Conceptual representations are the brain's way of chunking the overwhelming data that surrounds us into smaller bits of meaningful information. For example, the concept 'cat' fully encapsulates all relevant attributes of a cat, without the need to specify that we mean the furry domestic mammal that has a long tail and makes a 'miao' sound. However, the ways in which these representations are organized in the brain is not well understood. In this project, I examine the organization principles of conceptual representations and the neural mechanisms involved in integrating the features of concepts together. In particular, this project attempts to map the intrinsic processes with which we activate conceptual representations via spontaneous thought processes. The results of these studies may provide a better understanding of conceptual representations and processing of our everyday life and help us to develop better rehabilitation procedures to help patients with semantic impairments.