DEVELOPMENTAL NEUROPSYCHOLOGY NOTES
Developmental Neuropsychology notes
21-04-2021: Webinar 1: Course introduction
Child neuropsychology = paediatric neuropsychology
Study of brain-behaviour relationships in the context of an immature but rapidly developing brain.
If there’s damage in a child brain, it has different consequences than damage in an adult brain.
Developmental neuropsychology = lifespan perspective on child neuropsychology. We will also look
at future consequences, when a child had early child damage. It takes a longer perspective than child
neuropsychology.
Child neuropsychological assessment
Essential ingredient: theoretical knowledge of typical and atypical brain structure and associated
cognitive skills. A theoretical basis that prepares you for child neuropsychological assessment.
The course The course syllabus
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Webinar 1: the ‘bio’ int the biopsychosocial model
The biopsychosocial model
This is the leading model in the field of developmental neuropsychology. 3 dimensions are important
when studying the developing child.
The idea of the biopsychosocial model is, that biological, psychological and social influences
determine the outcome of the brain maturation.
- The first part, the bio part, concerns neurotransmitters, cells, and structures of the brain, but
also brain functions.
- The psycho part is part of the field of developmental psychology and is concerned with al the
observable cognitive and social behaviour of children, for example the milestones that are
developing in the child.
- The social dimensions are the environmental influences of brain development, so they are
the external factors. Such as familial and extra-familial factors.
This webinar we will focus on the bio/neuro part.
The first is the pre-natal brain, the
second is the post-natal brain. In the pre-
natal brain, the hardware is formed, and
in the post-natal brain the software if
formed.
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Brain maturation is not a linear trajectory. The most parts of the
brain, especially the frontal parts, follow cubic trajectory. Only a
few part of the brain follow linear trajectory, those are mostly the
most basic brain parts.
The cortex develops from posterior to anterior, from the back of
the brain to the front of the brain. The frontal lobes are the last to
mature, they still develop until adulthood. Animation 1.
The brain develops from lateral to medial, it develops from the
outside to the inside. Animation 2.
Brain development is hierarchical. It develops according to a certain
sequence. This is always the same. Brain maturation is
characterised by growth spurts. You have those growth spurts, and
afterwards the brain maturation is much slower. This is inline with
the theories of developmental psychology: the developmental
stages. There are certain stages that children are suddenly able to
develop skills. It is a non-linear process.
The bio model part of the biopsychosocial model holds 3 contemporary parts
- Brain maturation: this view holds that the development of the neuroanatomical regions are
genetically determined. They follow a certain sequence of development (topic of next week:
pre-natal).
- Interactive specialisation: emergence of new skill reflects refinement of connectivity
between regions is refined. This is happening post-natally, after birth (this week).
- Skills learning: brain activation changes during skill acquisition. With age there is much more
focal brain activity and less distributed brain activity (week 3: post-natal).
All three views provide explanations of brain development. They are complementary views on brain
development.
Interactive specialisation explained
Specific brain areas are involved in complex functions. More brain areas are involved in complex
functions, and if several brain areas are active together (e.g., while performing a certain task), they
will be connected. “Brain areas that fire together, wire together.” By wiring together, specialised
networks are evolving. The stimulation of the environment is crucial in shaping these networks.
There are many overlapping networks, e.g.:
- Social information processing (face network);
- Language (left hemisphere specialisation);
- Reading;
- Executive function;
- Etc.
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Face network
For most people located in the right hemisphere of the
brain. Across ages the same brain areas are involved in face
processing (processing of identity, expression, gaze (where
the person is looking at)).
Together these functions are made possible by the face
network. This area contains of at least three core networks
(RH).
- IOG: inferior occipital gyrus.
- FG: fusiform ‘face’ area.
- STS: superior temporal sulcus.
Task accuracy on face processing tasks is still improving
until mid-childhood (10-11 years).
