Insight, also known as the Aha phenomenon, is the sudden awareness of the solution to a problem. In contrast, analysis is problem solving by consciously and deliberately manipulating the elements of a problem. The Gestalt psychologists began studying insight about a century ago. On the basis of their research with complex “insight problems,” they characterized insight as a reinterpretation or restructuring of one's representation of a stimulus or situation after a period of unconscious processing. The emergence of cognitive psychology later during the twentieth century led to another period of advancement in insight research during the 1980s and 1990s. This work further characterized the unconscious nature of the processing leading up to an insight. More recently, the development of techniques for measuring and manipulating brain function has sparked a new renaissance in insight research. Cognitive neuroscience research has highlighted the key role of the right hemisphere and has discovered a number of neural precursors to insight, including its origins in patterns of resting-state brain activity and in neural preparatory activity immediately before a problem is presented. The latest trend is work aimed at developing techniques to enhance insight, including recent research showing that direct stimulation of the right hemisphere can facilitate the solving of insight problems. Cognitive neuroscience approaches should continue to fuel rapid advances and may lead to the development of practical technologies for insight enhancement.