Energy use constrains brain information processing

The brain is an energetically expensive organ to build and operate, and a large body of literature links the evolutionary development of many of the human brain's components to the need to save energy. We, and others, have shown experimentally and through computational modelling that synapses in the brain do not maximise information transfer, but instead transfer information in an energetically efficient manner. Strikingly, this optimum implies a high failure rate in the transmission of individual information-carrying signals (action potentials or spikes). This design principle may be important when considering trade-offs between energy use and information transfer in man-made devices.