It's not even known how many kinds of cells there are in the brain. If you were looking for a periodic table of the brain, there is no such thing. I really like to think of the brain as a computer.

If our brain is understanding some parts of the universe and not understanding other parts, and those understandings are about the laws of physics that our brains are built on top of, then it's kind of a loop, right?

For the last century of neuroscience, lots of people have tried to control neurons using all sorts of different technologies - pharmacology (drugs), electrical pulses, and so on. But none of these technologies are precise. With optogenetics, we can aim light at a single cell, or a set of cells, and turn just that set of cells on or off.

The skill-providers want to have more impact and solve problems; the problem people want new tools to get their problems solved.

The brain is really hard to see. The whole thing is very large - the human brain is several pounds in weight - but the connections between brain cells, known as synapses, are really tiny. They're nanoscale in dimension. So if you want to see how the cells of the brain are connected in networks, you have to see those connections, those synapses.

We don't have a "consciousness meter" that'll tell us exactly how conscious something is. I think we might get there eventually.

Work backward from your goal.