Task-Dependent or Task-General? The Impact of Valence Ambiguity on Word Processing in Lexical Decision and Valence Judgment

Word valence, or emotionality associated with words, is a key factor influencing word processing. It is typically assessed using self-rated scales. Recent studies have highlighted the role of valence ambiguity—variability in self-reported valence across raters—as a distinct variable impacting word processing, which is quantified by standard deviation of valence ratings. This study aimed to examine the effects of valence ambiguity and its task-specific nature through lexical decision and valence judgment tasks by orthogonally manipulating word valence (positive or negative) and valence ambiguity (low or high) across 256 two-character Chinese words, selected from the Chinese Lexicon Project (Tse et al., 2017, 2023, see also Chan & Tse, 2024). Separate linear mixed-effect models were applied to analyze the data from lexical decision and valence judgment tasks, with controls for word arousal, familiarity, and concreteness. The findings revealed that the main effect of valence ambiguity was non-significant in lexical decision, suggesting similar reaction times for ambiguous and unambiguous words in word/nonword decisions. However, in valence judgment, the effect was significant, indicating faster categorization of unambiguous words as either negative or positive. Moreover, a significant valence × valence ambiguity interaction in the lexical decision task showed faster reaction times for positive words compared to negative words only when valence ambiguity was low. These novel findings underscore that the influence of valence ambiguity on word processing is task-dependent, being more pronounced in the valence judgment task. Future research should incorporate valence ambiguity as a variable when exploring the processing of emotional words.