(a) The Problem
Understanding the neural mechanisms underlying creativity is an enterprise of the utmost importance. For starters, there is, naturally, the eternal quest to understand ourselves, which, in the case of creativity, is a quest that is likely to identify, without hyperbole, a defining element of what makes us human. It ought to be clear to everyone, I hope, that when it comes to creative thinking, we are not just slightly better chimps. But in addition to this lofty, humanistic goal is an equally important, if more practical, reason to forcefully drive this research program. By identifying the basic principles, the nuts and bolts if you will, of how, exactly, the human brain manages to be the single boldest invention machine that has ever existed, human artificers can build computers that do, in principle, the same thing, with potentially enormous benefits for society.
In the hope of identifying the brain mechanisms of creativity, psychologists and neuroscientists have advanced a number of ideas designed, for the most part, to delineate creativity from ‘normal’ thinking – whatever that is. Creative cognition is obviously special in some way and there must be something that makes it so. All in all, however, those proposed demarcation lines have largely turned out to be theoretical duds and the field of creativity is still plagued by the pernicious fossil traces of this kind of misguided theorizing. Open any source on the topic, academic or otherwise, and you will find creativity linked with, say, divergent thinking, low arousal, defocused attention, right brains, unconscious processes, lateral thinking, altered states of consciousness, or mental illness, to name but a few popular themes, when commonsense alone tells you that (1) they also underpin noncreative thinking and (2) their opposites are also sources of creative thinking. I substantiated these arguments in two papers in 2007 ( Dietrich, 2007b; Dietrich, 2007c).
(b) The Theory
To help us think about the neural basis of creativity, I attempted to build a theoretical framework that integrated the knowledge base of creativity research with that of cognitive neuroscience. I published a general version of this in 2004 ( Dietrich, 2004a) and a version more specific to the concept of flow ( Dietrich, 2004b), also in 2004. In these papers, several types of creativity are distinguished. At the most basic level, the framework sees human creativity as fundamentally Darwinian in nature; that is, it entails a variation-selection process. Apart from providing the best fit for the existing data, this view makes it possible to link critical elements of creativity seamlessly to what we know about normative information processing, in terms of anatomy and process modularity. For the variation component, the production of ideational combinations, a basic assumption the framework makes is that neural circuits that compute specific information that yield noncreative combinations of that information must also be the neural circuits that generate creative combinations of that information. This is to say, with the exception of working memory in prefrontal regions, which is capable of generating novelty from information normally coded elsewhere in the brain, the recombination of bits and pieces of information into novel configurations must come from the very neural circuits that normally store those bits and pieces of information. This is very bad news for the localizationist camp because it means that all brain circuits, in principle, produce ideational combinations from the information they normally handle. Novelty, then, is computed everywhere! This needs to fully sink in. The brain isn’t, of course, an unconstrained generator of ideational combinations but we can, at best, assume that the more integrative the neural structure involved in the computation, the more combinational novelty might occur. As for the selection component, this depends, naturally, on higher-order integrative structures, such as prefrontal cortex. So, regardless of how or where novelty is generated initially, circuits in the prefrontal cortex perform the computations that transform the novelty into creative behavior. To that end, prefrontal circuits are involved in making novelty fully conscious, evaluating its appropriateness, and ultimately implementing its creative expression.
As for the different types of creative mentation, the framework proposes that creativity results from the factorial combination of four kinds of mechanisms. Neural computation that generates novelty can occur during two modes of thought (deliberate and spontaneous) and for two types of information (emotional and cognitive). While deliberate searches for insights are instigated by circuits in the prefrontal cortex and thus tend to be structured, rational, and conforming to internalized values and belief systems, spontaneous insights occur when the attentional system does not actively select the content of consciousness, allowing unconscious thoughts that are comparatively more random, unfiltered, and bizarre to be represented in working memory. In other words, while the deliberate mode allows the thinker to direct cerebral capacities to a particular problem, it has the disadvantage of limiting the solution space. In contrast, the spontaneous mode is different (1) qualitatively, because it is not initiated by prefrontal database searches that are limited to preset mental schemas and (2) quantitatively, because information is not subject to the capacity limit of working memory. Again, both processing modes, deliberate and spontaneous, can guide neural computation in structures that contribute emotional content and in structures that provide cognitive analysis, yielding the four basic types of creativity. Once generated, to turn a novel combination into a creative idea, a value assessment by the prefrontal cortex is required. Thus, all four types of creativity share a final common pathway, regardless of the brain region that initially generated the novelty.
Current research in this area focuses on (1) testing this framework ( Dietrich & Srinivasan, 2007), (2) studying the role of exercise, daydreaming and other ASC in the occurrence of creative insights, and (3) theoretical work that sees human creativity as a Darwinian algorithm and thus understands all the creative work that is manifest in the world, be they biological artifacts, human artifacts, or artificial artifacts, as part of a single, unified design space .