 Consciousness re-emerged over the past three decades as a topic of research focus in philosophy of mind, and in the cognitive and brain sciences. Instead of ignoring it, many physicalists sought to explain it (Dennett 1991). Here we focus exclusively on ways that neuroscientific discoveries have impacted philosophical debates about the nature of consciousness and its relation to physical mechanisms. (See links to other entries in this encyclopedia below in  Related Entries  for broader discussions about consciousness and physicalism.)