Predictability of trajectory modulates manual tracking: from real-time feedback to internal-model-based control

Area of Science:

• Human sensorimotor control
• Visuomotor adaptation
• Internal representations in motor control

Background:

• Humans exhibit remarkable environmental adaptation.
• Fundamental questions remain regarding internal representations for efficient feedforward control in sensorimotor tasks.

Purpose of the Study:

• To investigate whether and how internal representations facilitate feedforward control.
• To examine the modulation of manual tracking by trajectory predictability in humans.

Main Methods:

• Manual tracking tasks with varying trajectory predictability.
• Kalman filter modeling to analyze visuomotor processes.
• Assessment of human participants' tracking performance and adaptation strategies.

Main Results:

• No significant improvement in tracking performance was observed due to trajectory predictability, even when participants were aware of it.
• Kalman filter analysis revealed participants reduced reliance on real-time visual input for more predictable trajectories.
• Adaptation in visuomotor processes occurred despite unchanged overall tracking performance.

Conclusions:

• Humans adapt sensorimotor control by adjusting reliance on internal mechanisms versus real-time feedback based on trajectory predictability.
• The study highlights adaptive use of environmental information redundancy.
• Findings provide insights into the balance between feedforward and feedback control mechanisms in human motor behavior.