Multivariate Decoding and Drift-Diffusion Modeling Reveal Adaptive Control in Trilingual Comprehension.

Area of Science:

• Psycholinguistics
• Cognitive Neuroscience
• Bilingualism Research

Background:

• The Adaptive Control Hypothesis suggests varying language control demands in production, but its role in comprehension remains unclear.
• Trilinguals manage multiple language contexts (L1-L2, L2-L3, L1-L3), offering a unique model to study control demands.
• Investigating differential control demands in trilingual comprehension is crucial for understanding language processing.

Purpose of the Study:

• To investigate proactive and reactive control demands in trilinguals during auditory comprehension across different dual-language contexts.
• To determine if language switching mechanisms in comprehension differ from those in production.
• To explore the neural underpinnings of context-dependent control in trilingual language switching.

Main Methods:

• Thirty-six Uyghur-Chinese-English trilinguals performed an auditory word-picture matching task.
• EEG recording coupled with behavioral analysis, drift-diffusion modeling, ERP analysis, and MVPA were used.
• Experimental design manipulated language context, trial type (switch vs. repetition), and switching direction.

Main Results:

• Behavioral performance was comparable across contexts, but drift-diffusion modeling showed context-specific processing efficiency.
• The L1-L2 context exhibited lower comprehension efficiency due to slower evidence accumulation.
• Proactive control (indexed by P300/N400) was observed in the L1-L3 context, while reactive control costs were absent.

Conclusions:

• Trilingual language switching in comprehension differs from production, with reactive control being non-essential.
• Proactive control is context-dependent, emerging in high-conflict L1-L3 contexts.
• This proactive strategy enhances comprehension efficiency by directing attention to the weaker language (L3).