Event-related potentials, heart period, and brain-heart responses during a threat-of-shock oddball task: Replicability and 6-month-reliability

Unpredictable threat triggers neural and cardiac responses, and modulates the communication between brain and heart as measured with cardio-electroencephalographic covariance tracing (CECT). Individual differences in brain, heart, and brain-heart responses to threat have been linked to individual differences in personality and psychopathology. However, to serve as psychophysiological markers for these conditions, these responses need to be replicable and reliable. To address this issue, N = 60 participants completed an auditory oddball paradigm with threat of shock at two time points, separated by 6 months (T1, T2). Frequent (standard) and infrequent (deviant) tones were presented in both safe and threat contexts. During threat contexts, temporally unpredictable shocks were delivered. Event-related potential (ERP; N1, P2, P3), heart period (HP; full timeframe, A1), and CECT components reflecting within-subject correlations of EEG and HP were measured. Experimental effects replicated after a 6-month period. Raw amplitudes of ERP (.78 < r < .91), HP (.56 < r < .62) and CECT (.13 < r < .44) components within conditions showed different levels of test-retest reliability. Differential test-retest ERP correlations of the magnitude of the experimental threat effect ranged from .30 (P2) to .54 (N1). Taken together, ERP, HP and CECT provide replicable and relatively reliable measures in the context of unpredictable threat and may be helpful for better understanding key mechanisms and individual differences in threat processing.