Related Experiment Videos
Tactile detection of slip: surface microgeometry and peripheral neural codes
M A Srinivasan1, J M Whitehouse, R H LaMotte
1Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06510.
Journal of Neurophysiology
|June 1, 1990
Summary
Human touch can detect tiny surface features, enabling slip detection. Microscopic textures activate specific nerve fibers, crucial for perceiving motion and texture on skin.
Area of Science:
- Neuroscience
- Biomechanics
- Sensory Physiology
Background:
- Human tactile perception relies on complex interactions between skin and surfaces.
- Understanding how microgeometry influences mechanoreceptor activation is key to deciphering touch sensitivity.
Purpose of the Study:
- To investigate the role of surface microgeometry in detecting sliding motion on human fingerpads.
- To identify the peripheral neural codes associated with tactile slip detection.
Main Methods:
- Utilized a servo-controlled tactile stimulator to press and stroke glass plates on human fingerpads.
- Recorded evoked responses from single, low-threshold mechanoreceptive afferent fibers in anesthetized macaque monkeys.
- Tested smooth and microfeatured surfaces to assess human discrimination of skin stretch and slip detection.
Main Results:
- Humans could not detect slip on smooth surfaces but perceived skin stretch direction via slowly adapting afferents.
- Micrometer-sized surface features enabled slip detection through the activation of rapidly adapting fibers (Meissner and Pacinian).
- Specific microfeature geometries (e.g., raised dots, textured matrices) elicited distinct neural codes (spatiotemporal for RA, intensive for PC).
Conclusions:
- Surprisingly small surface features are detectable and crucial for slip perception.
- The geometry of microfeatures dictates the specific neural codes used for tactile sensation.
- Redundant sensory information is available for slip detection when surface features exceed receptor response thresholds.