACE AS A PREFERRED OBJECT

As expected, scientists have confirmed that the human face takes on special significance for the young infant but this preference for faces does not appear to be innate--some learning is involved. Once the infant has discriminated and comes to prefer the caregivers face, that face will express emotion, give permission, encourage, reinforce, punish, cajole, tease, sympathize, and arouse in an infinite series of transactions with the infant's emerging facial expressions.

Binocular information

Each eye views nearby objects from a slightly different angle, thus producing two slightly different retinal images. The infant must learn to blend these slightly discrepant views into a single image and to estimate the distance of the object. The infant's ability to interpret binocular cues is reasonably well developed by about four months

plasticity

If one part of the nervous system becomes damaged or unable to function, other parts of the system will be able to take over.

visual cliff

Most babies who could crawl are sensitive to the visual kinetic depth cues and stop when they perceive the droop; showed that even 3 month old babies perceive depth cues, but only those who had been in walkers showed fear. Apparently, experience propelling oneself through space--by crawling or "walking"--is essential to learning to recognize depth cues as signs of danger.

SMELL

Newborns can smell and this sense develops rapidly during the neonatal period. Newborns, like adults, turn away from strong pungent odors, smile when exposed to the smell of bananas, and wrinkle up their faces to the smell of rotten eggs

TASTE

Sensitivity to taste is present soon after birth; The sense of taste develops quite rapidly during the first month; By 4 months, infants show interest in salty liquids

pruning

Synapses and cells that are not stimulated are eliminated through a massive and continuing destructive process

synaptogenesis

Synapses begin to develop in very large numbers prenatally and continue to increase in extraordinarily large numbers through the first 3 years of life in a process called...; At its highest level of synaptic density at the end of the third year , it is estimated that a single neuron may form 15,000 synapses with adjoining nerve cells. At that point in development, the brain contains approximately 1,000 trillion synapses in the nervous system

CHANGES IN HEIGHT AND WEIGHT

The average newborn weighs 7 1/2 pounds and measures about 20 inches from head to toe. In the next two years, the infant will grow faster than at any later period, including adolescence. Birth-weight typically doubles by five months (to 15 pounds) and triples by the first birthday (to 22 pounds). The baby gains only 5 to 6 pounds in the second year, and 4 to 5 pounds in the third year. Height increases by about half in the first year (to 30 inches) and by an additional 5-6 inches in the second year. Despite the overall rapid growth during the first two years, the rate of growth tapers off from the first to the second year.

kinetic information

When the infant's head moves from side to side, the image of a near object moves more rapidly across the retinal surface than the image of a more distant object. The infant's ability to detect and interpret this difference emerges slowly during the first months life

retina

a complex layered tissue on the back surface of the eye made up of light-sensitive cells and nerve cells. The retina transforms visual information into neural impulses. The optic nerve carries the impulses to the brain for interpretation.

ciliary muscles

bend (or focus) light waves reflected off objects at varying distances toward the fovea. However, control of those muscles develops gradually over the few weeks of life, and adult-like ability to make out objects at varying distances is not achieved until three months

reflexes are controlled by...

clusters of cells within the brain stem, located at the upper end of the spinal cord, just below the cortex

central nervous system (CNS)

constitutes the most complicated physical structure in the body. All aspects of development--everything from thinking and making friends to walking and tying shoes--are mediated either directly or indirectly by central nervous system activity.

smooth pursuit movements

enable infants to track the movement of objects in space; Thus by the end of the fourth month, infants' eyes can locate objects in the visual field, focus on individual objects at varying distances, move from object to object, and track their motion through space.

reflexes

involuntary stimulus-response patterns. a congenital "wired-in" circuit in the nervous system that provides for a specific behavioral response to a fairly specific form of stimulation.

proliferation of nerve cells

is extremely rapid during the early prenatal stage, adding 250, 000 new nerve cells each minute, resulting in approximately 100 billion nerve cells in the newborn

rhythmical movement stereotypies

repetitious movement patterns that help infants to slowly learn to control their body parts; One of the more disconcerting rhythmic activities of babies is headbanging

visual acuity

sharpness of vision; is quite low Since the retina and the fovea are not mature at birth

synapse

structured to allow Impulses to be conducted from cell to cell by chemicals known as neurotransmitters.

visual preference method

the researcher presents pairs of stimuli to the baby. The researcher observes the infant from a hidden vantage point between the two stimuli, detects which stimulus the infant is looking at by the reflection of the fixated stimulus on the pupil of the infant's eye, and records changes in fixation. Using this procedure, one study (Fantz, 1963) the researcher presents pairs of stimuli to the baby. The the researcher observes the infant from a hidden vantage point between the two stimuli, detects which stimulus the infant is looking at by the reflection of the fixated stimulus on the pupil of the infant's eye, and records changes in fixation. Using this procedure, one study showed that 2-day- old infants discriminate among visual stimuli and preferred patterned stimuli such as faces and concentric circles to disorganized arrays of lines.

OBJECT PERCEPTION

the young infant has no familiarity with the vast majority of images that come into its view. The very young infant sees various shapes, virtually all of which are unfamiliar.