Methodological choices in event-related potential (ERP) research and their impact on internal consistency reliability and individual differences: An examination of the error-related negativity (ERN) and anxiety.

Researchers in clinical psychophysiology make several methodological decisions during the analysis of event-related potentials (ERPs). In the current study, we review these choices from the perspective of individual differences. We focus on baseline period and reference scheme (i.e., average, mastoid, current source density), as well as choices regarding where (i.e., single electrode site vs. pooling of sites), when (i.e., area, area around peak), and how (i.e., subtraction- or regression-based difference scores) to quantify ERPs. To illustrate the impact of these analytic pathways on internal consistency reliability and individual differences, we focus on the error-related negativity (ERN) and anxiety-and present data from 2 samples: 1st, in adults with diagnosed generalized anxiety disorder (GAD); 2nd, in relation to continuous self-reported symptoms of GAD in a large community sample of female adolescents. Results generally indicated similar internal consistency and between-subjects effect sizes across all evaluated methods. Nonetheless, some patterns of variation emerged, such as that, across both data sets, difference-based ERN measures, especially with mastoid reference, yielded more robust associations with GAD diagnosis and symptoms, despite somewhat lower internal consistency. The current analyses suggest that the association between ERN and anxiety is robust across a range of commonly used methodological choices. The present study is an example of how systematic analyses of analytic strategies on measures of internal consistency and between-subjects variability could help inform individual-differences ERP research. (PsycINFO Database Record (c) 2019 APA, all rights reserved).