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Child Neuropsychology

A blog by Dr Jonathan Reed

  • I have been reading an excellent book on personality research called Personality: What makes you the way you are by Daniel Nettle. It is written for the non expert and is easy to read and full of interesting observations. In the UK the psychology of personality has not been very influential on clinical practice. Most Clinical Psychologists do not assess personality, particularly in children and young people. In addition the study of personality has not featured on many university courses and certainly was not part of my undergraduate degree. However, recently I have began to take an interest in this area of psychology because it makes a lot of sense clinically. The children and young people I see have clear personality traits which fit with the current research. Having read Daniel Nettles’ book I believe that there will be a renaissance in personality assessment and understanding over the coming years. There are three key facts driving this, which are:

    1. Researchers studying personality using factor analysis have come to a consensus that there are five main personality factors, which are:

    Extraversion

    Agreeableness

    Conscientiousness

    Openness

    Neuroticism (emotional stability)

    2. The behavioural genetics work fits with the five factor model and also suggests that these traits have a large genetic component.

    3. There is increasing interest in the neuroscience of personality. The five factors are associated with different neural pathways e.g. Neuroticism (amygdala, hippocampus and R dorsolateral prefrontal cortex); Conscientiousness (dorsolateral prefrontal cortex); Extraversion (mid brain dopamine reward systems).

    Given the genetic and neuroscientific evidence it would make sense to consider personality when looking at development, emotional and social difficulties in childhood.

    There are lots of thought provoking issues raised in the book but I will highlight three that I think have major implications:

    Firstly behavioural genetics studies have shown consistently that shared family environment i.e. parents, have little to no effect on development of adult personality (not sure what the Freudians make of this!).

    Secondly that multivariate analysis shows that children’s personality seems to affect the way parent’s treat them rather than the other way round.

    Thirdly : Personality seems to predict quite strongly, certain life experiences. For example high scores on Neuroticism predicts higher likelihood of divorce and low scores on conscientiousness predicts early death. Nettle argues that personality assessment together with IQ are two of the strongest predictors for how you will do in life. It is important to note that the genetics of IQ and personality account for about 50% of variance and environment is also important. There are ways of course that you can alter your environment to influence your life course. However, I think that it is likely that without intervention the genetic biases we all have will lead us in certain directions.

    If you want to find out what your personality is there is a online test at the personality project website where you can take an anonymous personality test as part of an online research study. More information on personality can be found at the main personality project website.

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  • There is an interesting article in the Sunday Times this week entitled ‘how to make your child more intelligent’. It seems to be based in part on a new book by Richard Nisbett entitled ‘Intelligence and How to Get it: Why Schools and Cultures Count. Whilst the article makes a number of important points the overall tone feels a bit like the old nature/ nurture debate, which I thought was over years ago. The article starts by stating that ‘Over recent years most experts have concluded that intelligence is largely genetic in origin, and that nurture does relatively little to raise an individual’s potential’. I am not sure which experts they are referring to here as anyone who knows anything about the genes and IQ literature knows this not to be true. The relationship between IQ and genes has been researched very thoroughly. The consistent finding is that genes account for about 50% of variance, which leaves 50% due to environmental factors. The article seems to try and overemphasize the role of environment and diminish the role of genes. It states ‘demolishing the finding of twin studies is part of the argument against genes controlling intelligence.’ This is the argument that twins who are adopted and reared apart have similar IQ. The article argues that twins who are adopted and reared apart have a similar environment in that adopted parents are highly likely to give their children a good start in life. This seems a highly tenuous argument. Are all adoptive environments the same? Would this produce such consistent findings? Also would this argument hold for all the twin studies looking at heritability in schizophrenia, autism, ADHD etc. Dismissing twin studies is a familiar ploy of people who want to dismiss the genetic factors and one I thought had died years ago. It undermines what is otherwise a good argument. The results for the gene and IQ studies are very consistent and researched in some detail. It seems silly to me to claim that genes don’t have an effect on brain and psychological development. You don’t need to knock the gene studies to show that environment is important. The gene studies already do this.

