1 Introduction

Information-based approaches to brain function have been very successful in recent years (Pouget et al. 2000; Haynes & Rees 2006; Kriegeskorte et al. 2006). Most importantly, they allow to study how mental contents are represented and transformed during information processing in the brain. My target article in this volume (Haynes this collection) emphasized the importance of an information-based approach for the study of human consciousness, especially for understanding the neural mechanisms of visual awareness. Whereas many previous studies mainly aimed to establish which additional processing needs to occur for a stimulus to reach awareness, a second question is equally important: how and where the brain encodes the specific contents of consciousness. Research on these neural correlates of the contents of consciousness (NCCCs; Chalmers 2000; Block 2007; Koch 2004) has been sparse. For identifying NCCCs, simply establishing that a brain area responds stronger under conscious than under unconscious processing is not sufficient, because this could merely reflect unspecific processes such as attention or memory (Corbetta & Shulman 2002; Goldman-Rakic 1995). Instead, for identifying the neural code of contents several specific questions need to be addressed: Which brain regions encode sensory information in a representational space that exactly matches perception? And under which circumstances does a crossing of the threshold to awareness involve changes of representations in these specialized coding spaces?