Cognitive and symptom profiles in Asperger's syndrome and high-functioning autism

Asperger syndrome (AS) and autistic disorder are two subtypes of pervasive developmental disorders (PDD), but there has been considerable debate over whether AS and autistic disorder without mental retardation (IQ > or = 70), called high-functioning autism (HFA), are distinct conditions or not. The aim of the present paper was to clarify this issue through a comparison of cognitive function and autistic symptom profiles. Based on the DSM-IV and ICD-10 definitions of language acquisition, 36 age- and IQ-balanced subjects with AS (mean age, 12.8 years; mean full-scale IQ, 98.3) were compared with 37 subjects with HFA (mean age, 12.6 years; mean full-scale IQ, 94.6) on the Japanese version of the Wechsler Intelligence Scales and the Childhood Autism Rating Scale-Tokyo Version (CARS-TV). Compared with the HFA subjects, the AS subjects scored significantly higher on Verbal IQ, Vocabulary, and Comprehension, but scored significantly lower on Coding. Although the total CARS-TV score did not differ significantly between the two groups, AS subjects scored significantly lower (i.e. less abnormal) on Verbal communication and Non-verbal communication than did the HFA subjects. A history of normal language acquisition in early childhood could predict his/her better verbal ability in mid-childhood or later. Autistic cognitive characteristics shared by both AS and HFA subjects appear to support the validity of the current diagnostic classification of PDD.     

Brief report: Thought disorder in asperger syndrome: Comparison with high-functioning autism

Asperger syndrome (AS) is a pervasive developmental disorder generally regarded as a variant of autism. While it has been included in the ICD-10 and DSM-IV as a distinct diagnostic entity, it is still unclear to what extent it differs from highfunctioning autism (HFA). Persons with HFA have been reported to show a variety of deficits of thought processes. Abnormalities such as poor reality testing, perceptual distortions, and areas of cognitive slippage have been described using the Rorschach inkblot test (Dykens, Volkmar, & Glick, 1991). Since AS has been conceptualized as a mild variant of autism, we hypothesized that persons with AS will have fewer abnormalities on the Rorschach test compared to persons with HFA. To test this hypothesis, we compared 12 subjects with AS (ICD-10, 10 male, mean age = 12.2±3.3 years, mean full-scale IQ = 99.6) with 8 subjects with HFA (ICD-10/DSM-III-R, 7 male, mean age = 12.2±3.8 years, mean fullscale IQ = 83.4) on the Rorschach test. AS subjects demonstrated a trend towards greater levels of disorganized thinking than the HFA group. They were also more likely to be classified as Introversive suggesting that AS subjects may have more complex inner lives involving elaborate fantasies. Also, AS subjects tended to be more focused on their internal experiences. However, overall, the Rorschach test was not found to differentiate the two diagnostic groups on the majority of structural variables. Implications of these findings are discussed with regard to the diagnostic validity of Asperger syndrome.     

Is clumsiness a marker for Asperger syndrome?

ABSTRACT. Although Asperger syndrome (AS) has been included in the ICD-10 as a distinct category within the pervasive developmental disorders, it is still unclear to what extent it differs from normal-intelligence autism (high-functioning autism; HFA). Persons with AS are said to be particularly clumsy. To test the hypothesis that clumsiness can reliably distinguish AS from autism, the present authors compared 11 patients with AS (ICD-10; 10 males; mean age, 13–6 years; mean IQ, 98) with nine patients with HFA (ICD-10/DSM-III-R; eight males; mean age, 12–9 years; mean IQ, 84). Clumsiness was assessed by the Bruininks-Oseretsky test. Both groups showed problems with coordination and the distribution of standard scores was virtually identical. This suggests that motor clumsiness, as measured by tests of coordination, may not reliably distinguish AS from HFA. However, qualitative differences may occur between the two groups in the manner in which movements are performed. Further research with larger samples may elicit differences into the pattern of motor deficits that occur in autism and AS.     

