Autism – Current Issues 41
This set of summaries begins with an expression of concern about the (perceived) limitations of research with its emphasis upon aetiology and the relative lack of ongoing information about the effectiveness of interventions.
There is additional evidence for the existence of a frequent pattern of regression at some point before the second birthday among children who are diagnosed as autistic.
The question of environmental toxins (metals) as significant in aetiology, and the benefits of supplementary minerals and vitamins in interventions, is further explored.
The significance of under-connectivity among brain areas is reinforced; and the final section quotes some interview points made by Temple Grandin with particular reference to autistic style including the issue of limited central coherence.
M.J.Connor November 2005
Status of Research
A current survey completed by Charman and Clare (2004) has indicated how little is really known about the nature of autism and ASD …. especially the effectiveness of interventions.
Their study, which represented a collaboration between The Institute of Child Health, the National Autistic Society, and the Parents’ Autism Campaign for Education, sampled the opinions and experiences of around 200 researchers and 130 parents of children with autism, and examined a number of databases for evidence of current scientific research.
The outcomes indicated that almost 60% of UK autism research focused solely upon symptoms, with only 22% examining causation, 8% interventions, and 5% the effects of family history and circumstances.
Meanwhile, the majority of families felt there should be more attention paid to environmental factors while the researchers were more likely to favour genetic research.
A commentary from the NAS referred to the desirability of further research across a number of areas, but made a particular note of the under-investment in research concerning interventions. It was stressed that there is a need for a more consistent coordination and funding of research so that parents can be confident in their awareness of what works for children with autism.
(The present writer – MJC – would highlight the parallel with research into dyslexia with its endless quest for correlates or for what symptoms and behaviours constitute the condition. Here, too, there is a tradition of much research into the physiology of dyslexia [ eg hemispheric functions ] or psychological features [ eg auditory sequencing capacities ] but not a great deal of evidence concerning the most effective programmes of intervention [ educational features ].
It might also be speculated that a practical problem common to both areas of research is that of identifying sufficient numbers of participant children who are adequately matched for both endogenous and exogenous characteristics and who can form viable experimental and control groups. There is also the complication whereby apparently similar interventions are actually of limited comparability in terms of the precise methodology, intensity, etc., with the additional risk of therapy drift coming into play over time so that there is a failure to compare like with like.)
The plea for knowledge about the effectiveness of interventions is well made given the ongoing quest for some overall answer or means of recovery when, actually, the children will continue to be autistic but can be helped by certain interventions or by shifts in the nature of demands and expectations.
What is needed is valid and empirical evidence by means of which to match a given child with the most appropriate intervention as opposed to the continuing situation where reported success for some children of some intervention may be taken as evidence that there will be equal probability of success for any other child, and where new treatment options emerge but then gradually fall into disuse … such as “Holding Therapy” or “Auditory Integration Therapy.”
One ongoing study (Millonig et al 2005) is an example of the emphasis upon physiological or genetic aetiology in that this team have reported the identity of an autism susceptibility gene.
Their work has indicated that there is an association between the symptoms of ASD and the expression of a specific gene (ENGRAILED2 Gene) given that alterations in this particular genetic marker were observed across three separate samples of families all affected by ASD.
The lead researcher has estimated that up to 40% of individuals with ASD would show some anomaly in the way this gene is expressed.
Further work has highlighted a possible mechanism by which the mal-expression of the gene can bring about altered neuronal functioning, namely, some altered response to an environmental toxin … supporting the view of autism as the outcome of an (innate) propensity for the condition which is realised via some environmental trigger.
Further Evidence for Autistic Regression
The paper by Werner and Dawson (2005) begins by citing the report that anywhere between 20% and 50% of parents of an autistic child describe how the child appeared to be developing normally until around 18 months to 2 years of age at which point a marked regression in communication and social skills occurred.
The existing evidence has been dependent upon parental memory and reporting with the attendant risk of recall bias.
Therefore, the present researchers obtained home videotapes of a range of children with autism or PDD, children with ASD and regression, and typically developing children which provided clear evidence of their behaviour at the times of their first birthday and of their second birthday.
The children were assessed by the confederates of the researchers who were blind to the diagnostic status of the children, using a range of published rating scales, such as the Autism Diagnostic Interview-Revised.
The focus was upon behavioural variables such as language (including complexity of babbling), joint attention (pointing), direction of gaze, orienting to the call of their name, smiling, and repetitive behaviours.
The analysis highlighted developmental changes between the ages of 12 months and 24 months.
At 12 months, the children with ASD and parentally-reported subsequent regression were found to be babbling and speaking more readily than the other children with ASD and the typically developing group.
At 24 months, both the ASD samples had less use of language than the latter group.
Similarly, the shared attention observed among the ASD-regression group at 12 months was greater than in the other ASD group; but, at 24 months, both these groups showed significantly less shared attention than the typically developing group.
