PSYC 206 Lifespan Development Bilge Yagmurlu

Chapter Overview Physical Growth Brain Development Motor Development Cognitive Development Conceptual Development The Growth of Attention and Memory

Physical Growth During the first year, babies: Triple in weight Grow about 10 inches Changes in body proportions

Body Proportions 25% 12%

Musculoskeletal System Bones ossify (harden) Increase in muscle mass, length and thickness. Sex difference in physical growth (e.g., skeletal development)

Brain Development Cerebral cortex development Increased myelination of neurons Development of prefrontal cortex Myelination and growth of language-related areas Attentional capacity increases Increased synchrony among the brain areas

Brain and Behavior Neural development: length and degree of branching of neurons approach adult status by the end of infancy Myelination of neurons between prefrontal cortex, frontal lobes and brainstem

Brain and Experience Effects of prolonged deprivation Example: Romanian orphans Importance of first 6 months Effects of lack of experience Experience-expectant and experience-dependent neural connections

Development of the Brain To what extent does experience or the lack of it enhance or impede brain development and function? Experience-expectant process Species-universal experiences are required for fine-tuning neural connections. When expected experiences lack in sensitive periods, then the brain will fail to develop normally Experience-dependent process Have evolved to allow the organism to take advantage of new and changing information in the environment.

Brain and Experience Effects of prolonged deprivation Example: Romanian orphans Limbic system Vulnerability to high stress levels http://www.youtube.com/watch?v=zWgNPLNmEoQ 10

Motor Development Development between 3 and 24 months: Fine Motor Skills Gross Motor Skills

Fine Motor Skills Fine Motor Skills: Reaching and grasping Involve the development and coordination of small muscles Reaching and grasping Manual dexterity

Major Milestones

Reaching and Grasping

Fine Motor Skills By age 2, feed and dress themselves turn book pages cut paper string beads

Gross Motor Skills Gross Motor Skills: Involve the large muscles of the body and make locomotion possible

Progression of Locomotion

Gross Motor Skills Crawling By 8 to 10 months Wariness of heights Special aparatus that gives the illusion of a dangerous drop-off

Control of Elimination Maturation of sensory pathways From reflex to control Must learn to associate sensory signals with the need to eliminate.

Cognitive Development: The Great Debate When does conceptual understanding begin? Piaget’s explanation Other developmentalists’ explanation

Piaget’s Stage Theory Sensorimotor intelligence at birth: understanding the world through one’s own actions and perceptions Representational thinking begins around 18 months Acquisition of knowledge

Alternative Explanation Representational thinking begins as early as birth The conceptual system develops separately from the sensorimotor system

Sensorimotor Substages

Sensorimotor Substages Substage 6: Beginning of Symbolic Representation 18 to 24 months Basing their actions on representations Stage of Representation and Symbolizing: the child uses mental images that can represent actions that are not actually occurring and things not actually present the child uses images, words and actions to stand for objects Important for problem solving, symbolic play, deferred imitation, and the use of language 24

Problem Solving Infant in substage 5 carries out deliberate problem solving, but still relies principally on trial and error Infant in substage 6 pictures a series of events in her mind before acting (i.e., via inference)

Conceptual Development Object Permanence The understanding that objects maintain their identities when they change location, and ordinarily continue to exist when out of sight. The existence of other objects is fundamentally independent of our psychological contact, that is, perception of and interaction with the object

Piaget’s Theory Object Permanence Out of sight does not mean out of existence 27

Object Permanence

Piaget’s Theory Object Permanence Active searching starts at 8 months A-not-B Error: when the child looks in place A, where the object had been previously found, even though the child just observed the object hidden at location B. 29

Alternative Explanation Infants are capable to represent objects they cannot see. There are performance problems tendency to perseverate: memory limitations: Success with 7.5 month old babies if not prevented to reach immediately 30

Alternative Research Methods Violation of Expectations Method Habituate babies to a particular event: Habituation: the infant forms associations and develops specific expectations Then present two variants of the event “possible” under normal circumstances “impossible” 31

Violation of Expectations http://home.cc.umanitoba.ca/~mdlee/Teaching/impossible.html 32

Other Physical Laws Violation of expectations method Initial grasp of various physical laws Example: law of gravity 33

Violations of Expectations 34

Reasoning about Objects Challenges to Piaget’s view of cognitive development: infants cannot reason about objects even if they are aware of their physical properties Counting Categorization 35

Counting 36

Categorization Ability to form categories As early as three months Support from brain studies: electrical activity of brain suggests that basic neurological processes that support early categorization have evolved 37

Eimas and Quinn study (1994) Categorization Trial 1 Trial 2 Test Trial Eimas and Quinn study (1994) 38

Categorization Ability to form categories Study of “generalized imitation” with 9-11-month old babies 39

Categorization Changes in categorization abilities Study conducted with 7-9-11 month-olds. Birds with outstretched wings and airplanes had perceptual similarities. 40

The Growth of Attention and Memory Significance of attention and memory Each plays a role in previously discussed developments 41

The Process of Attention Four distinct phases: Stimulus-Detection Reflex: awareness of some change in the environment Stimulus Orienting: attention becomes fixed on the stimulus Sustained Attention: cognitive processing and paying attention (important for learning) Attention Termination: breaks contact 42

Attention Processing information takes time Younger children need more time to process Show a picture of a puppy Attention and IQ Attention to simple vs. complex stimuli Sesame street vs. computer generated geometric patterns 43

Memory Development of procedural memory Time to forget procedure: kicking to start a mobile Shift from relying on implicit memory to explicit memory 44

Memory Recognizing what has been experienced before Implicit Memory: Explicit Memory: Recalling absent objects and events without a reminder. Requires generating a representation for something that is not present to the senses. 45