Please enable JavaScript.
Coggle requires JavaScript to display documents.
Developmental - Neurodevelopment Conditions (Y1) - Coggle Diagram
Developmental - Neurodevelopment Conditions (Y1)
Terminology and definitions
Neurodevelopmental condition, not a disorder
cooccurrences not comorbidities
Differences not dysfunction / deficit / impairment
-Identity first v person first language - autistic person, not person with autism
What is a neurodevelopmental condition? A group of conditions that are heterogenous - although clinically and etiologically disparate, typically manifest during childhood and involve some form of disruption to brain development
Apparent in early childhood and affect all major developmental systems - social, cognitive, language and emotional
Prevalence rates of individual neurodevelopment conditions range significantly (0.5-18%)
-> 5-6% - dyspraxia, developmental coordination disorder
-> 1.6% - Autism spectrum disorder
Differences in development can present in many different ways across neurodevelopmental conditions
Diagnostic classification - the official system for classifying disorders is prepared by the American Psychiatric Association
The diagnostic and statistical manual of mental disorders identifies and evaluates behaviours, thoughts and feelings that have a negative impact on an individual's life (DSM-5)
Some examples of conditions from the DSM-5 includes - Autism, ADHD, developmental coordination disorder (dyspraxia), intellectual disability - down syndrome, fragile X syndrome
Why we research - knowledge of individual conditions, without understanding we cannot identify risks, provide support, education, person-environment fits and early intervention
Adds broader knowledge and understanding of atypical and typical development by learning about the opposite
A crucial component of these disorders is that individuals show difficulty from birth onwards, and that the cause is from gestation or birth
It is a term that refers to many meanings and conditions (Bishop and Rutter, 2006)
DSM-5 is broad, and includes all developmental conditions in this category such as intellectual, motor, communication, specific learning disorders, ASD, ADHD and other non-specified conditions
ICD-10 also includes pervasive development disorders and so the work in this field is broad in how it covers atypical development
Importance of researching neurodevelopment conditions - obtain a better understanding that can subsequently inform better and more accurate diagnosis and lead to more successful treatment / training programmes or interventions
Have to look at cognitive, psychological, behavioral and biological aspects - aim to provide full causal accounts for specific conditions; Morton and Frith (1995) which incorporates all three levels and environmental influences
Vital to understand and further our knowledge of typical development - Spelke and Kinzler (2007); infants are born with certain core systems for knowledge - number development for example
Some neurodevelopment conditions have uneven cognitive profiles, with some abilities underperforming and some overperofrming - WS can perform better on verbal reasoning, whereas DS is better at numeracy
https://docs.google.com/document/d/1dXLKT74DVC3EZQKCVzMrzm2XUQBNyqJ8fspVLDyGIg4/edit
Critical issues when researching neurodevelopment conditions: usually adopts models used for adult brain damaged patients; recent cognitive views of development suggest that specialisation of brain structures is the result of brain maturation over development through interaction with the environment, genes, brain and behaviour (development that is atypical in these areas leads to conditions) - development is in the wrong order
More developmental approach required to understand these conditions as the brain changes over time and brain plasticity is larger in children than adults and so subtle differences over time can impact the development of cognitive abilities, especially for specialisation of the brain in neurodevelopment
Researchers have begun to include a wider age range and tracing development back to infancy, using fewer matched group designs also as they represent static timepoints - interest is in period of dynamic change; can also lead to underestimation of of the abilities of the condition group as the control group is displaying chronological age development they never follow
Matching groups also requires a standardised test, which neurodiverse individuals never perform well on
Also suggests that performance could be similar between groups, whereas the nature of the studies is to identify clear differences - blurred line on continuum of low performing NT and high performing ND
Best option to study cognitive changes in neurodevelopmental conditions using longitudinal studies
However, these are time consuming and expensive, and so cross sectional studies are often used instead (same time, lots of people)
However, this has been criticised for showing static points and snapshots of development