    Another factor that points to the importance of genes in IQ is that clinical experience and research suggests that IQ is remarkable stable through lifetime. Twins actually become more similar in IQ scores as they get older. Something must be driving this. IQ doesn’t change easily, although there are obvious environmental factors at work. Certainly it is clear from the Flynn effect that IQ has been steadily rising over the last 100 years (obviously genes are not evolving that fast). There is a lot of research on environmental factors influencing IQ. IQ is a complex concept that is not totally understood, but from the research there are some candidates for strong environmental factors that have an impact on IQ development. These include having a stimulating early environment, good early nutrition, an environment rich in language and literacy. There is also research showing how targeted computer games may raise IQ. There are other suggestions in the article although i am not sure about the research to back them up – I am certainly not aware of the value of meditation on IQ, encouraging self control or having bigger babies to name a few mentioned in the article.

    So overall, yes I believe we can encourage children to be more intelligent (although as IQ as currently assessed is a comparison measure it will be difficult to measure this) and I applaud the article for highlighting this. I think we should try. But don’t dismiss the influence of genes. That influence is always there and if ignored can result in my opinion in insidious effects such as a lack of social mobility. Parent’s genes are important in part in determining early child environments (i.e. stimulating, language rich environments with high levels of nutrition) and therefore IQ development. This is a political question. I think that overall improved IQ and literacy should lead to a better society (although many other factors are important too). To achieve this early intervention by the State will be probably be needed. We will need to understand the whole picture if we are to move forward.

    PS the article does contain a good section demolishing the race, genes and IQ argument and should be read for that alone.

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  • The world of genetics is moving so fast it is hard to keep up. Luckily one of my favorite writers on the subject Robert Plomin (together with Oliver Davies) has written an update on the genetics of child psychology and psychiatry in the Journal of Child Psychology and Psychiatry. There is a lot of information in the article regarding the latest genetic findings but the issue that stuck me most was about how our understanding about how genes work is changing. My understanding of genes was the classic model described succinctly by Plomin and Oliver as a gene is a sequence of DNA that is transcibed into messenger RNA which is then translated into amino acid sequences, the building block of protein”. The proteins then build to form brain structure, neurotransmitters etc.

    The hunt has been on to find the genes that affect behavior and illness using this classic DNA process. There have been successes with a number of single gene neurological disorders identified such as Huntington’s Chorea and PKU. For these conditions the gene has been located and the sequence from gene to protein to behavior is well documented. Unfortunately this process has not worked in discovering the genes for most other psychological/ psychiatric disorders or for behavior in general. Although it is clear that there is a substantial genetic component in behaviors such as IQ, reading and language and disorders such as ADHD and Autism, as shown by twin studies, the actual genes responsible have not been found. Recent arguments have focused on the idea that many genes may be involved in combination to influence such behaviors. Plomin’s article however also raises another difficult issue. There may also be a problem with the standard DNA model as an explanation for gene- behavior effects. There are a number of puzzles regarding the standard coding DNA model. Firstly there are far fewer of these traditional genes than expected (about 24,000 in humans). Also they only make up about 2% of DNA, the other 98% were said to be junk, a byproduct of evolution. Another factor is how little these traditional genes vary between individuals and species for example simple worm like creatures called called nematodes have 19000 genes compared to the 24000 in humans. Are we not that much different to nematodes? Chimpanzees share 99.4% of DNA coding genes with humans.

    Plomin and Oliver show that part of the problem may be that we have not focused on the way that RNA works. Out of the 98% thought to be junk DNA about 1/2 does produce RNA but not the type of RNA that codes for amnio acids. Instead the non coding RNA ‘plays an important role in regulating the expression of the protein coding DNA‘. RNA is also much more complicated than once thought and many different types of RNA have now been identified, including microRNA, tRNA, snRNA, rasiRNA, snoRNA, etc. How RNA works is explained in detail in the article but that explanation is too detailed to describe here other than to say that there is much more variation between individuals and species in terms of their RNA profile and that it is the RNA that may hold the key to understanding more complex gene behavior effects. The implication of these findings according to Plomin and Oliver is that we should be analyzing the whole genomes of individuals rather than searching for individual genes. This is becoming cheaper and easier to do but so far the results are still very limited.

    My take home message from the article was that genes and their effects are not as simple as most people believe and as much of the media describes. It is very unlikely that we will find the gene for Autism, for IQ or for being gay. Instead such behavior is likely to be the result of a complex interaction of many different genes, with different types of RNA dictating how the genes are expressed which in turn will probably be influenced by factors in the environment. Hugh discoveries are being made all the time but I think the more that is known the more complex it all seems.

