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The study is a big improvement over early experiments. In past studies, because researchers didn’t keep track of the same set of neurons, they had to reprogram the decoder every time to adapt to the new cortical activity. The changes also meant that the brain couldn’t form a cortical map of the prosthetic device. That limitation raised questions about whether paralyzed people would be able to use prosthetics with enough proficiency to make them really useful.

But perhaps more surprising, the researchers also tested a shuffled decoder. They took one of the existing decoders and randomly redistributed the weights in the equations among the neurons. This meant that the new decoder, unlike the early ones, had no relationship to actual movements of the monkey’s arm. It was a bit like giving a tennis player a hammer instead of a different racket.

What followed was a big surprise: After about just three days, the monkeys learned the new decoder. Just as before, practice allowed the neurons to develop a cortical map for the new task.

The science behind the robotic experiments is straightforward. The Blue Brain team genetically engineers Chinese hamster ovary cells to express a single type of ion channel—the brain contains more than 30 different types of channels—then they subject the cells to a variety of physiological conditions. That’s when the robot goes to work. It manages to “patch” a neuron about 50 percent of the time, which means that it can generate hundreds of data points a day, or about 10 times more than an efficient lab technician. Markram refers to the robot as “science on an industrial scale,” and is convinced that it’s the future of lab work. “So much of what we do in science isn’t actually science,” he says, “I say let robots do the mindless work so that we can spend more time thinking about our questions.”

The results revealed exactly the expected pattern: people found it harder to to suppress thoughts about cold flames presumably because they had less practice.

It's not yet clear how ultrasound triggers electrical activity in neurons, but some believe that it is through thermal energy generated by sound waves. Tyler, however, says he has evidence that the neurons are activated through mechanical energy. Previous research has indeed shown that the neuron channels that control electrical activity in the brain can be activated with mechanical pressure. "What we think is happening is some kind of microcavitational effect, such as radiation or sheer strain, which affect the channels that control neural activity," he says.