The performance of these hubs of the face network, depend on each other. The correlations
between the brain areas are not established in childhood (you see nonsignificant, ns, results). They
need environmental stimulation to strain this network.
Conclusion: continuously specializing and fine-tuning within regions of networks throughout
childhood. This process can be hampered. For example in autism…
Autism
Atypical connectivity within and between functionally specialized brain networks, so also the face
network. It is also between networks, because networks need to work together. For example, you
see a face, than you also need social information to know who it is.
Atypical connectivity, or problematic interactive specialization, can explain part of the deficits of
children with autism.
What happens when a maturing brain gets disrupted?
“Early brain insults will have different consequences at different times throughout development and
may be more detrimental than later injury, because some aspects of cognitive development are
critically dependent on the integrity of particular cerebral structures at certain stages of
development.” (Maureen Dennis).
Early disruption can have irreversible consequences. This is different from adult injury, where some
of the consequences may not be irreversible and functions may come back. Also, with children the
function is more diffuse, so affecting the whole brain. The brain functions have not al been
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developed yet, so if there’s damage done to one brain area, the whole brain may be affected. Also, in
children you fined more generalized disturbances in information processing, executive function and
social cognition. So more general disturbances, also including intelligence. What is typically observed
in children, is that after brain damage there is normal acute recovery, but worse long-term recovery.
This is the opposite of what you can find in adults. This makes the prognosis more difficult to predict,
because there are so many variables that can influence the outcome.
Growing into deficits
Progressively emerging cognitive deficits, after early brain injury (congenital/traumatic). They fail to
acquire age-expected skills; slowing of cognitive development.
This growing in deficits has nothing to do with deterioration of brain areas or progressive neurologic
condition, this is something totally different. Because in those cases, neurologic conditions, you see
progressive cell death, this is not the case with growing into deficits. It’s just that specific skills, more
complex skills usually, do not come online, because this brain area, that develops in later age, has
been damaged at an early age. This means that IQ is decreasing with age.
Bio/neuro summary
- Hierarchical brain development, not linear, that is inline with the developmental stages.
- Three views on brain development:
o Early maturation.
o Interactive specialisation.
o Skill learning.
- Brain-wise, children are not little adults.
o Irreversible consequences.
o More diffuse and generalized disturbances.
o ‘Growing into deficit’: important concept to know when investigating children with
brain damage.
Webinar 1: The ‘psychosocial’ in the biopsychosocial model
The psycho part is more about developmental psychology, because it’s all about observable
behaviour in children.
Cognitive development – Piagetian stages
Children need to pass through pre-set developmental stages. It’s a hierarchical process, so each stage
must be passed.
Object permanence: when an object
disappears it still exists.
Conservation task: children have to
estimate how much water is in glass.
Logical thinking: the amount of wat stays equal, even when it’s poured into another glass.
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Children go through these stages when they are ready. You can’t force them through stages.
These stages coincide with the maturation of the brain. Young children make ‘mistakes’ that older
children and adults do not. Piaget: people go through stages with qualitatively different ways of
thinking.
Hierarchical neural development
These maturational spurts coincide with the stages of development.
This maturation is not a one direction road. It’s an iterative process. It
repeats itself constantly.
Psycho summary
- Stage-like development.
- In line with hierarchical brain development.
- Psychological development is an iterative process.
o Driven by neural maturation.
o Which allows new cognitive skills to arise.
o Which will change the way the child will interact with its environment.
Social dimension
Environmental influences: familial and extrafamilial.
Metaphor: brain as lockers
The brain maturation can be seen as lockers being placed. These lockers are still empty. For these
lockers to be filled, with information, skills, etc. the social environment needs to be filled. The social
environment will open the lockers and information and skills can be added.
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In very young children, the family unit is the most important social environment. Because the
parents, but also the brothers and the sisters, provide the role models of how to behave. They all
provide the context for learning.
- Language.
- Cognitive skills.
- Social behaviour.
- Rules.
