Interaction forces reflect the perception of texture during active exploration.

Area of Science:

• Neuroscience
• Haptics
• Robotics

Background:

• Active touch involves coordinated movement and force for exploration.
• The relationship between exploration forces and tactile perception is not well understood.
• Everyday touch is an active process, not passive reception of information.

Purpose of the Study:

• To investigate how exploration forces and fingertip motion relate to perceived texture properties.
• To understand the physical signals underlying judgments of hardness, slipperiness, and roughness.
• To support a sensorimotor account of tactile perception.

Main Methods:

• Measured fingertip motion and exploration forces during texture exploration.
• Participants explored 14 different textures and rated hardness, slipperiness, and roughness.
• Analyzed the relationship between movement, forces, and perceptual ratings.

Main Results:

• Exploration strategies varied by task: hardness judgments used pressing, while slipperiness/roughness used sweeping motions.
• Harder textures involved larger forces; slippery textures involved faster motion and lower forces.
• Perceived slipperiness correlated with friction, while roughness correlated with force vibrations, indicating distinct physical bases.

Conclusions:

• Humans actively tailor their contact mechanics to specific perceptual goals during exploration.
• Different physical signals (friction, vibration) support distinct tactile judgments.
• Touch perception is an active sensorimotor process, with implications for various fields.