Internal Consistency of Functional Magnetic Resonance Imaging and Electroencephalography Measures of Reward in Late Childhood and Early Adolescence

Background Abnormal neural response to reward is increasingly thought to function as a biological correlate of emerging psychopathology during adolescence. However, this view assumes that such responses have good psychometric properties, especially internal consistency—an assumption that is rarely tested. Methods Internal consistency (i.e., split-half reliability) was calculated for event-related potential (ERP) and blood oxygen level–dependent (BOLD) responses to monetary gain and loss feedback from the same sample of 8- to 14-year-old girls (N = 177). Internal consistency for ERP (i.e., feedback negativity) and BOLD responses within the ventral striatum and medial and/or lateral prefrontal cortex to gain, loss, difference scores (gain − loss), and residual scores (gain controlling for loss) was compared. Moderation analyses were conducted to investigate whether internal consistency differed by age. Results ERP and BOLD responses to gain and loss feedback showed high internal consistency in all regions (Spearman-Brown coefficients ≥.70). When considering difference and residual scores, however, responses showed lower internal consistency (Spearman-Brown coefficients ≤.50), with particularly low internal consistency for subtraction-based scores (Spearman-Brown coefficients ≤.36). Age was not a significant moderator of split-half relationships, indicating similar internal consistency across late childhood to early adolescence. Conclusions Within the same subjects, high internal consistency was observed for both ERP and BOLD responses to gains and losses, which did not vary as a function of age. Moreover, excellent psychometric properties were evident even within the first half of the experiment. Difference scores were characterized by lower internal consistency, although regression-based approaches outperformed subtraction-based difference scores.