Neurocognitive considerations for the future body
To successfully design devices for the human body, engineers often view the body itself as the ideal design template. But ultimately, the success of artificial limb will critically depend on the successful allocation of neural and cognitive resources which might differ radically, depending on the user’s life experiences and needs. Here I will present a series of studies where we investigated the neural basis of artificial limb use for both substitution and augmentation technologies. First, we explored how the hand is typically represented in the brain, and how this representation changes e.g. following hand amputation. We find that despite amputation the representation of the missing hand persists in the brain, providing potential opportunities and barriers for artificial limb interface. Second, we investigated how amputees represent their prosthetic limb, relative to a biological hand. We find that contrary to folk wisdom, the brain does not assimilate neural representations for the artificial limb with those for the biological body, creating opportunities for novel technological interfaces. Finally, we explored the neurocognitive resources needed to support successful learning of a motor augmentation device – the Third Thumb. We found that even with relatively short training, motor augmentation can be readily learnt, with potential for flexible use, reduced cognitive reliance and increased sense of embodiment. This learning was aided by integrating sensory information from the body part operating the Thumb. Consequently, augmentation impacted key aspects of hand representation and motor control. Collectively, these studies suggest that although, in principle, opportunities exist for harnessing hand neural and cognitive resources to control artificial limbs, alternative non-biomimetic approaches could be also well suited for successful human-device interface.