Neuroscientific investigations often cross the borders between scientific disciplines; they walk boldly from biology to psychology and stride straight through to the other side, dipping their toe - and sometimes their entire leg - in the murky waters of philosophy.
Neuroscience can be a dense and unrelentingly complex area of study. The scientists involved strive to answer disparate questions ranging from "how do we walk?" to "how do we remember things?" and from "how do nerve cell membranes communicate?" to "what is pleasure?"
It takes a brave researcher to attempt to bridge the gap between the physics of a firing neuron and the construction of a jazz drum solo.
The gap is nowhere near fully bridged, but strides are being made to answer some of the more esoteric questions humanity has posed.
One such intractable topic is creativity. What is it? Why does it exist? And how on earth does a spongy 3 lb lump create surreal landscapes and construct soaring arias?
Some scientists believe creativity is not a subject worth pursuing, that it is too ethereal and perhaps not relevant to science. Others disagree.
Humanity's ability to create novel solutions to problems has allowed us to thrive on almost every patch of ground on this blue ball we call home. From the frozen north to the tropical waistband of our world, humanity has figured out creative ways of staying alive, solving life-threatening problems every step of the way.
Evolution has fostered and rewarded creativity. Creativity is as human as conversation.
In this article, we will look briefly at some aspects of the brain that are suspected to be involved in creativity, as well as some experiments and theories that shed a little light on such a difficult area of science.
Networks vs. regions
The first point to make is that creativity is not to be found in one distinct section of the brain or a singular clump of nerves behind your left ear. The process is shared across a number of regions and involves a concerto of brain-wide neuronal activity.
This makes sense when considering the variety of tasks that exercise our creative bent. Completing a jigsaw or a sudoku involves a certain amount of creative thought, but the sections of the brain relevant to carry out these types of tasks will be different from those involved in designing an art installation or forging the perfect sentence to explain a complex concept.
The general consensus is that the creative process has two stages. The first stage (which we will mostly be discussing here) is the free flow of experimentation and the creation of a new concept or work of art. The second phase involves rehearsing, editing and assessing the final product as it evolves into the final piece.
As with the study of other dense areas of neuroscience, like emotions, brain-wide networks are key to understanding our thoughts. Below are three such networks that are considered to play important roles in creative thought.
The executive attention network
If a task requires a thorough level of concentration, the executive attention network will be called into play. Connecting lateral regions of the prefrontal cortex and areas toward the back of the parietal lobe, this network is engaged when focusing all of your attention on a task and utilizing your working memory.
For example, as you read this, your executive attention network will be busying itself (as long as you are paying attention, of course).
The executive attention network is not engaged for all creative processes; sometimes, allowing your mind to wander away from its watchful gaze is necessary, as we shall see.
The executive attention network is probably used more heavily in the second phase of creativity mentioned above - focusing on, checking and sharpening the final product, rather than the initial freeform creative process.
The default network
The default network, also referred to as the imagination network, is used to construct dynamic mental simulations. Situated deep in the prefrontal cortex and temporal lobe, with connections to parts of the parietal cortex, it builds pictures based on previous experiences and imagines alternative scenarios and events.
Active during bouts of daydreaming, when the brain is not focused on the outside world, the default network is implicated in functions such as collecting facts about the self, reflecting on personal emotions and remembering past events.
This network also appears to be involved in social cognition and empathy; it plays a part in helping us imagine what another individual might be thinking.
The salience network
The dorsal anterior cingulate cortices and anterior insular house the salience network. This set of circuitry helps the brain decide what to pay attention to. Our eyes, ears, mouth, nose and skin are constantly bombarded with sensory stimulation. The salience network helps us choose which inputs to pay attention to and which to ignore.
The salience network is thought to be involved in switching between relevant networks of neurons, turning the most appropriate groups off or on depending on its assessment of a situation.
As an example, while driving a car, your visual field is filled with asphalt, sky, trees, traffic lights, birds, the steering wheel, your eyelashes and much, much more. Despite the wealth of options, the salience network draws your attention to the woman with the buggy attempting to cross the road 200 m down on the right.
The ability to switch between networks is a vital aspect of creativity. For instance, focusing on a creative puzzle with all of your attention might recruit the skills of the executive attention network. On the other hand, if the creative task involves producing a sonically pleasing guitar solo, focus might be switched from intense concentration to areas more involved in emotional content and auditory processing.
