6B. Infant, Child, and Adolescent Brain Flashcards
Average brain weight of newborn baby
370 grams or 13 ounces (slightly less than a pound)
Average weight of adult brain
3 pounds or 1.3-1.4 kg
Growth rate of brain immediately after birth
1% per day
Growth rate of brain 3 months after birth
0.4% per day
Volume of brain 90 days after birth compared to volume at birth
64% larger
Fastest growing region of brain
Cerebellum. More than doubles its volume during first 90 days
During first three months of life, number of neurons in cortex increases by ____ to ____%
23-30%
By __ years of age, brain has reached __% of its adult size
5, 90%
2-year old’s brain has ___% more/less? synapses than adult brain
50% more synapses
2-year old’s brain is __% the size of an adult brain
80%
Compare human brain development to that of other animals
Humans are born with less developed brains, they take longer to mature. Develop extensively after birth, allowing them to be easily shaped by experience
Changes in neural connections during critical periods coincide with…
High rates of learning
Brains develop until…
30 years of age
Gray matter density of most regions ______ with age, but ______ in ____________ until ____
Gray matter density of most regions declines with age, but increases in left temporal lobe until age 30
Describe brain development in 20-somethings
Changes in where myelination occurs. Earlier in life, more myelination is found in visual, auditory, and limbic cortices. Closer to 30, frontal and parietal neocortices become more myelinated, which helps working memory and higher cognitive functions
Plasticity is crucial for…?
Critical periods
Plasticity is unique to humans. True or false?
False.
Two types of plasticity
Experience-expectant and experience-dependent
Experience-expectant plasticity
Integrating environmental stimuli into normal developmental patterns. Being exposed to common experiences (language, faces, touch) during critical periods is essential for healthy brain function
Experience-dependent plasticity
Continuing changes in organization and specialization of brain regions as result of life experiences that are not universal or anticipated. Includes skills developed throughout life, with no critical period for their acquisition. Occurs all the time.
