Autism - Current Issues 48
This current set of summaries is linked by the theme of early recognition of possible autism or ASD, and of developmental trajectories which may include a remission of symptoms indicative of autism or a confirmation of the initial diagnosis.
The first section highlights the range of symptoms and features which link ASD, language disability, and general developmental delay; and those which appear to act as differentiators among young children.
The next sections concern response-to-name as a possible
tool in identification; and reference is made to work which further implicates
dysfunction in the mirror neuron system as a causal and identifying
A finding, contrary to existing evidence, is cited, suggesting that autistic children can read others mental states; while a recent study has explored the validity of using an (in)ability to understand and explain idioms as an indicator of autism.
The final section returns to the theme of behavioural and cognitive features, and environmental features (such as early intervention), which might prove to underlie differential trajectories including the loss of an autistic diagnosis in some cases.
M.J.Connor June 2007
Differentiating Autism/ASD and Other Developmental Disorders
The report of research completed by Ventola et al (2007) begins with a reminder that young children with ASD share a number of features with children who experience other pervasive conditions, such as global developmental delay or language delay.
These similarities make for difficulty in accurately diagnosing very young children, which becomes all the more significant a dilemma in the light of the importance for children with ASD to receive early intervention specific to their particular profile of needs and circumstances.
The authors describe a general paucity of research evidence specifically concerned with behavioural differences between children with ASD and other children; and where there has been attention to language, cognitive, or social differences, the findings have largely related to older children and not to the differences that may exist among very young children.
Certainly, the authors have not been able to identify any studies comparing behavioural differences in toddlers with ASD and those with global or language delays based upon standardised assessment devices combined with parental reports.
Their review of the evidence that does apply to toddlers has indicated that those with ASD rather than other developmental delays are more impaired in joint attention, imitation skills, empathic responding, pointing to show interest, and the use of a range of facial expressions. This pattern matches what is typically observed among older children.
Nevertheless, the authors argue, while certain social behaviours and interaction styles do appear to discriminate between children with ASD and those with other developmental needs, the differential diagnosis remains problematic because at least a proportion of the children with these other developmental needs show some of the characteristic social and communication impairments of ASD.
Meanwhile, it has been shown that children with ASD share a specific style of, or pattern of impairments in, communication compared to other children with developmental delays. In particular, the young children with ASD use fewer conventional gestures such as nodding or shaking their heads, show more echolalia ands stereotyped phrases (where speech is present), and are less likely to initiate or respond to verbal communications.
Shared characteristics among toddlers include impairments in pretend play skills, although, with time, a differentiation is discernible so that, by rising 4 or 5 years of age, the children with ASD show significantly less pretend play than these other children.
The extent of symbolic play can differentiate very young children, but the differentiability via observed symbolic play between those with ASD and those with other developmental may only become significant over time.
In respect of possible differentiators in the domain of sensory processing, the results have been inconsistent with some findings indicating ASD-specific sensory processing anomalies (an under- or over-responsiveness to stimuli) along with repetitive behaviours, and other findings suggesting that such behaviours can also be observed among children with language and developmental delays even if not usually to the same degree.
The authors summarise their review of existing data by noting that identifying ASD and differentiating ASD from other developmental disabilities remains challenging especially in the case of very young children.
Children with ASD and children with other needs can show similar features and many of the available diagnostic instruments do not accurately make the necessary discriminations; and there is the further complication of changes in the presentation and the symptomatology of ASD and the other disabilities with the increasing age of the children.
Their own study set out to investigate further the behavioural differences between toddlers with ASD and other developmental delays among a sample of children who all showed risk according to the Modified Checklist for Autism in Toddlers (M-CHAT) and who, therefore, represented that population of children referred for more specialist investigation for possible autism.
The participant children included 152 boys and 43 girls screened on the M-CHAT at a mean age of 24 months (range 16-30 months) diagnosed with either an ASD or a pervasive disorder not otherwise specified, a global delay, or a language delay.
The follow up assessments were made by means of the Autism Diagnostic Observation Schedule; the Autism Diagnostic Interview-Revised; The Childhood Autism Rating Scale; Vineland Scales; and a cognitive measure (Bayley or Mullen Scales). In addition, clinical judgement was involved, based upon the DSM-IV criteria for autistic disorder.
