Rethinking the way we think about thinking: A Q&A with Dan Feldman

January 4, 2024

Photo of Dan Feldman

Neuroscience is in a historic era of major discovery, according to Dan Feldman, a professor of neurobiology at UC Berkeley.

For years, neuroscience has steadily grown as a major strength at Berkeley. Now, to cement Berkeley's place at the forefront of innovation, Feldman is leading the effort to form a cohesive Department of Neuroscience, the first new department within the Division of Biological Sciences in more than three decades. Soon, faculty who study the brain from diverse perspectives, from neurobiology and psychology to engineering and vision science, will be able to unite under one banner.

Feldman talked with UC Berkeley writer Alexander Rony about how the field of neuroscience is changing society for the better, the advances that Berkeley researchers have contributed, and where neuroscience will lead us in the future.

Alexander Rony: What first attracted you to the field of neuroscience?

Dan Feldman: I've long been fascinated with how learning works in the brain. How is it that you remember someone you met when you were 10 years old up until you're 80? That's a remarkable feat for a biological system to perform and indicates that memory traces somehow exist in the physical structure of the brain. But before understanding learning, you need to understand how nervous systems process information in the first place.

My lab studies this question by asking how we sense the physical world around us. We take measurements in mice to assess how the brain constructs the internal stream of images, sounds, and feelings of the sensory world. This is a construct of your brain based on the electrical impulses that your brain receives from your fingertips, your eyes, and your ears.

What are some significant ways in which neuroscience has already impacted society?

There are so many ways! Let's start with the redefinition of addiction as a disease rather than a moral failure. And the understanding that the brain takes many years to develop has helped change how the justice system views the legal responsibility for acts by children and teenagers. Likewise, neuroscience has shown that brain activity bears signatures of a person's educational level and childhood experiences, and this has informed the debate about equity.

Another example would be neurodiversity. Brains are individually distinct, and people have different communication, perception, and thinking styles. These are not deviations from a norm; they represent the natural range of ways people are built.

How has Berkeley been at the cutting edge of neuroscience research?

Many technologies driving neuroscience discovery forward were invented, optimized, or applied at Berkeley. One of the most powerful technologies in studying how the brain works at the circuit level is called optogenetics, in which genetic tools are used to make neurons sensitive to light. Flashing a light can then turn brain cells on or off. One of the earliest optogenetic constructs was developed here at Berkeley, as were later methods that study how neurons communicate at synapses. Recently, optogenetics has been applied at Berkeley to restore vision in animals with retinal degenerative disease.

Another example is fMRI, which is a type of brain imaging that can see functional activation of the brain. Some of the founding physical principles of fMRI scanners were worked out at Berkeley. Even more exciting, the world's most spatially precise fMRI machine has just built on the Berkeley campus. It will give a much better view of what's "going on under the hood" as a person thinks, feels, sees, and remembers. 

Berkeley is also engaged in the Brain Initiative's cell census. Can you talk about the importance of that project?

One of neuroscience's biggest goals and challenges has been to develop a complete wiring diagram of the brain. If you think about it as a gigantic circuit, you need to understand what the components are. Those would be the cell types in the brain. Defining a cell type is a surprisingly complicated and nuanced task. Berkeley is one of the early sites that developed the computational methods used to analyze genetic signatures that define discrete cell types within the brain. John Ngai, who was a faculty member in neuroscience at Berkeley for many years, left to become the head of the Brain Initiative at the National Institutes of Health.

Our field is well on the way to that wiring diagram — the connectome of the brain. It's going to be coming in the next couple of decades. We'll essentially have a computational resource — a lookup tool — that we can use to figure out how different regions of the brain might be performing their functions. That will be the equivalent of the human genome for understanding the nature of brain computations.

The Li Ka Shing Center on Berkeley's campus houses the Helen Wills Neuroscience Institute, the Brain

The Li Ka Shing Center on Berkeley's campus houses the Helen Wills Neuroscience Institute, the Brain Imaging Center, and many neurobiology classes. (UC Berkeley photo by Keegan Houser)