The latent dynamical structure of mental activity

The human brain is composed of billions of neurons. Each neuron is capable of complicated computational feats, yet the brain as a whole is able to carry out vastly more complex functions than could any individual neuron alone. This remarkable computational power of the brain hinges on the fine coordination among neurons. However, though we understand a great deal about how an individual neuron functions, we have little knowledge as to how their collective activity in neural circuits gives rise to computations in the brain. Much of what we have learned about the brain has come from experiments that record the electrical activity of one neuron at a time, then look at the average profile of  the response of that neuron to a stimulus or a task. However, in the brain, there is no “average” response.  Rather, the collective activity of populations of neurons reflects the unique response of the brain each time a stimulus is experienced or a task performed. Now, new technical advances have allowed us to monitor the activity of hundreds or thousands of neurons simultaneously. We will take advantage of this technology to develop algorithms and data-analytic tools to discover how neurons are coordinated in the brain, and how that coordination effects the brain’s computations. These tools will be developed and applied in close collaboration with experimental laboratories, studying a range of brain functions spanning the arc of perception to cognition and action.  By identifying how the concerted action of neurons gives rise to these processes (instead of recording one neuron at a time), we will be able to see—as the brain would—how those computations unfold moment by moment.