2: Brain and Cognitive Development Flashcards
Brain Structure
-what is the brain made of, and how are its pieces put together
Brain function
-what does the brain do
ventricles and cerebrospinal fluid
- fluid filled cavities inside the brain
- CSF acts a protective cushion, supplies nutrients, removes waste-products
subcortical structures
- below the cortex
- thalamus, midbrain, pons, medulla oblongata, spinal cord
cortex
- highly develop more in humans than in any other species
- major focus of cognition research
- consists of grey matter and white matter
- made of: skull, meninges (dura matter, arachnoid mater, pia mater)
white matter
-made of myelinated axons
grey matter
-made of cell bodies and dendrites
neurons
cell body (soma) –>dendrites –> axon –> axon terminals
dendrites
-receives information
axons
-where information travels
synapses
- neuron to neuron connection
- electrical signal within the axon turns into chemical signal (neurotransmitter) that travels across synapse
- part of neuron that release chemical signals
myelin
- white fatty substance
- helps info travel faster
the brain supports cognition and behavior … how do wee know this?
- when a person engages in a cognitive task, there is corresponding activity in the brain
- when the brain is impaired, cognition is also impaired
- when the brain is stimulated/activated, cognition can be ‘activated’
3 methods for revealing links btw brain and cognition
- EEG/ERP
- fNIRS
- fMRI
EEG/ERP
-electrical sensors detect changes in neural activity directly (measures ELECTRICAL SIGNALS from populations of firing neurons )
fNIRS
-near-infrared light sensors detect changes in OXYGEN CONCENTRATION OF BLOOD FLOW as consequence of firing neurons
fMRI
-magnetic principles detect changes in OXYGEN CONCENTRATION OF BLOOD FLOW as consequence of firing neurons
How does language-learning in hearing children acquiring a spoken language compare to deaf children acquiring a gestural/sign language?
- we compare brain activity
- brain activity was the same for both groups
prenatal development steps
- ectoderm formation
- neurogenesis
- cell migration
- differentiation
- synaptogenesis
ectoderm
- outer layer
- gives rise to brain
- folds into neural tube
neurogenesis
premature brain cells are formed
cell migration
-newly formed cells move to predetermined locations
differentiation
-once cells reach their location, cells develop axons and dendrites
synaptogenesis
-mature neurons can then form synapses (neuron to neuron connection)
postnatal development steps
- synaptogenesis continues
- synaptic pruning
- myelination
role of experience and genes
- genes provide the basic plan for brain development
- environmental experience adjusts this plan
- We can “see” the effects of different experiences (that have consequences for cognitive development) in different underlying brain structure and function!
- early experiences have lasting effects on the Brian and cognition
individuals born blind
-Individuals born blind use their occipital “visual” cortex to process language!
bilingualism
Those who grow up bilingual have different ways of processing language in the brain compared to those who grow up monolingual
neglect alters white and grey matter
Early experiences of extreme neglect are associated with altered white and grey matter in the brain
Why is an understanding of the brain helpful for understanding cognitive development?
- if we know about the brain, we can make inferences about cognition
- if we know about brain development, we can make inferences about cognitive development
- studying the brain can reveal experiences that can have considerable consequences for brain and cognitive development
why are the early years so important
- During these early years, the most drastic brain development occurs
- drastic brain development happen in early life, and when the brain is developing and undergoing massive reorganization like this, it is particularly ‘open’ to effects of experience
- Most of these critical/sensitive periods occur in the first few years of life
sensitive period
- time in development during which the brain is particularly responsive to experiences in the form of patterns of activity
- if experience happens after the time it will have some effect but not fully
critical period
Time in development during which the brain is responsive to experiences, and the presence or absence of an experience during this time results in irreversible change
-if experience doesn’t happen during a specific time it will never happen
experience-expectabt development
- development that occurs as a result of basic experiences common to a species
- applies to all members oof a species and critical for survival
- The brain is ‘prewired’ to respond to certain experiences, and the way the brain develops as a result of these experiences is very similar across members of the species.
experience-dependent development
- development that occurs as a results of experience unique to certain individuals
- experiences not met universally by all members of the same species
- brain develops differently based on these unique experiences
why do we have critical/sensitive periods?
- Best thing is to have a malleable/flexible system early on to adapt to its current environment (sensitive), and then to become stable for efficient and effective use in adulthood (critical)
- critical periods are adaptive
Nelson et al., 2007 results demonstrate a critical or sensitive period
-sensitive period for the effect of social intervention on IQ
