NP: Child Psychology Flashcards
Rasmussen’s encephalitis
chronic inflammation -> seizures -> need to remove the entire right hemisphere
when does the brain start to develop
about 21 days after conception
neural tube =
cylinder of cells that develops into the nervous system
when does the developing brain look like a human brain
100 days after conception
when do sulci and gyri form
around 28-30 weeks
where are neurons formed
near the walls of the ventricles -> from there migrate to their destinations
Brain development involves a massive overproduction of cells and connections, followed by apoptosis, or programmed cell death, to remove the excess cells
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kijken naar model brain development
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stages of brain development
- Cell birth (neurogenesis; gliogenesis)
- Cell migration to final destination
- Cell differentiation
- Cell maturation (dendrite and axon growth)
- Synaptogenesis (formation of synapses)
- Cell death and synaptic pruning (apoptosis)
- Myelogenesis (formation of myelin)
how do stem cells differentiate
stem cell -> 2 cellen, 1 stemcell en 1 progenitor cell -> neuroblast and glioblast
zie model neuron generation
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where is neurogenesis in adults
in olfactory bulb and hippocampus! dus er is wel neurogenesis in human adults
neuron generation
- Neural stem cells line the neural tube and give rise to two
daughter cells, one of which is another stem cell and one of
which is a progenitor cell - Progenitor cells divide to produce neuroblasts or glioblasts, which ultimately develop into neurons or glia
- Stem cells exist throughout life and produce new neurons in the
hippocampus and olfactory bulb - The presence of stem cells suggests that neural injuries could be
repaired, but that does not routinely happen in the adult brain - The rate of neurogenesis decreases with age, and the function of
neurons produced later in life may be different
cell migration
- Neuroblasts that form the cortex are produced by about 4.5 months gestation
- Brain is more susceptible to injury during the cell migration phase than during the
neurogenesis phase - Cell migration begins around the time the first neurons are formed, but migration will not
be complete until about 8 months after birth
differentiation, migration, maturation, myelination and glial genesis when?
differentiation - birth
migration - 8 mo after birth
maturation - adulthood
myelination - adolescence
glial - throughout life
neuroblasts are generated in the …
subventricular zone
how do neurons migrate
in columns, from the inside to the outside. dus cells that end up in the outside layers migrate first, from the inside.
development of cortical maps
- Subventricular zone contains a map of the cortex that
enables cells from a part of the zone to migrate to a specific
part of the cortex - Neurons migrate along radial glia, which extend from the
zone to the related region of the cortex - Cortex is built from the inside out, so the deepest layer, VI,
forms first, then V, and so on until layer I is formed
neural maturation
- During maturation, the cells produce dendrites to increase their surface area to form synapses
- Dendritic arborization involves branching
- Dendritic spines are the targets for the synapses
- Dendrites start to form prenatally, and this continues long after birth
- Dendrites grow slowly, only micrometers per day
- In addition, axons grow toward the appropriate targets
- Axons grow at a fairly constant rate of 1 millimeter per day
- The faster axon growth means axons reach their targets before dendrites have developed,
so can influence dendritic development
guiding the development of axons
- Axons need to synapse on specific targets in order to be functional
- Failure of the axon to reach the appropriate target results in the death of the neuron
- There are many different mechanisms to guide an axon to the target
what can interfere with the development of axons
- Growth of neurons can be blocked by scarring or disruption, lack of oxygen, or exposure to toxins
- Genetic abnormalities can result in problems with axonal migration
-> If the axonal target is damaged, the axons may degenerate or make a connection with an inappropriate target
synapses
- There are on the order of 10^14 synapses in the human brain
- Genes likely specify the broad outlines of these connections, not the specifics of each
connection - Various cues and signals specify the individual connections
5 pases of synapse formation that occur between conception and death
- Phase 1 and 2 synapses are independent of experience
- Phase 3 synapses are formed rapidly from birth through the first few years of life based on experience
- Phase 4 represents a plateau of synaptic number, followed by a rapid pruning through puberty, based on experience
- Phase 5 is a plateau in middle age through a decline later in life, based on experience
kijken naar model phases of synapse formation and pruning
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striate cortex is involved in…
visual processing
prefrontal cortex is also involved in visual processing,
maar later. dus sensory areas develop earlier than more higher order processes
glial development ~
Glial development begins after neuron formation and continues throughout life
* Myelination is not essential for neuronal function, but does make functioning more efficient
* Myelination proceeds from birth through adolescence
* Different parts of the brain are myelinated at different times in that process
* Areas that myelinate earlier are associated with simple movements or sensory analysis; areas that are myelinated later are associated with higher cognitive functions
