New paper: paralyzed man uses thoughts to control robotic arm

This is from Science Daily. (H/T The Best Schools)


Researchers at the University of Pittsburgh School of Medicine and UPMC describe in PLoS ONE how an electrode array sitting on top of the brain enabled a 30-year-old paralyzed man to control the movement of a character on a computer screen in three dimensions with just his thoughts. It also enabled him to move a robot arm to touch a friend’s hand for the first time in the seven years since he was injured in a motorcycle accident.

With brain-computer interface (BCI) technology, the thoughts of Tim Hemmes, who sustained a spinal cord injury that left him unable to move his body below the shoulders, were interpreted by computer algorithms and translated into intended movement of a computer cursor and, later, a robot arm, explained lead investigator Wei Wang, Ph.D., assistant professor, Department of Physical Medicine and Rehabilitation, Pitt School of Medicine.

“When Tim reached out to high-five me with the robotic arm, we knew this technology had the potential to help people who cannot move their own arms achieve greater independence,” said Dr. Wang, reflecting on a memorable scene from September 2011 that was re-told in stories around the world. “It’s very important that we continue this effort to fulfill the promise we saw that day.”

Six weeks before the implantation surgery, the team conducted functional magnetic resonance imaging (fMRI) of Mr. Hemmes’ brain while he watched videos of arm movement. They used that information to place a postage stamp-size electrocortigraphy (ECoG) grid of 28 recording electrodes on the surface of the brain region that fMRI showed controlled right arm and hand movement. Wires from the device were tunneled under the skin of his neck to emerge from his chest where they could be connected to computer cables as necessary.

For 12 days at his home and nine days in the research lab, Mr. Hemmes began the testing protocol by watching a virtual arm move, which triggered neural signals that were sensed by the electrodes. Distinct signal patterns for particular observed movements were used to guide the up and down motion of a ball on a computer screen. Soon after mastering movement of the ball in two dimensions, namely up/down and right/left, he was able to also move it in/out with accuracy on a 3-dimensional display.

“During the learning process, the computer helped Tim hit his target smoothly by restricting how far off course the ball could wander,” Dr. Wang said. “We gradually took off the ‘training wheels,’ as we called it, and he was soon doing the tasks by himself with 100 percent brain control.”

I think that this is relevant to the physicalism vs immaterial mind/soul debate. Here’s a person using mental effort to control matter.

2 thoughts on “New paper: paralyzed man uses thoughts to control robotic arm”

  1. Right, and it really shows that creating the ‘mind’ is the primary function of the brain. The article talks about the electrodes attached directly to his brain and wires running under his skin. So it’s the electrochemical processes in the brain that stimulate the electrodes and move the arm. Physicalism demonstrated.


    1. Reality check, Michael!
      Ever heard of Emergent Dualism? The brain generates the mind, but the mind has causal power of its own. Physicalism is only “demonstrated” if we show that the theories of Dualism are inadequate models of cognition.

      Now of course, I’m making a weak case. Allow me to make a stronger one:

      Part One: Answering Detractors.
      You have committed three logical fallacies:
      Fallacy of Equivocation
      You equivocate the source of the electrical impulses with the source of the desire to move the arm in the first place. As it is logically possible for a mind to exist without a brain, we are allowed to challenge this notion you propose, until we see reason to believe it is really impossible.
      The Question-Begging Epithet
      This brings us to our next fallacy. You assume that physicalism is true in order to eliminate the other possibilities beforehand, without actually considering them. Assuming we have somehow refuted Thomistic Hylomorphism, or even property dualism, it does not follow that physicalism is proven; maybe Emergent Dualism is correct?
      Selection Bias
      You are only considering one type of causation, when others should also be considered. Namely, you only considered material causes, when mental causes should also be considered. Remember that this person CHOSE to move their arm (a mental act). Unless you have good reason to reject this hypothesis, you will have to allow us the possibility to believe that the person’s desire to move their arm generated the electrical impulses in their brain, and not the other way around.

      Part Two: Why this Supports Dualism over Physicalism.
      In all theories of dualism, the mind has causal power. Causal power of the mind has been demonstrated. Therefore, dualism as a whole is confirmed.
      But what of physicalism? The mind does not really have causal power, as it is a side-effect of matter, and only material things have causal power. Hence, the fact of the causal power of the mind refutes one of physicalism’s predictions. The only ‘outs’ available are to make the mind a physical thing in itself, or to say that non-physical things can have causal power. The first out either makes a brain a mind (in which case, property dualism is confirmed, and physicalism is refuted), or makes the mind a separate structure from the brain (in which case, your argument that the BRAIN caused the arm to move, rather than the mind, is dead-wrong, AND confirms property dualism), and both of these options are unacceptable. The second escape hatch is to confirm emergent dualism, in which case, you are refuted.

      Physicalism, unless we have warrant, is falsified by this major prediction.


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