Most of the issue with research is floor and ceiling effects, assumptions of developmental trajectory and that we cannot study dynamic change - should follow cross sectional study with longitudinal
Examination of domain-general activities such as eye movement, behaviour, attention, processing speed, cognitive control, memory abilities and how these building blocks impact cognitive abilities later in life
More studies needed to explore how participants with conditions understand task instructions or how domain general difficulties such as attention span affect performance scores
Move towards developmental approach over static is positive, but studying plasticity is difficult due to the invasive nature of procedures and how still you have to remain for scanning
Can use EEG but no spatial resolution
Functional Near Infrared Spectroscopy (fNIRS) - uses same BOLD responses in a similar experimental setup to EEG, and so has better spatial resolution than an EEG and better temporal resolution than a fMRI
Not always possible to investigate which domain-general abilities present early in life can affect cognitive ability due to neurodevelopment conditions may not be diagnosable early on
However, as they are commonly genetic, we can study at risk sibling groups to understand developmental trajectories of those with these conditions - helpful, but not all those in the groups then develop the disorder, and so it can refine understanding but not infer causality of atypical development
Issues with reliability and validity of diagnosis: using different criteria means there is no commonality over the presentation of symptoms and what classifies as enough for diagnosis - leading to people not being diagnosed and therefore this impacts their access to interventions that would help them
Additionally, changing criteria can cause issues with comparability between studies that have been conducted in different diagnostic times (e.g. Asperger's studies are now incomparable to modern autism studies)
Furthermore, if genetic deficits are known, the size of the genetic deletion often varies, which can impact diagnosis - e.g. DS is commonly due to trisomy of chromosome 21, but in some cases it is due to moasicism or translocation of the genes on the same chromosome - impact of different origins poorly understood in diagnosis
Research on typical individual genetics has also found that they have some breakages and fragility
Multifactorial, not due to a deficit in a single chromosome
Environments can also impact gene expression
Impacts of co-occurences and variability - is the condition qualitatively different in its causal framework or is it the result of general variability in the population as the norm
Large variability in the neurodevelopmental conditions in terms of cognitive and behavioural outcomes have led to the emergence of subgroups of conditions
Variability of ability leads to blurred lines between highest functioning sub group and lowest functioning TD
Normally solved through sample size
Further research needed to determine if variablity is specific to or larger in neurodevelopmental disorders by looking at in depth within disorders and across syndromes
Also need to understand origin of variability - should conditions be viewed on a continuum rather than specific or discrete classifications or categories
Considerable overlap in disorders also, known as co-occurence - symptoms shared in a few conditions, such as DS children having memory difficulties - could be DS or early onset Alzheimer's
Some people receive dual diagnosis
Shared symptomatology between some disorders - ASD being paired with different primary disorders, and so how we conceptualized overlapping diagnosis and symptoms across conditions
Help development of causal frameworks but also for training and intervention to be administered
Question over continuum argument - do we classify by causal factors or symptoms
Increased research needed to investigate the concurrent symptoms at different levels
The need for theoretical based interventions and issues of complexity and cumulative risk
One of the most well researched areas is reading ability - Burgoyne et al (2012)
programme of reading and language comprehension for DS children found that after 20 weeks they improved massivey (50 children)
Very few interventions have good theoretical basis, despite positive effects - makes outcome unpredictable
Not studied the importance of timing and focus of interventions
Different abilities may also have important impacts on the development of figurative language at different times - complexity of development means that a number of issues or difficulties are likely cumulative in the failure they cause
Very few models, training and interventions take environmental issues into account - TD study groups have shown that socio-economic status, parental rearing styles and sleep are factors that affect cognitive development and intervention success
