The effect of force feedback delay on stiffness perception and grip force modulation during tool-mediated interaction...

Area of Science:

• Human-Computer Interaction
• Neuroscience
• Robotics

Background:

• Humans create internal models of object mechanical properties for perception and action.
• Grip force modulation in precision grip relies on predicted load forces.

Purpose of the Study:

• To investigate the link between grip force adjustment and stiffness perception.
• To explore how time delays in force feedback affect stiffness perception and grip control.

Main Methods:

• Participants performed a forced-choice task, comparing stiffness of virtual linear elastic force fields.
• Haptic device provided force feedback; half of trials included delayed feedback for one field.
• Grip force magnitude and grip-load force lag were analyzed during exploratory movements.

Main Results:

• Participants underestimated the stiffness of delayed force fields compared to non-delayed fields.
• Grip force magnitude and lag were similar for both delayed and non-delayed conditions.
• Internal representations of stiffness and time delay accurately informed grip force adjustments.

Conclusions:

• Accurate grip force control can coexist with biased perception of environmental stiffness.
• Separate neural mechanisms likely govern perception and action-related computations in proprioceptive tasks.