The authors begin their summary and discussion of the results by restating the increased frequency with which clinicians are asked to assess children for ASD and developmental/language delays whose presenting symptomatology is not clear; and this present study sought to compare and contrast the cognitive, language, and adaptive skills of those children initially identified with ASD and those with general or language delays (DD/DLD). .
The ASD group scored lower than the DD/DLD groups in all areas adaptive skills, expressive language, receptive language, fine motor, and visual reception skills and the differences reached a statistically significant level in all but the language and fine motor subtests of the Mullen Scales of Ability.
In other words, the children with ASD showed a generally greater level of impairment than children in the other categories, but language skills did not differentiate the children, possibly because language difficulty or delay was commonly the issue causing concern in the first place and the reason for referral to specialist clinicians.
Fine motor skill also failed to differentiate the children, with the suggestions from the authors that motor skills tended to be a relative strength for most of the children, especially those identified with ASD, or that the sample size and the degree of differences among scores were not sufficient to achieve significance.
However, the overall view was that, in this current sample anyway, the children identified with ASD appeared to be operating at a younger developmental level; and more specific analyses of score patterns on the various assessment instruments indicated areas where the ASD and DD/DLD groups could be contrasted.
For example, with language levels controlled, all of the items concerned with reciprocal social interaction (such as eye contact, showing, initiation of joint attention, etc.), and the item concerned with pointing from the items concerned with communication, were found to separate the groups. It was the area of joint attention that provided the greatest amount of variance.
The implication drawn was that social deficits, especially joint attention deficits, are largely limited to the children with ASD; and that many of the communication items failed to differentiate between the groups.
This kind of finding is consistent with those of earlier studies, such as Trillingsgaard et al (2005), in the conclusion that social behaviours especially joint attention behaviours are most salient in characterising children with ASD and in comparing such children against those with other delays or disabilities.
The use of the CARS served to highlight further the differentiability of the ASD group in respect of social and social-communication items as well as some of the atypical sensory-related items. This pattern held when language level was controlled, with the implication that the CARS may be considered a valid measure of autistic symptomatology rather than general developmental level.
Again, the authors highlight that effects sizes were greatest for those items concerned with social relatedness.
Returning to the M-CHAT, it was noted that the children identified with ASD failed most items more frequently than children in the DD/DLD groups, but that, with controls in place for language level, only four items produced significant differences. These were . response to name; pointing for interest; pointing to make a request; and ability to respond to pointing and all of these are a matter of (limited) joint attention and social responsiveness.
The overall conclusion was that the current findings indicate how children with ASD and DD/DLD have many shared characteristics that set them apart from typically-developing children; but there are behavioural markers, notably in the area of joint attention deficits, that are observed more frequently in children with ASD than in children with DD/DLD and in typically developing children. Such symptoms may be considered central to ASD.
The authors acknowledge some limitations to this study, such as the relatively small sample size in the DD/DLD groups, coupled with the emphasis upon children who had all failed an initial screening assessment so that there was no control group comprising normally-developing children.
Nevertheless, it was repeated that children with ASD appear significantly differentiable from children with general or language-related delays on a number of behavioural features. These behaviours involve an impairment in socialisation and social interaction skill, particularly when it comes to joint attention (and associated features such as eye contact, imitation, etc.) which can be regarded as the central and perhaps unique area of deficit among children with ASD.
Early Social Communication and Response-to-Name Research
The April issue of Archives of Pediatrics and Adolescent Medicine was given over to the theme of ASD, and a summary of two of the papers (concerned with early social communicative and cognitive development) has been prepared by Busko and Barclay (2007).
The first study was that of Stone et al who have focused upon children in their second year mean age of around 16 months which is earlier than the typical age at which ASD is identified.
These authors report 4 main observations :
These authors go on to highlight the evidence for a genetic basis for autism, with the estimate that between 6 and 9% of the younger siblings of children diagnosed with autism will also develop this condition, while others are at risk of developing some of the features of the broader autism phenotype.
Therefore, their ongoing study has examined the early cognitive and communicative differences between this at-risk group and control peers by monitoring a sample of infants with an older sibling with ASD and a control sample with one or more normally-developing siblings. The assessment materials examined cognitive performance, play, communication, and autistic symptomatology; and parental ratings were made of social, language, and communication skills.