These factors have been almost entirely neglected within cognitive research and intervention programmes with neurodevelopmental disorder groups
Morton and Frith's causal model does suggest that environmental factors are likely to affect all levels of development and thus are also likely tp affect development outcomes at all levels and impact interventions
Investigation of specific environmental factors that affect development will also advance theoretical understanding and diagnosis, allowing discrimination between disadvantage v impairment
Need for more case studies that look into children who have responded and not responded to interventions to understand how interventions work and why they do so
Cross syndrome comparison studies are also needed to allow investigation of syndrome specific v syndrome general difficulties
Cognitive differences
IQ - intellgience quotient; measure verbal (comprehension), non-verbal skills (reasoning), processing speed and working memory
IQ across the population is normally distributed
Different relationships/associations between IQ and neurodevelopmental conditions
Lower than 70 = intellectual disability
Autism - to be diagnosed, there must be deficits in these areas:
social communication skills - building friendships, reciprocity, imitating and maintaining, emotions, poorly integrated verbal and nonverbal communication, eye contact, gesture and facial expressions
-Repetitive behaviour and restricted interests - repetitive, motor movements, insistence on sameness and adhering to routines, restrictive interests, repetitive speech and compulsive behaviours
Monotropism - focus on specific interests
Pervasive, present from childhood, impacts on quality of life, autism is a spectrum
Autism occurs in approximately 1% of the general population
Autism is more common in males than females - could just be an issue of diagnosis
Genetic basis of autism - genetic mutation in 10-20% of autistic individuals, siblings at greater risk of autism, concordance rate of 82-92% monozygotic twins v 1-10% of dizygotic twins
Environmental factors - prenatal, perinatal and postnatal all linked to autism
Overall, autism is a multifactorial system condition with multiple causes
Autism and IQ - Muglia et al, 2018 - lower average IQ (80) and when categorised IQ is differently impacted - but it is a similar bel curve to general population
DSM-5 notes that autism is simply with or without intellectual disability
With categories, some have a higher IQ such as Asperger's, whereas AD has lower average IQ than PDD-NOS (non-specified) - categories do not however exist in DSM-5
Categories remove as it is a spectrum, but it was helpful for identifying varying IQ in different parts of the spectrum
Tuberous Sclerosis Complex - Joinson et al (2003) - 1:6000 births (rare)
Mutation in TSC1 gene (chromosome 9) - 15-20% of TSC2 gene (chromosome 16) - 60-70%
Range of health and physical differences
Epilespy in 80-90% of individuals
Intellectual disability in 40-65%
high prevalence of autism
In IQ -
Bimodal distribution - bell curve slightly shifted to the left (average lower than general population) - subgroup of TSC which has a profound phenotype with very low IQ
Cohort effects - individuals who are more profoundly affected might be slightly older and might not have benefitted from early intervention, especially regarding epilepsy
Uneven profiles of IQ in Neurofibromatosis1 and ADHD: Potvin et al (2015)
NF1 - verbal comprehension relative strength / higher and non-verbal (perceptual reasoning), working memory and processing speeds lower than NT norms / ADHD - not too low, but lower in comparison
Different profile observed for children with ADHD
Global IQ is inadequate for describing the cognitive phenotype - in case of too much difference between 2 or more sub scores, we do not compute a global IQ - happens for a lot of NDCs
Difficulties measuring cognitive abilities in NDCs but neurophysiological tests can be a good index of atypicality
need to evaluate profiles of strengths and differences
When IQ masks profiles of strengths and difference - high IQ does not necessarily equate with people's ability to engage effectively in society e.g. masks social challenges
Similarly, low IQ may lead to people undestimating a person's ability to effectively engage in society
Educational implications - not receiving enough support to engage in classroom environments and expectations are too high or too low
https://www.spectrumnews.org/opinion/viewpoint/intelligence-scores-not-predict-success-autistic-adults/
constant support for autistic adults, the distinction between high functioning and low functioning means that needs are unmet (no adaptive functioning) or assets are ignored
https://redefiningnormalayoungwomansjourney.blogspot.com/2018/05/why-iq-scores-are-erroneous-for.html?spref=tw
high functioning labels on autistic people prevent support for them in daily tasks - they are masked struggles due to high intelligence; even the structure of an IQ test places them at a disadvantage (sitting still for a long time, distress over higher functioning in one area etc such as having low language ability - if you test this, not an accurate picture)