More distal factors, extrafamilial context, provide a context for learning, for example the schooling
the child receives. But also sports and skills, which teaches them how to use motoric skills. At a later
age, peers become more important to develop their identity.
- Academic skills (school).
- Motoric skills (sports, games).
- Identity development (peers).
The importance of these different social context changes.
- Baby: parents are most important.
- Transition: extra familial context become more important until young adulthood.
The brain develops within the context of experience
When children are raised in a stimulating and responsive environment, we can expect an optimal
development. However, when children are deprived from a caring environment, and have an
unresponsive environment, than the development may be compromised our abnormal.
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Institutional neglect leads to…
- Reduction in brain volume.
- Reductions in brain connectivity.
- Reductions in brain function.
The environmental is very important in brain development of children.
Healthy brain development requires adequate nurturing relationships.
- Regulation of physiology: hunger, sickness, sleep, body temperature, physical contact.
- Self-regulation/cognition: adequate exposure to language, interactive play, emotional
feedback.
Caregiving quality feeds emotional health and intelligence. The social environment is extremely
important.
Adequate nurturing can be deprived:
- Chronic illness and/or hospitalization.
- Parental mental illness (depressed or distressed).
- Combination of factors:
o Low SES.
o Multiple stressors in the family.
o Low levels of maternal education.
o Previous psychological disturbance.
We need to have 3D view when assessing children’s
developmental functioning.
Webinar 1: Principles of child neuropsychological assessment
Goals of (child) neuropsychological assessment (same as adults)
1. The cognitive assessment to determine integrity of the brain.
2. Detect or diagnose symptoms, syndromes and disorders.
3. Characterize strengths and weaknesses in cognition and function.
4. Guide towards appropriate rehabilitation, intervention or support… based on NP profile.
5. Monitor outcomes and evaluate interventions/treatments.
Depends on setting: acute medical setting vs. secondary care (school, outpatient clinic, rehabilitation
unit). In each of these settings, there are different goals.
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What needs to be included in the assessment?
The biopsychosocial model should be part of the assessment.
- History taking.
o Medical.
o Developmental.
o Psychosocial.
- Behavioural approaches.
o Observations (behaviour, motivation, emotions).
o Rating scales – parent/teacher.
- Cognitive tests.
o Intelligence (step 1).
o Specific cognitive skills (step 2).
Determine the age-appropriate for the behavioural approach. Often for these type of assessment
you don’t have good norms, you don’t have good comparison groups. This is something that can be
determined with cognitive testing, because for these tests norms have been created.
4 principles
1. Longitudinal follow-up is crucial. Children’s brains develop very rapidly, so it is important to
do check-ups on these developments.
2. IQ-testing is the foundation (but simplistic).
3. Age-appropriate tests have to be used, and age-appropriate norms should be available.
4. Lower levels of functioning should be tested first.
1. Longitudinal follow-up is crucial.
“Children have a wide range of possible outcome trajectories, but also delayed effects and
developmental arrests, and degermation, all of which can vary with different skills.”
“The effects of childhood brain insults are seen in the entire trajectory of development, not only
from single time points.”
Normal developmental trajectory
1. Early intercept = developmental starting point.
2. Mature intercept = developmental end point.
3. Developmental slope = speed of development.
This can apply to global cognitive skills (IQ) or specific skills. This
trajectory can differ between skills. E.g., language development
compared to motor skill development.
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Early onset disorders: lower starting point and end point:
- Genetic syndromes – e.g., down, Ullrich-Turner
- Neural tube errors – e.g., spina bifida meningomyelocele
- Hormone biosynthesis – e.g., congenital adrenal hyperplasia.
- Prenatal environment – e.g., foetal alcohol spectrum syndrome.
- Developmental and learning disorders – e.g., autism, ADHD, dyslexia.
Later onset injury: changed slope (dip and speed)
- TBI (traumatic
brain injury).
- Epilepsy.
- Brain tumour.
- Stroke.
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