The younger siblings of children with ASD have been found to have significantly poorer performance in non-verbal problem solving, directing others attention, understanding words, understanding phrases, gesture use, and social-communicative interactions with their parents. Increased autistic symptoms have also been noted.
The authors have suggested that the weaker performance of the children in the autistic-sibling group may reflect early emerging features of a broad autistic phenotype, with the implication for accepting that, with one autistic child in a family, the risk for subsequent children of having autism is increased.
The practical need is closely to monitor these younger children in order that intervention strategies can be put in place at the first signs of anomalous behaviours or developmental impairments.
The second study summarised by Busko and Barclay is that of Nadig et al who have assessed the sensitivity and specificity of response to name at age 12 months as a possible early screening measure for ASD.
These authors have reported a commonly poor behavioural reaction (and a possible marker for ASD) in some children when the researcher give them a small toy, then stand behind them and call their name to see if they will turn round (or otherwise show some response).
The absence of any observable reaction was not claimed to be a firm predictor but was held to be suggestive of later developmental problems and as justifying a closer monitoring of the performance and progress of the children in question, and the use of a range of social communication measures.
The suggestion is that earlier identification of autism (before the typical age of diagnosis of 3+ or 4 years) would offer the possibility of beginning an intervention earlier than is also typically the case, with potentially improved outcomes.
The authors compared the results of response-to-name trials among infants with an older sibling with ASD (ie those with enhanced risk of ASD) and among a control sample of infants whose older sibling(s) showed typical development. The trials were conducted when the children were aged 6 months, and repeated when they were 12 months old.
At the 6-month testing, there was a trend (albeit non-significant) for more of the control infants to pass the test by showing a reaction such as turning round and making eye contact. At 12 months, all the control infants passed the test, compared to 86% of the target group.
Failure to respond to name at 12 months was found to show a very high specificity for outcome at 24 months in respect of identification as ASD or as having a significant developmental delay . of 12 infants who failed the test at age 12 months and for whom data were available at 2 years, 9 were found to have either ASD (5) or developmental delay (4).
The authors restated in their final conclusion that a failure to respond to name at the 12 month check could prove a useful indicator of children who would merit a more thorough assessment and ongoing monitoring.
(An editorial commentary in this journal, written by Geraldine Dawson, highlights the significance of research into early features of ASD and the critical significance of recognising as early as possible those children at risk for ASD.
Possible markers of enhanced risk may include the failure to respond to name, and also a failure to demonstrate imitative behaviours, babbling behaviour, eye contact, and the use of gesture.
The importance of early intervention lies in matching the timing of intervention with the maximal plasticity of brain functioning and the emergence of particular brain systems concerned with language, communication, and social behaviour.)
Dysfunctional Mirror-Neuron Systems and Empathy Deficits
A recent study, Cox et al (2007) has produced further evidence for the significance of severe mirror-neuron dysfunction as underlying social-relatedness deficits in ASD, such as an inability to imitate facial expressions or to demonstrate empathy.
Mirror neurons are those that are activated not simply when the person performs some actions but when those actions are observed being carried out by somebody else, and memory traces or activation pathways may be stimulated; and it is possible to gain a clear message about what the other person is doing as a basis for imitation and empathy.
These researchers reported on a series of studies concerning the operation of mirror neurons as observed via magnetic resonance imaging, with one major theme concerned with the finding that, in autism or pervasive developmental disorder, it is not that the mirror neurons are defunct, and not showing any activation, but that the system is in place albeit not operating to the appropriate extent to facilitate social interactions.
The most recent study involved an observation of the brain activity in a sample of children with high functioning autism with a mean age of 12-3 and who were presented with a series of stimulus photographs of faces showing various emotions for them to examine and imitate.
It was found that the ability to imitate the facial expressions, as measured by the appropriate subscale of the Autism Diagnostic Interview-Revised, was correlated with activity in the right inferior frontal gyrus and, to some extent, in the amygdala and insula. Poor scores were linked with low levels of activation.
Further, poor scores on a test (Interpersonal Reactivity Index) were closely associated with low mirroring activity in these brain regions.
