Bidirectional brain-computer interfaces.

Brain-computer interfaces (BCIs) are devices that interface with the brain to enable interaction with the environment. BCIs have the potential to improve the quality of life for many individuals affected by debilitating disorders of the brain, spine, limbs, and sensory organs through direct interface with the nervous system. While much progress has been made in terms of BCI motor control, significantly less attention has been given to the restoration of tactile, or cutaneous sensations, which can be very important during grasping or manipulation of objects. BCIs will need to integrate both the motor and sensory modalities to truly restore arm and hand function. Here we describe a bidirectional BCI, a system which translates neural signals recorded from the motor cortex into signals to control a device and provides somatosensory feedback by translating external sensor information to electric stimulation patterns delivered to the cortex. In this chapter, we review the neuroscience of somatosensation, the history of sensory feedback in BCI applications, specifically for restoration of hand function and cutaneous sensations, and describe additional work that needs to be completed to make bidirectional BCI a clinical reality.