Human Development – Lecture 23 – Brain, hormones, sexual
differentiation
Pre-natal tuning (afstemming);
• Motor circuits; feedback and control networks refined (verfijnd) as the infant
moves its limbs.
• Visual circuits; Moving patterns of activity are spontaneously generated
prenatally in the retina (netvlies). Changes provides training data for tuning
(afstemmen) the connections between visual maps.
• Auditory circuits; after birth preference for sounds of their native language.
• Mother tells same story to unborn child, heartbeat and activity goes down
during story
Post-natal tuning;
Many of their development occurs after birth and experience is necessary for correct
development.
Child one weak eye? Place patch over the stronger one forcing the weaker to gain
experience; amblyopia
Only possible during the critical period of plasticity (verandering in de organisatie van
de hersen van individuen als gevolg van ontwikkeling, leren of ervaring)
First 10 years brain twice as active as that of adult
60% of nutrition used by the brain during first year of life. 3 year it is 30% of nutrition.
By 3 years, 80% of synaptic connections are made.
Second decade the growth levels take off and synaptic pruning (snoeien) begins.
Increase experience define the wiring (bedrading) of the infant’s brain.
Brain maturation;
Older regions mature first, higher-order association areas mature last.
Cortical thickness between 4 and 20 years
Older? Less gray matter (synaptic pruning/cell lose)
Adult plasticity and regeneration;
Cause of brain damage; Tumors, infections, exposure to toxic
substances, degenerative disease, closed head injuries,
cardiac arrest.
• Stroke (beroerte) died; swelling
• Stroke survivor; cells lost
• Gunshot died
Brain can reorganize itself through new pathways and connections
• Through practice; motor regions for the skilled (vakman)
• Stimulation for stroke victim rehabilitation (rehabilitatie van beroerte)
• After damage or injury; undamaged neurons make new connections and take
over functionality or establish new functions
Damage to CNS will not recover!
differentiation
Pre-natal tuning (afstemming);
• Motor circuits; feedback and control networks refined (verfijnd) as the infant
moves its limbs.
• Visual circuits; Moving patterns of activity are spontaneously generated
prenatally in the retina (netvlies). Changes provides training data for tuning
(afstemmen) the connections between visual maps.
• Auditory circuits; after birth preference for sounds of their native language.
• Mother tells same story to unborn child, heartbeat and activity goes down
during story
Post-natal tuning;
Many of their development occurs after birth and experience is necessary for correct
development.
Child one weak eye? Place patch over the stronger one forcing the weaker to gain
experience; amblyopia
Only possible during the critical period of plasticity (verandering in de organisatie van
de hersen van individuen als gevolg van ontwikkeling, leren of ervaring)
First 10 years brain twice as active as that of adult
60% of nutrition used by the brain during first year of life. 3 year it is 30% of nutrition.
By 3 years, 80% of synaptic connections are made.
Second decade the growth levels take off and synaptic pruning (snoeien) begins.
Increase experience define the wiring (bedrading) of the infant’s brain.
Brain maturation;
Older regions mature first, higher-order association areas mature last.
Cortical thickness between 4 and 20 years
Older? Less gray matter (synaptic pruning/cell lose)
Adult plasticity and regeneration;
Cause of brain damage; Tumors, infections, exposure to toxic
substances, degenerative disease, closed head injuries,
cardiac arrest.
• Stroke (beroerte) died; swelling
• Stroke survivor; cells lost
• Gunshot died
Brain can reorganize itself through new pathways and connections
• Through practice; motor regions for the skilled (vakman)
• Stimulation for stroke victim rehabilitation (rehabilitatie van beroerte)
• After damage or injury; undamaged neurons make new connections and take
over functionality or establish new functions
Damage to CNS will not recover!
