PSYC 255: CH. 3 - PHYSICAL AND COGNITIVE DEVELOPMENT IN INFANCY

Growth follows two patterns, which are?

• The cephalocaudal pattern.

• The proximodistal pattern.

Cephalocaudal pattern

The sequence in which the earliest growth always occurs at the top with physical growth and differentiation of features gradually working their way down from top to bottom.

Proximodistal pattern

A sequence in which growth starts at the center of the body and moves toward the extremities.

Growth is what?

Episodic, which means it occurs in spurts.

Infants double their birth weight by?

4 months and nearly triple it by 1 year.

Infants grow about ¾ inch per month during the first year, increasing their length by?

About 40% by 1 year.

By the second year, infants have reached?

1/5 of their adult weight and almost ½ of their eventual adult height.

Shaken baby syndrome

Occurs when a baby is shaken and their still developing brain is injured, including brain swelling and hemorrhaging.

At birth, the brain weighs?

About 25% of its adult weight.

By 2 years, the brain weighs?

75% of its adult weight.

The brain has reached its final size by?

Age 6.

How do we assess infant brain activity/development in infancy?

Using:

• Electroencephalogram (EEG)

• Magnetoencephalography (MEG)

• Near-infrared spectroscopy (fNRIS)

Electroencephalogram (EEG)

An electrical measure of brain activity.

Magnetoencephalography (MEG)

Map brain activity by recording magnetic fields produced by electrical currents.

Near-infrared spectroscopy (fNRIS)

Uses very low levels of near-infrared light to monitor changes in blood oxygen during many types of brain activity.

What is the portion of the brain farthest from the spinal cord?

The forebrain.

What does the forebrain include?

The cerebral cortex and several structures beneath it.

Cerebral cortex

Covers the forebrain and has two halves or hemispheres, which are lateralized.

Lateralization

The specialization of function in one hemisphere or the other.

What are the other important parts of the brain that are developing during infancy?

• Cerebellum

• Hypothalamus

• Hippocampus

• Amygdala

• Pituitary gland

Cerebellum

Linked to balance and motor movements.

Hypothalamus

Linked to sleeping, eating, drinking, and reproduction-linked behaviors.

Hippocampus

Linked to some types of memory.

Amygdala

Linked to fear responses.

Pituitary gland

Regulates the hypothalamus and other glands through the release of hormones.

Based on ridges and valleys in the cerebral cortex, scientists distinguish four main areas called?

Lobes in each hemisphere.

What are the 4 lobes?

• Frontal lobe

• Occipital lobe

• Temporal lobe

• Parietal lobe

Frontal lobe

Involved in personality, intelligence, control of voluntary muscles.

Occipital lobe

Responds to visual stimuli and processes information about what people see, such as color, shape, and motion.

Temporal lobe

Involved in hearing, language processing, and memory.

Parietal lobe

Involved in registering spatial location, attention, and motor control.

What are the important areas of the lobes?

• Motor area

• Broca’s area

• Prefrontal cortex

• Primary visual cortex

• Visual association area

• Primary auditory cortex

• Wernicke’s area

• Auditory association area

• Somatosensory area

• Somatosensory association area

Motor area

Voluntary movement, with specific parts controlling corresponding parts of the body.

Broca’s area

Center of speech and language production.

Prefrontal cortex

Linked to complex human behaviors, such as planning, decision-making, and appropriate social responses.

Primary visual cortex

Responsible for conscious processing of the visual field.

Visual association area

Translates basic sensory input into meaningful information.

Primary auditory cortex

Basic processing of sound.

Wernicke’s area

Speech comprehension.

Auditory association area

Processes signals related to speech, music, or basic tones.

Somatosensory area

Involved in perceiving touch and pressure in corresponding parts of the body, with areas of greater touch sensitivity mapping into larger portions of the somatosensory area.

Somatosensory association area

Integrates sensory and motor information and is associated with higher-level cognitive processes such as thinking, problem solving, language, memory, and speech.

Neuron

A nerve cell that handles information processing.

Neurons send what?

Electrical and chemical signals to communicate with each other.

Synapses

Tiny gaps between neurons.

Extending from the neuron’s cell body are two types of fibers, which are?

• Axons

• Dendrites

Axons

Carry signals away from the cell body.

Myelin sheath

A layer of fat cells that encases axons, providing insulation and helping electrical signals travel faster down the axon.

Myelination

The process of encasing axons with fat cells, which can provide energy to neurons and facilitate communication.

Terminal buttons

Sit at the end of the axons and release chemicals called neurotransmitters into the synapse.

Dendrites

Carry signals toward the cell body.

Axons and dendrites are connected through what?

Chemical interactions in the synapse, allowing information to pass from one neuron to another.

Neurons change in two significant ways in the first year of life, which are?

• Myelination

• Connectivity

Myelination

Speeds up neural transmissions.

Connectivity

Creates new neural pathways.

Synaptic pruning

Refers to the disappearance of neural connections that are not used.

Before birth, it is mainly what?

Genes that direct how the brain establishes basic wiring patterns.

After birth, what guides the brain’s development?

Environmental experiences.

