Systematic Influence of Perceived Grasp Shape on Speech Production

Area of Science:

• Cognitive Neuroscience
• Motor Control
• Speech Science

Background:

• Previous studies indicate simultaneous articulation affects precision and power grip performance.
• Power grips are faster with open-back vowel [a], precision grips with close-front vowel [i].

Purpose of the Study:

• To investigate the bidirectional influence between grip types and speech sound production.
• To explore the underlying visuomotor mechanisms connecting grasp actions and articulation.

Main Methods:

• Participants viewed images of precision or power grips.
• They produced speech sounds, aligning with the visual grip perspective.
• Articulatory responses were measured based on grip type and speech sound produced.

Main Results:

• Precision grip stimuli facilitated rapid production of the front-close vowel [i].
• Power grip stimuli influenced vertical vowel dimensions, promoting back-open [a] and back-mid-open [o] vowels.
• Consonant production ([k], [t]) remained unaffected, suggesting a role for vertical articulatory changes.

Conclusions:

• Grip type significantly modulates speech sound production, particularly vowels.
• A shared visuomotor network likely underlies the planning of both grasp actions and articulatory gestures.
• Findings reveal an intimate interaction between motor control of hand grips and speech articulation.