In a Wall Street Journal article, “Robot Puts Mind Over Matter” May 17th, 2012 explains the company, BrainGate2’s new technology allowing paralyzed individuals Cathy Hutchinson and Robert Veillette to move through brain machine interface or BMI. Despite being paralyzed 15 to 6 years respectively, both Hutchinson and Veillette were able to control a robotic arm through their thoughts alone. Principal investigator Dr. Leigh Hochberg of Brown University describes how the patients’ thoughts control the robot. The robotic arm moves because “they [patient] thought about using their own arm or hand as though they were reaching out themselves with their own limb and the robotic arm moved much as if their own arm had moved.” Hutchinson’s thoughts were able to control a robotic arm to bring a bottle of coffee to her lips and drink through a straw. Watch WSJ BrainGate Video here.
Principal investigator, John Donoghue of Brown University mentioned that one of the most difficult parts of the technology is to align the algorithms of the machine to the patients’ patterns of neurons firing. A training period is required for Veillette or Hutchinson to practice moving the robots arm so that they are capable of such complex tasks like grasping a coffee cup. I propose four simple ideas to simplify movement thought patterns through education and research based techniques so that patients of BMI can improve thought to action transfer.
As exciting as the machine portion of the BMI interface is, it is ultimately the brains of Veillete and Hutchinson moving the robot. Practical steps taken to clarify the movement thought patterns might facilitate the creation of the algorithm connecting the machine to the brain.
I believe a way to improve BMI interface is to have a framework for patients to think about how they are moving. Perhaps BrainGate already has a framework but from the literature found thus far I cannot find any. I propose three practical ideas for how patients think about movement to improve BMI and one idea for researchers to improve BMI.
3 ideas to improve BMI for patients
The first is through basic education. The researchers describe how it is necessary for the patient to think through all the components of picking up a cup, from bending the elbow to grasping with the fingers. Of course on the surface this sounds simple. However, it takes great cognitive effort to think all this through. If one has to think through every step of moving, it is helpful to have an understanding of how the body moves. More specifically, when you have to think of grabbing a coffee cup it helps to know the simple anatomical and biomechanical concepts that occur in reaching and grasping a cup. This need not be a semester course. But if Hutchinson and Veillette are clear about how their shoulder, elbow, wrist, and hands flex, extend, and articulate, it may help their thoughts be clearer about how to move the robotic arm. It could be as simple as placing an anatomy book in front of the patients or having an occupational therapist give them a short tutorial about how to think through moving. From my experience teaching movement, when I give my students brief anatomical tutorials they are better able to control their movement almost immediately. Usually, it is because they were not aware that their shoulder was a ball and socket joint or just where supination and pronation occur in the forearm. All of these motions are necessary to pick up a mug and therefore intellectually understanding how to move these joints may hasten the BMI from thought to action.
The second idea to improve BMI from the patient perspective is research based. Since the researchers described that Veillete and Hutchison imagine his and her movements, research regarding motor imagery could be helpful. Lorey et al. (2009) questioned whether 1st person perspective (1PP) imagery elicits greater excitation in the motor cortex than with action in 3rd person perspective (3PP). 1PP is when someone imagines moving their own limbs in an embodied stance. 3PP motor imagery would be imagining watching a movie of yourself or someone else moving. Their results suggested that 1PP imagery “lead to stronger activation in motor and motor-related areas of the left-hemisphere, that is, the left inferior parietal lobe, the left SMA, and the left PMC” (p. 239). Lorey et al. suggested implications for rehabilitation techniques. Specifically, if patients have trouble learning an action a teacher may want to clarify to their patients to create motor imagery in the 1PP instead of 3PP. Within BrainGate’s experiment it is unclear how they explicitly told Hutchinson or Veillette to imagine their movements. Ideally they are being trained to imagine themselves creating the movement and not someone else or the robot creating the movement.
My third idea that might lead to better BMI thought to action from the patient perspective is to assume compatible body postures. Lorey et al. study also found greater activation in the motor cortex when a patient imagines performing a movement while in a posture compatible with the movement about to be performed. Specifically, if the patient were to move their arm to pick up a cup it might be helpful to have their own arm in a position congruent with picking up a cup such as resting on the side of the wheel chair or potentially already grabbing the cup himself or herself. Obviously, an outside assistant may have to position the patient to hold the cup and it may not work due to tightness in the body. But it is a simple practical activity to try and it might yield better results from thought to action.
1 idea to improve BMI for researchers
The fourth option and I think a very important one is outside the patients’ control. It involves the researchers adjusting the robot or prosthetic arm to be in the 1PP of Hutchinson or Veillette. Currently it seems as if the robot is positioned in the 3PP. This requires an extra reconfiguration from the brain itself to reorient the task within the body. Research by Meltzoff, Jackson & Decety 2006 reported that neural circuits seem to activate best during 1PP when observing or imitating movement and currently BMI seems to favor 3PP for the patient. Therefore when asking a patient learning BMI to control the machine in 3PP it is like asking them to do more work than necessary because they have to reconfigure from 3PP to 1PP.
View of Robot in 1PP
View of Robot in 3PP
Again these are just ideas aimed at giving the patient more control and confidence about thinking and imagining movements while training with BMI. Yet as technology rushes forward to convert thought into action it is important to not forget whose brain is creating the thought and how to distill those thoughts for effective BMI thought to action transfer.
Lorey, B., Bischoff, M., Pilgramm, S., Stark, R., Munzert, J., & Zentgraf, K. (2009). The embodied nature of motor imagery: The influence of posture and perspective. Experimental Brain Research, 194(2), 223. doi:10.1007/s00221-008-1693-1