The researchers held that these findings provided validation for the phenomenon of regression in a subgroup of children with ASD … although this should not be taken as evidence that such children had entirely ordinary development until that regression point. On the contrary, the children were reported by parents to have shown a range of behavioural anomalies such as sleep disorders, and sensory hypersensitivity.
The authors describe the need for continuing investigation of the trajectory of the ASD signs and symptoms in the children with regression ASD and early onset ASD, but they report currently no available evidence of significant differences between the two groups when assessed for the level and nature of behaviours at 48 months.
Toxin Effects : Essential Mineral/Vitamin Effects
One major environmental factor is the nature of what substances are ingested either through the air breathed or the foods eaten.
The study by Adams et al (2003) recognises the range of factors that could underlie the psychological disorders observed in an estimated 25% of children and young people but makes particular reference to either excessive levels of toxic metals or deficiencies in essential minerals as significant influences upon day to day functioning.
The example is given of low levels of calcium, as assessed via analysis of hair samples, as possibly significant in the (partial) aetiology of difficult and distractible behaviours.
The authors also acknowledge that the precise cause or causes of autism and ASD are not clear, but there are indications that mercury or other toxic metals may play a role. For example, Bernard et al (2000) refer to a large number of similarities between autism and the kinds of effects observed in prenatal or infantile exposure to mercury. Such similarities include the greater prevalence or sensitivity to autistic problems among males than among females, inhibited language and communication skills, decreased social relatedness, repetitive behaviours, and gastrointestinal problems.
The study by Adams et al (op. cit) compared a sample of children with ASD (N=51) with a sample of neuro-typical children, and the focus of the study was an analysis of hair samples completed by specialists blind to the group to which the samples related.
The results perceived as most important were as follows …..
(thimerasol in vaccines, maternal seafood consumption, and maternal dental
The authors concluded that all of the above results should be treated with some caution until they were replicated in a study involving much larger samples. Nevertheless, it was held that these findings could prove significant in terms of highlighting nutritional problems as a contributory factor in the aetiology of autism. It may also be found that dietary supplementation such as enhanced lithium ingestion, including prenatal intervention, can be effective in treating some of the symptoms of ASD in at least some of the children.
A subsequent study by Adams and Holloway (2003) examined the use of multi-vitamin and mineral supplements for children with ASD, and the author introduced the report by describing the lack of previous studies of the effectiveness of such interventions despite their relatively common use. It was also held that there are few existing data concerning the nutritional status of children with autism, despite the growing belief that nutritional deficiencies may well be significant in the expression of ASD and that, correspondingly, food supplementation could prove a beneficial intervention.
Adams and Holloway go on to cite the awareness of widespread nutritional deficiencies in the USA including the estimated 30% of the general population with inadequate vitamin C status, or the even greater estimated of insufficient intake of folic acid and magnesium.
Given this, it is held to be unsurprising that there is growing evidence for the benefits of targeted vitamin and mineral supplementation in enhancing cognitive performance, achievement, and behaviour among children with certain learning disadvantages.
It is further suggested that the low levels of nutrients such as zinc or magnesium or calcium, and of vitamins, among individuals with ASD may be explicable on three counts ….
· The frequency of intestinal problems among individuals with autism, including chronic diarrhea.
· Gastro-intestinal inflammation and general problems with the digestive tract in the absorption of nutrients.
· Inadequate diets as a result of the limited choice of foods - akin to the autistic characteristic of restricted interests and behaviours - with the probability of a loss of essential nutrients.
The study completed by these researchers involved a sample of participants diagnosed with ASD, aged between 3 and 8 years; and set out to determine the level of vitamin absorption among these children and whether supplements are effective in (partially) reducing some of the observable symptoms … acknowledging all the while the limitations of the study in terms of the size of the experimental sample (N=25) and the dependence upon parental assessments and reports concerning the behaviours of the children.
With the above caveats, it was reported that a 3-month treatment with a multi-vitamin and essential mineral supplement did produce significant improvements in sleep and in gastro-intestinal functioning in the children.
The results were seen as very encouraging and as justifying a larger study with more participants and more targeted pre- and post-intervention assessments.
One would interpret the conclusions not as suggesting that dietary intervention can prevent or remediate ASD, but as intimating that, in a multi-causal and multi-symptomatic condition such as autistic spectrum disorder, there is logic in the use of relatively non-intrusive interventions as part of any overall package.
More Evidence for Central Coherence Deficiencies in ASD
Ongoing studies by Just et al (2004) have shown how individuals with autism, in contrast to those who do not show autistic traits, remember letters of the alphabet in a part of the brain that usually serves to process shapes.
This finding is interpreted as support for the theory which regards autism as a matter of failure of coordinated working of different brain areas. The upshot is that the individuals concerned cannot produce an overview of a task or cope with complex information, but the independent working of the various brain areas leads to a focus upon details.
