Developmental neuropsychology
Anderson, Northam, Wrennall (2018-2019)
Anderson, V., Northam, E., & Wrennall, J (2019). Developmental neuropsychology, a
clinical approach. Second edition. New York: Routledge, Taylor & Francis Group. ISBN
9781848722026.
1
,Chapter 1 Child neuropsychology: theory and practce
What is child neuropsychology?
Child neuropsychology refers to the study of brain-behaviour relatonships within the
context of an immature but rapidly developing brain and the implementaton of the
knowledge gained into clinical practce.
What does plasticity and critical period mean?
Neuroplasticity, also known as brain plasticity, neuroelasticity, or neural plasticity, is the
ability of the brain to change throughout an individual's life, e.g., brain actvity associated
with a given functon can be transferred to a diferent locaton, the proporton of grey
matter can change, and synapses may strengthen or weaken over tme.
The Kennard principle: if you are going to have brain damage, have it early. Kennard
describes a relatve sparing of functon following early brain insult. Children are more
capable of transferring functons from damaged to healthy tssue.
Critical period: The tme window during which external infuences have a signifcant efect.
Consistent with this view is that early brain insult is more detrimental because some aspects
of cognitve development are critcally dependent on the integrity of partcular cerebral
structures at certain stages of development. For example essental interconnectons
between brain areas.
Adult neuropsychology: the brain is statc, tghtly organized, less plastc. There is a one-to-
one relatonship between structure and functon. Symptoms (= functon impairment) can be
related to the underlying neurological defect (= localizaton).
For example. One expects a low score on the Wisconsin Card Sortng Task when there
is brain damage in specifc parts of the prefrontal cortex
Developmental neuropsychology: the brain is dynamic. Changes (e.g. spurts) in brain
development are closely related to changes in behavioural, social and cognitve
development. Symptoms and the underlying neurological defect are not clearly related.
For example, the same brain damage can lead to diferent symptoms in
childhood. The reverse is also true: the same symptoms might point to quite
diferent neurological causes. It all depends on the tming of the brain
damage, the social environment and factors within the child.
But developmental neuropsychology also states that brain development is a dynamic
process in which many factors are involved: biologic, cognitve, social-emotonal,
developmental and environmental. Therefore later outcome is difcult to predict and there
is a need to address the totality of a child.
2
,Theoretical models
According to the cognitive reserve model (Dennis et al. 2007) there are individual
diferences in a child’ss reserve capacity, both brain reserve capacity (BRCC) and cognitve
reserve capacity (CRCC).
Brain reserve capacity is measured directly by quantfying variables such as insult severity,
brain volume or structural connectvity. When BRCC is depleted below thresholds levels,
functonal defcits emerge which might include physical, cognitve and socio-emotonal
symptoms. CRCC refers to factors both intrinsic (pre-and post insult functoning), extrinsic
(SES, family functoning) which impede or facilitate various functonal outcomes.
Moderatng factors are age (at testig, iisult) and tme siicee iisult, but also the iisult
loceatoin. A key concept of the model is that the infuence of these moderatng factors is not
constant over tme. For instance: in children with traumatc brain injury; the greater the tme
elapsed since injury the less the efect of brain insult characteristcs and the greater the
efect of environmental variables on cognitve functoning.
Recovery continuum model (Aidersoi et aln. 2011), pn. 9
According to this model neither early plastcity nor early vulnerability theories in isolaton
are sufcient to explain the myriad of outcomes that occur following early brain insult.
RCather, the model proposes that recovery is best understood by employing a contnuum
approach whereby a number of potental risk and resilience factors interact to determine
long-term outcome.
Recovery depends on the interaction between potential risk and resilience factors:
Nature aid severity of the iisult
Developmeital stage of the cehild aid tmiig of the assessmeit
Pre-iijury cehild ceharaceteristces, en.gn. ceogiitve skills
Eiviroimeital ceoitext (distal aid proximal), aceceess to iiterveitois aid soceial
supports
Biopsychosocial view (Aidersoi et aln. 2019)
Threats to healthy development are numerous and span multple domains from health and
environment to cognitve development, mental health and quality of life. For example it is
well established that the development of a child’ss cognitve and socio-emotonal skills is
dependent, to a large extent on the quality of the home environment and the role models
provided by the parents
Brain: the ‘bio’s dimension
The brain, in partcular brain development, plastcity, neural recovery
Environment: the ‘social’s dimension
In partcular stmulaton and responsiveness, parent well-being
3
, Child cognitve and socio-emotonal functon: the ‘psych’s dimension
Child cognitve and social-emotonal development, in partcular the development of domain-
specifc (e.g. language, social cogniton) and domain-general skills (e.g. processing speed,
memory capacity)
The challenge is to improve predicton of outcome by measuring the interactng infuences of
neural, cognitve and psychosocial parameters and their ever-changing matrix through
childhood.
Chapter 2 The developing brain
Localisation approach: Specifc brain regions support partcular cognitve processes (for
example Broca’ss area).
RCecent evidence challenges traditonal localisatonist approaches proposing that many
behaviours and skills are mediated by complex neural networks, incorporatng both frontal
and extra-frontal systems.
Functonal neural networks underpin a range of more complex skills, including attenton,
working memory, executve functon and social cogniton. Thus, it appears that, even in the
mature adul brain integrity of the whole brain may be necessary for efcient executve
functon.
Early researchers argued that the infant’ss brain was equipotential with all brain regions
equally able to take responsibility for any functon. Functonal specialisaton was thought to
emerge gradually through early childhood and that, in the event of early brain insult,
‘healthy brain regions’s could be recruited to take up the normal functons of damaged brain
regions.
In contrast, the innate specialisation model argues that key skills such as language are
localised at birth, an argument that is supported by fndings that language-dominant
cerebral hemisphere is larger in the new-born.
Interactive specialisation approach: Also accountng for the infuence of genetcs and
experience on the developing organisaton of the brain. Employing this framework, M.
Jonhson (2007) acknowledges these infuences and identfes three separate but not
necessarily incompatble, approaches to understanding progression of cognitve abilites in
infants: (a) maturatoi; (b) iiteracetve speceialisatoi; and (c) skill leariiig.
(a) Maturation view proposes there is a genetcally predetermined developmental
sequence of specifc neuroanatomical regions, which provides the foundaton for the
hierarchical emergence of sensory, motor and cognitve processes (infant is frst
dependent on lower-order sensory functons but by the second year of life the
prefrontal cortex is getng more important)
4
