Psychometric properties of neural responses to monetary and social rewards across development.

Reward-related event-related potentials (ERPs) are often used to index individual differences that signal the presence or predict the onset of psychopathology. However, relatively little research has explored the psychometric properties of reward-related ERPs. Without understanding their psychometric properties, the value of using ERPs as biomarkers for psychopathology is limited. The present study, therefore, sought to establish the internal consistency reliability and convergent validity of the reward positivity (RewP) and feedback negativity (FN) elicited by two types of incentives commonly used in individual differences research - monetary and social rewards. A large, developmentally-diverse sample completed a forced-choice guessing task in which they won or lost money, as well as a social interaction task in which they received acceptance and rejection feedback. Data were analyzed at both Cz and at a frontocentral region of interest (ROI) using techniques derived from classical test theory and generalizability theory. Results demonstrated good to excellent internal consistency of the RewP and FN within 20 trials in both tasks, in addition to convergent validity between the two tasks. Results from a regression-based approach to isolating activity specific to a single response demonstrated acceptable to good internal consistency within 20 trials in both tasks, while a subtraction-based approach (∆RewP) did not achieve acceptable internal consistency in either task. Internal consistency was not moderated by age and did not differ between Cz and the frontocentral ROI; however, the magnitudes of the RewP and FN were significantly associated with age at Cz but not at the ROI. This work replicates previous studies demonstrating good psychometric properties of the monetary RewP/FN and provides novel information about the psychometric properties of the social RewP/FN. These data support the use of reward-related ERPs elicited by multiple reward types in studies of biomarkers of psychopathology.