Underspecification in toddlers' and adults' lexical representations

Area of Science:

• Psycholinguistics
• Developmental Psychology
• Phonology

Background:

• Previous research indicated toddlers' lexical representations are quantitatively similar to adults'.
• Psycholinguistic theories based on underspecification predict asymmetrical sensitivity to mispronunciations in lexical processing.
• Some studies support these theories, showing greater sensitivity to noncoronal-to-coronal changes than coronal-to-noncoronal changes.

Purpose of the Study:

• To investigate whether toddlers' and adults' lexical representations are qualitatively similar.
• To test predictions of underspecification theories regarding asymmetrical sensitivity to mispronunciations.
• To examine developmental continuity in the nature of early and mature lexical representations.

Main Methods:

• Employed on-line visual world procedures in three experiments.
• Tested 19-month-old toddlers and adult participants.
• Assessed sensitivity to both noncoronal-to-coronal and coronal-to-noncoronal mispronunciations of familiar words.

Main Results:

• Both 19-month-olds and adults demonstrated sensitivity to both types of mispronunciations (noncoronal-to-coronal and coronal-to-noncoronal).
• No asymmetries in sensitivity were observed in either age group.
• Findings contradict predictions derived from underspecification theories.

Conclusions:

• Toddlers' and adults' lexical representations appear to be qualitatively similar.
• There is considerable developmental continuity in lexical representation from toddlerhood to adulthood.
• Methodological differences likely account for discrepancies with previous studies questioning underspecification claims.