Dissociation of positive and negative priming effects between more and less proficient Chinese-English bilinguals.

A unilingual and a bilingual primed lexical decision task were used to investigate priming effects produced by attended and ignored visual stimuli. In the Chinese language unilingual experiment, accelerated responses to the traditional Chinese character probe targets were observed when the traditional character probe target was the same as the preceding prime target (i.e., attended repetition, AR). However, when a traditional character “matched” a preceding simplified Chinese character prime distractor (i.e., ignored repetition, IR), the expected impaired responses (negative priming) were not observed. In the bilingual experiment (Chinese – English), prime stimuli were in Chinese and probe stimuli were in English. Both AR positive priming and IR negative priming between Chinese – English translation equivalents were produced by bilingual subjects in experiment 2. Further analyses were carried out by dividing subjects into two groups, one less proficient and the other more proficient in English. The contrasting patterns of performance produced by the more and less proficient bilinguals indicate that inhibitory mechanisms can simultaneously operate at two levels of abstraction – global language and local word; and these two types of inhibition can work in a quite independent manner. The contrasting response patterns by the more versus less proficient bilingual subjects also convincingly suggest shared storage for the conceptual representations of a Chinese-English bilingual’s two languages. Moreover, obtaining negative priming in Experiment 2, which uses a large set of 795 words as stimuli, provides strong evidence against the notion that negative priming is contingent on stimulus repetition. Rather, it confirms that processing demand or selection difficulty is critical for producing negative priming