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Scientists have grown a brain in a petri dish and taught it to pilot an F-22 jet simulator

23 点作者 seren6ipity超过 17 年前

3 条评论

palish超过 17 年前
No, they haven't. It's hard to explain what they did do since it was so overcomplicated, but bear with me.<p>They took a few thousand rat neurons and placed them on electrodes. At that point, each neuron's charge could be measured as it fired. A neuron doesn't fire instantly and stop - its charge rises sharply, then falls over time. The graph of a neuron firing resembles a bell curve.<p>Now that the charge of an individual neuron could be measured, they selected two (one to control the F-22's roll, and one to control the elevation) and began the simulation.<p>First, imagine a steady, level plane. We say that the plane's error is 0 degrees. Now roll the plane 5 degrees clockwise (or counterclockwise). The error is 5 degrees. So the plane's error is known, and maxes out at 180 degrees (inverted flight).<p>Second, imagine the graph of a neuron firing: <a href="http://img515.imageshack.us/img515/3873/graphet3.png" rel="nofollow">http://img515.imageshack.us/img515/3873/graphet3.png</a> ... We'll say that if we sample from the left side of the graph, we've sampled at X=0 degrees. If we sample from the right side of the graph, we've sampled at X=180 degrees.<p>Third, a technique exists to deaden a neuron's response. This technique is applied throughout the simulation, so the graph you're looking at is slowly being squished toward the bottom (the dashed line).<p>Let's say our plane has an error of 10 degrees. Go ahead and sample the graph at X=10. You know what X=10 was at the start of the simulation (the solid line), and you know what it is currently (the dashed line). They use the difference between those values to determine the airplane's corrective action.<p>Since the simulation starts with the solid line equal to the dashed line, our airplane takes no corrective action and continually plows into the ground. Eventually, the dashed line departs from the solid line enough to cause significant corrective action, and the plane flies straight and level. There is no learning involved, and no decoding of neural communication protocols. They're just decrementing a variable - only the variable is a firing neuron.<p>It's basically a hi-tech Rube Goldberg device.<p>You can read the paper here: <a href="http://neural.bme.ufl.edu/page13/assets/NeuroFlght2.pdf" rel="nofollow">http://neural.bme.ufl.edu/page13/assets/NeuroFlght2.pdf</a> ... If you can't read a scientific paper, try. It's good to be able to know when a scientist is full of it.
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daniel-cussen超过 17 年前
If this is true, it is kind of ridiculous. That's pretty cool that they can do that.<p>edit: I read palish's comment. It <i>would</i> be cool <i>if</i> they could do that.
davidw超过 17 年前
Next thing you know, the brain in a petri dish will be a leading light in the Church of Scientology. <i>In to the danger zone</i>
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