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Abstract:
Abstract: The P300 event-related potential (ERP) component
has demonstrated considerable utility in studying the genetic
influence of alcoholism. ERP comparisons of individuals at
high-risk (HR) and low-risk (LR) for alcoholism, as determined by
family history, indicate that stimulus modality, task difficulty,
and gender contribute to P300 as the index of alcoholism
heritability. The present study was designed to identify stimulus
and task variables underlying the ERP sensitivity to the genetic
influence of alcoholism. Corresponding auditory and visual
paradigms were used, which included oddball-P3b, P3a, stimulus
location and matching tasks. Each paradigm contained two levels of
difficulty to manipulate the intra-task information processing
requirements. P300 ERP amplitudes from 12 LR and 12 HR young adults
were obtained. The findings suggest that although P300 amplitude is
generally smaller for the HR compared to the LR subjects, that
modality and task differences also contribute to the overall effect
size. Specifically, the visual paradigms elicit larger
(HR<LR) inter-group differences than the auditory paradigms,
with larger differences generally more evident for the difficult
task conditions. The P3a visual task produced a particularly large
group difference, and this procedure may be a sensitive condition
for discriminating between the HR and LR groups. Because
surprisingly little is known about the nature of ERP task variables
and the heritability of alcoholism, these findings offer promise
for identifying phenotypic markers for alcoholism.
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