Modeling Infant Speech Sound Discrimination Using Simple Associative Networks

Area of Science:

• Developmental Psychology
• Cognitive Science
• Linguistics
• Computational Neuroscience

Background:

• Infant speech sound discrimination performance can exhibit nonmonotonic patterns over time.
• Previous research indicated a decline in discrimination abilities in older infants (14-month-olds) compared to younger infants (8-month-olds) for minimal contrast pairs.
• This decline was previously attributed to a qualitative shift in infant cognition, specifically the processing of stimuli for meaning.

Purpose of the Study:

• To propose and describe an associative connectionist model that replicates the observed decrement in infant speech sound discrimination.
• To investigate whether this performance decrease can be explained by a nonmonotonic function of language experience, rather than a qualitative cognitive shift.
• To provide a formal computational framework for studying habituation-dishabituation behaviors in infant language development.

Main Methods:

• Development of an associative connectionist model.
• Simulation of infant speech sound discrimination tasks within the model.
• Analysis of model performance changes in relation to simulated language experience.

Main Results:

• The connectionist model demonstrated a similar decrement in discrimination performance without requiring any qualitative shift in processing mechanisms.
• The model's results suggest that infant responses to phonemic contrasts can be a nonmonotonic function of their cumulative experience with language.
• The findings challenge the notion of a necessary qualitative cognitive shift to explain the observed developmental pattern.

Conclusions:

• The study provides a computational explanation for the nonmonotonic development of speech sound discrimination in infants.
• Language experience, rather than a fundamental change in cognitive processing, may underlie the observed decline in discrimination abilities.
• The developed model offers a valuable tool for further research into infant habituation and dishabituation paradigms in language acquisition.