Integration of perception and conception in the human brain

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In any given day, we interact with hundreds of objects. The ability to do so is central to our survival. When we look at an object - a hairdryer, for example - we are able to effortlessly recognize it and use it in a way that matches its function. We don't, for example, mistake it for the handheld power drill, despite the fact that they have a similar visual appearance and engage similar hand movements. And conversely, despite the fact that tape and glue neither look alike nor engage similar hand movements, we have no trouble recognizing that they would be both be suitable objects for the task of sticking two things together. Thus, in any given set of objects, many visual features will be highly similar and will not always have a direct correspondence with an object's identify. How, then, are we able to understand what we see? In a series of inter-related projects, we will address this question. We will focus on a core hypothesis: that the ability to understand and interact with objects depends on a particular kind of neural code. Specifically, we will argue that because neither perceptual nor conceptual features are perfectly diagnostic for an object's identity when considered on their own, the brain must integrate perceptual and conceptual features to make a highly specific object representation. We will show that these integrated representations are essential to behaving in a flexible manner when faced with many features that are distracting to the task at hand. Project 1 will use cutting-edge neuroimaging techniques to map information patterns in the brain. We predict to observe an integrated information code, such that when participants think about the visual attributes of objects, brain activity will also reflect the conceptual properties of those objects (and vice versa). We predict to observe this in the perirhinal cortex, a part of the brain that is connected both to regions important for perception, as well as to regions important for conceptual processing. Thus, it is well-placed to integrate these streams of information. Project 2 will investigate how behaviour is affected when this integrated information code is compromised. Specifically, we will work with patients who have perirhinal cortex damage due to an acute injury (e.g., an infection or tumor), and also those who have subtle perirhinal damage because they are in the early stages of Alzheimer's disease. Project 3 will investigate how different brain regions communicate with each other to understand how neural coding dynamically adapts based on task demands. Project 4 will investigate how object knowledge is formed in the first place - focusing on how information becomes integrated from multiple modalities to create a coherent representation if an object. For each project we will create large stimulus sets that precisely characterize the objects' perceptual and conceptual features. These stimulus sets may be helpful to other researchers, and so we will freely share them.