Physical DevelopmentPhysical Development• In Utero:– Zygote: conception-2 weeks– Embryo: 2 weeks-2 months (8 weeks)

• Cell differentiation– Fetus: 2 months to birth

• Functioning organ systems develop, early reflexes seen (e.g. non-nutritive sucking)

• Infancy: – Very slow development, comparatively– Brain development takes off: synaptic growth then

pruning– Spurts of growth throughout childhood (body and

brain)

Physical DevelopmentPhysical Development

• From birth:– Reflexes:• Grasping• Rooting• Foot flexing

– Sensory• Discriminate high and low sounds, vowels, mother’s

voice• Very near-sighted, but can discriminate brightness and

color and track moving objects

Physical DevelopmentPhysical Development• Gross motor skills

– 7-8 months: sitting up– 8-10 months: crawling– 10-12 months: “cruising”– 12-15 months: walking– 2 years: hopping on one foot, kicking– 4 years: jumping rope, balancing on one foot

• Fine motor skills– 1 month: reflexive grasp– 4 months: reaching, hands at midline– 6 months: reach precisely, grabs at objects– 12-14 months: throwing objects– 2 years: unscrewing jars– 3 years: cutting with scissors, holding pencil– 6 years: writing, drawing shapes

Physical DevelopmentPhysical Development• Brain:– Making/pruning connections

• Attention– Infants have little selective attention. If something is

interesting, they will look at it.– Development of Prefrontal cortex (PFC)development of

attentional control• 1-2 years: single-channeled attention: can concentrate on task,

but not external verbal/visual stimuli• 2-3 years: still single-channeled, but with help can adjust focus

back and forth• 3-4 years: single-channeled, but can adjust focus on their own• 4-5: two-channeled, but short attention span• 5-6: audio, visual, and manipulatory channels integrated

Physical DevelopmentPhysical Development

Physical DevelopmentPhysical Development• Brain:– Making/pruning connections

• Attention– Infants have little selective attention. If something is

interesting, they will look at it.– Development of Prefrontal cortex (PFC)development of

attentional control• 1-2 years: single-channeled attention: can concentrate on task,

but not external verbal/visual stimuli• 2-3 years: still single-channeled, but with help can adjust focus

back and forth• 3-4 years: single-channeled, but can adjust focus on their own• 4-5: two-channeled, but short attention span• 5-6: audio, visual, and manipulatory channels integrated

Jean Piaget (1896-1980)Jean Piaget (1896-1980)

• Swiss Psychologist• “Father of Developmental

Psychology”• Creator of “constructivist theory of

knowing”

Stage Theory of DevelopmentStage Theory of Development• Children progress

through a series of stages of development

• Long periods of time spent in each stage, abrupt transition to next stage

SensorimotorStage

SensorimotorStage

PreoperationalStage

PreoperationalStage

Concrete Operations

Stage

Concrete Operations

Stage

Abstract Operations

Stage

Abstract Operations

Stage

Sensorimotor StageSensorimotor Stage

• From birth to ~2 years old• Experience the world through senses and

motor movements (progress from reflexes to deliberate directed movements)

• Schema: mental representation of what things are/how we deal with them

• Object Permanence• Internal Representation• Egocentrism

PreoperationalPreoperational

• 2-7 years of age• Symbolic thought• Egocentrism• Animism• Failure of Conservation

Concrete OperationalConcrete Operational

• Ages 7-11• Logical thinking• Development of rational, “operational”

thought• Can think logically about object, if they are

able to manipulate it.

Formal OperationalFormal Operational

• 11 and up• Abstract thinking• Can think logically about objects even if not

present• Problem solving

Arguments against PiagetArguments against Piaget

• Argument 1: Discrete stages do not properly explain child development– A lot of child knowledge is more context-

dependant

• Argument 2: Young children are actually more advanced than Piaget gave them credit for.

Using Habituation in InfantsUsing Habituation in Infants

• More boring babies!• Procedure: Show baby

image/scene until he/she no longer looks at it.

• Test: Introduce new image/scene.

• If baby looks longer at new image, it’s perceived as new.

Drawbridge ExperimentDrawbridge Experiment• Child habituated on (A)• Child sees possible

outcome (B) and impossible outcome (C)

• Child looks more at impossible event than possible event

• Child knows block is there, even if he can’t see it

Numerical Reasoning RevisitedNumerical Reasoning Revisited

• Number Conservation Task

• Children are confused by experimenter’s questions- why is he asking the same question again?

• Knowledge still tentative, but there

An alternative theory: An alternative theory: Information ProcessingInformation Processing

• Human brain as computer– Representation of

information– Processes: applied on

representations– Limitations: memory

• Development = change in processing abilities

Rehearsal as Information ProcessingRehearsal as Information Processing

• Increase in rehearsal speed, increase in memory

• Older children actively use rehearsal as a memory strategy and remember more

The Sociocultural accountThe Sociocultural account

• Vygotsky• Cognitive development happens in the

context of social interaction• Development happens through internalization

of socially shared processes• Zone of Proximal Development