For the very first time, researchers at California Institute of Technology have induced sensations which are natural to human body, in the arm of a paralyzed man by stimulating a particular area of the brain through an array of electrodes. The patient has come with a high-level spinal cord lesion and, in addition to that, he is not only unable to move his limbs, he can also not feel them. One day, this research could allow paralyzed people make use of prosthetic limbs so as to feel physical feedback from that the sensors that have been placed on these devices.
Surgically Inserted Tiny Electrodes Generates Natural Sensations
The research was being conducted at the laboratory of Richard Andersen and James G. Boswell Professor of Neuroscience, T&C Chen Brain-Machine Interface Center Leadership Chair, and director of the T&C Chen Brain-Machine Interface Center.
The somatosensory cortex refers to that very strip of brain that regulates bodily sensations, both proprioceptive sensations (sensations of body’s position or movement in the space) and cutaneous sensations (those of touch, vibration, pressure, and the like). Prior to this new work, neural implants that target similar brain areas predominantly generated sensations like buzzing or tingling in the hand. The implant at Andersen lab’s is capable of producing much more natural sensation through intracortical stimulation which is akin to the sensations that are experienced by the patient before his injury took place.
Three years before, the patient had become paralyzed from below the shoulder following a spinal cord injury. Two arrays of tiny electrodes were inserted surgically into his somatosensory cortex. By making use of those arrays, the researchers made a stimulation of the neurons in the region with very tiny pulses of electricity. The research participant reported feeling various natural sensations such as a sense of upward motion, tapping, squeezing, and many others.
A research paper describing the work has on the April 10 issue of eLife, a science journal.