For example, there can be excellent performance at spelling even if the meaning of a sentence or story containing the words in question is not fully grasped. Similarly, there may be great difficulty in organising and interpreting the considerable information, verbal and non-verbal, that emerges in interpersonal encounters.
The implication is for the provision of a series of tasks which gradually increase in complexity and which activate several brain areas simultaneously.
Language skill is seen as a microcosm of the disorder in that the person with autism can manage lower levels of interaction but show increasing deficits as the interchange becomes more subtle and complex.
In their own study, the present authors assessed the data from MRI patterns of brain functioning as the participants performed a simple memory task involving letters.
Typically, the participant would be shown a sequence of letters and asked to name the letter that came before the current letter, or the one before last.
Differences were observed between the brain activation patterns revealed by the autistic participants and the control group.
The autistic pattern emphasised activation in the right hemisphere which is heavily involved in processing shapes and visual information, and less activation in the left hemisphere which is usually involved in processing letters, words, and sentences.
In other words, the autistic pattern involved spatial recognition - the letters present as shapes rather than as linguistic elements.
Similarly, the autistic brain activation was greater in the posterior areas of the brain, with implications for an attention to detail, and less evident in the anterior areas associated with reasoning and higher-order thinking.
The issue of non-synchrony of brain working was highlighted.
In sum, the findings were seen as support for the theory of “Underconnectivity” in autism …. a failure of the wiring of the brain and a lack of inter-connections such that different brain areas can only work independently with implications for an excellent focus on component parts of a task but problems in integrating those different parts into a coherent whole.
Self-Report (Temple Grandin)
An interview with Temple Grandin appeared in the national press (Guardian 25-10-05) in which she described the idiosyncratic pattern of thinking that she regards as part of her autistic style and condition.
Reinforcing the comments set out in the above section, Grandin describes how she thinks in images – words are seen only as a second language. Ideas are illustrated by pictures as opposed to being set out verbally.
She goes on to acknowledge the characteristically profound difficulties among autistic individuals in respect of communication and imagination … a detachment from the immediate world around … and an indifference to social cues.
Reference is made to the un-connectedness of autistic brains with implications for a potential for specialised knowledge and expertise in contrast to limited capacities in many or most other areas.
One plus factor perceived by Grandin (whose qualifications and career are in the realm of animal welfare and humane handling) is the ability to empathise with infra-human organisms whose cognitions are largely in the form of images; and she argues that the well-developed and well-connected frontal lobes of normally-functioning individuals means that people are usually too verbal to perceive how the world appears to organisms who lack the capacity for verbal and abstract thought.
Reference is made to the growing belief that certain eminent scientists (including Einstein and Newton) could well have been identified as autistic given their ability to focus upon almost obsessive details and to persevere in some very narrow academic field. It is further speculated that Einstein might not have the (social or practical) skills necessary to apply for and gain a place at a university in today’s world !
Grandin holds that she was fortunate to have been a child during the 50’s when many social skills were taught and practised by rote so that children, including children with higher functioning ASD, were “moulded into shape”. It was also the case at that time, she believes, that the curricula were a little more varied and that children and young people with ASD had more access to the practical (and less verbal-dependent) skills where they could perform well.
The implication is for recognising and seeking to understand the nature of the style and cognitive preferences and perceptions of individuals with autism, and to beware of the assumption that adequate cognitive ability will ensure a successful and happy experience of mainstream schooling when actually such an assumption could not only be unrealistic but also insensitive and even damaging.
* * * * *
M.J.Connor November 2005
Adams J. and Holloway C. 2003 Pilot study of a multi-vitamin/mineral supplement for children with ASD. Tempe, Arizona : Arizona State University.
Adams J., Holloway C., George F., and Quig D. 2003 Toxic metals and essential minerals in the hair of children with autism and their mothers. Tempe, Arizona : Arizona State University
Bernard S., Enayati A., Roger H., et al 2000 Autism : a unique type of lead poisoning. ARC Research Report
Charman A. and Clare P. 2004 The Causes and Treatment of Autism London : Institute of Child Health
Grandin T. 2005 “I’m an anthropologist from Mars” Interview recorded in The Guardian (25th October). By-Line : David Cohen
Just M., Minshew N., et al 2004 Autistic recall of letters of the alphabet. Washington : National Institute of Child Health (Article published in the July 2004 edition of Brain)
Millonig J., DiCicco-Bloom E., and Brzustowicz L. 2005 Autism susceptibility gene. New Jersey : National Alliance for Autism Research (Paper to be published in the November issue of the American Journal of Human Genetics)
Werner E. and Dawson G. 2005 Validation of the phenomenon of autistic regression using home videotapes. Archives of General Psychiatry 62(8) 889-895
© Mike Connor 2005.
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