The authors highlighted the strength of the observed correlations, and noted that the more impaired the children were in terms of empathic or imitative capacities, the less the activity in the mirror neuron system (and the less impairment of such capacities, the greater the level of activity).
Their conclusion was that these findings supported the view that a dysfunctional mirror neuron system could underlie the impairments characteristic of autism in that the dysfunction negatively impacts upon imitative behaviour with a whole range of adverse consequences for social cognition and social behaviour.
Reading Mental States
A study by Black et al (2007) also suggests that theory of mind capacities, based upon the ability to read facial expressions, are potentially available to children with autism.
However, this research has indicated that the critical factor underlying success in such a task is access to animated rather than static examples.
The research team compared the ability of autistic children and non-autistic control children, aged between 10 and 14, in judging the mental state of strangers by looking at various parts of the face displayed on a computer as still or dynamic images.
The performance of the children with autism in attributing a range of mental states was markedly poorer than that of controls when examining the static images of faces.
(The expressions represented distrust, deciding, disapproving, not interested, not sure, relieved, surprised, and worried previously trialled for distinctiveness on a sample of typically-developing children.)
Their performance improved when the whole face, including the eyes and the mouth, conveyed the emotional information in a brief video recording, compared to the condition where the eyes and mouth remained static and neutral.
The implication drawn was that the children with autism could extract emotional information from the portrayed faces, notably from the eyes, and, to an extent, from the mouth.
This view is at odds with existing evidence that children with autism have a specific deficit in processing emotional information conveyed in facial expressions (eyes); but the present authors further supported their implication by showing that children with autism were as competent as controls in recognising facial expressions when only the eyes were visible, whether presented as moving or still.
It was suggested in the conclusion that a specific impairment in reading emotional information from the eyes appears not to be the explanation for some or much of the social and empathic anomalies observed among children with autism.
(Simon Baron-Cohen is quoted in the June 2007 edition of The Psychologist as questioning the significance of this research and as pointing out that there may have arisen some artifactual implications as a result of inadequate control over all the variables that can exert some influence over performance, and that ongoing studies into social cognition are required.
The present writer MJC would speculate that the issue may only be partly concerned with the presence or absence or level of a capacity for reading social information, and that a critical variable may be the nature of the task. Where attention is specifically drawn to some aspect of a stimulus, and where the salience of this aspect is emphasised, there may be a greater match between observed and required performance. In other words, the children with autism may not usually or spontaneously seek to extract social and emotional information from a face (or any other stimulus) but can gather some of this information when given appropriate instructions or cues or prompts, so that a degree of capacity is indeed available but its implementation requires direct teaching or facilitation.)
Understanding of Idiom
A piece of action research by Male et al (2007) followed up the issue of weaknesses among children with autism in respect of dealing with abstract language and of literal interpretation of what they hear.
It was noted that a failure to grasp the meaning of idioms can provide diagnostic pointers towards autism and ASD, but the question was raised whether children generally are familiar with many or most idiomatic phrases (and whether observed difficulties could hardly be considered ASD-specific).
These authors, accordingly, set out to identify a set of frequently used, and putatively well understood, idioms, and to assess their meaningfulness among children without developmental or learning disabilities.
Samples of children from mainstream schools (aged between 6 and 13 years) were interviewed in order to gain an indication of the typical level of understanding of 10 traditional and 10 current idioms . (an example of a traditional idiom is It is raining cats and dogs , and an example of a current idiom is You are driving me up the wall ).
It was found that the children were more successful when it came to interpreting current idioms than traditional idioms. Mean accuracy score for the traditional idioms was 2.8 out of 10; and 6.3 out of 10 was the mean for the current idioms.
This difference was further highlighted by the greater percentage of literal interpretations applied to traditional idioms compared to current idioms.
The authors also noted that, as might have been predicted, increasing age of the children was matched by an increasing percentage of correct interpretations and a decrease in the number of literal answers ie age (and, presumably, experience) will influence idiom interpretation; and that the 10 most readily understood idioms across the age range were all current . such as I laughed my head off ; Feeling under the weather ; or Keep your hair on .
