Dissimilar Phonemes Create a Contextual Interference Effect During a Nonword Repetition Task.

Area of Science:

• Motor learning
• Speech-language pathology
• Cognitive psychology

Background:

• The contextual interference effect enhances motor learning for new tasks when practice conditions are varied.
• Speech motor learning research shows mixed results, potentially due to stimulus differences.
• Dissimilar phonemes may induce interference, impacting speech motor learning outcomes.

Purpose of the Study:

• To investigate if phonemic dissimilarity in nonwords influences speech motor learning and generalization.
• To test the hypothesis that dissimilar phonemes decrease training accuracy but increase transfer accuracy.

Main Methods:

• Thirty adults with typical speech and hearing completed a cross-over design study.
• Participants underwent nonword repetition training with similar or dissimilar phonemes.
• Percent consonants correct measured accuracy during training and transfer stages.

Main Results:

• A contextual interference effect was observed based on phonemic similarity.
• Similar phonemes yielded higher accuracy during training.
• Dissimilar phonemes resulted in higher accuracy during the transfer stage.

Conclusions:

• The hypothesis was supported: dissimilar phonemes enhanced accuracy in the transfer phase.
• Phonemic dissimilarity creates contextual interference, influencing speech motor learning.
• Linguistic properties of stimuli are crucial for speech motor learning and generalization.