> My point is that we may or may not find that there is some critical ingredient of cognition hiding in this place or that, and you can't very well tell us where that will be if nobody knows if it's there.
It's like the parable of the Drunken man looking for his lost keys under the street-lamp. He only looks under the lamp for his keys because that's the only place the light is.
Similarly, in neuroscience, we only have a few tools to look at the brain. By some miracle, the brain happens to be electrically active to a degree that we can shove wires into it and pick up signals. So, dutifully, grad students across the world have been shoving needles into brains and trying to pick up signals and then tell advisers what that means.
Another miracle is that blood has a ferromagnet in it and the brain has a fair bit of blood in it. So, after a lot of trial and error, we've been able to build very complicated fMRI machines that can give grad students an idea of the usage of blood in the brain. This is then correlated with other measurements to find out what is happening in the brain.
Recently, we've been able to combine two different little miracles together. One is opto-genetics, a little serendipity we pulled out of the chromatic hot-pools in Yellowstone. Essentially, when you shine light on a little bacteria, it's cell wall opens up and you can squeak certain ions through the hole. The other little miracle is CRISPR-CAS9. Here, you can again use some tricks bacteria have made up to more easily copy-paste in the genetic code. Using these tricks and a lot of help from post-docs, yet more grad students have been able to report results in lab meetings to their advisers.
More techniques exist, of course, but my point is that the vast majority of neuroscience is still in the dark, away from the drunken man searching for his keys in the light.
Look at astrocytes. These guys make up ~50% of the brain. Very recent research says that they play something of a role in the synapse, moving NMDA receptors around the cleft, recycling, phospho-tagging recpetor, etc. It's super recent work. But also super important. Before, we thought that only the neurons were involved in the synapse, but now we have good evidence that other, action-potential lacking, cells are also deeply involved.
That vein of research is also really hard to do and preform experiments in. As such, most grad students are wise not to do their work in that kinda lab. It's hard and has a high potential of failure, and therefore no degree.
So, wait and see. Our understanding of the brain is still very much in it's infancy. We've not really even got a good accounting of all the cell types and connections in the brain yet.