Readers of Chinese characters need to recognise how they are formed in order to identify them correctly. However, our understanding of the cognitive processing of characters in working memory is limited. Using the character N-back task paradigm, electrophysiological data were recorded from 30 participants to investigate the effects of the number of radicals and from 30 participants to investigate the effects of the function of radicals on neural activity during the recognition, updating, and maintenance of characters in working memory. Results showed that compound and irregular characters were less correct and required longer response times than single-component and regular characters. In addition, the compound character condition had more negative N2pc, lower P300 and lower SW amplitude than the single-component character condition. Meanwhile, there was a larger P200 in the irregular character condition than in the regular character condition, but there was no difference between the regular character and the irregular character in the N2pc, P300, and SW components. The number of radicals and the function of the radicals may have different effects on the character processing. This study reveals the neural effects of Chinese character radicals on cognitive processing in a working memory task and provides behavioral and electrophysiological evidence for a theoretical model of verbal working memory subprocesses.

Using the N-back task, we investigated how memory load influences the neural activity of the Chinese character cognitive subprocess (recognition, updating, and maintenance) in Mainland Chinese speakers. Twenty-seven participants completed the Chinese character N-back paradigm while having their event-related potentials recorded. The study employed time and frequency domain analyses of EEG data. Results showed that accuracy decreased and response times increased with larger N values. For ERPs, N2pc and P300 amplitudes decreased, and SW amplitude increased with larger N values. For time frequency analyses, the desynchronization of alpha oscillations decreased after stimulus onset, but the synchronization of alpha oscillations increased during the maintenance phase. The results suggest that greater memory load is related to a decrease in cognitive resources during updating and an increase in cognitive resources during information maintenance. Results of a brain-behavior relevant analysis showed that the ERP indicators in the maintenance phase predicted behavioral performance.