Robotic Arm Controlled By Monkey Thoughts 327
mallumax writes "The BBC reports that Pittsburgh University scientists have succeeded in creating a robotic arm, controlled by probes inserted into the brain of monkeys. The probes interpret signals from individual nerve cells in the motor cortex. Monkeys were able to grasp and hold food with the robotic arm. Since the number of nerve signals for even small movements is huge the scientists used an averaging algorithm to obtain the movement signals."
University of Pittsburgh NOT Pittsburgh University (Score:5, Informative)
http://www.cnbc.cmu.edu/faculty/schwartz.s
It seems he does joint work with CMU but his official position is at UPitt(as we sometimes call it).
No, the tool is the arm. (Score:2, Informative)
Wired has a better story (Score:4, Informative)
Re:University of Pittsburgh NOT Pittsburgh Univers (Score:2, Informative)
Mechanical arms reading motion of other moscles still works a lot faster than any of the neural implants. Look at David Edell's work at MIT for examples of potentially useful electrode technologies, involving electroplated slots in semiconductor grade silicon.
Human Testing (Score:2, Informative)
Re:Tool use? (Score:2, Informative)
Links and more info (Score:3, Informative)
The actual web site for Schwartz's lab:
http://motorlab.neurobio.pitt.edu/ [pitt.edu]
The above link has neat videos [pitt.edu] of the monkey moving the arm around.
Researchers like Schwartz who record from motor areas of the brain do cool stuff, but I'm personally more interested in folks like the Andersen Lab [caltech.edu] who do recording from more goal-oriented areas. Basically, it's a difference between a command to "move my elbow this much" versus "I want to grab this object."
Here's a PDF link [google.com] to a paper published by Schwartz and others in 2002. Here's the abstract:
Direct Cortical Control of 3D Neuroprosthetic Devices
Dawn M. Taylor, Stephen I. Helms Tillery, Andrew B. Schwartz
Three-dimensional (3D) movement of neuroprosthetic devices can be controlled by the activity of cortical neurons when appropriate algorithms are used to decode intended movement in real time. Previous studies assumed that neurons maintain fixed tuning properties, and the studies used subjects who were unaware of the movements predicted by their recorded units. In this study, subjects had real-time visual feedback of their brain-controlled trajectories. Cell tuning properties changed when used for brain-controlled movements. By using control algorithms that track these changes, subjects made long sequences of 3D movements using far fewer cortical units than expected. Daily practice improved movement accuracy and the directional tuning of these units.
Re:Why is there a block on transhumanism? (Score:2, Informative)
Well, that wasn't really my point, I was just stressing the point that an extra arm attached in this fashion at the age of 20 wouldn't be easy to "manage."
As for the other point, you're partially correct. Sensory information is conducted, and elaborated, in the thalamus, but it reaches consciousness only at the last neuron in the pathway, which is located in an area of the cortex just behind the one controlling motion. Such area also has extensive connections with memory, associative and "biohumoral" areas. Damage to the thalamus may lead to absent or impaired sensation, whereas destruction of the sensory cortex leads to total absence of conscious sensation. Both structures are part of the sensory pathways, though, so they're both essential.
As for that recent case, I haven't read about it, but that would depend on the level of the lesion. For example, if only axons (the 'cables') conducting information from the inner ear to the brainstem were damaged, the injection of stem cells might have stimulated the repairs of those connections. A broken axon can nowadays be repaired, although it depends on the lesion. A dead neuron cannot.
Of course, this doesn't mean we couldn't be able one day to "start over" by injecting new, indifferentiated neuronal stem cells which could then differentiate into full-fledged neurons and get back to work. This is actually being researched in Parkinson's disease, where a particular kind of neurons in the basal ganglia die. There's hope that by injecting stem cells in the area might lead to re-population and renewed functionality. Such procedures might turn out to also work in brain injured patients, or in those who just had their third arm installed...
Re:Tool use? (Score:3, Informative)
A little history (Score:2, Informative)
Re:Acceptable question now... (Score:2, Informative)
I've seen similar experiments at Med School, and they involved "population vectors" too, back in 1998-99.
That's right, it's a pretty much painless procedure (according to our perception of the animal's reaction), and it's performed in a safe and sterile fashion.
The probes are really fine needles, much less than a millimeter in diameter. They don't cause particular brain trauma, and a variation of those probes is even used in surgical procedures and critical care monitoring in humans. The portions of skull removed to access the brain are put back in place and allowed to heal. Or, the probes can be left in place (as is the case here) using surgical material in a relatively safe manner.
Relatively safe here means that it's not like sticking a fork through the poor monkeys head: an increased risk of brain infection, trauma etc. is of course present.
However, by looking at the picture in TFA, it seems as though the monkey is only moving the robotic arm. If that's the case, to the best of my knowledge, there's no way they could have prevented the real arm from moving or sending feedback signals other than by damaging the descending and/or ascending pathways (outgoing connections) of the motor cortex being studied. Such damage would be pretty much permanent.
TFA says the monkey's arms were restrained, but that brings up one more question: how did they bypass automatic feedback signals coming from the restrained arm, telling the brain it wasn't actually moving, and thus to increase the strength and/or to try other movements/recruit different vector populations? I can't see how the movement might have resembled "natural" ("like your own arm," as TFA say) in the presence of contrasting feedback coming from the real arm.
Re:Acceptable question now... (Score:1, Informative)
Sandra Laville
Tuesday February 8, 2005
The Guardian
http://www.guardian.co.uk/uk_news/story/0,3604,14
Re:Tool use? (Score:4, Informative)
http://www.primates.com/faq/index.html [primates.com]
Didn't Duke University already do this? (Score:2, Informative)
I was under the impression that this experiment occured in October of 2003 at Duke University.