Lexical-perceptual integration influences sensorimotor adaptation in speech

Area of Science:

• Speech Production and Perception
• Auditory Feedback Mechanisms
• Linguistic Processing

Background:

• Speech motor control involves complex auditory-perceptual feedback loops.
• The influence of linguistic knowledge on real-time speech adaptation is not fully understood.
• Altered auditory feedback (AAF) is a key tool for studying speech motor learning.

Purpose of the Study:

• To investigate how higher-order linguistic knowledge affects speech motor control under altered auditory feedback.
• To determine if the lexical status of a word influences adaptation to auditory feedback perturbations.
• To explore the interaction between auditory perception and lexical processing in speech production.

Main Methods:

• Participants produced real words and pseudo-words with a specific vowel ([ε]) under altered auditory feedback conditions.
• Auditory feedback was manipulated to decrease the first formant (F1) frequency, shifting the perceived vowel.
• Lexical-Change (LC) and Non-Lexical-Change (NLC) groups were established based on whether the feedback altered the word's lexical status.

Main Results:

• In Lexical-Change groups, speech motor learning was sensitive to the lexical status of the produced stimuli.
• Speakers adjusted their productions to maintain the boundary between real words and pseudo-words.
• No such effect of lexical status was observed in the Non-Lexical-Change control groups.

Conclusions:

• Auditory-feedback-based speech motor learning is influenced by the lexical status of stimuli.
• Speakers' speech motor systems utilize linguistic knowledge to guide adaptation to auditory perturbations.
• This suggests that higher-order linguistic processing plays a role in the perceptual aspects of speech motor control.