The Aha ! Moment The Cognitive Neuroscience of Insight

A sudden comprehension that solves a problem, reinterprets a situation, explains a joke, or resolves an ambiguous percept is called an insight (i.e., the ‘‘Aha! moment’’). Psychologists have studied insight using behavioral methods for nearly a century. Recently, the tools of cognitive neuroscience have been applied to this phenomenon. A series of studies have used electroencephalography (EEG) and functionalmagnetic resonance imaging (fMRI) to study the neural correlates of the ‘‘Aha! moment’’ and its antecedents. Although the experience of insight is sudden and can seem disconnected from the immediately preceding thought, these studies show that insight is the culmination of a series of brain states and processes operating at different time scales. Elucidation of these precursors suggests interventional opportunities for the facilitation of insight. Aha!moment; creativity; EEG; fMRI; insight; neuroimaging; problem solving Insight is a sudden comprehension—colloquially called the ‘‘Aha! moment’’—that can result in a new interpretation of a situation and that can point to the solution to a problem (Sternberg &Davidson, 1995). Insights are often the result of the reorganization or restructuring of the elements of a situation or problem, though an insight may occur in the absence of any preexisting interpretation. For several reasons, insight is an important phenomenon. First, it is a form of cognition that occurs in a number of domains. For example, aside from yielding the solution to a problem, insight can also yield the understanding of a joke or metaphor, the identification of an object in an ambiguous or blurry picture, or a realization about oneself. Second, insight contrasts with the deliberate, conscious search strategies that have been the focus of most research on problem solving (Ericsson & Simon, 1993); instead, insights occur when a solution is computed unconsciously and later emerges into awareness suddenly (Bowden & Jung-Beeman, 2003a; Smith & Kounios, 1996). Third, because insight involves a conceptual reorganization that results in a new, nonobvious interpretation, it is often identified as a form of creativity (Friedman & Förster, 2005). Fourth, insights can result in important innovations. Understanding the mechanisms that make insights possible may lead to methods for facilitating innovation. AN APPROACH TO STUDYING INSIGHT In our studies, we have used electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to examine processes that would be difficult to detect using behavioral measurements alone. EEG has the benefit of high temporal resolution; fMRI complements EEGby affording the high spatial resolution necessary for precise localization of brain activity. We used a type of problem called compound remote associates (Bowden & Jung-Beeman, 2003b) that affords two advantages. When a participant solves one of these problems, he or she can typically do so within 10 seconds; much longer time is often needed to solve classic insight problems (Fleck & Weisberg, 2004). This relatively short solution time allowed us to produce the large number of trials necessary for EEG and fMRI. In addition, compound-remote-associates problems can be solved either with or without insight, enabling researchers to compare insight and analytic solving without changing the type of problem. In our experiments, compound remote associates that were solved by insight and by analytic processing were sorted according to participants’ trial-by-trial judgments of how the solution entered awareness—suddenly for insight, incrementally for analytic processing. Each compound-remote-associates problem consists of three words (e.g., crab, pine, sauce). Participants are instructed to think of a single word that can form a compound or familiar twoword phrase with each of the three problemwords (e.g., apple can join with crab, pine, and sauce to form pineapple, crabapple, and applesauce). As soon as participants think of the solution word, Address correspondence to John Kounios, Department of Psychology, DrexelUniversity, 245N. 15 Street,Mail Stop 626, Philadelphia, PA 19102-1192, ; or Mark Beeman, Department of Psychology, Northwestern University, 2029 Sheridan Road, Evanston, IL 60208-2710,  mjungbee@northwestern.edu. CURRENT DIRECTIONS IN PSYCHOLOGICAL SCIENCE 210 Volume 18—Number 4 Copyright r 2009 Association for Psychological Science they press a button as quickly as possible. Participants are instructed to respond immediately and not take any time to verify this solution. They are then prompted to verbalize the solution and then to press a button to indicate whether that solution had popped into awareness suddenly (insight) or whether the solution had resulted from a more methodical hypothesis-testing approach. An example of a methodical strategy for solving the problem would be to start with crab and generate associates of this word, such as cake.Crabcake is an acceptable compound, as is applecake. But pinecake and cakepine are both unacceptable, leading to the rejection of cake as a potential solution. One might then try grass.Crabgrass is acceptable, but neither pinegrass nor applegrass works—and so on. Participants in our studies immediately and intuitively understood the distinction between sudden insight and methodical solving. NEURAL CORRELATES OF THE ‘‘AHA! MOMENT’’ Our first neuroimaging study included separate EEG and fMRI experiments that examined brain activity during a time interval beginning shortly before the derivation of the solution (JungBeeman et al., 2004). Brain activity corresponding to analytic G am m a Po w er 1.7e-10