A Potential Role for Reinforcement Learning in Speech Production

Area of Science:

• Motor control
• Speech science
• Neuroscience

Background:

• Reinforcement learning is crucial for motor development and speech disorder rehabilitation.
• Existing evidence does not confirm reinforcement's ability to alter human speech behavior.
• Speech is a complex, high-dimensional motor task with self-generated goals.

Purpose of the Study:

• To investigate if reinforcement learning alone can change speech behavior.
• To test the impact of reinforcement signal informativeness on speech learning.
• To examine the role of sensory feedback in speech reinforcement learning.

Main Methods:

• Four experiments were conducted to assess speech learning under varying reinforcement conditions.
• Participants received auditory feedback, with some conditions masking movement outcome information.
• The informativeness of the reinforcement signal was parametrically manipulated.

Main Results:

• Speech learning was observed, indicating reinforcement can drive changes in speech production.
• Learning was enhanced when auditory feedback provided an implicit production target.
• Masking sensory feedback about movement outcomes did not impede speech learning, unlike in limb motor tasks.

Conclusions:

• Reinforcement learning plays a potential role in speech motor control.
• Speech learning via reinforcement appears to operate differently than in other motor domains.
• Auditory feedback, even implicit, is important for speech reinforcement learning.