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15 Cards in this Set
- Front
- Back
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Brain development |
- At infancy the brain contains all the neurons it will have despite being a quarter the size of an adult brain - Infant begins life with all of its survival mechanisms developed - Allows the automatic functions of the heart beat, breathing rate, circulation and feeding. - six months: three quarters of an adult brain - age six: 90-95% fully sized brain - mid- 20s: the brain is fully sized |
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Development of Myelin |
- Growth and development of white, fatty substance around axons - contributes to the increase in brain size - enables neurons to increase speed and efficiency of the neural impulse - starts before birth and continues through childhood, adolescence and into adulthood - most intense period of myelination occurs shortly after birth |
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- emerges in the hindbrain then spreads overtime into the midbrain and forebrain - sensory areas of the cerebral cortex are myelinated before the motor areas - association areas of the cortex are myelinated last |
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Synaptogenesis |
- "formation of new synapses between brains neurons" - Synapse occurs between an axon terminal and dendrites - neurotransmitters initiate communication between these neurons - dendrites grow more branches the amount of interconnections due to synaptogenesis also increases - occurs quickly in sensory and motor neurons rather than association areas - as it allows the brain to respond to environmental cues |
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- synapses form long before birth
- after birth, synaptogenesis occurs rapidly within the first 15 months - total number of synapse increase by 10 - infant has too many neural connections than it will ever need so pruning takes place |
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Synaptic pruning |
- neural pathways that are unused or weak are removed - elimination of dendrites - allows strong, functional neural pathways to develop - increase effectiveness between neurons - occurs first in sensory areas and last in association areas - age 30: frontal lobe pruning has stabilised - adolescence: almost half synaptic connections have been removed |
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Frontal lobe development |
- prefrontal cortex last section to mature - during childhood frontal lobe connections via synaptogenesis increases significantly |
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Brain injury |
- any brain damage that interferes or impairs normal functioning of the brain, either temporarily or permanently ( common cause a stroke) - acquired brain injury, brain damage that occurs after birth - traumatic brain injury may be caused by an accident, an intentional blow, violent shaking of the head - sudden onset, due to blow, infection, stroke or drug use - insidious onset, due to prolonged drug use or tumour - occurs when blood vessel becomes clogged or bursts
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Biological, psychological and social changes due to frontal lobe injury |
- when damage occurs to any section of the cerebral cortex there is inevitably a behavioural consequence - type and severity of patient outcomes depends upon how much of the cortex is damaged and where the damage is |
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Phineas Gage |
- Behavioural changes due to a work accident that had damaged his prefrontal cortex Biological changes: motor activity and voluntary movements reduced Psychological changes: Lack of responsive and concern, forgetfulness Social changes: break down in personal relationships and loss of social support |
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Spatial neglect |
- individuals unable to notice objects on either their left or right sides - Damage in the rear of the parietal lobe in the RH will cause patients to neglect their left side - if damage occurs to LH parietal lobe the outcome is not as severe - neglect noticed in visual fields but can also occur in hearing, touch and even movement |
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Brain Plasticity |
- ability of the brain to change in response to experience - due to changes at the synapse of neurons, specifically synaptogenesis - internal changes include new neural pathways, new connections between existing and new neural pathways in both neurons and glial cells - two types of neural plasticity- developmental and adaptive |
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Developmental plasticity |
- changes in neuronal connections as a result of interactions with the environment as a consequence of developmental processes Changes occur as a result of 4 processes: - Synaptogenesis - Myelination - Synaptic pruning - Neural migration - movement of neurons to different parts of the brain |
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Adaptive plasticity |
- ability of the brain to compensate for a loss of function and/or maximise functioning in the event of brain injury - recovery, and the period of psychological stabilisation may take months or years but evident that children recover faster and fully than adults |
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- effectiveness and efficiency of brain recovery depends on where and how severe the brain injury is:
Rerouting: new connections are made between active neurons Sprouting: growth of new dendritic or axonal fibres which allow for new connections between neurons -through adaptive plasticity functions that were localised in a brain area may transfer to other undamaged area to address the change |
