In Julian Schnabel's 2007 film The Diving Bell and the Butterfly, Jean-Dominique Bauby, a man unable to move any part of his body except his left eye, says: "Two things aren't paralyzed: my imagination and my memory. I can imagine anything, anybody, anywhere." The movie is based on the true story of Jean-Dominique, the former editor of Elle France, who suffered a stroke and developed locked-in syndrome, a condition caused by damage to the brainstem that prevents a patient from moving all voluntary muscles, including those needed for verbal communication. Locked-in syndrome does not affect the brain or intelligence, but it essentially 'locks' a patient into an immobile body. Despite the seeming impossibility of his condition, Jean-Dominique learned to communicate by blinking his eye. In this system of communication, he blinked once to answer "yes" and twice for "no," and when an alphabet was read aloud to him, he blinked to indicate which letter he wanted to use.
But what if there were a way Jean-Dominique could move again--a device he could use to transform his thoughts into actions? A Brown University neuroscience research laboratory may have the answer.
Hope is the Thing with Microchips
The BrainGate project is currently one of the most promising projects in the field of neuroscience, and is managed by a team of Brown researchers that includes Professor John Donoghue, the chair of the Department of Neuroscience and Professor Leigh Hochberg of the Engineering Department. The BrainGate Neural Interface System project is working on a Brain Computer Interface (BCI), a technology that establishes a direct communication pathway between an implanted sensor chip in the brain and an external device. The chip is embedded in the brain to read neurons and translate their signals into movements so that patients can perform tasks using a computer or other devices such as a wheelchair.
Paralysis can result from anything from a stroke to a car accident. As of now, doctors can do little to restore movement. The BrainGate chip, however, offers hope. It functions mainly to restore a connection between thoughts and actual movements, whether through a patient's own limbs or through a computer. In other words, the chip acts as a surrogate to the damaged nervous system, converting cellular signaling into movement. Professor Leigh Hochberg told the Independent that the project is founded on the idea that "those signals, despite paralysis, are still trying to talk to limbs" and initiate an action.
In 2002, Donoghue published findings from a study in which a prototype sensor in a monkey's brain allowed the monkey to play pinball remotely, without the physical movement of the monkey's arms or hands. Over the past seven years, Hochberg has worked with Donoghue as this research has progressed.
Currently in the clinical trial stage, the project is making a lot of headway. Patients in the trials have had a silicon chip the size of a baby aspirin implanted onto their motor cortexes, the portion of the brain's surface area responsible for movement. The brain's cortex has different specialized regions, and the neurons in the motor cortex are especially useful for fine hand and finger control. In normal brains, the intention to move a limb is sent as an electric impulse through the brain's cortex, through the spinal cord and finally to the muscle responsible for movement. Patients who are paralyzed have a disconnect in their nervous system, usually between the brain and spinal cord, causing their signals to be cut off before physical movement occurs.
In order to reconnect the brain to a person's limbs, the BrainGate sensor reads and records the electric signals that go off in someone's brain when he or she attempts to move. It then translates and "decodes that activity in real time towards [movement of] a cursor on a computer screen," said Professor Hochberg of one trial.
One of BrainGate's successes was featured on 60 Minutes this past November. Cathy, a woman who has been paralyzed for over nine years, had the BrainGate system implanted onto her brain. 60 Minutes showed a clip where Cathy was able to perform everyday activities by 'thinking' the steps necessary to execute them. Her thoughts were converted to the movements of a cursor on a computer, so that she could type, play music, read email and even turn lights on and off.
From Email to Marathons
Professor Hochberg told the Independent that their current research focuses on ways to make the BrainGate sensor completely wireless (it currently needs to be hardwired to a computer), "just like a cardiac pacemaker." Even though BrainGate's novel system will improve the lives of many patients with paralysis, the need to be physically attached to an external device can be cumbersome at best and impractical in the long run. A wireless sensor would, ideally, be implanted into the brain and connected to another electrode sensor right under the clavicle. That sensor would then transmit the neuronal signals to a receiver stuck to the skin or other external device via infrared or radio waves. Professor Hochberg envisions that this wireless BrainGate system would "restore independence as much as possible," and have only minor restrictions, like passing through metal detectors.
Another goal for the project is to further develop the BCI so that the sensor can manipulate not only the movement of an external computer or device, but also one's own paralyzed or nonfunctional limbs. The research being done at Brown brings novel information into the field of neuroscience: "This is the first time that anybody has been able to record from dozens and dozens of cells in the human brain for months on hand," Professor Hochberg said. Hochberg hopes that the BrainGate research will soon help to "reestablish the connection between the brain and the arm" or other limbs. BrainGate would work to enhance a current medical technology called Functional Electrical Stimulation (FES), which can be used to activate the nerves that supply paralyzed extremities with brain signals.
With current technologies, patients using FES have electrodes placed under their skin that detect the brain's neuronal signals and then transmit them through nerves that cause an arm or leg to move, allowing someone with a cervical spinal cord injury to move again. FES has worked for some, and though "these FES techniques are good, what's desperately needed is a better controller," says Professor Hochberg. In other words, instead of having to go through the electrode (a stimulator that requires extra intermediary signals from neurons) the new BrainGate technology would bypass this extra step by reading the signal immediately from the brain and then sending it directly to the FES stimulator, without the need for an electrode.
Finally, the future of BrainGate may also lead to a way to prevent seizures in patients who have epilepsy, which is caused by rapid misfiring of neurons in the brain at the wrong time. Though the reasons for this signaling irregularity have yet to be completely understood, the extensive observations of neuronal activity gained during the course of the BrainGate project may lead to a better understanding of these irregularities.
Professor Hochberg stresses that the BrainGate project is founded on the idea of "the importance of basic, fundamental research and how we can translate that basic research to helping patients with paralysis or limb loss." Research has come a long way since 1995, the year that Jean-Dominique Bauby's stroke caused him to become fully paralyzed with locked-in syndrome. Fourteen years ago, the prospect of restoring movement to those who are paralyzed may have seemed like futuristic fantasy. Today, Brown's team of researchers is well on its way to making it possible.
MELANIE CHOW B'11 only plays pinball with monkeys.