First and second languages differentially affect rationality when making decisions: An ERP study

The present study examined how decision-making is affected by first (L1) and second languages (L2), emotion, and cognitive load. In a cross-task study, 30 Chinese-English bilinguals were asked to implement lexical-semantic judgment and gambling task. The results showed that after lexical decisions under high cognitive load, P3 was more positive for negative words than for neutral words in L1. The reverse was the case in the L2 in which P3 was more positive for neutral words compared to negative words. Critically, under high cognitive load, as the P3 effect increased for negative words relative to neutral words, the rationality of the decisions after these negative words decreased in the L1 but increased in the L2. The results moreover revealed that the increased Granger causal strength predicted more rational choices in the L2 high-load negative condition. Altogether, the findings offer evidence of how L1s and L2s can differentially influence rational decision-making.