Researchers examining the brain at a single-neuron level found that computation happens not just in the interaction between neurons, but within each individual neuron. Each of these cells, it turns out, is not a simple switch, but a complicated calculating machine. This discovery promises changes not only to our understanding of how the brain works, but better understanding of conditions ranging from Parkinson's disease to autism. The findings are also expected to advance machine learning, offering inspiration for new architectures.