The role of latent inhibition
As mentioned, the brain is required to constantly weed out irrelevant information entering our senses and to put the correct emphasis on incoming information that is deemed relevant.
This ability to essentially ignore information we have previously rated as irrelevant is called latent inhibition. For instance, if we are attending a lecture and hear a lawnmower start up outside, it is not long before the lawnmower's sound moves to the back of our consciousness as the speaker's voice moves to the front.
Without the subconscious' ability to pick and choose what enters our attention, the world would be a loud, bright and confusing place to inhabit.
Some studies have linked a reduction in latent inhibition to psychosis. However, a study using high-IQ individuals found that those with lower latent inhibition scores were more likely to be creative.
The authors wonder whether an innate propensity to be open to experience might play a role in creativity. Simply put, people who are less likely to classify an object or a sound as "irrelevant" are at an advantage when it comes to producing creative, original content.
Jazz piano and brain scans
A study published in 2008 investigated the neural correlates of jazz improvisation in pianists' brains. They took MRI (magnetic resonance imaging) scans of pianists' brains as they performed well-practiced pieces and compared the results with scans taken while they improvised.
The authors reported that during the creative act of improvisation, they found:
"A dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex."
In other words, parts of the brain responsible for self-monitoring and the conscious control of actions were suppressed; the inner critic was silenced. The dorsolateral prefrontal and lateral orbital regions can be viewed as the brain's self-checking modules, making sure we conform to social demands and inhibiting inappropriate performance.
On the other hand, the medial prefrontal (frontal polar) cortex is thought to be involved in generating autobiographical narratives and the creation of self. So, an activation in this region might imply that the pianist's improvisations had a personal, story-like property.
Although this is vastly over-simplifying things (while inflating others), the idea of a jazz musician weaving an intimate tale with his melody is a tempting conclusion to draw.
The authors conclude that in this particular activity, a reduction in self-monitoring with increased activity in the "story-telling" part of the brain worked together to produce an original composition in real time.
Freestyle rapping in a scanner
Another study, conducted in 2012, took MRI scans of rappers as they "freestyled." They compared these with scans of the artists' brains as they performed raps they had rehearsed and knew well.
The results shared some similarities with the jazz pianist experiment. The frontal cortex was once again the primary area of activity. The medial (autobiographical area) was activated while the dorsolateral (self-monitoring) region was deactivated.
The team also found increased activity in areas of the brain involved in motor activity, which is unsurprising given the task at hand.
Additionally, increased activation of the cerebellar hemisphere and vermis was found; other studies have implicated both of these regions in tasks involving remembering and matching rhythmic patterns.
The alpha wave
Since the discovery and perfection of electroencephalography (EEG), scientists have measured the electrical output of the brain during a variety of tasks. One type of neurological output referred to as alpha waves has been implicated in the process of creativity.
Alpha waves are strongest during wakeful relaxation with closed eyes and show reduced activity with open eyes, drowsiness and sleep.
Initially, these types of waves were considered to be the "sound" of the visual cortex at rest. A more recent theory is that alpha waves might inhibit areas of the cortex when they are not in use.
Some scientists have linked the strength of alpha waves to levels of creativity. One study measured EEG alpha waves while participants solved verbal problems. Individuals were asked to come up with as many original solutions as possible. The results showed that the most creative solutions were accompanied by measurable increases in alpha power.
Other research has shown similar matches between creative acts and alpha waves; it seems we might have yet another player in the neural game of creation.
The future of creativity
Although some investigations into the neuroscience of creativity have generated similar or overlapping results, others have not; we are still a long way from understanding or taming the process. There is, quite clearly, a lot going on.
Literature reviews on the neuroscience of creativity yield confusing results. Depending on the type of task being studied, the way it is assessed and a myriad of other factors, the results differ. Controlling and monitoring the creative process and allowing it to flourish inside a brain scanner makes experimentation difficult.
Having said that, the question of creativity is not a dead end; signs and clues abound. The problem truly comes when we try to tie them into a neat bundle.
Although we might not have the key to unlocking creativity just yet, pointed research is slowly yielding some intriguing results. Sadly, it is unlikely that a "creativity pill" will be hitting the shelves anytime soon.