Phase transition may explain how brain neurons encode information

While scientists know that information is represented in the brain by the electrical activity of neurons, the details of this representation, called "neural coding," remain mysterious. How exactly do pulses of electricity get translated into thoughts and ideas?

In the standard model of neuronal firing, neurons can use two kinds of neural codes: rate codes, in which information is encoded only in the average rate of firing; and temporal codes, in which information is encoded not only in the average rate but also in the precise timing of each pulse, with sensitivity down to the submillisecond range. Temporal firing means that firing patterns with the same average rate can encode different messages—a key insight into understanding neural coding. While the distinction between the two neural codes has previously been considered one of degree, a new study has found that neurons change between the two coding regimes abruptly rather than smoothly due to a phase transition separating the two regimes.

The researchers, Thibaud Taillefumier and Marcelo Magnasco at The Rockefeller University in New York, have published their paper on their discovery of a neural phase transition in a recent issue of PNAS.