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  • My early career involved working with patients with multiple sclerosis (MS) and undertaking research into how people cope with this. This experience left a lasting impression as MS is a horrible disease to live with. It is neuro-degenerative disorder resulting in progressive loss of function leading to both both physical and neuropsychological disability. There are different forms with some slow moving and some with very rapid deterioration. MS results in the destruction of the myeline in the brain. Myelin is the substance that coats and insulates brain cell in a similar way to the way that plastic coating insulates electric wiring. When the myelin is destroyed the brain short circuits. Whilst most people associate MS with older adults there is an early onset version affecting children and adolescents which is particularly devastating.

    When I was working in the area a key puzzle was the geographical distribution of MS. It becomes more prevalent the further North you go. It is far more prevalent in Scotland for example, than it is in Southern Europe. Recent speculation has been that sunshine and as a result levels of vitamin D may be the reason for this geographical distribution A recent research study by Ramagopalan et al and published in PLoS Genetics has started to show in more detail the possible causal factors. They have identified a gene HLA-DRB1 that is associated with MS. More interestingly they found that vitamin D interacts with HLA-DRB1*1501 and effects whether this gene is expressed i.e the vitamin D influences whether the gene is switched on or off.

    As well as identifying possible causes of MS I think this work is important as it shows the way that genes and environment can interact in neurology and neuropsychology. Genes are not totally deterministic i.e. that there is nothing you can do if you have the relevant gene. Factors in the environment can influence whether a gene is expressed. Therefore by changing the environment or behaviour we may be able to prevent genetic neurological and neurodevelopmental disorders from occurring. In the future it may be possible to screen for all genetic risk factors and then to change behaviour or take supplements to prevent neurological illness and disorder developing. In the case of MS it may be that supplementing vitamin D or exposure to sunlight for people with the deviant gene at the right critical period, can prevent the onset of MS and thus prevent a lot of distress.

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  • One of my favourite columnists from The Times newspaper Daniel Finkelstein has written a thought provoking column today criticizing the latest report The Good Childhood Enquiry. This report was about how unhappy children are today because of selfish parents. In the column Daniel makes some simple points which I often think about myself when seeing children. The key issue is the extent to which parents influence children’s behaviour and personality. The points he makes are 1- children and parents share the same genes and therefore are likely to be somewhat alike to start with. 2- children who are difficult are going to influence the way their parents react to them. It is easy to be an authoritative parent with a child who is easy to manage- the traffic is not all one way. I happen to believe that parents do have an affect on their children but there are so many other issues affecting development as well. The issues about genetics that Daniel raises are penitent as well as the effect of the peer group, diet, sleep, exercise, brain injury, neurodevelopmental issues etc etc. Finally the column ends with an interesting take on the pros and cons of individualism and it’s effect on social relationships – but you will have to read that HERE yourselves.

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  • One of the fastest moving and most exciting areas in developmental neuroscience is neurogenetics. The key is to understand how genes produce the proteins that make up the brain and how they in turn affect behaviour. This week a study published in The New England Journal of Medicine looks at the role of a specific gene in Specific Language Impairment (SLI)- see study details here. The researchers have found that the gene CNTNAP2 is associated with performance on a non word repetition task which is a behavioural marker for SLI. The gene seems to have a role in brain development and more specifically in enrichment of frontal gray matter. I have to say I am really surprised by these findings. I tend to take the view that Professor Robert Plomin at the Institute of Psychiatry takes which is that genes are likely to be more general in their effects with genes likely to mainly effect several different brain areas and functions. This would make sense from a biological and evolutionary perspective. He and his colleague Yulia Kovas have written a good summary about these issues in our Child Neuropsychology book. My understanding is that language development is a very dynamic process involving many brain areas at first and then fixing in set areas. If these set areas are damaged language can still develop in different brain areas. I am not sure how damage to one area of the brain from birth due to genes would have such a specific effect. Also I would be amazed if this brain area affected by this gene just affected such a specific task as non word repetition- I am sure that it would affect other functions as well. The paper is however detailed in terms the genes involved, the brain areas they affect and the behaviours that are affected as a result. We will need to see whether the findings are replicated and whether they generalise. A previous very promising finding by the same research group which suggested that the FOXP2 gene was involved in language disorder proved to only relate to a few very unusual cases. Over the next few years expect to see increasing research into neurogenetics. Some of these findings are likely to challenge the way we understand child development. It should lead to a revolution in our understanding of child disorders and how to treat them. It is an exciting time for child neuropsychology.

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