Neural Mechanisms of Scrambled-Order and Reverse-Order Priming Effects in Chinese Four-Character Word Processing

Orthographic coding flexibility during visual word recognition stands as a core focus in cognitive psychology. Cross-linguistic research has consistently demonstrated that position tolerance varies substantially across different writing systems. As a typical logographic language, Chinese is characterized by the near-absence of “anagrams”, a feature that implies native Chinese speakers may rely on distinct mechanisms for character position coding compared to speakers of alphabetic languages. However, prior studies on Chinese four-character words have been limited to investigating reverse-order priming effects, failing to address the more complex and ecologically relevant scenario of scrambled-order priming. To fill this gap, the present study hypothesized two key points: first, both scrambled-order and reverse-order priming effects would emerge in the processing of Chinese four-character words; second, these effects would adhere to the “character identity over position” principle and be associated with distinct event-related potential (ERP) correlates.A total of 48 native Chinese college students participated in the experiment. All participants provided written informed consent prior to the study and received a monetary compensation of 30 yuan upon completion. The study adopted a 2 (priming type: reverse-order vs. scrambled-order) × 2 (relevance: relevant vs. irrelevant) within-subjects experimental design. A masked priming lexical decision task was employed to measure participants’ responses. Responses were recorded using a keyboard: participants pressed the “J” key for real words and the “F” key for pseudowords. Behavioral results revealed a significant main effect of relevance on reaction time (RT): participants responded significantly faster in relevant priming conditions than in irrelevant conditions. This finding confirms the presence of both reverse-order and scrambled-order priming effects in Chinese four-character word processing. Notably, neither the main effect of priming type nor the interaction between priming type and relevance reached statistical significance, indicating that the magnitude of the priming effect was comparable between the reverse-order and scrambled-order conditions. In terms of accuracy, no significant main effects of relevance or priming type were observed, nor was there a significant interaction between these two factors, suggesting that the priming effects did not compromise response accuracy. ERP results further uncovered distinct neural correlates for the two priming types. For scrambled-order priming, a significant relevance effect was observed in both time windows: in the 200-350 ms window, the ERP amplitude was more negative in the irrelevant condition than in the relevant condition, with this effect being most prominent in the right hemisphere; in the 350-500 ms window, the irrelevant condition also elicited a more negative amplitude, but the effect was dominant in the left hemisphere. For reverse-order priming, the pattern differed: no significant relevance effect was found in the 200-350 ms window overall, though a marginal relevance effect was observed specifically in the right hemisphere; in the 350-500 ms window, however, a significant relevance effect emerged, mirroring the scrambled-order condition, the irrelevant condition produced a more negative amplitude.This study is the first to provide neurophysiological evidence for scrambled priming in Chinese four-character word processing. Results confirm that native Chinese speakers exhibit both reverse and scrambled priming effects, supporting the “character identity over position” principle in Chinese orthographic processing. These findings highlight the flexibility of Chinese word recognition, differing from alphabetic languages with stricter position coding, and advance understanding of how writing systems shape orthographic processing mechanisms.