Decoding P300 as a shared neural mechanism for oddball target detection and working memory updating

The P300 is a well-established neurophysiological component that has been extensively investigated within the oddball paradigm and is commonly interpreted as reflecting context or working memory (WM) updating. This interpretation implies that the P300 elicited by oddball target detection shares neural mechanisms with the P300 elicited by WM. To test this hypothesis, we applied multivariate pattern analysis to perform cross-task decoding between EEG patterns during an oddball task and an n-back task, a classical WM paradigm. We found that classifiers trained on EEG patterns from the oddball task successfully decoded those from the n-back task, and vice versa, with the effect concentrated in the parietal/occipital region within the P300 time window. These findings suggest that the P300 serves as a shared neural mechanism for oddball target detection and WM updating, supporting the WM updating account of the P300 from the perspective of neural representation.