Bilingual emotional word processing: A behavioral and event-related potential study

The current studies examined healthy Chinese-English bilinguals in their responses to visual word stimuli. The words were of different emotional valences (positive, negative, neutral) or categories (math, object, measure) in Chinese (L1) and English (L2) during a multistimulus oddball paradigm. Six conditions, with four using emotionally-valenced words and two using categorical words, were designed for an event-related potential (ERP) and behavioral study. The words in each condition were grouped into one infrequent target stimulus type (with a probability of 1/6) and five frequent non-target stimulus types (with a probability of 1/6 each) in random order.;As hypothesized, an enhanced late P300 (400-700 ms post-stimulus) was elicited by targets relative to non-targets, by non-targets in the same language as targets relative to other non-targets, and by L1 relative to L2 words, with the maximal enhancement at central and parietal scalp locations. Language and emotion interacted on late P300 amplitude with a larger enhancement elicited by L1 relative to L2 negative words than by L1 relative to L2 positive words and by L1 relative to L2 neutral words. A greater emotional arousal was found associated with word stimuli in L1 than in L2. Also as hypothesized, the reaction time data showed faster responses to L1 relative to L2 words, to non-targets relative to targets, and to neutral relative to negative or positive words. In addition, an unexpected enhancement was observed for an early ERP component (250-350 ms post-stimulus) to words in L2 relative to in L1 and to positive or negative relative to neutral words, with the maximal enhancement at frontal and central scalp locations.;The current studies further extended findings that P300 is an index of similarity between target and non-target stimuli. In particular, non-target words in the same language as target words, while exhibiting P300s that were similar to but smaller in amplitude than those elicited by target words, elicited larger P300s than non-target words that were in a different language from target words. The current studies also suggested that the early ERP component (250-350 ms post-stimulus) may be strongly correlated with language acquisition and proficiency in L1 and L2 among Chinese-English bilinguals. The implications of findings from the current studies on theories of bilingualism and emotion are discussed.