Each patch of area 3b is driven strongly by one digit and weakly, below threshold, by its neighbours. Remove the dominant input and watch what those weak inputs do. Keys: 1–4 touch, 0 release, Space play, ←→ time.
Coronal section through the hand area of area 3b
Input strength versus threshold across the hand area
What an electrode finds 24 penetrations, 0.2 mm apart