Language-related ERPs as learning signals during language processing (Study 1)

Two event-related potentials (ERPs) that are prominently studied within the neurolinguistic field include the N400, a negative deflection peaking around 400ms, and the P600, a later, positive component (Delogu et al., 2019; Kutas & Federmeier, 2011). Whilst the N400 is maximal following unexpected or semantically incongruous information (e.g., Kutas & Hillyard, 1980, 1984), the P600 often peaks following syntactic violations (e.g., Hagoort et al., 2003). As such, traditional notions have related the N400 to semantic processing and the P600 to syntactic processing, respectively (for discussion see Bornkessel-Schlesewsky & Schlesewsky, 2008; Delogu et al., 2019). However, this dissociation has been questioned by work demonstrating N400 and P600 effects that are either not limited to, or are not present, in their respective, and traditionally postulated, realms of semantics and syntax (e.g., Hoeks et al., 2004; Kim & Osterhout, 2005). This calls for more work regarding the functional significance of the two ERPs. Of relevance is recent literature suggesting that the two ERPs may relate more generally to correction and adaptation, with the N400 proposed as reflecting an implicit prediction error that drives implicit learning (Hodapp & Rabovsky, 2021; Rabovsky & McRae, 2014; Rabovsky et al., 2018), and the P600 as reflecting explicit, control-based processes associated with reanalysis, that drive explicit memory (Contier et al., 2025; Rabovsky & McClelland, 2020). To our awareness, no study has directly compared the connection between both the N400 and implicit memory and the P600 and explicit memory in a unified investigation, with most prior research involving separate investigations of each ERP and either type of memory (e.g., Contier et al., 2025; Jano et al., 2024, Hodapp & Rabovsky, 2021). However, a combined analysis of the two ERPs and memory types is necessary to adequately dissociate the components and their relationship to learning. The present study seeks to replicate the associations between the N400 – implicit memory and the P600 – explicit memory with a combined investigation.