Anti-Heartbeat-Evoked Potentials Performance in Event-Related Potentials-Based Mental Workload Assessment

The aim of this study was to determine the effect of heartbeat-evoked potentials (HEPs) on the performance of an event-related potential (ERP)-based classification of mental workload (MWL). We produced low- and high-MWLs using a mental arithmetic task and measured the ERP response of 14 participants. ERP trials were divided into three conditions based on the effect of HEPs on ERPs: ERP(HEP), containing the heartbeat in a period of 280–700ms in ERP epochs after the target; ERP(A-HEP), not including the heartbeat within the same period; and ERP(T), all trials including ERP(A-HEP) and ERP(HEP). We then compared MWL classification performance using the amplitude and latency of the P600 ERP among the three conditions. The ERP(A-HEP) condition achieved an accuracy of 100% using a radial basis function-support vector machine (with 10-fold cross-validation), showing an increase of 14.3 and 28.6% in accuracy compared to ERP(T) (85.7%) and ERP(HEP) (71.4%), respectively. The results suggest that evoked potentials caused by heartbeat overlapped or interfered with the ERPs and weakened the ERP response to stimuli. This study reveals the effect of the evoked potentials induced by heartbeats on the performance of the MWL classification based on ERPs.