Brain-controlled interface experiment provides empirical support for one-way neural activity paths

Neural network models that are able to make decisions or store memories have long captured scientists’ imaginations. In these models, a hallmark of the computation being performed by the network is the presence of stereotyped sequences of activity, akin to one-way paths. This idea was pioneered by John Hopfield, who was notably co-awarded the 2024 Nobel Prize in Physics. Whether one-way activity paths are used in the brain, however, has been unknown.