Sunday, January 12, 2014

Executive Function (EF) in Autism Spectrum Disorder

Research evidence suggests that deficits in executive function (EF) are an important feature of autism spectrum disorder (ASD). Executive function is a broad term used to describe the higher-order cognitive processes such as response initiation and selection, working memory, planning and strategy formation, cognitive flexibility, inhibition of response, self-monitoring and self-regulation. It is generally acknowledged that these higher order processes are associated with the prefrontal cortex, which are necessary for regulating and controlling behavior. Executive functions include the many of the skills required to prepare for and execute complex behavior, such as planning, inhibition, organization, self-monitoring, cognitive flexibility, and set-shifting. 

Markers of executive dysfunction may include difficulty initiating action, planning ahead, inhibiting inappropriate responses, transitioning, switching flexibly between response sets, and poor self-monitoring. Indeed, poor performance monitoring and self-regulation may be associated with the core features of ASD such as a lack of social reciprocity, perseverative responses, and intense emotional responses to change (e.g., meltdowns). Moreover, school success depends on mastery of basic EF skills, including remembering and following instructions, completing tasks independently and smoothly transitioning between tasks, and inhibiting inappropriate behaviors. Consequently, EF plays an important role in the acquisition of knowledge and social skills; the better children are at focusing and refocusing their attention, holding information in mind and manipulating it (i.e., working memory), resisting distraction, and adapting flexibly to change, the more positive the social, adaptive, and academic outcomes.
It is important to note, however, that executive function deficits are not experienced by all individuals on the autism spectrum nor do they appear to play a primary causal role in ASD. Nevertheless, executive dysfunction places a child at-risk and is likely to have an adverse impact on many areas of everyday life and affect adaptability in several domains (personal, social and communication). Consequently, an assessment of executive function can add important information about the child’s strengths and weaknesses and assist with intervention/treatment planning. The following measures may be included in a comprehensive developmental assessment battery for ASD.
§         The Delis-Kaplan Executive Function System (D-KEFS; Delis, Kaplan, & Kramer, 2001) was co-normed on a large and representative national sample designed exclusively for the assessment of executive functions, including flexibility of thinking, inhibition, problem solving, planning, impulse control, concept formation, abstract thinking, and creativity. The D-KEFS, is composed of nine stand alone tests that can be individually or group administered that provides a standardized assessment of executive functions in children and adults between the ages of 8 and 89.
§         The Developmental Neuropsychological Assessment, Second Edition (NEPSY –II: Korkman et al., 2007) measures several neuropsychological abilities and was normed on children 3 to 16 years to 11 months of age. The NEPSY-II assesses six domains: 1) Attention and Executive Functioning, 2) Language, 3) Memory and Learning, 4) Sensorimotor, 5) Social Perception and 6) Visuospatial processing. It offers 32 subtests that the examiner can tailor to the specific examinee. In addition to tests of memory and executive functioning, the NEPSY-II also includes tests on Theory of Mind (which assesses the ability to recognize the feelings and thoughts of others) and Affect Recognition (which measures the ability to recognize feelings expressed on faces), both of which should be useful for assessing children on the spectrum.
§         The Wide Range Assessment of Memory and Learning, Second Edition (WRAML2; Sheslow & Adams, 2003) is a direct assessment of both immediate and delayed memory ability, as well as the acquisition of new learning that can be useful in evaluating learning and school-related problems of students with ASD. This comprehensive measure includes a Core Battery and supplemental subtests that provide index scores for General Memory, Verbal Memory, Visual Memory, Working Memory, and Attention and Concentration. A brief four subtest Memory Screening Form that correlates highly with the full test is also available.
§         The Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000) is a parent-or-teacher rated questionnaire for children ages 5 to 18 years of age that can be used to assess executive functioning in ASD. The BRIEF is comprised of eight clinical scales (Inhibit, Shift, Emotional Control, Initiate, Working Memory, Plan/Organize, Organization of Materials, Monitor) and two validity scales (Inconsistency and Negativity). The clinical scales form two broader Indexes (Behavioral Regulation and Metacognition) and an overall score, the Global Executive Composite.
Because executive functions are important to social competence, academic success, and overall adaptability, these measures enable practitioners to assess impaired multi-task performance, document the impact of executive function deficits on functioning, and to plan educational interventions and classroom accommodations. Further information on best practice guidelines for assessment of ASD is available from the award-winning book, A Best Practice Guide to Assessment and Intervention for Autism and Asperger Syndrome in Schools, published by Jessica Kingsley Publishers.