IQ is a bad system
They also demonstrate intelligence in ways the IQ test does not measure
Social cognition - refers to the range of processes that underlie out ability to extract, store and interpret social information around us; important to enable us to engage with social interaction
Social attention - the cognitive process that underlies gazing at or with another person
Social orienting - preference for social v non social information
Emotion recognition and interpretation - recognise and understand facial expressions of emotion
Theory of the mind - ability to understand other's thoughts and desires
Variability - across neurodevelopment conditions regarding the way in which social information is processed - Autism and Williams Syndrome
Williams Syndrome - microdeletion of 26-28 genes on chromosome 7 - between 1 in 7500-20000 births
Physical characteristics - distinguishing facial features, short stature
Mid-moderate intellectual disability (low non-verbal IQ)
Health and sensory issues - heart problems, hyperacusis, impairment in visuospatial and visuomotor skills
Behavioural features - relatively intact language and face processing skills, hypersociability, hyperactivity, impulsivity and anxiety
Strong drive and motivation for social interaction
Heightened sociaability irrespective of familiarity
Impairments in social reciprocity, skills and understanding and often experience social isolation and maintenance of friendships is also difficult
A limited awareness of danger - approaching and interacting with strangers
Vulnerability to exposure of dangerous or risky social situations, particularly for adults who may have more social independence
Challenges for research: so rare that only small sample sizes are possible
Substantial age band - 10-20 years; because of difficulties in recruitment - cannot focus on specific developmental period like other NDCs
Very few longitudinal studies
Social cognition varies across cultures - children with WS in Japan were rated lower in sociability compared to children in the USA
Eye-tracking technology - used to study Williams Syndrome / Autism social processing: Riby et al 2008 and Klin et al 2002
Capture attention with no overt task demands, can be used in infants
Experimenter can control the stimulus to make subtle changes
Easy task for those with NDCs as they simply have to watch a stimuli
Social processing - eye tracking technology - when viewing naturalistic social situations, autistic individuals process social information around them differently (different eye patterns) than neurotypical individuals
Reduced looking towards the eyes and increased looking towards mouths, bodies and objects (preference for information)
Fixation times on mouths and objects but not on eyes predict social abilities
Autism - more white and gray matter - too many neurons and axons, leads to oversensitivity and firing
Autism v Williams Syndrome
Hotspots represent the relative amount of time fixating throughout the scene for each group (typically developing children, autism and WS)
Two NDC with two very different profiles of atypicality in relation to social cognition (hyper and hypo - WS and autism) highlighting the different conditions having different patterns of development
Autistic children do not look at the face as much - difficulties maintaining friendships, attachment, struggle with social interaction
WS children look more at the face compared to a neurotypical individual
More focus on the eyes = more sociability
How development is impacted by the different social processing styles:
Different social input
Difference in social-communicative learning
Understanding and interpreting the social world
Language and communication development - non-verbal and verbal communications
WS and autism have different social development profiles
Part 3: Differences in social development - Angelman syndrome (AS) - Oliver et al (2007)
https://www.findresources.co.uk/the-syndromes/angelman
First described in 1965 - present in approximately 1 in 10,000 and 1 in 40,000 live births
Caused by a loss of genetic information at maternal chromosome 15
Four genetic mechanisms involving the UBE3A gene
Deletion (70-75%)
Mutation (5%)
Uniparental disomy (2%)
Imprinting defect (2%)
Severe to profound intellectual disability
Some common physical features
Seizures / sometimes stay up for a long time
Motor development atypicality - ataxic gait
Limited expressive language skills
Social motivation in Angelman syndrome:
Strong social motivation (heightened sociability) noted in 88% of cases
Frequent social approach behaviours
Characteristic laughing and smiling - atypical laughing and smiling - not seizure activity but true behaviour, social interaction appropriately modified according to the environment (structured environments increase smiling and laughing)
As in WS, heightened sociability but manifest in slightly different ways because Angelman had profound intellectual disability