The authors acknowledged some methodological weaknesses, such as overall small sample size and the uneven distribution of ages within the sample of participants, but the implications drawn for any attempt to use idiom interpretation as an indicator of some developmental disorder or delay include the need to use up to date idioms as they are more familiar and meaningful. Using traditional idioms may produce false positive indicators of possible difficulty given that their interpretability is challenging for children generally (and especially children towards the younger end of the age range studied).
Further, the advice continued, the idioms need to be set out in semantically simple language so that results about idiom understanding are not confounded by linguistic problems.
Meanwhile, further studies are desirable with a view to assessing performance among different samples of participants, notably those identified with ASD and typically developing controls, using the identified set of 10 best understood (current) idioms, while exploring further the effects of age and greater language experience per se.
Predictors of Optimal Outcomes in Young Children Diagnosed with ASD
The study by Sutera et al (2007), which returns to the theme of developmental trajectories, was stimulated by the observation that ASD may be diagnosed in children as young as 20 months by means of characteristic impairments in social interaction, communication, and restricted patterns of behaviour (observable in limited joint attention, or eye contact, or play skills, etc).
At this young age, repetitive behaviour appears not to be a viable differentiator between children with autism and those with other developmental disorders.
A review of evidence indicates that an early diagnosis of autism is usually stable over time. However, the authors were particularly interested in the (small) number of children who are diagnosed with autism at a young age but who do not meet the diagnostic criteria at some later point in time and who are no longer identified as autistic.
The concept of recovery was
first mooted by Lovaas (1987)
albeit with some critical commentaries
referring to perceived shortcomings in the methodology or to the somewhat
limited extent of what was actually involved in recovery.
Reference is made to another study (Sigman and Ruskin 1999) who followed the progress of 51 children diagnosed with autism at a mean age of 45 months to find that 9 children were no longer so-diagnosed by a mean age of 154 months.
The linking factor between these two samples appeared to be the early initiation of intensive intervention; and the authors summarise further evidence to the effect that effective intervention seems to require a considerable number of hours per week of direct working (high intensity), direct instruction, an emphasis upon attending to others, social skills and imitation, and a focus upon functional language all within a highly structured and consistent routine.
However, positive change appears to be not simply a matter of the intervention (and its particular elements) but to involve also certain existing characteristics of the children. Pre-treatment skill levels in areas such as imitation, receptive language, IQ, social interaction, and adaptive skills were predictive of outcomes more so than the factor of clinic-based rather than parent-directed intervention.
In other words, intervention did not independently produce positive outcomes. The nature of intervention is very important, but the prognosis appears to depend upon the interaction between the (amount of) intervention and child characteristics such as initial language level and joint attention capacity.
Meanwhile, even in the case of children who no longer fit diagnostic criteria for autism or ASD, it might be anticipated that there will be residual and observable symptoms in language, attention, and social domains.
The authors cite evidence from previous studies in their series which, in one case, showed significant problems in attention by the age of 7 years among those whose diagnosis switched from ASD to ADHD (and social functioning ranging from very positive to significantly impaired); and, in the other case, indicated that children who no longer met the ASD criteria may have had adequate scores on standard tests of language, but still displayed problems with higher level and complex language, or social-cognitive challenges relating to interpreting mental states, inductive reasoning, and the capacity to build narratives.
On this issue, it was proposed by Koegel et al (2001) that there are critical areas among the childrens skills that influence outcome, such as the spontaneous initiation of social behaviours and social communication (some of which are amenable to direct instruction).
Cognitive ability level has similarly been shown to be a significant influence upon outcomes and a good predictor of developmental trajectory; and children with higher levels of (non-verbal) intelligence are more likely to display symbolic play and communicative skills, and improved social skills over time .
However, symptom severity appears not to have any significant predictive power for later outcomes. Non-verbal cognitive ability and language ability are more reliable predictors than the severity of early symptoms.
The focus of the present study by Sutera et al was upon the children with an early diagnosis of ASD but who achieved optimal outcomes. Optimal outcomes were defined as no longer meeting the DSM-IV criteria for ASD, and functioning in the average range on standard measures of cognition, language, and adaptive skills.
Unlike previous studies, the participants were of pre-school age at the times both of initial identification as ASD (2+years) and of follow up (4+) . with 13 of 73 children originally diagnosed with ASD no longer meeting the diagnostic criteria at the follow-up assessment.
