Richard J. Caselli
Mayo Clinic, Scottsdale, Arizona, United States (Spring 2014)
|Alfred Russel Wallace, c. 1895
London Stereographic & Photographic Company
The ability to think creatively is a defining feature of modern humans. Creativity is motivated by the pursuit of reward and the avoidance of punishment. Creative goals start with a vision, the idea of something that is better than what is perceived to exist. Creativity requires action that involves the formulation of a plan and its effective execution to attain the desired envisioned goal. Creative achievement takes time requiring a temperament capable of patience and perseverance. Human creativity has been facilitated by the development of language and large communities, and it is the impact of a creation on the community that defines the creator’s success. The neurological and psychological structures that underlie human creativity also form the substrates of our most uniquely human medical and societal disorders.
In the 1950’s, James Olds clearly defined, for the first time, that reward was not simply the absence of punishment, nor was punishment the mere absence of reward, but that these were distinct behaviors controlled by distinct brain regions. Olds implanted electrodes into the brains of rats and placed them in a cage containing a footswitch that delivered an electrical shock to the region of brain with the implanted electrode. By varying the location of the electrode within the brain and conditions under which the rat was tested (hunger, satiety, and so forth), Olds found some regions and situations led to self-stimulation rates as high as 7000 shocks per hour (appetitive behavior), and others that led the rats to avoid self-stimulation (aversive behavior).
The neurobiological reward and punishment system is comprised primarily of three interacting brain regions: the hypothalamus, the mesolimbic dopaminergic system (comprised of the ventral tegmental area, nucleus accumbens/ventral striatum, and orbitofrontal cortex linked together by the median forebrain bundle), and the amygdala; and all other brain regions interact with it to generate a reward/punishment signal for any perception, thought, or action. The interplay of appetitive and aversive signals defines a most rewarding (or least punishing) goal. Neurons within the earliest anatomical stage of action planning and movement (the anterior cingulate gyrus) are influenced by this reward signal. If a monkey has been pressing a lever for an expected reward of one banana, and unexpectedly gets only half a banana, anterior cingulate activity changes immediately in advance of a change in the monkey’s response. Discrepancies between anticipated and predicted reward quickly change behavior.
There is unfortunately another way to quickly change behavior. Neurons in these reward system structures contain opiate receptors that allow for direct pharmacological stimulation, and are the basis for drug abuse. Other disorders of our motivation system include thrill seeking behavior, pathological gambling, and avoidant personality disorder. Because our reward system responds best when our expectations are exceeded, there is a biologically driven tendency to always want more. We accommodate to any improvement in our life circumstances, for example a higher income, so that an initial increase in satisfaction rapidly recalibrates to baseline. This has been called “the hedonic treadmill.” Compassion fatigue, in which our empathy for the stricken gradually diminishes with time, is another example.
Perception of the world around and within us is critical for the generation of ideas, that is, the ability to envision the difference between what is and what should be. Each time we perceive something, the neurons involved in forming that perception within our brain retain a memory of it in the form of “synaptic facilitation.” Synaptic facilitation is a kind of practice effect between two brain cells, so that the more they pass information between themselves, the more easily they can do it the next time. The neuronal networks that have been activated by people we have seen and places we have been remain more easily activated by similar new experiences, for example, someone who resembles your brother or a place that looks or smells like home.
Previous experiences leave mental traces that similar new experiences evoke. William James in 1890 noted that “sensations once experienced, modify the nervous organism, so that copies of them arise again in the mind after the original outward stimulus is gone.” This is mental imagery. Because these sensations are stored in an essentially digitized form, we can reconstruct them in infinite ways, like rearranging little perceptual Lego blocks. What we are motivated to imagine depends on what we perceive (what is), what we have stored, and what we want, and so arises the first step of creative behavior, the generation of ideas (what should be).
The failure to generate ideas has been called writer’s block, although it pertains equally to any creative domain. False images may arise within the context of a psychotic disorder such as schizophrenia. Consider the following:
At 3:00 he will fall the pink dragon will eat him all hell walk through the corridor of the hall and watch the buzzards pick his bones this is so because he took me from my home
At 3:00 peace will be everlasting on earth the child has been baptized into her birth no sacrifice is made this lamb is saved
While this may seem creative, it is actually the psychotic vision of a patient with poorly controlled schizophrenia.