In the neuroconstructivist view of brain development?

• Biological processes and environmental experiences influence the brain’s development.

• The brain has plasticity and is context dependent.

• Development of the brain is closely linked with the child’s cognitive development.

In the neuroconstructivist view of brain development, what influences the brain’s development?

Biological processes and environmental experiences.

In the neuroconstructivist view of brain development, the brain has what?

Plasticity and is context dependent.

In the neuroconstructivist view of brain development, the development of the brain is closely linked with the child’s?

Cognitive development.

The neuroconstructivist view is much like the?

Epigenetic view which emphasizes the interaction between gene expression and experience in development.

World Health Organization (WHO) recommends what?

• Infants 0-3 months of age should get 14 to 17 hours of good-quality sleep daily.

• Infants 4-12 months old should get 12 to 16 hours of good-quality sleep daily.

• 1 to 2 years olds should get 11 to 14 hours of good-quality sleep daily.

Infants 0-3 months of age should get what?

14 to 17 hours of good-quality sleep daily.

Infants 4-12 months old should get what?

12 to 16 hours of good-quality sleep daily.

1 to 2 years olds should get what?

11 to 14 hours of good-quality sleep daily.

What type of sleep in infancy takes up a much greater amount of time than at any other point in the lifespan?

REM (rapid eye movement).

Sudden infant death syndrome (SIDS)

A condition that occurs when an infant stops breathing, usually during the night, and dies suddenly without an apparent cause.

Recent research has indicated that there is a positive link between infant sleep and what?

Cognitive functioning.

Nutritionists recommend that infants consume approximately?

50 calories per day for each pound they weigh.

Arnold Gesell

Discovered that infants and children develop rolling, sitting, standing, and other motor skills in a fixed order and within specific time frames.

• He thought that this demonstrated that motor development is an unfolding genetic plan.

Esther Thelen

Proposed the dynamic systems theory, in which infants assemble motor skills for perceiving and acting by putting together a goal, their body, and the environment.

Dynamic systems theory

Infants assemble motor skills for perceiving and acting by putting together a goal, their body, and the environment.

In dynamic systems theory, to develop motor skills, an infant must?

Perceive something in the environment that motivates them to act, and then use these perceptions to fine-tune their movements.

In dynamic systems theory, the development of motor skills involves many factors, which are?

• The development of the nervous system.

• The body’s physical properties and possibilities for movement.

• The goal the child is motivated to reach.

• Environmental support for the skill.

Newborns have?

Basic reflexes which are built in, genetically carried, automatic and involuntary reactions to stimuli.

Gross motor skills

Skills that involve large-muscle activities.

Postural control

Provides a foundation for the development of gross motor skills and is closely linked to locomotion.

Posture is a dynamic process that is linked with sensory information in?

• The skin, joints, and muscles, which tell us where we are in space.

• Vestibular organs in the inner ear: regulate balance and equilibrium.

• Vision and hearing.

Karen Adolf (1997)

Investigated how infants learn to locomote by studying how experienced and inexperienced crawling and walking infants go down steep slopes.

Two important findings from Karen Adolf’s research include what?

• Locomotor experience

• Specificity of learning

Locomotor experience

The primary predictor of adaptive responding on slopes of varying steepness.

Specificity of learning

Learning does not transfer across crawling and walking. When expert crawlers began to walk, they would again make mistakes and fall.

Karen Adolf’s research is a demonstration of?

Perceptual-motor coupling in motor development.

• That is, the infant must integrate perceptual information with the development of a new motor behavior.

Accomplishments in gross motor skills in the first year culminate in the ability to what?

Walk easily.

A development such as walking can be linked to?

Advances in other aspects of development.

The timing of milestones, especially the later ones, vary by as much as?

Two to four months.

What can modify the onset of gross motor skill accomplishments?

Experiences.

Increased _______ in the second year is vital to development of competence, so exploration should not be restricted.

Mobility.

A key theme of motor development in infancy is that an infant’s development of a skill requires?

Behavioral flexibility, which is the ability to do what is necessary to attain life’s everyday goals.

• This Continues to be required as their bodies, environments, and tasks they face change.

Part of this concept of behavioral flexibility is that infants must use what?

Adaptive behavior to find an accurate solution to a current situation and challenge.

Fine motor skills

Involve finely tuned movements.

The achievement of _____ and ________ increases interaction with surroundings, because the better able they are to reach and grasp, the more they will interact with their environments.

reaching; grasping.

By 4 months of age, reaching is guided by?

Proprioceptive cues from muscles, tendons, and joints, not the sight of the limb.

Infants refine their ability to grasp objects by developing two types of grasps, which are?

• The palmer grasp

• The pincer grasp

Palmer grasp

Grip with the whole hand.

Pincer grip

Involves the forefinger and thumb, is a big fine motor achievement toward the end of the first year.

What plays a role in the achievement of reaching and grasping?

Experience.

Amy Needham and colleagues (2002)

Used “sticky mittens” to enhance the active grasping and manipulation of objects in young infants.

• Infants who used the mittens grasped and manipulated objects earlier in their development than infants who did not get to use the mittens.