What is perception? The most intuitive and influential answer to this question has long been the one given by David Marr: To see the world is “to know what is where by looking” — to transform light into representations of objects and their features, located somewhere in space. But is this all that perception delivers? Consider the figure to the right; certainly you see some colored shapes, as well as where they are located. Yet, beyond this, you may also see how they relate to one another: The green piece can fit into the others, and even create a new object with a shape of its own.

Investigating the Role of PFC-NAcc Sub-circuits in the Acquisition, Maintenance, and Expression of Methamphetamine Use.