Publication Date

2009-07-17

Availability

Open access

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Psychology (Arts and Sciences)

Date of Defense

2008-06-18

First Committee Member

Peter Mundy - Committee Co-Chair

Second Committee Member

Heather Henderson - Committee Co-Chair

Third Committee Member

Jutta Joormann - Committee Member

Fourth Committee Member

Marygrace Kaiser - Committee Member

Fifth Committee Member

Jeffrey P. Brosco - Outside Committee Member

Abstract

This study examined the moderating role of motivational tendencies for social approach and avoidance behavior, as measured by anterior EEG asymmetry, on symptom expression. In particular, this study aimed to replicate and extend previous findings that measures of anterior EEG asymmetry provide an important marker of subgroups of HFA children that significantly differ from each other, and controls, on measures of social communication impairment. EEG data were collected across two occasions on 51 HFA and 44 non-HFA children. EEG asymmetry was computed for homologous electrode pairs (e.g., lnF4-lnF3). More positive scores were indicative of relative left frontal asymmetry. Data on social and behavioral functioning were collected via parent- and self-report. Results of this short-term longitudinal study revealed moderate test-retest reliability for midfrontal asymmetry, r (65) = .39, p < .01. Results supported previous research demonstrating the differential relation of EEG asymmetry to symptom impairment among HFA children, such that parents of LFA-HFA children reported lower levels of impairment than RFA-HFA children on the SCQ Total Score, F (3, 47) = 3.58, p = .065, and Social Interaction Domain, F (3, 47) = 4.59, p < .05. Results also indicated that parents of LFA-HFA children reported higher levels of general communicative competence on the CCC-2, GCC, F (3, 47) = 6.83, p = .01, but greater impairment in pragmatic communication when compared to RFA-HFA children, SIDC, F (3, 47) = 4.41, p < .05. Additional analyses indicated that RFA was associated with early and more confident recognition of atypical (and stereotypically autistic) development based on retrospective parent-report (ADI-R #86), while LFA was associated with early, but less unambiguously autistic impairment, X2 (51) = 3.75, p = .05. This study demonstrates that anterior EEG asymmetry subgroups are reliable and useful markers of phenotypic variability that are meaningfully related to the experience and expression of symptoms of core autism impairment.

Keywords

Phenotypic Heterogeneity And Autism; Anterior EEG Asymmetry And Autism; High Functioning Autism

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