A Family History Study of Asperger Syndrome

Asperger syndrome (AS) is a childhood-onset disorder often described as a mild variant of autism. Although classified as a distinct disorder in the DSM-IV, its overlap with autism continues to be a matter of ongoing debate. While the family genetic origins of autism are well established, few studies have investigated this topic in AS using current operational criteria. In this report, we examined the family psychiatric history of 58 subjects with AS diagnosed according to DSM-IV criteria (48 males; mean age 13.34; mean full scale IQ 104.87). All subjects had a history of mild autistic social deficits; focused special interests; normal level of intelligence; and an odd and often pedantic manner of speaking. None had a previous diagnosis of autism. Of the 58 subjects with Asperger syndrome, three had first degree relatives with AS; nine (15%) had a family history of schizophrenia; and 35 (60%) had a family history of depression. Of the 64 siblings, four had a diagnosis of AS and none of autism. Compared with a group of 39 subjects with normal intelligence autism (high functioning autism, HFA; 33 males; mean age 15.34; mean full scale IQ 85.89) subjects with AS were more likely to have relatives with depression; schizophrenia; and the broader autistic phenotype. Possible reasons for and implications of these findings are discussed.     

Brief Report: Social and Communication Abilities and Disabilities in Higher Functioning Individuals with Autism and Asperger Syndrome

Individuals with higher functioning autism (HFA) fail to translate their cognitive potential into real-life adaptation, and the severity of their symptoms is considerable despite their intellectual ability. This paper reports on a subsample from a larger study (A. Klin et al., in press) analyzed here by autism spectrum subtypes. It focuses on the nature of ability and disability in HFA and Asperger syndrome (AS) in relation to age and IQ. Participants included 32 individuals with autism and 35 with AS. Individuals with AS had significantly higher Verbal IQ scores and less symptomatology than individuals with autism, but their Vineland scores were equally impaired, highlighting the adaptive deficits in ASD regardless of classification. No relationship was found between adaptive functioning and symptom severity.     

The Autism-Spectrum Quotient (AQ) Children’s Version in Japan: A Cross-Cultural Comparison

In the current study, the child AQ was administered in Japan, to examine whether the UK results for reliability and validity generalize to a different culture. Assessment groups were: Group 1: n = 81 children with Asperger Syndrome (AS) or high-functioning autism (HFA); Group 2: n = 22 children diagnosed PDD-NOS with average IQ; and Group 3: n = 372 randomly selected controls from primary and secondary schools. Both clinical groups scored significantly higher than controls (AS/HFA mean AQ = 31.9, SD = 6.93; PDD-NOS mean AQ = 28.0, SD = 6.88; controls mean AQ = 11.7, SD = 5.94). Among the controls, males scored significantly higher than females. The pattern of difference between clinical groups and controls was found to be similar in both countries.     

Asperger’s syndrome and high-functioning autism: language, motor and cognitive profiles

The objective of this study is to compare the cognitive profile, the motor and language functioning and the psychosocial adaptation of children with Asperger syndrome (AS) and with high-functioning autism (HFA). Subjects were recruited through the department Autism and Developmental Disorders of the Heckscher-Klinikum. To be included in the study, the full-scale-IQ had to be at least 80. Subjects with AS had to have a normal early language development and subjects with HFA a clear delay in language development, as reported by their parents. The sample consisted of 57 children with Asperger syndrome and 55 children with high-functioning autism. The mean age of the children was 10 years. All subjects were examined with a standardised test battery. Children with AS had a higher full-scale-IQ than children with HFA. This was due to a higher verbal-IQ. There were no significant differences in the performance-IQ. At a mean age of 10 years, subjects with AS had better language skills than subjects with HFA, but at least 30% showed clear receptive language problems. Motor problems were present in about 50% of the children with AS and HFA. The level of psychosocial adaptation was clearly reduced, but was comparable for the two groups. The differences in verbal-IQ and language skills between the two groups could be explained through the definition of the syndromes. The presence of language problems in the subjects with AS at age 10, the comparable degree of motor impairment and level of psychosocial adaptation question the validity of the distinction between AS and HFA within the category of pervasive developmental disorders.     

