ABSTRACT
One of the frontiers in the biomedical sciences is developing prostheses for the central nervous system (CNS) to replace higher thought processes that have been lost due to damage or disease. Prosthetic systems that interact with the CNS are currently being developed by several groups (1), though virtually all other CNS prostheses focus on sensory or motor system dysfunction and not on restoring cognitive loss resulting from damage to central brain regions. Systems designed to compensate for loss of sensory input attempt to replace the transduction of physical energy from the environment into electrical stimulation of sensory nerve fibers (e.g., cochlear implant or artificial retina), or sensory cortex (2-4). Systems designed to compensate for loss of motor control do so through functional electrical stimulation (FES), in which preprogrammed stimulation protocols are used to activate muscular movement (5,6), or by ‘‘decoding’’ premotor=motor cortical commands for control of robotic systems (7-9).
