Development and Neuropsychology Flashcards
What advancements in neuropsychology were made during the late 20th century?
The emergence of new brain modalities such as CT, MRI, fMRI and PET allowed greater understanding brain biology.
The development of neuropathological techniques for assessing brain tissues such as immunocytochemistry and epigenetics
Standardisation of research criteria for making diagnosis
Recognition of risk factors for neuropsychological conditions; particularly pregnancy and perinatal complications
Despite this:
There are no pathological tests that diagnose psychological illnesses
All illnesses are diagnosed clinically
How many neurons are in the human brain?
How much energy does a human brain use?
How many synapses are in the human brain?
The human brain contains 100 billion neurons
25% of an adult’s basal metabolic rate is allocated to the brain
87% of a child’s available energy is utilised by the brain
There are 100 trillion synapses in the human brain
Discuss the development of the pre-frontal cortex during adolescence
Synaptic pruning, the final stage of synaptogenesis, occurs relatively late in frontal cortex compared to all other brain regions - it is one of the last areas to mature.
Synaptic pruning is a regulatory process of the CNS to remove neurons in order to leave more efficient synaptic configurations.
This process is associated with a loss of grey matter (neuron bodies) from the frontal cortex throughout adolescence
Synaptic processes/spines likewise decrease during puberty (child has 2-3x density of synaptic spines)
The process of synaptogenesis and synaptic pruning continues into the 3rd decade before it becomes stable - but the majority of changes occur during adolescence
What neuronal and glial cell changes are associated with Schizophrenia?
Astrocyte number are reduced in Schizophrenia
- particularly decreased in the dorsolateral pre-frontal cortex (layer 5 & 6)
Microglia number are elevated in Schizophrenia
- potentially changed functions as well
Neuron sizes are decreased in Schizophrenia
- particularly decreased in the dorsolateral pre-frontal cortex (layer 5 & 6)
What animal model is able to replicate OCD?
What implication does this have on microglia involvement in OCD?
Knockout Hoxb8 gene mice have obsessive compulsive disorder
Hoxb8 exclusively labels bone marrow derived microglia
Implicates microglia in OCD pathogenesis
What evidence suggests autism may be associated to microglial abnormalities?
Patients with autism have enlarged prefrontal cortexes
Microglia within the DLPFC are shown to have retracted processes but increased cell body size in patients with autism -> thought to be a result of activation/functional change of the cells.
There is an increased density and volume of microglia in Autistic DLPFC
What does the Wnt/GSK3b cellular pathway contribute to neural development?
Wnt, and it’s downstream effector protein GSK3b, are important to maintaining cytoskeleton stability - particularly in dendrites
Discuss how the use of SNPs and genetic classification of the autism spectrum can be used as a diagnostic tool
The Autism Genome Research Exchange database is able to give a distrubution of autistic and non-autistic individuals based on their genetic classification (SNPs)
There is a classification accuracy of 85% using 237 SNPs as predictive markers of Autism Spectrum Disorder (1st time there has been a diagnostic test)
Parents of autistic children map between controls and autism patients
Some SNPs are more heavily weighted as contributing stronger risk to ASD phenotype than others; while some SNPs are resilence SNPs protective of ASD.
The balance between risk and protective ASD SNPs is the dominant factor that accounts for the discordance between mono-zygotic and di-zygotic twins.
What is development from a neuropsychological point of view?
Development is the processes that drive the origins and course of individual behaviour and adaptation throughout one’s life.
It encompasses:
- Cellular and neurobiological changes
- Physical skills
- Cognitive and language functions
- Social and emotional processes
- Personality and attitudes
- Behavioural repertoire
Discuss the relevance of culture to development
All development occurs within a cultural context.
Culture is composed of values, beliefs, norms, symbols and behaviours that are learned by those that exist within it -> allows shared social experiences and norms. They are transmitted from generation to generation and progressively changes with time.
For example: what is normal for a Melbourne 18 y.o girl is different from an 18 y.o in Botswanna or an 18 y.o from Melbourne in 1890
Discuss Erickson’s Theory of Development
This theory is described as ‘epigenetic’; implying:
- Step by step growth
- Critical and discrete time periods
- Importance of psychosocial “crises” that must be overcome
- Believed in the values of both positive and negative emotions that opposed each other in “crises” – the outcome of which would develop the individual.