is myelination essential for neuronal functioning
nee, maar maakt het wel meer efficient
when is myelination present
birth through adulthood
areas that mature last
prefrontal cortex, temporal and parietal cortex
kijken naar model myelination in the cortex
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adolescence =
age 10-17 in girls
age 12-18 in boys
wat gebeurt er met connections during adolescence
rapid pruning and rapid growth of new connections. increase of WM, daardoor verandert de balans tussen GM and WM. (a lot of new wm, a little bit of pruning van gm)
Throughout adolescence, there are periods of
Increased glia production, decreased cortical thickness, and changes in connectivity
Physical and hormonal changes are related to patterns of brain maturation
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kijken naar model neural development over time
- sensorimotor
- temporal and parietal
- prefrontal cortex
Which of these would appear earliest in the developmental sequence:
a. Synaptogenesis
b. Cell migration
c. Differentiation
d. Functional validation
b
plasticity =
the ability of the brain to adapt to environmental changes and compensate for injury
experience results in…
changes to the connections in the brain
what is the molecular basis of plasticity
not clear, but likely related to epigenetic changes that alter gene expression
are epigenetic changes heritable
at least some of them
what are triggers for plasticity
hormones, injury, nutrients, the microbiome, and stress
what were the findings of studies amongh romanian orphans
- Early experience has a large impact on brain development
- Children adopted by 6 months of age had normal IQ scores
- Children adopted after 18 months of age had decreased IQ scores and smaller brains
Adverse childhood experiences (ACEs) include..
verbal or physical abuse, addiction of a family member, and loss of a parent
what do ACE’s predict
- ACEs predict mental and physical health at middle age
- Individuals with 2+ ACEs were 50 times more likely to have an addiction or attempt suicide
- ACEs compromise frontal-lobe development -> dus minder goede frontal lobe development als je ACEs hebt gehad
Prenatal experiences, such as stress or toxins, can also impact dendritic organization and behaviors
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hoeveel zwangere vrouwen gebruiken toxins ~
- 7% to 10% of expectant mothers use nicotine
- 10% of expectant mothers consume alcohol
- Low doses of antidepressants and antipsychotic drugs alter neuron development in the prefrontal cortex
- 4% to 5% of expectant mothers use illicit drugs at least once during pregnancy
- A high percentage of children are exposed to caffeine in utero
Researchers suspect that disorders such as learning disabilities and ADHD may be related to prenatal drug exposure
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early life experiences influence brain organization, hoe zie je dit in animals?
- Some cortical regions of domesticated animals are 10% to 20% smaller than animals raised in the wild
- Animals born in the wild and domesticated at a young age have brain sizes similar to animals who live their whole life in the wild
- Differences are observed in the density of glial cells, length of dendrites, density of
spines, and size of synapses - Young brains and old brains seem to react differently to the same experience
- Children who are exposed to multiple languages early in life will be able to learn other
languages more quickly later in life
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kijken naar model effect of complex housing on rats
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effects of diet and nutrients
- Maternal diet while pregnant influences the brain development and
later behaviors of the offspring - Mechanism seems to be through the pattern of gene methylation,
with a more nutritious diet resulting in greater methylation - The microbiome can influence behavior
- Microbiome varies in different geographical regions, possibly
influencing culturally specific behaviors - Microbiome can influence neurodevelopmental processes and
the integrity of the blood–brain barrier - Disruptions of the microbiome are associated with clinical
conditions such as autism spectrum disorder
SES and brain development ~
- There is a relationship between socioeconomic status and academic achievement
- Causes likely include parental education, child health, school quality, stress, and language exposure
- Lower family income is associated with decreased cortical volume across the frontal, temporal, and parietal cortex, independent of sex or race
- Cortical thickness negatively correlates with language and executive function scores, with thinner cortex predicting higher scores
- At age 3, children from high-SES families are exposed to 11 million words per year, while children from low-SES families are exposed to only 3.2 million words per year
functional organization of the visual system ~
- Cataracts or abnormalities of the cornea or lens can result in changes to how the visual cortex is organized and the ability to perceive objects
- Restricting input to one eye changes the structure of the ocular
dominance columns in the visual cortex due to the lack of visual
experience - Restricting the visual input to only horizontal or only vertical lines
alters the visual system so it cannot detect lines of other orientation later in life - Early life is a critical period for the development of the visual system; without exposure to a range of stimuli, it will never learn to detect and respond to such stimuli
A child that comes from a low-SES home with prenatal nutrient deficiencies, like iron, would have
what likely result?
