Doctor of Philosophy
Department of Psychology
Johnstone, Stuart J., Auditory event-related potentials in attention-deficit hyperactivity disorder: developmental and clinical aspects, Doctor of Philosophy thesis, Department of Psychology, University of Wollongong, 1999. http://ro.uow.edu.au/theses/1648
This thesis examined the developmental aspects of auditory stimulus processing in children and adolescents with Attention-deficit/Hyperactivity Disorder (AD/HD) and age-matched control children via event-related potentials (ERPS). A simple auditory oddball task was used for each study. In addition to four studies addressing ERP data in the time-domain, which extended previous research via consideration of (i) topographic analyses, (ii) components to standard stimuli, and (iii) two subtypes of AD/HD as defined by DSM-1Y, an additional two studies examined similar considerations in the time-frequency domain. Main results indicated that (a) in healthy children and adolescents the activation and timing of some cognitive processes related to auditory stimulus processing were age-dependent, while others showed age-independence, (b) some topographic differences from controls were common to both AD/HD subtypes, while others were unique to a particular subtype, and these group differences showed different age effects, (c) event-related low-frequency activity contributes importantly the differences in component amplitude and morphology between sites observed in raw ERPs, and (d) the event-related low-frequency activity of the two AD/HD subtypes differed from controls in entirely unique ways, while the majority of the clinical versus control group-differences evident in components from a residual ERP (i.e. the raw ERP minus the low-frequency activity) were similar between the subtype groups. Overall, the results suggest that increased diagnostic specificity would be achieved with concurrent consideration of the low and high frequency components of the ERP.