Strategic action requires that we integrate our perceived circumstances with relevant background information, formulate possible responses, calculate their predicted outcomes, select among them, and execute the strategic action successfully. The greater the dexterity of our executed response, the greater is the chance for success.
Dexterity varies greatly between individuals, and truly extraordinary dexterity has itself been equated with creativity (for example, the virtuoso performance of a master musician). Dexterity is influenced by both nature and nurture (especially practice effects). With regard to nature, identical twins perform more like each other than genetically unrelated people on tests of intellectual skills, reading ability, reaction time, and other cognitive and physiologic measures, suggesting there is a strong genetic component to these behavioral traits. Studies of Albert Einstein’s brain have revealed a variety of anatomical peculiarities such as a thinner cortical mantle with more “densely packed” neurons, and larger and more symmetric parietal lobes. While it is risky to generalize from one man’s brain, an unusual group of individuals who also share an extraordinary ability are autistic savants. Savants display remarkable talent in a circumscribed area (typically memory, mathematics, music, or calendrical skill, and less consistently mechanical or artistic skill) that is disproportionate to their intellect. Patterns of savant level talents have led some to implicate frontotemporal and limbic structures, and some patients with frontotemporal dementia have shown remarkable new artistic abilities (although these are exceptions).
The neurophysiological effects of practice differ between sensorimotor and cognitive tasks. With exposure to a new sensorimotor task, there is an initial phase of rapid performance improvement that reflects learning the task routine (for example, the finger placements and movements required to play the scales on a violin) followed by a much slower learning phase requiring thousands of training trials. As dexterity approaches virtuoso levels, there is a gradual expansion of the task relevant sensory and motor representations resulting in expanded activation of these brain regions. Cognitive tasks, in contrast, rely upon the integration of multiple brain regions that are geographically distant and serve different functions. With time and practice, the integration of these regions becomes more efficient resulting in reduced effort and activation.
The inability to think strategically is a characteristic of many cognitive disorders including Alzheimer’s disease, stroke, and traumatic brain injury. The dissolution of thought in such patients has been graphically demonstrated in art, science, politics, and even sports.
Robert Cloninger defined four dimensions of temperament: novelty seeking (motivated by the possibility of unexpected reward), harm avoidance (happy to simply avoid punishment), reward dependence (in need of praise), and persistence (“perseverance despite frustration and fatigue”); and three dimensions of character: self-directedness (willpower to achieve one’s own goals), cooperativeness with other individuals, and self-transcendence (the acceptance that the self is part of a universal whole). Within Cloninger’s formulation of temperament, creative expression requires patience and perseverance in the face of frustrative non-reward. Such patience and perseverance in turn will reflect our ability to mentally envision an appropriate timeframe, correctly match it to the perceived timeframe, and self-sustain our mental image of anticipated reward in order to maintain our efforts in the absence of external reward.
The following experiment illustrates this point. During a task in which subjects were asked to rate facial expressions as pleasant, unpleasant, or neutral, individuals with higher persistence scores on Cloninger’s personality test performed more accurately than less perseverant subjects. Interestingly, during test periods in which the majority of faces were neutral and thus “boring,” the more perseverant group maintained activation of brain regions associated with reward, while the low-persistence individuals deactivated those reward regions. If the goal of the task is itself assumed to be rewarding to the participant, reward activation during this period of boredom suggests that the goal was more effectively maintained in the minds of the more perseverant individuals who thus outperformed their less perseverant peers.
Personality influences our creative ability in other ways. Who we are and see ourselves to be influences our choice of the domain in which our creative efforts will be expressed. Among medical students, for example, those who elect to pursue a career in surgery have lower harm avoidance and reward dependency scores than those who elect a career in primary care and other specialties.
Most creative achievements take time. Our ability to maintain our efforts until the goal has been completed is a direct consequence of our temperament. Similarly, we must be able to accurately judge our progress over time and to change strategies when our initial plan is failing. Both impatience and inertia are counterproductive to creative achievement, and are reflections of our temperament. Psychiatric disorders such as obsessive-compulsive and attention deficit disorder impede our ability to be patient and perseverant yet flexible enough to know when to alter strategies in response to lack of progress.