A range of assessment measures was involved, including the M-CHAT, Autism Diagnostic Interview-Revised, Diagnostic Observation Schedule, Childhood Autism Rating Scale, Vineland Adaptive Behaviour Scales, Mullen or Bayley Scales, and the Differential Abilities Scale as well as clinical observation and judgements.
The findings indicated that the children who eventually achieved a non-ASD outcome were, at 2 years of age, just as impaired as those children who did not recover in terms of socialisation, communication and language, and symptomatology thus confirming the difficulty of predicting outcomes at a young age.
Symptom severity showed no differences between the two groups at the initial assessments suggesting that the initial diagnosis was legitimate and supporting the existing evidence that the nature and number and severity of symptoms have weak predictive validity.
Relatively limited repetitive behaviour and resistance to change appeared more predictive of positive outcomes.
Meanwhile, and despite the fact that motor skills and cognitive level are not critical for an ASD diagnosis, it seemed to be the case that relatively positive motor and cognitive skills are associated with the positive outcomes. The authors summarised these issues by suggesting that adequate motor and cognitive skills may be indicative of a more positive prognosis, but are neither necessary nor sufficient for optimal progress.
The skills of those children who did achieve the optimal outcome were further examined and it was noted that they were more likely than their non-improving counterparts to have some specific skills in various areas of adaptive functioning such as use of scissors, ability to open doors, positive motor skills like a smooth gait and ability to pedal a tricycle, feeding themselves, etc. which seemed to underlie the capacity for greater independence and a sense of self-efficacy.
It was speculated that children who achieve optimal outcomes might have a greater motivation at a young age to master those skills which will bring about a higher level of independence with their mastery indicative of higher cognitive skills or a greater capacity to take advantage of early intervention. An interest in, and attention to, language (as precursors to higher-level communicative interactions) may prove a requirement for eventual optimal outcomes.
Perhaps, too, the more advanced motor skills, or parental expectation/encouragement, are significant for better performance in respect of some daily living skills; and it may be that parents who work towards greater self help skills in the children are the more likely to identify, and persevere with, therapeutic interventions.
The authors conclude by acknowledging the fairly basic state of play and that there are likely to be various differences in brain structure, cognitive development, genetic vulnerability that will be identified over time, and which will enable greater predictive accuracy when seeking to differentiate children likely to achieve optimal outcomes from those unlikely to do so (and when seeking to determine the most appropriate intervention).
They acknowledge, too, some limitations in this present study such as the questionable generalisability of the findings about optimal outcome based upon small numbers of children; and all the children were receiving early interventions which varied in type and intensity and quality, with the corresponding need for ongoing research to unravel the possibly significant interactions for later outcomes of child, family, and intervention characteristics.
* * * * * *
M.J.Connor June 2007
Busko M. and Barclay L. 2007 Sibling studies show promise in the early detection of autism. Medscape Medical News (April 11th, 2007)
Cox S., Dapretto M., et al 2007 Dysfunctional mirror neuron system and empathy deficits in autism. Presentation to the 6th Annual Meeting for Autism Research. Seattle, Washington. May 3rd -5th 2007
Lovaas O. 1987 Behavioural treatment and normal educational and intellectual functioning in young autistic children. Journal of Counselling and Clinical Psychology 55 3-9
Male I., Slattery S., and Phillips R. 2007 Understanding of idiom in school children. Unpublished research findings. Presentation to members of the SE Regional Group
16th May 2007
Sigman M. and Ruskin E. 1999 Continuity and Change in the social competence of children with autism, Down syndrome, and developmental delay. Monographs of the Society for Research in Child Development 64 (1)
Sutera S., Pandey J., Esser E. et al 2007 Predictors of optimal outcome in toddlers diagnosed with autistic spectrum disorders. Journal of Autism and Developmental Disorders 37 98-107
Trillingsgaard A., Sorenson E., Nemec G., and Jorgenson M. 2005 What distinguishes autism spectrum disorders from other developmental disorders before the age of 4 years ? European Journal of Child and Adolescent Psychiatry 14 65-72
Ventola P., Kleinman J., Pandey J., et al 2007 Differentiating between autism spectrum disorders and other developmental disorders in children who failed a screening instrument for ASD. Journal of Autism and Developmental Disorders 37 425-436
© Mike Connor 2007.
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