Caltech Collaboration Separates Touch Intensity From Perception in Single-Neuron Recordings From Three Participants
A collaboration involving Caltech recorded single-neuron activity in three participants with tetraplegia while applying vibration to a sensate upper-limb region. Primary somatosensory cortex responses tracked stimulus amplitude more closely, while posterior parietal activity was more strongly associated with perception and confidence. Only two participants provided confidence ratings. The preprint distinguishes associations with physical input and subjective perception; it does not establish that one brain region alone generates conscious touch.
Why it matters
The study distinguishes stimulus strength from whether participants perceived the stimulus and how confident they were. Comparing these dimensions helps clarify whether neural activity reflects physical input or changes in subjective perception.