a. A deficit in language abilities and emotional regulation
b. Increased reading abilities with deficits in emotional regulation
c. Increased probability of motor dysfunction
d. Decrease in both spatial abilities and visual acuity
a
- Early studies found that brain injuries sustained at a younger age seem less severe and
more short-lived than the equivalent injuries sustained as an adult - Other results contradicted this, finding that early prefrontal damage can result in very poor outcomes
dus wat is het?
The effect of damage depends on many factors, including the behavior affected, the extent and location of damage, and the age at which the injury occurred
damage at which age leads to what …
- Damage before age 1 can result in significant impairments
- Damage between ages 1 and 5 allows some reorganization of function
- Damage after age 5 allows for little functional recovery
language early age
Early damage (<age 1) produces short-lived damage and an almost full recovery
Brain-imaging studies and behavioral results suggest language is able to reorganize to the right hemisphere, although there is a strong predisposition for localization in the left hemisphere
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rats brain injury effects
- If cortical injury occurs during neurogenesis (embryonic day 18), recovery tends to be complete, even if the destruction of the cortex is complete
- Damage during neuronal migration and differentiation (postnatal days 1–5) results in permanent damage, regardless of size or location of the lesion
- Damage after migration (postnatal days 7–12) results in nearly complete recovery of cognitive functions and partial recovery of motor functions
Children can “grow into deficits” because regions that were previously compensating for the lost function can no longer do so
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ways plasticity could support recovery after early injury
- Changes to the organization of intact circuits in the brain could enable the brain to do more with less
- Generation of new circuits through natural processes or following stimulation by a treatment
- Generation of neurons and glia to replace some lost neurons
In terms of escaping with minimal effects of brain damage on language, the BEST time to
incur the damage would ____ years of age:
a. Before 1
b. Between 1 and 5
c. Between 6 and 10
d. After 10
a
(language is before 1 year!!! de andere functies zijn anders)
neurodevelopmental disorder
- Characterized by onset between in utero development and the start of formal schooling
- Result in deficits in social, personal, or school functioning
- Impairments may be specific to one function or more global
- Incidence may be as high as 17% of school-age children
- Deficits often emerge gradually, making it difficult to identify the disorder
- Testing and assessment identify variation in the population, so may fail to identify individuals who have difficulties but are still performing close to standard levels
autism spectrum disorder first described by…
Leo Kanner and Hans Asperger
prevalence asd
16,8 in 1000 children
asd gender
4 men 1 women
dsm 5 criteria of asd
- Deficits in social communication and social interaction
- Restricted and repetitive behaviours, interests, or activities
- Symptoms must be present in the early developmental period
- Symptoms must cause clinically significant impairment in
social, occupational, or other important areas of functioning - Symptoms are not better explained by intellectual disability or
global developmental delay
social communication in asd
- Deficits in social reciprocity
- Deficits in non-verbal communication
- Deficits in understanding, maintaining, and developing social relationships
Restricted and Repetitive Behaviours and Interests (RRBIs)
- Stereotyped or repetitive motor movements, use of objects, or speech
- Insistence on sameness, inflexible adherence to routines
- Highly restricted, fixated interests
- Hyper- or hypo-reactivity to sensory input
when is the diagnosis of asd usually
around 3 years
Early signs of autism (<12months):
- Lack of eye contact
- No orienting to name (dus naam noemen = ze kijken naar iemand anders)
- Little social engagement
Signs asd (12-24months):
- Delay in language and/or motor development
- Repetitive and stereotyped movements become apparent
genetics of asd
- highly heritable (90% in twin studies)
- some single-gene disorders have a similar presentation, e.g. Fragile-X, Rett syndrome
- however:
- most cases are idiopathic (no known cause)
- unaffected family members may share traits
in specialist clinics asd can be diagnosed from the age of
12 months
biological difference in asd
larger head size in infancy, typical head size later (misschien due to neurogenesis and synaptogenesis)
Some differences in subcortical structures, mainly amygdala and striatum, but….
