Flashcards in Lecture 2 - Main Paediatric Issues Deck (15):
Describe the notion of 'critical periods'
a period during someone's development in which a particular skill or characteristic is believed to be most readily acquired.
A developmental stage during which a child is more vulnerable to brain insult and long term cognitive impairment.
When is the, generally agreed upon, major prenatal critical period of development?
Embryonic period from day 18 to 55 is a period of extreme vulnerability to teratogenic ages.
What are experience expectant synapses?
If you don’t have certain experiences then development won’t normally occur
If you don’t have certain experiences/environmental stimulation during critical periods than development won’t occur normally.
What are experience dependent synapses?
* Events that shape brain development, but are not essential in order for brain development to occur, and, to the contrary, often have harmful effects on the brain
* e.g., chronic stress, child abuse are harmful to brain development
*Positive effects e.g., nurturant environment, may also be beneficial for brain development
What is 'Lateralisation'?
The lateralisation (i.e., side of the brain) of specific cognitive functions in the mature CNS.
i.e., that certain areas or hemispheres of the CNS may specialise in specific cognitive functions. and the developmental timing of this specialisation.
What are the two main differing views regarding lateralisation?
(1) that is is inherent at birth OR
(2) that it is a developmental process (dependent on external/environmental input)
##These two views have important implications for early cerebral insult - there is probably a little evidence of both theories.
What is the 'laterality of language'?
The dominant hemisphere taking on a progressively more important role in language; such that by middle childhood (e.g., 5 years) language functions are fixed within the dominant hemisphere
What is the theory of plasticity in childhood?
The idea that the child brain has greater capacity for recovery than the adult brain
What is the theory of vulnerability in childhood?
The idea that the child brain is more vulnerable to the effects of injury relative to the adult brain
Plasticity vs Vulnerability in childhood, which has stronger evidence?
* The debate is argued at both neurological (biological) and functional (Cognitive) levels
* In general, many factors such as severity of lesion, nature of lesion, age at onset, sex and psychosocial factors all determine the developing brains capacity for recovery.
* Generally speaking more evidence for vulnerability over plasticity. - due to cascading and diffuse effects of brain impairment early in development.
What is intrahemispheric maintenance, when and why might it occur?
Intrahemispheric maintenance is when there is an absence of transfer, where skills subsumed by damaged tissue are maintained within that tissue, resulting in maximum dysfunction (no plasticity).
May occur prenatal/perinatal ages, when there is small unilateral lesions; or generalised lesions
What is interhemispheric transfer, when and why might it occur?
Intrahemispheric transfer is when the the brain has significant unilateral damage or small unilateral damage including the language cortex (E.g., hemispherectomy) --> resulting in the transfer of the affected functions to an area in the unaffected hemisphere (often in an analogous area)
Most likely to occur between the ages of 0-2.
What is Intrahemispheric transfer
Intrahemispheric transfer is when brain areas nearby lesions (in the same hemisphere) take-up the cognitive/functional role of that was/should have been in the now-lesioned area.
Children 2-8 years
Explain why a normal performance on testing does not necessarily suggest normal development.
A child may perform normally on a task, but do it in an abnormal way.
(e.g., for example childrens with Williams Syndrome have intact face processing, but they attend to faces in a way that is abnormal - looking predominately at the eyes and ignoring other elements of the face).