Today, when researchers spend long hours in the lab performing tricky experiments, they might listen to music or podcasts to get them through the day. But in the early years of neuroscience, hearing was an essential part of the process. To figure out what neurons cared about, researchers would translate the near-instantaneous signals they send, called "spikes," into sound. The louder the sound, the more often the neuron was spiking--and the higher its firing rate. "You can just hear how many pops are coming out of the speaker, and if it's really loud or really quiet," says Joshua Jacobs, associate professor of biomedical engineering at Columbia University.

When Chad Latham was convicted to spend 15 years behind bars for growing marijuana, he couldn't have predicted what the future would hold for him. A decade into his sentence, marijuana was legalized in his state (Washington), and shortly afterward he received clemency from President Obama. Sent out into the world a free man, Latham had some recalibrating to do. The looming question, of course, was "What now?" In his teenage years he'd been interested in computers, and it had stuck.

Harold Cohen was already an acclaimed artist when he represented the United Kingdom at the Venice Biennale back in 1966, and his work subsequently appeared in top-ranked galleries and museums around the world. So in 1969, when he began dabbling in computers, his intent was simply for the machines to help him create his drawings and paintings. I thought of designing a program as a kind of assistant, he recalls. I was to think up the heavenly paradigm and it was to do the earthly instantiation. But as Cohen found himself devoting less and less time and energy to his own paintings, his computerized alter ego, dubbed Aaron, began to take on a career of its own. In 1983, Aaron took up a pencil in its robotic hand and tirelessly produced drawing after drawing for an audience of captivated visitors to the Tate Gallery in London. It didn't matter to them that Cohen had to add color to the drawings with his own hand; many an onlooker walked out with one of the new drawings tucked under his arm. By last year, when the Computer Museum in Boston devoted an entire exhibit to Cohen's stepchild, Aaron had mastered paintbrush and palette and, once Cohen set up the apparatus, produced whole paintings, many of them quite pleasant to look at. Cohen's success with his computer program raises the question: Who is the creator of these paintings? The answer is by no means clear. Perhaps the creative intelligence is Cohen's because, after all, Aaron merely does what he programs it to do.