The Utility of Event-Related Potentials in Clinical Psychology

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).

Novel rewards occlude the reward positivity, and what to do about it

Both the Reward Positivity (RewP) and the novelty N2 component appear within the same spatio-temporal window. This signal overlap impedes the assessment of the RewP evoked by complex novel rewards like affective or motivational imagery. Here we conducted a series of experiments which successfully isolated signals of reward and novelty through spectral decomposition as well as with experimental manipulations that systematically removed the influence of novelty on the reward-evoking image. Together, these findings help explain the nature of this component overlap and provide methodological and analytic techniques for isolating reward- and novelty-specific computations to complex stimuli.