College 1.
Why a Developmental perspective?
Developmental disorders differ from acquired disorders
•Developmental disorders: detected early in childhood, require early intervention to minimize
associated deficits and protect development of unaffected functions
•Acquired disorders:
–different causes
–different consequences for recovery: children’s brains are developing rapidly →
•greater plasticity – Kennard principle (posits a negative linear relationship between age
of a brain lesion and the outcome expectancy: in other words, the earlier in life a brain lesion
occurs, the more likely it is for some compensation mechanism to reverse at least some of the
lesion's bad effects).
•greater vulnerability
Diagnosis is different
•A child’s behavioral repertoire changes continuously making it difficult to determine when a
process is dysfunctional
–Behavior considered “normal” at one age is considered deviant at a different age e.g.
language, self regulation
–The same observable behavior can be mediated by different underlying mechanisms at
different ages → disorders are not immediately apparent
–Not all behaviors are sufficiently well-developed to be directly measurable at all ages
e.g. cognition in infants
Prognosis for long-term development are less clear for neurological or anatomical reasons
–positive consequences of plasticity
–negative consequences of plasticity: “crowding” (girl, 7 years, lesion in left fronto-
temporal hemisphere. Right hemisphere will take over langauge functions, so right
hemisphere becomes crowded. Visual-perceptual problems are to be expected!)
–greater vulnerability
•for functional or behavioral reasons
–positive: behavioral compensation
– negative:“growing into deficit”
TBI: Children versus Adults
Dose-response relation the same (more cerebral pathology leads to greater impairment).
However, consequence in adults is specific, consequence in children is global! Recovery patterns
differ in favor of the more mature brain (NOTE: this is against the Kennard principle!). In
children there is an ongoing interaction cumulative and often global dysfunction and deficits
often emerge later in life (growing into the deficit). In adults there are more immediate
consequences.
Clinical vs experimental neuropsychology
•Clinical neuropsychology measures skills in the individual child to sharpen intervention
•Theoretical neuropsychology is model driven to investigate brain-behavior relationships
Why a Developmental perspective?
Developmental disorders differ from acquired disorders
•Developmental disorders: detected early in childhood, require early intervention to minimize
associated deficits and protect development of unaffected functions
•Acquired disorders:
–different causes
–different consequences for recovery: children’s brains are developing rapidly →
•greater plasticity – Kennard principle (posits a negative linear relationship between age
of a brain lesion and the outcome expectancy: in other words, the earlier in life a brain lesion
occurs, the more likely it is for some compensation mechanism to reverse at least some of the
lesion's bad effects).
•greater vulnerability
Diagnosis is different
•A child’s behavioral repertoire changes continuously making it difficult to determine when a
process is dysfunctional
–Behavior considered “normal” at one age is considered deviant at a different age e.g.
language, self regulation
–The same observable behavior can be mediated by different underlying mechanisms at
different ages → disorders are not immediately apparent
–Not all behaviors are sufficiently well-developed to be directly measurable at all ages
e.g. cognition in infants
Prognosis for long-term development are less clear for neurological or anatomical reasons
–positive consequences of plasticity
–negative consequences of plasticity: “crowding” (girl, 7 years, lesion in left fronto-
temporal hemisphere. Right hemisphere will take over langauge functions, so right
hemisphere becomes crowded. Visual-perceptual problems are to be expected!)
–greater vulnerability
•for functional or behavioral reasons
–positive: behavioral compensation
– negative:“growing into deficit”
TBI: Children versus Adults
Dose-response relation the same (more cerebral pathology leads to greater impairment).
However, consequence in adults is specific, consequence in children is global! Recovery patterns
differ in favor of the more mature brain (NOTE: this is against the Kennard principle!). In
children there is an ongoing interaction cumulative and often global dysfunction and deficits
often emerge later in life (growing into the deficit). In adults there are more immediate
consequences.
Clinical vs experimental neuropsychology
•Clinical neuropsychology measures skills in the individual child to sharpen intervention
•Theoretical neuropsychology is model driven to investigate brain-behavior relationships
