Inhibitory Control Modulates the Orthographic Neighbourhood Frequency Effect in Chinese Two-Character Word Recognition: An ERP Study

In Chinese reading, inhibitory control has been proposed to influence the orthographic neighbourhood frequency (ONF) effect by regulating the activation of competing orthographic neighbours. However, it remains unclear whether individual differences in inhibitory control modulate the ONF effect during Chinese word recognition. In the present study, 36 participants with high inhibitory control (HIC) and 36 with low inhibitory control (LIC) were selected through a preliminary experiment. The formal experiment employed a 2 (inhibitory control: high vs. low) × 2 (ONF: high vs. low) mixed design, combining a lexical decision task with event-related potential (ERP) measures to investigate the influence of inhibitory control on the ONF effect in Chinese two-character word recognition. The main findings were as follows: (1) Behaviourally, reaction times showed significant main effects of ONF and inhibitory-control group, but the ONF × group interaction was not significant. For accuracy, only the main effect of group was significant; neither the main effect of ONF nor the ONF × group interaction reached significance. (2) ERP results showed ONF effects in both the N400 and LPC time windows. In the N400 component, a significant interaction between ONF and group was observed over the left posterior region. The LIC group elicited a larger amplitude in the condition with higher-frequency orthographic neighbours, whereas the HIC group exhibited comparable responses between the two ONF conditions. Taken together, the findings confirmed an inhibitory ONF effect in Chinese two-character word recognition. Although no ONF × inhibitory-control interaction was observed in behavioural performance, the significant interaction in the left posterior N400 suggests that individual differences in inhibitory control are reflected in ONF-related lexical-semantic processing at the neural level. These findings highlight the role of individual differences in inhibitory control in Chinese word recognition and suggest that readers may differ in their susceptibility to interference from higher-frequency orthographic neighbours.