Strengths:
- Makes intuitive sense – “face validity
- High level of abstraction leads to broad ways for further study and application
- Enduring interest in his ideas
- Particularly with regard to his ideas on later life – there is value and development even in the stages of old age
Weaknesses:
- Hard to test empirically
- Broad and abstract
- Reflects 1950’s
- Insufficient attention to negative or maladaptive development
- Simplistic in its assumption of the need to linearly pass from one stage to another
Discuss Havinghurst’s Tasks Theory of development
Havighurst (1948) proposed that human development moves through stages but each stage is associated with “tasks
A development task is one “which arises at or about a certain period in the life of an individual, successful achievement of which leads to happiness and to success with later tasks, while failure leads to unhappiness in the individual… and difficulty with later tasks”
Strengths:
- Integrates challenges from different domains
- Stresses the individual’s active role in negotiating tasks
Weaknesses:
- Time frames no longer appropriate
- Huge sociocultural changes have transformed expectations of what is normative
Recent research has challenged link between achievement of tasks and future happiness / success and stressed the importance of other constructs such as self-esteem
Discuss the Trajectory and Turning Points Theory of development
A trajectory is the continuation of a direction, the sum of the forces that propel us towards a destination.
Turning points are disruptions to a trajectory that has the long-term impact of altering the probability of life destinations.
Strengths:
- Recognises the importance of early experiences on later events and experiences of development – chain reaction of events causing cumulative effects.
- Identifies the potential for change in development following turning points
Discuss the transaction model of development
States that development takes place through transacting factors:
- Genetic
- Constitutional
- Biological/biochemical
- Psychological
- Environmental
Multiple factors operate together dynamically and bi-directionally to direct one’s development
Explain the “matrix of disadvantage” as it relates to children with disruptive behavioural disorders
Parents of children with DBDs have higher than average rates of:
- domestic violence
- substance abuse
- depressive disorders
- social deprivation
- tend to use harsh physical punishments
Children enter school with attential and motivational difficulties
Poor performance elicits punishment and leads to negative self views
Behaviour drives peers away and thus potential buffers to stress
Is it nature or nurture that contributes to behavioural traits?
Genetic contribution to behavioural traits and psychiatric disorder vary in the range from 30-80%
Expression of genes always occurs in an environment - behaviour results from gene-environment interactions
Provide an example of a gene-environment interaction
Non-human primates deprived of early maternal care sustain life-long derangements of monoamine neurotransmitter systems
Genotype interacts with adverse parenting to increase the risk of antisocial behaviour
What are risk factors to development?
Risk factors are those factors that contribute to development in an adverse way.
One risk factor can be associated with multiple different outcomes = **multifinality **
This is contrasted with **equifinality = **multiple pathways to the same outcome.
What are protective factors of development?
Many factors can protect an individual from adverse outcomes:
- Internal resources
- External /environmental resources
Are considered moderators of trajectories
“The more positive you are in attitude about certain things the better the outcomes are likely to be”
What is Temperament?
Temperament is the automatic associative responses to basic emotional stimuli that determine habits and skills
i.e how one responds to emotions
There are four dimensions of temperament:
- Harm avoidance
- Reward dependence
- Novelty seeking
- Persistence
What is resilience?
Resilience is the dynamic process encompassing positive adaptation within the context of significant adversity
Resilience is not just a quality - it is a skill
- can be learnt and developed across the course of life. Is not just limitied to early development but all stages of development
If basic adaptive and support systems are in place, development is robust and developmental tasks can be achieved and people can cope with trauma and loss
Trajectories need not be disrupted
Why is resilence increasingly recognised as important in the later stages of life?
Older adults face numerous changes to which they must adapt
Most do so successfully through processes of:
- assimilation (adjusting the environment to fit with changes)
- accommodation (adjusting self and attitudes)
In childhood development, what must be considered when determining whether a behaviour is abnormal?
Must consider whether the behaviour is appropriate:
- For age
- For context
But must also be alert to “unproblematic behaviour” -> for example, a 2-year old who is not distressed about separation from mother or a 3 year old that always does what he’s told.
Across what domains does childhood development occur?
Physical Development
- Physical growth
- Gross motor skills
- Fine motor skills
- Puberty changes
- Health / illness
Cognitive development
Allows for new ways of understanding and interacting with the world
- Language
- Knowledge
- Memory
- Reasoning
- Planning
Social Development
Developments in cognition allow new ways of thinking about self, others and moral dilemmas
Progression in the nature of social interactions across childhood
Emotional Development
- emotional language
- emotional knowledge
- emotional recognition
- emotional regulation
Demonstrate ways in which chronic illnesses may affect the developmental tasks of an adolescent
