Bilingual infants control their languages as they listen

Area of Science:

• Cognitive Science
• Developmental Psychology
• Linguistics

Background:

• Bilingual infants acquire two languages simultaneously without apparent delay.
• The underlying cognitive mechanisms supporting simultaneous bilingual language acquisition are not fully understood.

Purpose of the Study:

• To investigate the language-control mechanisms bilingual infants employ during listening.
• To determine if bilinguals actively monitor their languages for efficient comprehension across the lifespan.

Main Methods:

• A naturalistic eye-tracking procedure was used with bilingual infants and adults.
• Object recognition accuracy was measured for same-language versus switched-language object labels.
• Infant pupil size was monitored to assess cognitive load during language switching.

Main Results:

• Bilingual infants demonstrated higher accuracy in recognizing objects labeled in the same language compared to switched languages.
• Language switching increased cognitive load, indicated by pupil dilation, especially when switching from a nondominant to a dominant language or mid-sentence.
• Adults exhibited similar patterns, suggesting consistent language monitoring strategies from infancy through adulthood.

Conclusions:

• Bilingual infants and adults utilize language-control mechanisms to preferentially activate the currently heard language.
• Efficient language monitoring is crucial for comprehension in bilinguals.
• The cognitive advantages observed in bilinguals may stem from the lifelong practice of managing multiple languages.