Lecture 3-Intelligence Flashcards
2 techniques in studying neural changes
positron electron tomography (PET):3D image of functional processes in the body
functional magnetic resonance imaging (FMRI):detects neural activity in brain by detecting associated changes in blood flow related to changes in energy used by brain cells.
Neural developments over the lifespan
infancy: brain growth
childhood: lateralisation/plasticity-organs change and develop
adolescence: cortical changes
adulthood: gain-loss dialectic
neural developments in infancy
-birth: brain 25% adult weight
-2 years: brain 80% adult weight
SUBCORTICAL STRUCTURES-at birth, most mature
CEREBRAL CORTEX-most immature, particularly frontal cortex
dendrites+synapses+cortex? what happens at infancy..
-rapid growth of dendrites and synaptic connections among brain cells combines with cortical maturation
resultant behaviours: capacity to control neck muscles/motor coordination for sitting upright/gains socialization
Cortex take-over?what happens..
- cortex takes over voluntary control from lower brain centre
- changes in:reflexes/attention/sleep patterns
- positive babinski sign
4 factors in increased brain weight in infancy
neurons
dendrites
synapses
myelination
dendrites
-addition of dendrites and axon terminals to form interconnections with each other.
TRANSIENT EXUBERANCE: initial dramatic burst in growth of dendrites
-allows brain to organise itself in response to stimulation from outside world.
synapses
- growth of synapses, followed by pruning to simplify brains wiring
- streamlines brains activities with maximum efficiency
myelination process
-speeds transmission of neural impulses
-rapid information processing
-brain control over motor functioning
GLIAL CELLS: myelination process governed by this, continues to grow throughout life, unlike neurons
2 developments of cortex
medial temporal lobe: 6 to 12 months-remember and imitate actions/recognize picture of object held in hands/crucial in language development.
frontal temporal lobe: later childhood-higher cognitive functions
primary neural developments in childhood
- increase in brain size
- myelination
- lateralization
- brains plasticity:growth and flexibility to change in response to experience
increase in brain size in childhood
-90% of adult volume by age of 5
GIEDD (2003): mri of brains of 1500 healthy children, growth in brains grey ARBORIZATION
-enhances plasticity in response to early experience
3 myelination process in childhood
- sensory pathways:birth
- hippocampus: 6 years-improved memorisation ability in preschool
- reticular formation: brainstem, alertness and arousal + frontal cortex- process complete in adolescence
lateralisation in childhood
left hemisphere : speech-comprehension, problem solving,analytic thinking, language skills and reading
right hemisphere: music perception, artistic and musical, form/shape perception,spatial cognition, intuitive thought, creative inspiration
-specialisation for handedness and language begins in preschool and ends in puberty
-critical for language development
-implications for second language learning.
neural developments in adolescence
-cognitive abilities are more developed than in childhood
in comparison: abstract/metacognitive/multidimensional/relativistic
3 aspects linked with behavioural/emotional and cognitive development during adolescence
-cortical synapses
-neurotransmitters in limbic system
synaptic pruning and myelination of the prefrontal cortex
cortical synapses
growth means more efficient and focussed
neurotransmitters in limbic system
more emotionality
more responsive to stress
less responsive to rewards
synaptic pruning and myelination of the pre fontal cortex
more efficient at high level cognitive tasks
importance of brain exercise
- brain cells continue to grow and regenerate throughout adult life
- exercising the brain: wards off decline/enhances psychological functions