Meaning for the Brain and Meaning for the PersonFellowship
Humans make many things that carry meaning: an encyclopaedia entry on Ghandi, a toy model of the battle of Waterloo. Both are about things in the world. They represent Ghandi and Waterloo. Their meaning comes from us, their users, from what we take them to mean. It derives from human thought and understanding.
Our thoughts also have meaning. They are mental representations, representations that are about things in the outside world. How do they get their meaning? We can’t say it comes from how people interpret them, because that just pushes back the question – how do those interpretations get their meaning? Thoughts must have underived meaning. Understanding how that can be so is one of the deepest questions about the mind.
This project will use case studies emerging from science to uncover the nature of meaning in the brain. Psychology tells us that mental representations are the result of a series of stages of internal information processing. Powerful new methods in cognitive neuroscience reveal information processing in the brain in unprecedented detail. They show how the brain performs complicated calculations on neural representations, which are states with meaning. That gives us a powerful insight into how those meanings arise.
But philosophers see a big problem here. There is an important distinction between representations at the “personal level” and representations at “subpersonal levels”. The science mostly tells us about subpersonal representations, like the intricate calculations of light and shadow performed by the visual system on the way to recognising a three dimensional object. You couldn’t tell me about those representations. They are not representations for you, the person. In contrast, personal level representations are meaningful for the person: conscious thoughts, beliefs, desires, conscious decisions. The deep problem of meaning is to understand the nature of personal level representations.
The philosophical problem with starting with the subpersonal is that theories of meaning based on the best case studies from neuroscience don’t seem to be applicable to personal level mental representations. So the theories are rejected. This project takes a new tack. Maybe we need different theories for different cases: different theories for different kinds of subpersonal meaning and, crucially, a different theory of the meaning of personal level states like our conscious thoughts.
Once we take that tack the obvious question is: what is going on differently at the personal level? But then we run into trouble with the psychologists, because many think that nothing important is going on at the personal level – that it has little to do, because so much behaviour is driven subpersonally and automatically, and that what it does, it does badly, blundering through with a host of approximations, heuristics and biases. The science presents a kind of paradox: why is the personal level so error prone when subpersonal processes can perform highly intricate calculations optimally?
A growing body of data suggest that this is a serious oversimplification, because the personal level has a different job to do, which is difficult and important. Personal level representations undergo different kinds of computations – computations tailored to their special functions. We will analyse that body of results to understand what is being done differently at the personal level. But we are looking at the data through a new lens – with a focus on understanding how meaning arises, and arises differently from the subpersonal case.
This will be the first systematic investigation of how information is processed differently at the personal level in a way that makes a difference to how meaning is constituted. Drawing the contrast with meaning for the brain, we will lay the foundations for understanding meaning for the person.