Ownership, ERPs and the self-referential encoding effect

Items owned by self are remembered better than items owned by others. This self-referential encoding effect is present even in hypothetical situations where ownership is newly established. We previously reported that differences in ERP components associated with early visual/perceptual processing and attention for self- and other-owned objects. These findings were presented as indicative of a positive relationship between these neural markers and memory bias. The current inquiry was designed to explore this relationship. We recorded EEG while participants engaged in an ownership task. They sorted common objects into shopping baskets on the basis of a colour cue indicating item ownership (self/other). Self/other differences were observed in N1, P2, N2 and P300 ERP components. Latency and voltage measures from these effects were utilized in a correlational analysis exploring this relationship between memory bias and electrophysiological response. This analysis indicated negative relationship a between electrophysiological differences and memory bias, especially with regards to the P2. However, due to the high level of intercorrelations between the ERP effects we tested the relationship further by performing a regression to extract a single factor for the ERP components that accounted for 65% of their variance. This factor reflected a general positive shift in all the components and was highly predictive of memory bias. This result indicates that the relationship between electrophysiological response and memory bias may be more complex than we had initially proposed.