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Updated: Jul 2, 2026
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Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects
Published on: September 1, 2016
Attenuation of self-generated tactile sensations is predictive, not postdictive
Paul M Bays1, J Randall Flanagan, Daniel M Wolpert
1Sobell Department of Motor Neuroscience, Institute of Neurology, University College London, United Kingdom. p.bays@ion.ucl.ac.uk
Plos Biology
|January 13, 2006
Summary
Self-generated touch feels weaker due to predictive processes, not just post-event judgment. This sensory attenuation, even with failed contact, may enhance external sensation perception.
Area of Science:
- Neuroscience
- Somatosensation
- Predictive Coding
Background:
- Tactile sensation is attenuated when self-generated compared to externally imposed stimuli.
- This sensory attenuation may stem from predictive mechanisms (subtracting expected sensations) or postdictive mechanisms (reinterpreting self-generated sensations).
Purpose of the Study:
- To investigate whether sensory attenuation is primarily driven by predictive processes.
- To differentiate between predictive and postdictive explanations for the reduced perception of self-generated touch.
Main Methods:
- Participants performed self-touch actions involving finger-to-finger contact.
- Stimuli were applied to one finger, with or without actual contact from the other finger.
- Tactile perception thresholds were measured under different conditions.
Main Results:
- Sensory attenuation was observed even when the fingers unexpectedly failed to make contact.
- This finding supports a predictive mechanism where expected sensory consequences are subtracted before or during the action.
- The results challenge purely postdictive explanations for self-generated sensation attenuation.
Conclusions:
- Predictive processes play a significant role in attenuating self-generated tactile sensations.
- This predictive attenuation may serve an adaptive function, optimizing the detection of external stimuli.
- The brain anticipates the sensory consequences of movement to modulate perception.
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