Related to the environment - smiling and laughing - more frequent next to teachers, more frequent with adult attention and when adult eye contact is present, reduces with age - adults still smile and laugh too much but they are doing it less and learn to control this with development
Attract more adult attention than children with intellectual disability of heterogeneous cause because they laugh and smile more
Not seizure activity as they can control it
Part 4 - differences in emotional development:
emotional regulation - a broad set of processes, which are responsible for monitoring, evaluating and modifying emotional response that promotes adaptive or goal directed behaviour
Problems with emotion regulation make it difficult for an individual to feel better during difficult situations and think clearly and remain calm during challenges
React impulsively to emotional stimuli - temper outbursts, aggression or self injury
Often interpreted as deliberate or defiant but may be due to inadequate management of emotion
Attention deficit and hyperactivity disorder - ADHD: one of the most common neurodevelopment conditions (5-7% prevalence rate)
Similar prevalence to DCD and dyspraxia
Core symptoms - inattention, hyperactivity and impulsivity
Significant impact on social, cognitive, academic and behavioural functioning
Emotion dysregulation contributes to functional impairment - not considered as an important symptom in the DSM-5 as it is considered too difficult to measure emotions
https://www.youtube.com/watch?v=2kew2JhKq3Y
Prader-Willi Syndrome - 1:10,000-1:15,000, chromosome 15 (like AS but different genes)
Paternal deletion (70%)
Maternal uniparental disomy (25%)
Imprinting abnormality (2.5%)
Intellectual disability- shift in IQ distribution by approximately 40 points:
Deficits in inhibition
Repetitive behaviour
Physical phenotype
Hyperphagia
Temper outbursts
Component of temper outbursts - arguing, shouting, crying
In PWS, outburst can be quite brief or longer than 24 hours (can be less than 15 mins)
Multiple possible causes (change in routine or expectation, disagreement, making a mistake)
Progressive building of the outburst - Thornton and Matthews, 2008
Cold; calm, happy, usual self
Lukewarm; becoming anxious, raised voice
Simmering; shouting threats, swearing, not listening
Boiling - abusive, swearing, screaming and self harming
Motor differences - Part 5
Developmental Coordination Disorder (DCD) - Jolly and Gentaz, 2014
Dyspraxia
5-6% of school aged children - higher than ASD but less recognised
Motor impairment in absence of intellectual disability (often global IQ not adequate)
Diagnosis criteria from the DSM-5:
Acquisition and execution of coordinated motor skills below expected given the individual's chronological age and opportunity for skill learning use
-> Difficulties are manifested as clumsiness (e.g. dropping or bumping into objects) as well as slowness and inaccuracy of performance motor skills (e.g. catching an object, using scissors or cutlery, handwriting, riding a bike or participant in sports)
Interfere with daily life activities and academic achievement
onset during childhood (even if not diagnosed that early)
Deficit not better explained by intellectual disability or visual impairment and so are not attributable to a neurological condition affecting movement e.g. cerebral palsy, muscular dystrophy and degenerative disorder
Motor impairment can affect fine and gross motor skills
Other related problems in DCD - difficulty concentrating and following instructions
Poor organisation skills, time management, multitasking (executive functions)
Academic achievement - however, report higher creativity
Low self esteem and confidence, higher risk of anxiety and depression
High rates of co-occurrence with other NDCs
ADHD, dyslexia and ASD^
Can be difficult to distinguish as motor impairments in many NDCs exist, even if it is not DCD
Still so much to understand in DCD research
Diagnosis test for adults is only now being developed - 25 years old only
https://journals.sagepub.com/doi/full/10.1177/13623613231171980
Part 6 - Fragile X syndrome - 1:4,000 to 6,000 births
X chromosome - FMR1 gene, CGG repeat expansion, fragile chromosome
Intellectual disability is moderate to severe
Autism characteristics
Averted eye gaze
Repetitive behaviour
Guided learning - Fragile X profile differences
Both brothers, Tom and Robin, have a number of difficulties
Cognitively - issues with speech and focusing attention
Emotionally - Tom is very angry and easily annoyed, whereas Robin has a constant happy demeanour
Behavioural - Tom not able to easily adapt to social situations, Robin was able too
Both boys, despite having the same genetic condition, expressed their symptoms very differently - Tom’s weaknesses were Robin’s strengths and vice versa, and both ended up with different fixations and markedly different educational experiences (Tom went to assisted secondary, Robin went to a normal one)