Alfred Russell Wallace was a contemporary of Charles Darwin, and both men proposed a theory of natural selection as the basis for the evolution of species. Wallace was struck, however, by the explosion of human invention that was and still is without parallel in the natural world. He felt that natural selection, that seemingly small biological step from monkey to man, was a poor explanation for man’s unprecedented creative leap. As an alternative, he embraced a more spiritual explanation which his scientific contemporaries regarded with derision. This probably cost Wallace the fame that Darwin gained. Today, however, most anthropologists agree with Wallace that the relatively small incremental physiological, structural, and genetic “improvements” that occurred in homo sapiens are, by themselves, inadequate to explain this behavioral leap. Modern anthropology instead posits that a new form of evolution emerged among humans, one based on language and social behavior that permitted us to generate and pass knowledge between generations.
Human cultural evolution is the sharing of information within and across generations made possible by the emergence of language—further fostered by the growth of human communities. The social brain hypothesis correlates brain size with the size and complexity of social groupings. While some whales have larger brains, humans by far have the largest brain-to-body ratio, and this is especially true of the most evolutionarily advanced brain structures: neocortex generally and frontal neocortex especially correlates with increasingly complex social behavior. War and trade were some of the formative cooperative behaviors that eventually led to the development of cities and larger social groupings that in turn further catalyzed the exchange of ideas. Homo sapien success in developing a cumulative culture is based on cooperation with both kin and non-kin—and exceptional reliance on cultural transmission within and across generations. This is rare or absent in other primates whose cooperative behaviors are much more closely kin-focused. Human creativity parallels our social development. It took our species roughly 195,000 years to invent the wheel, and merely another 5000 to invent supercomputers, space shuttles, and everything else.
Cooperative behavior among a group of individuals defines a social grouping, and the agreed upon rules are the social norms of that group. Social norms are necessary because of the consequences of one person’s actions on others. Fehr and Fischbacher suggest that social norms are based on “conditional cooperation,” that is, the level of cooperation of each member within a group is based on the level of mutual cooperation of its members. Social norms, and the cooperative behavior that maintains them, have important implications. Aesthetics are the cooperatively determined hierarchical categorization and quantification of quality. As a society, we agree upon a set of principles that will define something as good or bad. Social norms define what is expected and tolerated within the given society. Morality is a special type of aesthetic, one that applies to culturally acceptable forms of social behavior. At any given point in history, there are social norms associated with various situations that represent the morality of the culture. Some of these situations are today considered wrong, yet in their time they were part of the social landscape. Just as there is a right and wrong way to react in a restaurant when a waiter brings you the incorrect order, there was a right and wrong way to treat slaves, and a right and wrong way to mete out medieval torture. In each example, it is the social context that determines this “cultural morality.”
Social norms and aesthetics change over time. When a social grouping, for example scientists, feel that current interpretations (paradigms) of observations (data) are no longer reliably true, then adherence to the prevailing scientific paradigm (the scientific equivalent of a social norm or aesthetic principle) falters leading to what Thomas Kuhn termed a “paradigm shift.” Paradigm shifts occur in all domains, from art to politics, influenced by leaders and their ability to persuade those who follow them. Unfortunately change is not always for the better. In social groups, there is a new identity that emerges implying the formation of in-groups (members) and out-groups (non-members). Taken to an extreme this can lead to socially diseased behavior, the most extreme example of which is genocide in which one group demonizes and then seeks to exterminate another.
Creativity is the basis of our human nature, and it is the product of both biological and cultural evolution. It explains the good and the evil that defines us as an individual, as a society, and as a species.
is a Behavioral Neurologist whose clinical specialty is Alzheimer’s disease and related cognitive disorders. He is Professor of Neurology in the Mayo Clinic College of Medicine, recent past Chair of the Department of Neurology, and former member of the Executive Operating Team at the Mayo Clinic in Arizona. He is also Associate Director of the Arizona Alzheimer’s Disease Center, and Director of the Clinical Core coordinating the clinical participation of its six member institutions. He is a member of the Board of Directors of the Flinn Foundation and Center for Services Leadership of Arizona State University. He is also Medical Director for the Patient Experience, and Associate Director of the Center for Individualized Medicine for the Mayo Clinic.
Highlighted in Frontispiece Spring 2014 – Volume 6, Issue 2