How Do Our Brains Construct Thoughts?

Three goats wearing vintage roller skates boarded an aircraft carrier. You have never before encountered the previous sentence, and yet you instantly grasped its meaning. You had some concepts ready to go in your head (aircraft carrier, goat, roller skate, boarding, vintage, three), and you put them together in just the right way to get just the right idea. What’s more, you can picture this absurd state of affairs in your mind’s eye, and you can give reasonable answers to questions about it. (“Did any animals end up on a boat?”) Finally, you can hold these silly ideas in your head without believing that they accurately reflect reality. We take these mental abilities for granted, but they are, from a neuroscientific perspective, rather mysterious. We don’t know how populations of interconnected neurons are able to do these things, and yet these abilities are essential to our intelligence. In this talk I will describe some new fMRI experiments that offer clues about how this works. More specifically, I will discuss results concerning semantic composition in sentence comprehension and visual imagery, the implementation of propositional attitudes, and simple deductive reasoning.

Speaker: Joshua Green, Harvard