Lee A. Wilkinson, PhD is editor of a recent volume in the APA School Psychology Book Series, Autism Spectrum Disorder in Children and Adolescents: Evidence-Based Assessment and Intervention in Schools and author of the new book, Overcoming Anxiety and Depression on the Autism Spectrum: A Self-Help Guide Using CBT.

Wednesday, January 1, 2014

The Gender Gap in Autism Spectrum Disorder

There has been a dramatic worldwide increase in reported cases of autism over the past decade. The prevalence rates have risen steadily, from one in 150, to one in 110, and now to one in every 68 children. According to estimates from CDC's Autism and Developmental Disabilities Monitoring (ADDM) Network, autism is almost 5 times more common among boys (1 in 54) than among girls (1 in 252). Statistics also indicate that referrals for evaluation of boys are approximately ten times higher than for girls. Moreover, girls are diagnosed with autism spectrum disorders at later ages relative to boys. This gender “gap” raises serious questions because many female students with ASD are being overlooked and will not receive the appropriate educational supports and services.
Why are fewer girls being identified?  Why do parents of girls experience a delay in receiving a diagnosis?  Are there gender differences in the expression of the disorder? Answers to these questions have practical implications in that gender specific variations may have a significant impact on identification practices and the provision of educational services. Although few studies have examined gender differences in the expression of autism spectrum disorders, we do have several tentative explanations for the underdiagnosis and late identification of girls with ASD. They include the following.
§         Social communication and pragmatic deficits may not be readily apparent in girls because of a non-externalizing behavioral profile, passivity, and lack of initiative. Girls who have difficulty making sustained eye contact and appear socially withdrawn may also be perceived as “shy,” “naive,” or “sweet” rather than   having the social impairment associated with an autism spectrum disorder.
§         The diagnosis of another disorder often diverts attention from autism-related symptomatology. In many cases, girls tend to receive unspecified diagnoses such as a learning disability, processing problem, or internalizing disorder. A recent survey of women with Asperger syndrome indicated that most received a diagnosis of anxiety or mood disorder prior being identified with an autism spectrum disorder.
§         The perseverative and circumscribed interests of girls with autism spectrum disorders may appear to be age-typical. Girls who are not successful in social relationships and developing friendships might create imaginary friends and elaborate doll play that superficially resembles the neurotypical girl.
§         Although Students with ASD are more likely to be the target of bullying than typical peers, this may not be recognized in girls due to gender differences in preferred modes of aggression. For example, girls may use covert verbal, social, and psychological forms of aggression while boys tend to rely on confrontational and direct modes of bullying. As a result, the more subtle nature of relational and indirect aggression (social exclusion and rejection) used by girls may be taken less seriously than the more obvious, direct aggression exhibited by boys.
§         Although girls may appear less symptomatic than boys, the genders do share similar profiles. Research suggests that when IQ is controlled, the main gender difference is a higher frequency of idiosyncratic and unusual visual interests and lower levels of appropriate play in males compared to females . As a result, the behavior and educational needs of boys are much more difficult to ignore and are frequently seen by teachers and parents as being more urgent, further contributing to a referral bias.
§         Over reliance on the male model with regard to diagnostic criteria might contribute to a gender “bias” and underdiagnosis of girls. Clinical instruments also tend to exclude symptoms and behaviors that may be more typical of females with ASD.
If girls do process language and social information differently than boys, then clinical and educational interventions based largely on research with boys may be inappropriate. If gender specific variations do exist, then the predictive validity of the diagnosis and developmental course may well differ between the sexes. Meanwhile, educators and school personnel should question the presence of an ASD in girls referred for internalizing disorders such as anxiety or depression. Best practice recommends that when a girl presents with a combination of social immaturity, restricted interests, limited eye gaze, repetitive behaviors, social isolation, and is viewed as “unusual” or “odd” by parents, teachers and peers, the possibility of an ASD should be given consideration.

Lee A. Wilkinson, PhD is the author of the award-winning book, A Best Practice Guide to Assessment and Intervention for Autism and Asperger Syndrome in Schools, published by Jessica Kingsley Publishers. Dr. Wilkinson is also editor of a recent volume in the APA School Psychology Book Series, Autism Spectrum Disorder in Children and Adolescents: Evidence-Based Assessment and Intervention in Schools and author of the new book, Overcoming Anxiety and Depression on the Autism Spectrum: A Self-Help Guide Using CBT.

©Lee A. Wilkinson

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