Screening Adults for Asperger Syndrome Using the AQ: A Preliminary Study of its Diagnostic Validity in Clinical Practice

The Autism Spectrum Quotient (AQ) has been developed to measure the degree to which an adult with normal intelligence has autistic traits. In this paper it is evaluated for its potential as a screening questionnaire in clinical practice on one hundred consecutive referrals to a diagnostic clinic for adults suspected of having Asperger Syndrome or high functioning autism (AS/HFA). The results indicate that it has good discriminative validity and good screening properties at a threshold score of 26. The implications of these results are discussed.     

Defining the Behavioral Phenotype of Asperger Syndrome

Asperger syndrome (AS) is characterized by social deficits and restricted interests in the absence of mental retardation and language delay. However, it is unclear to what extent the social deficits of AS differ from those of traditional autism. To address this issue, 58 subjects with AS were compared with 39 subjects with autism. Social deficits were classified according to Wing and Gould’s method. Forty-six (79%) subjects with AS were rated as active but odd, while 32 (82%) with autism were described as aloof and passive, while a few subjects showed mixed features. Thus, despite the overlap between AS and autism, subjects with AS showed a distinct pattern of social impairment. Implications of these findings are discussed.     

The Autism-Spectrum Quotient (AQ): Evidence from Asperger Syndrome/High-Functioning Autism, Malesand Females, Scientists and Mathematicians

Currently there are no brief, self-administered instruments for measuring the degree to which an adult with normal intelligence has the traits associated with the autistic spectrum. In this paper, we report on a new instrument to assess this: the Autism-Spectrum Quotient (AQ). Individuals score in the range 0–50. Four groups of subjects were assessed: Group 1: 58 adults with Asperger syndrome (AS) or high-functioning autism (HFA); Group 2: 174 randomly selected controls. Group 3: 840 students in Cambridge University; and Group 4: 16 winners of the UK Mathematics Olympiad. The adults with AS/HFA had a mean AQ score of 35.8 (SD = 6.5), significantly higher than Group 2 controls (M = 16.4, SD = 6.3). 80% of the adults with AS/HFA scored 32+, versus 2% of controls. Among the controls, men scored slightly but significantly higher than women. No women scored extremely highly (AQ score 34+) whereas 4% of men did so. Twice as many men (40%) as women (21%) scored at intermediate levels (AQ score 20+). Among the AS/HFA group, male and female scores did not differ significantly. The students in Cambridge University did not differ from the randomly selected control group, but scientists (including mathematicians) scored significantly higher than both humanities and social sciences students, confirming an earlier study that autistic conditions are associated with scientific skills. Within the sciences, mathematicians scored highest. This was replicated in Group 4, the Mathematics Olympiad winners scoring significantly higher than the male Cambridge humanities students. 6% of the student sample scored 327plus; on the AQ. On interview, 11 out of 11 of these met three or more DSM-IV criteria for AS/HFA, and all were studying sciences/mathematics, and 7 of the 11 met threshold on these criteria. Test—retest and interrater reliability of the AQ was good. The AQ is thus a valuable instrument for rapidly quantifying where any given individual is situated on the continuum from autism to normality. Its potential for screening for autism spectrum conditions in adults of normal intelligence remains to be fully explored.     

The ‘Reading the Mind in the Voice’ Test-Revised: A Study of Complex Emotion Recognition in Adults with and Without Autism Spectrum Conditions

This study reports a revised version of the ‘Reading the Mind in the Voice’ (RMV) task. The original task (Rutherford et al., (2002), Journal of Autism and Developmental Disorders, 32, 189–194) suffered from ceiling effects and limited sensitivity. To improve that, the task was shortened and two more foils were added to each of the remaining items. About 50 adults with Asperger Syndrome (AS) or High Functioning Autism (HFA) and 22 matched controls took the revised task. Results show the revised task has good reliability and validity, is harder, and more sensitive in distinguishing the AS/HFA group from controls. Verbal IQ was positively correlated with performance, and females performed worse than males in the AS/HFA group. Results are discussed with regard to multi modal empathizing deficits in autism spectrum conditions (ASC).     

