Unformatted text preview: Early Stimulation and Deprivation: Ch. 5 Overview McGraw study: Jimmy & Johnny Nature vs. Nurture Programs for Early Motor Dev't Concepts & Rationale for Early Stim Effects of Early Deprivation Jimmy and Johnny
No Exercise Exercise Jimmy & Johnny Twins (fraternal) 1st year: no differences in motor skills 2nd year, Johnny (13 m) End of 2nd yr, Jimmy trained (22 m) m mastered climbing, traversing slopes, bicycling took longer to acquire skills never gained same degree of confidence or efficiency in movement. Interesting results: Early Stimulation: NO effect on . . . Phylogenetic skills: Fundamental motor skills Aquatic exposure Tricycling Argues for "Readiness" Johnny trained at 11 mo but took interest only at 19 mo & mastered at 21 mo PROFOUND differences in some areas: Advantage Johnny: Analytical/Problemsolving skills (Blocks; Rope climbing) Aggressive Attitude in trying new skills Confounds in the McGraw Study Johnny: chosen due to developmental delay at birth??!!? had flaccid muscle tone, weak reflexes Note: fraternal twins Johnny's training may, have led to "catch up"; Training = Achieves milestones at "normal" ages. Incomplete experimental control: End of lab day, mom/dad played w/ Jimmy, Johnny, exhausted from lab activity, slept. Nature and Nurture Nature provides the structure Nature Nurture (experience) molds the structure Nurture Organism >>> <<<<Environmental & Task Constraints Readiness: when minimum requirements for a particular Readiness behavior established: then they are "ready" Catchup: power to return to a predetermined pattern or Catchup trajectory after being pushed away from "normal" course Critical Period: A time of particular or maximum sensitivity to Critical Period environmental stimuli 3 concepts arising from J & J "essential antecedent conditions" What necessary requirements...render an individual ready? Physical growth Neural/cognitive ability Motivation Concepts ....Readiness Hypothetical CATCHUP curve The capacity for "catchup" depends on... OnsetTime of deprivation Severity Length of time deprivation persisted Consider Anna's capacity for catchup on physical and language skills begins when? Critical Period (*... in science, `sensitive' & `critical periods' are distinct in meanings) In theory: ... 4 requirements of Critical Period...
1. Timelimit: FROM ___ TO ____ 1. Permanent & durable change 1. Critical periods are specific to behavior 1. Readiness
Appropriate stimuli must be present at crucial sensitive period Q: Theory or Reality? Are individual developmental schedules irrelevant? Are Critical Periods: theoretical or real? BioBehavioral Evidence Songbirds: Must hear birdsong (from mom) within first 100 + days Are Critical Periods: theoretical or real? NeuroPhysiological Evidence: Newborn monkeys: raised in the dark Birth to 36 mo: could not discriminate simple shapes Hubel & Wiesel (Nobel Prize): 1 week of light deprivation = near vision loss Brain altered: Visual Cortex adapts Are there Critical Periods (CP) for specific Human Functions? Still a Theory ... vs. Animal studies ... CP ... YES! Humans: NOT enough clear research! Alternative Theory: Plasticity Although .... Human language learning: e.g. Japanese; Chinese How Effective are Early Motor Dev Programs?
1. 2. 3. 4. 5. Gymboree Swim Programs Suzuki Methods Head Start Programs Infant Walkers Why do parents do this? Future Superstars? http://www.youtube.com/watch?v=9rDr_EX3K Early Motor Dev Programs
How effective? .... NO CONCLUSIVE Studies
Bottomline: Aim for 1. A stimulating home environment: facilitate child's natural dev't. 2. SAFETY, DO NOT COMPROMISE 3. Address individual personality differences and needs Summary: Early stimulation and Deprivation What's clear? ......Early (extended) deprivation CAN/WILL have devastating effects!!!! What's NOT clear?... Early Stimulation ... (recall marathon records, etc..); correlation between success in elementary, HS sports, and eventual success in college or pro sports performance LOW Can have debilitating effects? Trade-offs???? Swim Programs Is infantdrownproofing even possible? Erbaugh has shown that 24 yr olds make gradual improvement in swimming skills 45 yr olds make substantial improvement American Academy of Pediatrics (1985: reaffirmed Feb, `90) Regarding infant swimming programs: "... little justification for swimming or water adjustment programs."
2 "... health risks (Giardiasis and H O intoxication) outweigh potential benefits" Total submersion is to be avoided Reach the AAP at WWW.AAP.ORG Are Critical Periods: theoretical or real? Evidence in Social Development: Newborn monkeys isolated (Harlow, 1960's): Birth6 months Partial reversal: surrogate wooden dummy Full reversal: w/ "gregarious monkeys" Result: crouching, rock back & forth, no play, fight, or sexual interest w/ others ...
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- Spring '08
- critical period, critical periods