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I find it really fascinating that there's been problems using traditional brain-computer interfaces with these patients, and the researcher who developed this d

by themgt 10y ago

I find it really fascinating that there's been problems using traditional brain-computer interfaces with these patients, and the researcher who developed this device specifically believes it's because once completely locked-in they actually experience a dramatic shift in the nature of their mental activity that prevents them from utilizing traditional BCI: Niels Birbaumer, a neuroscientist at the Wyss Center for Bio and Neuroengineering in Geneva and coauthor of the new research, has an idea about why this may be, although there’s little evidence to support it so far. He proposed that it becomes harder over time for patients to channel their thoughts into voluntary action. “Anything you want, everything you wish does not occur. So what the brain learns is that intention has no sense anymore,” he says. “It is too difficult for them to switch from [a] more reflective state into an attentive state." And that the device they used itself was designed to be more a passive monitoring of mental perception of input: The team stuck to simple questions that could be answered with a yes or no. “The answer in your head…occurs quickly and it occurs like a reflex. You don’t have to mobilize a lot of resources for such a simple answer,” Birbaumer says. Earlier paper from Birbaumer: We propose that a lack of contingencies between goal directed thoughts and intentions may be at the heart of this problem. Experiments with chronically curarized rats support our hypothesis; operant conditioning and voluntary control of autonomic physiological functions turned out to be impossible in this preparation. In addition to assisted communication, BCIs consisting of operant learning of EEG slow cortical potentials and sensorimotor rhythm were demonstrated to be successful in drug resistant focal epilepsy and attention deficit disorder. First studies of non-invasive BCIs using sensorimotor rhythm of the EEG and MEG in restoration of paralysed hand movements in chronic stroke and single cases of high spinal cord lesions show some promise, but need extensive evaluation in well-controlled experiments. Invasive BMIs based on neuronal spike patterns, local field potentials or electrocorticogram may constitute the strategy of choice in severe cases of stroke and spinal cord paralysis. Future directions of BCI research should include the regulation of brain metabolism and blood flow and electrical and magnetic stimulation of the human brain (invasive and non-invasive). A series of studies using BOLD response regulation with functional magnetic resonance imaging (fMRI) and near infrared spectroscopy demonstrated a tight correlation between voluntary changes in brain metabolism and behaviour. [1] http://www.popsci.com/new-brain-computer-interface-helps-completely-paralyzed-people-communicate?dom=rss-default&src=syn http://www.popsci.com/new-brain-computer-interface-helps-com... [2] http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002593 http://journals.plos.org/plosbiology/article?id=10.1371/jour... [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2151357/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2151357/

M_Grey 10y ago
So... in essence, people are so psychologically and behaviorally devastated, that they lose the ability to even formulate whole classes of thoughts? That sounds like they've been utterly broken as people.
- derefr 10y ago
  "Thoughts" isn't quite what is being lost. Instead, you've still got the neurons that understand how goals relate to motor operations, and you've still got the motor neurons, but they've lost the neurotransmitter "protocol" (the calibrated receptivity-weights on the synapses connecting them) that allows them to communicate. For me, an analogy to speech helps: a baby learning to speak must learn not just language in a high-level sense, but at a lower level, they must "learn" (i.e. calibrate neurotransmitter receptors attached to motor pathways) for how strongly each muscle in their vocal cords should respond to a given low-level phonemic motor-intent-signal from the brain. If you didn't talk for years, those calibrations would drift, and although you'd remember what it was like to talk, you'd have to "learn to use" (i.e. calibrate) your vocal cords all over again. The interesting thing here, is that this "calibration" (or lack thereof) continues to cascade through the entire graph of neurons: think backpropagation in machine learning. Motor-neurons that have nothing to talk to lose their ability to talk; and then the motor-intent-recognizing neurons find the only thing they had to talk to (the motor neurons) are now silent—as good as dead—and so they no longer get reward-trained and lose their receptivity-calibration—and on and on, back until you reach whatever subset of neurons is still doing things that achieve "rewards."
  - baddox 10y ago
    Is this essentially the idea of "muscle memory"?
    - grogenaut 10y ago
      Muscle memory is generally for referring to higher order things like blocking in a fight, swinging a bat, and other fast reactions that get better through practice instead of thought. Eg actions that your brain higher order plans but isn't thought by many to be consciously controlled. In fact when you think about a lot of these things consciously you mess up. Think throwing darts, shooting pool, etc.

by themgt 10y ago

M_Grey 10y ago

So... in essence, people are so psychologically and behaviorally devastated, that they lose the ability to even formulate whole classes of thoughts? That sounds like they've been utterly broken as people.

derefr 10y ago
"Thoughts" isn't quite what is being lost. Instead, you've still got the neurons that understand how goals relate to motor operations, and you've still got the motor neurons, but they've lost the neurotransmitter "protocol" (the calibrated receptivity-weights on the synapses connecting them) that allows them to communicate. For me, an analogy to speech helps: a baby learning to speak must learn not just language in a high-level sense, but at a lower level, they must "learn" (i.e. calibrate neurotransmitter receptors attached to motor pathways) for how strongly each muscle in their vocal cords should respond to a given low-level phonemic motor-intent-signal from the brain. If you didn't talk for years, those calibrations would drift, and although you'd remember what it was like to talk, you'd have to "learn to use" (i.e. calibrate) your vocal cords all over again. The interesting thing here, is that this "calibration" (or lack thereof) continues to cascade through the entire graph of neurons: think backpropagation in machine learning. Motor-neurons that have nothing to talk to lose their ability to talk; and then the motor-intent-recognizing neurons find the only thing they had to talk to (the motor neurons) are now silent—as good as dead—and so they no longer get reward-trained and lose their receptivity-calibration—and on and on, back until you reach whatever subset of neurons is still doing things that achieve "rewards."
- baddox 10y ago
  Is this essentially the idea of "muscle memory"?
  - grogenaut 10y ago
    Muscle memory is generally for referring to higher order things like blocking in a fight, swinging a bat, and other fast reactions that get better through practice instead of thought. Eg actions that your brain higher order plans but isn't thought by many to be consciously controlled. In fact when you think about a lot of these things consciously you mess up. Think throwing darts, shooting pool, etc.