A Meta-Analysis of Differences in IQ Profiles Between Individuals with Asperger’s Disorder and High-Functioning Autism

A meta-analysis was performed to examine differences in IQ profiles between individuals with Asperger’s disorder (AspD) and high-functioning autism (HFA). Fifty-two studies were included for this study. The results showed that (a) individuals with AspD had significantly higher full-scale IQ, verbal IQ (VIQ), and performance IQ (PIQ) than did individuals with HFA; (b) individuals with AspD had significantly higher VIQ than PIQ; and (c) VIQ was similar to PIQ in individuals with HFA. These findings seem to suggest that AspD and HFA are two different subtypes of Autism. The implications of the present findings to DSM-5 Autism Spectrum Disorder are discussed.     

Reading the mind in the voice: a study with normal adults and adults with Asperger syndrome and high functioning autism

People with high functioning autism (HFA) and Asperger syndrome (AS) have deficits in theory of mind (ToM). Traditional ToM tasks are not sensitive enough to measure ToM deficits in adults, so more subtle ToM tests are needed. One adult level test, the Reading the Mind in the Eyes test has shown that AS and HFA subjects have measurable deficits in the ability to make ToM inferences. Here we introduce a test that extends the above task into the auditory domain and that can be used with adults with IQ Scores in the normal range. We report the use of the test with an adult sample of people with AS/HFA and with two adult control groups. Results suggest that individuals with AS/HFA have difficulty extracting mental state information from vocalizations. These results are consistent with previous results suggesting that people with HFA and AS have difficulties drawing ToM inferences.     

孤独症和Asperger综合征儿童的心灵理论对照研究

目的探讨孤独症和Asperger综合征(AS)儿童的心理推测能力。方法应用表情识别和虚假信念课题分别对21例高功能孤独症(HFA)儿童、54例AS儿童和70名正常健康儿童进行测试。结果表情识别题中, HFA组通过率明显低于正常组(P<0．01),AS组与正常组无显著差异;虚假信念题通过率为正常儿童组>AS组> HFA组(P<0．01)。结论 HFA和AS儿童基本能识别简单表情,但存在理解虚假信念的缺陷,说明他们的心理推测能力低下。     

Clumsiness in autism and Asperger syndrome: a further report

Clumsiness has been proposed as a diagnostic feature of Asperger syndrome (AS), a type of pervasive developmental disorder recently introduced in the ICD-10 and DSM-IV. However, the extent to which this symptom is specific to AS is not clear. To investigate this issue, we compared a sample of AS children with age- and sex-matched groups of children with autistic disorder and pervasive developmental disorder not otherwise specified (PDDNOS). Twelve subjects with AS (ICD-10/DSM-IV; 11 males; average age 11.4 years; mean full-scale IQ 104.9) were compared with 12 subjects with autistic disorder (DSM-III-R; 11 males; average age 10.3 years; mean full-scale IQ 78.4) and 12 subjects with PDDNOS (DSM-III-R; 10 males; average age 10.1 years; mean full-scale IQ 78.2). The BruininksOseretsky test, a standardized test of motor coordination, was administered blind by the same investigator to all the three groups. While coordination deficits were found in all three groups, children with AS were found to be less impaired than those with autistic disorder and PDDNOS. However, no significant relationship was found between coordination scores and diagnosis after adjusting for the level of intelligence. These findings suggest that some patients with AS may be less clumsy than those with autistic disorder and that this difference may be the result of their higher level of intelligence. Studies based on larger samples using multiple measures of coordination are needed to further clarify the role of clumsiness in the classification of pervasive developmental disorders.     

The Autism-Spectrum Quotient (AQ)—Adolescent Version

The Autism Spectrum Quotient (AQ) quantifies autistic traits in adults. This paper adapted the AQ for children (age 9.8–15.4 years). Three groups of participants were assessed: Group 1: n=52 adolescents with Asperger Syndrome (AS) or high-functioning autism (HFA); Group 2: n=79 adolescents with classic autism; and Group 3, n=50 controls. The adolescents with AS/HFA did not differ significantly from the adolescents with autism but both clinical groups scored higher than controls. Approximately 90% of the adolescents with AS/HFA and autism scored 30+, vs. none of the controls. Among the controls, boys scored higher than girls. The AQ can rapidly quantify where an adolescent is situated on the continuum from autism to normality.     

