Brain Mechanisms of Lexicality in Bilingual Emotion Processing

The study of how native speakers and second language learners process language varies significantly, leading to inconsistent results in emotional prosody processing. A key factor in this inconsistency is the lexicality of the stimuli used in the studies, which can be real words or pseudowords. To address this, researchers examined the brain activity of 15 native speakers and 15 L2 learners while they listened to Mandarin real-word and pseudoword stimuli.

Both groups displayed overlapping activity in auditory, cognitive, and emotional regions, such as the auditory cortex, inferior frontal cortex, superior temporal cortex, and temporoparietal junction. However, there were notable differences in their responses based on the lexicality of the stimuli. Native speakers demonstrated stronger activation in temporal regions for pseudowords, while L2 learners exhibited greater activity in frontoparietal areas for real words. These patterns were observed in both positive and negative prosody conditions.

Moreover, among the L2 learners, those with higher proficiency in the second language showed increased activation in the frontal regions when processing real words, although not pseudowords. These findings collectively illustrate that the disparities between native speakers and L2 learners in emotion processing are primarily influenced by the lexicality of the stimuli, underscoring the importance of lexicality in bilingual emotion processing.