- findings are not consistent across studies
- interactions with age and gender have been reported
- considerably heterogeneity in study samples
neurodevelopmental learning disorders
- Specific neurodevelopmental learning disorders impact the ability to learn and apply reading, writing, or math skills
- Children generally have average intelligence, but are unable to learn or use a particular academic skill
reading involves …
identifying letters, converting letters into sounds, combining sounds in sequence, and short-term memory
lexicon =
the memory of words and their meanings
Phonological reading…
decodes the letters of the words into sounds that can be pronounced
Graphemic reading …
looks at the whole word and produces the sound of that word from memory
Fluent reading
involves both phonological and graphemic reading
dyslexia cause
Children may be impaired at decomposing words into the phonemes that make them up
impairments of phoneme use are associated with…
the left-hemisphere language regions
Impairments in the auditory sensory pathway may be important ~
- Adult males with developmental dyslexia had weaker connections between the left medial
geniculate body and the left temporal cortex - Most people can separate two sounds separated by 10 to 40 milliseconds, but children with
learning disabilities required a greater separation - Many consonants contain sounds that change in less than 40 milliseconds
kijken naar model sound detection ability
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other theories of causes of reading disorders
attentional def
motor def
multicausal approaches
attentional deficiency
- Some argue that reading problems result from difficulty shifting attention to relevant cues
- This would be associated with the parietal-lobe association areas
motor deficiency
- Cerebellum is involved in timing, coordination, and attention
- Damage to cerebellum might result in problems with reading
multicausal theory
- It is possible the reading disorders are not one single condition, but multiple conditions with different causes
- Research has identified genes that could be associated with reading disorders
Which of the following is NOT considered a primary cause of dyslexia?
a. Auditory deficiency
b. Phonological deficiency
c. Attentional deficiency
d. Sensory deficiency
a
dyscalculia=
Difficulty representing and processing numbers in a typical way. + characterized by difficulty with number sense, calculation, or mathematical reasoning
incidence of dyscalculia
5 per 100 students
treatment dyscalculia
Treatment involves developing coping strategies or working to meet the child’s individual needs
neuropsychological evaluations
- IQ tests are commonly used to assess overall cognitive function as well as the pattern of performance on subtests
- The ACID profile (arithmetic, coding, information, digit span) on the Wechsler Intelligence Scale for Children suggests a specific learning impairment
- Results from tests such as IQ are not used to predict specific disabilities, but to predict problems related to cognitive function
- Supplementary specific tests are used to identify particular impairments
kijken naar acid profile foto
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adult outcomes
- Early studies of adult outcomes of neurodevelopmental disorders were optimistic, but later assessments were more pessimistic
what about parental outcomes
- Parents perceive greater impacts of learning disabilities on well-being, happiness, and social interactions than do the individuals with the disability
what is the most important thing to do for children with neurodevelopmental disorders
- Assessment of the strengths and weaknesses of the individual, followed by instruction to address those weaknesses, is important
- Counselling to focus on strategies to work around the individual’s challenges can play a large role
wanneer beste damage bij language krijgen
voor jaar 1
wanneer beste damage voor andere cognitieve functies dan language
tussen 1 en 5
