The individual sub-systems are slow and communications between them would not allow the creature to react fast enough to respond to the outside world if all the control an processing occurred at a single point. Therefore the individual elements must regulate themselves and leave only the central processing to the brain. Paradoxically, the control of exo-prosthetic systems, is still one of direct control of each joint by the operator. This results in a slow and arduous actions and limits their range of use.
Humans manipulate objects by adapting the shape of the hand to that of the target object.
They maximise the contact area and so minimise the contact forces required for stable manipulation. The reconfigurable nature of the human hand means the shape it adopts can reflect the task enabling the hand to impart larger forces through a power grip, or finer control using a precision grip.