Impact of EEG Reference Schemes on Event-Related Potential Outcomes: A Corollary Discharge Study Using a Talk/Listen Paradigm

The choice of the virtual reference schema is critical to determining the outcome of Event-Related Potentials (ERP) studies assessing corollary discharge(CD) non-invasively. This study focuses on ERP, specifically examining the effects of EEG reference schemas—Linked Mastoids (LM), Common Average Reference (CAR), and Reference Electrode Standardization Technique (REST)—on auditory N1 (talk and listen condition) amplitudes and their derivative, the Corollary Discharge Index (CDI). Twenty healthy participants engaged in a talk/listen ERP task; continuous EEG data was collected to assess the impact of different offline re-referencing schemas on auditory N1 responses and associated CDI values. Our results indicated significant variances in N1 amplitudes across the three reference schemas. The LM schema demonstrated the highest N1 amplitudes and CDI values, suggesting a more effective capture of CD signaling during speech production tasks. In contrast, the CAR schema recorded the lowest values, indicating reduced sensitivity, while the REST schema provided a balanced approach with intermediate sensitivity, potentially mitigating the biases inherent in the other two schemas. These findings highlight the crucial role of reference schema selection in influencing ERP outcomes, with potential implications for both research and clinical diagnostics in auditory and neuropsychiatric conditions. Further studies are encouraged to explore these findings with higher-density EEG arrays and to extend analyses to clinical populations to validate the utility of LM, CAR, and REST in different diagnostic contexts. This study advances our understanding of EEG referencing impacts on ERP measurements and suggests optimised strategies for assessing neural mechanisms underlying auditory processing and corollary discharge signalling.