Do individuals with high functioning autism have the IQ profile associated with nonverbal learning disability?

Previously researchers have noted a high level of occurrence of the IQ profile associated with nonverbal learning disability (NLD) in Asperger syndrome (ASP) but not in high functioning autism (HFA). We examined the IQ profile scores of a large sample of children (n = 69) and adults (n = 77) with HFA, stringently diagnosed according to ADOS, ADI-R, and DSM-IV criteria, and a corresponding sample of typical child (n = 72) and adult controls (n = 107). At least one of the three primary components of the Wechsler pattern seen in NLD were found in 17–26% of the children and 20–32% of the adults with HFA. All three components occurred in slightly more than 5% of the children and adults with autism. Overall, the VIQ > PIQ profile seen in NLD occurred in 18% of the sample of individuals stringently diagnosed with HFA. Therefore, obtaining this IQ profile is not a valid clinical discriminator between NLD and HFA.     

The French Version of the Autism-Spectrum Quotient in Adolescents: A Cross-Cultural Validation Study

We assessed the accuracy of the French version of the Autism Spectrum Quotient (AQ) in adolescents with Asperger syndrome (AS) and high-functioning autism (HFA) compared to healthy controls and adolescents with psychiatric disorders (PDs). Three groups of adolescents, aged 11–18, were assessed: 116 with AS/HFA (93 with IQ ≥ 85 and 20 with 70 ≤ IQ < 85), 39 with other PDs, and 199 healthy controls. The AS/HFA group scored significantly higher than the healthy control and PD groups. A cut-off score of 26 was used to differentiate the autism group from healthy controls with 0.89 sensitivity and 0.98 specificity. Scores did not vary by age or sex.     

Repetitive Behavior Profiles in Asperger Syndrome and High-Functioning Autism

Although repetitive behaviors are a core diagnostic domain for autism spectrum disorders, research in this area has been neglected. This study had two major aims (1) to provide a detailed characterization of repetitive behaviors in individuals with Asperger Syndrome (AS), high-functioning autism (HFA), and typically developing controls (TD); and (2) to examine whether differences in repetitive behavior profiles could provide evidence for the external validity of AS separate from HFA. Specifically, it was hypothesized that circumscribed interests would be more prevalent and cause more impairment in the AS group than the HFA group, while the reverse would be true for other categories of repetitive behavior. The parent(s) of 61 children and adolescents (19 with AS, 21 with HFA, and 21 TD) completed two interviews focused specifically on lifetime and current repetitive behavior symptoms. No reliable differences in repetitive behavior between AS and HFA children were found. Results suggested that circumscribed interests differ in developmental course from the three other DSM-IV-TR categories of repetitive behavior. Internal consistency among the four DSM-IV-TR categories of repetitive behavior was high, =.84, providing evidence for a unitary repetitive behaviors factor. The importance of expanding research in the repetitive behavior domain is highlighted as part of the necessary integration of behavioral and neurobiological approaches to understanding the etiology of autism.     

Visual search for basic emotional expressions in autism; impaired processing of anger,fear and sadness,but a typical happy face advantage

Facial expression recognition was investigated in 20 males with high functioning autism (HFA) or Asperger syndrome (AS), compared to typically developing individuals matched for chronological age (TD CA group) and verbal and non-verbal ability (TD V/NV group). This was the first study to employ a visual search, “face in the crowd” paradigm with a HFA/AS group, which explored responses to numerous facial expressions using real-face stimuli. Results showed slower response times for processing fear, anger and sad expressions in the HFA/AS group, relative to the TD CA group, but not the TD V/NV group. Reponses to happy, disgust and surprise expressions showed no group differences. Results are discussed with reference to the amygdala theory of autism.