Considering ERP difference scores as individual difference measures: Issues with subtraction and alternative approaches

There is growing interest in psychophysiological and neural correlates of psychopathology, personality, and other individual differences. Many studies correlate a criterion individual difference variable (e.g., anxiety) with a psychophysiological measurement derived by subtracting scores taken from two within‐subject conditions. These subtraction‐based difference scores are intended to increase specificity by isolating variability of interest....