AUDITORY ATTENTIONAL MECHANISMS IN SCHOOL- AGE CHILDREN WITH AUTISM SPECTRUM DISORDERS

Transcription

1 AUDITORY ATTENTIONAL MECHANISMS IN SCHOOL- AGE CHILDREN WITH AUTISM SPECTRUM DISORDERS Sridhar Krishnamurti, Kristen Phillips, Meghan Phillips, Benjamin King Auburn University

2 Relationship Disclosure Form We have no relevant financial relationships to disclose. We have no non-financial relationships to disclose.

3 Background on autism Autism Spectrum Disorders (ASD) refers to a spectrum of disorders characterized by a triad of symptoms: qualitative impairment in communication, and restricted, repetitive, and stereotyped patterns of behaviors, activities, interests (Tharpe et. al, 2006, p. 430). Clinically, ASD is defined by impairments in social interaction, as well as language and communication difficulties and stereotyped behaviors.

4 Our study Attentional processes in children with ASD has gained much interest. However, most research has spanned the visual system and not the auditory system. While visual attentional dysfunction has been implicated as a core deficit for individuals with ASD due to its role in information processing, it still does not completely explain all of the atypical responses shown by individuals with ASD to their environment.

5 Auditory System The auditory system should be considered as another key element in modulating information processing because language deficits are fundamental elements of impairments seen in ASD. It is not clear if possible attentional impairments in processing of auditory stimulu are at a sensory (perceptual) level or are mediated more centrally (executive level).

6 Purpose of Our Study: To investigate auditory attention to speech stimuli in a sustained attention or vigilance task in school-age children with- and without- ASD. This kind of sustained attention component has been measured previously using such continuous performance tasks in individuals with Attention-deficit Hyperactivity Disorder and was extended to children with- and without- ASD in the current study

7 Specific Aims for Our Study: To investigate: If school-age children with ASD make greater number of errors in a sustained attention task than peers without ASD If there is a greater vigilance decrement over time for school-age children with ASD in an auditory continuous performance task If errors in children with ASD are related to inattention (selective attention to target words) or impulsivity (inability to filter out irrelevant non-target words).

8 Types of attention (Patten &Watson, 2011) Orienting The initial physical adjustment toward a stimulus Sustained The ability to maintain attention to a stimulus Shifting Requires the individual to disengage from one stimulus and then shift and reorient to a new stimulus Joint Shared attention between two individuals and an object or another individual Involves all three of the previous components of attention Always social in nature

9 ASD Subject characteristics: Subject # Autism rating Language Achievement 1 GARS: SS= GARS: SS= 87 3 GARS: Parent Rating= 109 Teacher Rating= GADS: SS= 97 5 GADS: SS= GARS: SS= 85 OWLS: SS=44 OWLS: SS= 48 OWLS: SS= 56 CELF-P: SS= 55 OWLS: SS= 67 CELF-4: SS= 96 WJ III: SS= 43 WJ III: SS= 62 WJ III: SS= 93 From IEP Profile, achievement is judged to be below grade-level. WIAT-II: SS= 83 WJ III: SS= 98 Autism Rating Scale: Gilliam Autism Rating Scale (GARS) or Gilliam Asperger s Disorder Scale (GADS) Language: Oral and Written Language Scales (OWLS) or the Clinical Evaluation of Language Fundamentals- Preschool or 4 th Edition (CELF-P, CELF-4) Achievement: Woodcock Johnson III, Test of Achievement (WJ III) or Wechsler Individual Achievement Test- 2 nd Edition (WIAT-II)

10 Formal Testing Utilized: All children completed the Auditory Continuous Performance Test (ACPT) This is a standardized test that was given in recorded format, intended for auditory attention Vigilance decrement in this sustained attention task is measured by repeating the sequence of 96 words over six different runs and looking for accuracy and subtracting the inattention/impulsivity errors obtained in the sixth run from those obtained in the first run.

11 Procedure: During the ACPT, each individual listener hears a sequence of recorded monosyllabic words and is required to raise their thumb every time he or she hears the target word dog while ignoring other monosyllabic words, such as teach, shoe, need, etc. Based on subject responses, errors are classified as inattention errors (listener misses the target word dog ) or impulsivity errors (listener raises thumb for words other than dog ).

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13 Results: types of errors Overall, results indicated that children with ASD are more likely to have more inattention errors than the control group Independent samples t-tests were used to compare the groups with- and without- ASD. Significant differences were found between groups in number of inattention errors (p= 0.03) and total errors (p= 0.03) but no significant differences were found between groups in terms of number of impulsivity errors (p= 0.06). No significant differences in vigilance decrement from first to sixth runs were found between groups.

14 25 20 Number of errors Inattention errors Impulsivity errors Total errors 5 0 P<0.05

15 Results: Results indicate that sustained attention is typically maintained in children with ASD but they make more selective attention errors during such tasks while maintaining the ability to filter out irrelevant stimuli when needed. These results support the Weak Coherence Theory

16 Typically developing Child without autism

17 Weak Coherence Theory: Failure of a central system to integrate multiple sources of information to establish meaning Weak in individuals with ASD: They tend to attend only to small bits rather than to large, globally coherent patterns of information (Jolliffe & Baron-Cohen, 1999, p. 150). No significant vigilance decrements were observed for the ASD group, indicating that they can sustain attention when needed. Significantly greater number of inattention errors in the ASD group indicate that they are unable to differentiate globally across target (dog) and nontarget speech items.

18 Child with autism

19 Discussion: Results of the current study do not support previous models that postulated that children with ASD have greater difficulties related to arousal and inability filter out irrelevant stimuli. Our study results do indicate difficulties for ASD in shifting attention across stimuli.

20 Discussion: While there is no clear evidence in this study to show any hemispheric asymmetries for children with ASD, models that propose poor left hemisphere function (indicated by deficits in temporal processing and speech perception) seem plausible based on the inattention deficits to temporally succession of stimuli used in our study. Further attentional implications in terms of existing models will be discussed in further detail during the presentation session.

21 Autism Social Language Auditory

22 Implications: Poor selective attention No decrement (sustained attention is ok) Management strategies should be based on specific type of attention Sustained attention: target name versus others Selective attention: dichotic words Joint attention: social in nature, disengage and then reorient, gaze and eye contact

23 Therapist ASD child Bucket Balls

24 References: Goldstein, G., Johnson, C., & Minshew, N. (2001). Attentional Processes in Autism. Journal of Autism and Developmental Disorders, 31(4), Jolliffe, T., & Baron-Cohen, S. (1999). A test of central coherence theory: linguistic processing in high-functioning adults with autism or Asperger syndrome: is local coherence impaired?. Cognition, 71, Patten, E., & Watson, L. (2011). Interventions Targeting Attention in Young Children With Autism. American Journal of Speech- Language Pathology, 20, Tharpe, A. M., Bess, F., Sladen, D., Schissel, H., Couch, S., & Schery, T. (2006). Auditory Characteristics of Children with Autism. Ear & Hearing, 27,