Correspondence with Scientist: Dr. Gerald Edelman


Dr. Gerald Edelman is the founder of the Neurosciences Research Foundation and the Director of The Neuroscience Institute in La Jolla, California. Dr. Edelman received the Nobel Prize for Medicine in 1992. I was fortunate enough to be invited to be in residence during the three winters of 2004‐2006. Besides the spectacular beauty of the architecture of The Neurosciences Institute in La Jolla, I was able to have many conversations with Dr. Edelman during my time there. I also had wonderful dialogues with Dr. Anil Seth and Dr. John Iverson. A year later, Dr. Edelman invited my ensemble of dancers and musicians, The Emergent Improvisation Project, to perform in a theater on the campus of the Institute. The ensuing dialogue with scientists, artists and the general public of San Diego was profound and contributed to the ongoing research. Dr. Edelman who is an accomplished violinist, and might have had an artistic career as well as a scientific one, was extremely perceptive in his feedback on the emergent forms in our improvisation work. He was generous and encouraging in his responses. Because of his insights, I named a sub‐ sequent form “The Memory Form,” after his theory of the remembered present. I felt that Dr. Edelman’s critical eye went to the very heart of the work, and just as if I had been in a laboratory with him, I felt the benefit of his enormous intelligence and expertise.

November 15, 2012

Dear Susan,

I am responding to your request for my thoughts on possible relations between evolution, brain function, and improvisation. It is important at the onset to preface my remarks with the warning that they reflect an extended metaphor, not a scientific conclusion.

I take improvisation to be the initiation or composing of acts (in your case, dances) with little or no preparation. I presume that innovation in dance amounts to the spontaneous creation of movements. Presumably, this means freeing your body from habitual dance patterns.

Notice that my metaphorical comparison is made complicated by the fact that the brain is responsible for both rehearsed patterns and improvisations. The work of Dr. Charles Limb at Johns Hopkins University indicates that planned actions are accompanied by slowing down of parts of the brain called the dorsolateral pre‐ frontal cortex. Self‐expression (presumably in improvisation) is accompanied by increased activity of the medial prefrontal cortex.

With all this agreed upon I am ready to reflect on some biological facts and theories as they might relate to improvisation. First of all, we must recognize Darwin’s theory of natural selection. It states that variation in members of a species provides a basis for

selection of those individual variants who are more fit to survive in the environment. Their progeny survive while the less fit die off. Variation and selection is sometimes called the Darwinian two‐step!

Clearly, improvisation by the dancer involves variation and presumably also selection on this variation that must take place at some level or other.

The fundamentals of the far reaching Darwinian concept inform my global brain theory, (the theory of neuronal group selection), also known as Neural Darwinism. I am glad that you found the theory stimulating. It states that, in development and function of the brain, variation plays a key role. Instead of Darwinian selection occurring in a population over millions of years, selection occurs among the neural circuits of the brain which are variable in one’s lifetime. Those circuits that favor value or reward for an act are selected by increases in their connection strengths. These increases occur at so‐called synapses, regions of connection between one neuron and another.

Undoubtedly there will be an expected difference in the synaptic strengths in the brain of a dancer following a rehearsed pattern and that brain as it is involved in deliberately indulging in improvisation So if there is a metaphorical link it is provided by the notion of selection and variation.

One can speculate further and ask a whole lot of provocative questions. I shall give one example here. Are dreams not improvisations? Or is improvisation related to dreams? At this point I shall stop, constrained by the constraints of scientific practice and unwilling to indulge in further improvisation.

Yours ever, Gerry

A Conversation

Excerpts from a conversation that took place September 16, 2012.

SS: Why do we talk about the brain as an improvisational system?

DR. E.: There are a number of factors that favor considering the brain as an improvisational system.

The first is that there is no evidence of a central executive in the brain, no homunculus, no conductor, no choreographer, no one in charge. Nor is there a genetic program, or a score, or an individual’s equivalent of software telling the brain what to do beforehand, how to respond to the world. The brain can’t know everything it needs to know ahead of time, nor even how to discover all it needs to know before the fact. This means the brain can’t be programmed, prior to responding to a given set of circumstances, no matter how elaborate the instructions. Indeed, the conventional computer metaphor for the brain is deeply misleading. Brains are emphatically not biological hardware instructed by biological equivalents of software. Rather, they work by selection and variation and by planning called on the basis of past experience.

SS: What does it mean to improvise in a particular environment? Dancers have the experience of responding to stimuli from other dancers and signals from their sensory perceptions. What is the brain inside each of us responding to?

DR. E.: It is critical to remember that the brain doesn’t exist or operate in isolation. The brain is embodied and that body is embedded in the environment. Therefore, a related reason that the brain must improvise is that—like other non‐instructed systems such as evolution, the immune system, a jazz band, or a troupe of improvisational dancers—the brain’s most significant challenge is that it must operate in a complex, open‐ended environment teeming with novelty, unanticipated events and circumstances.

In biology, the alternative to an instructional system is a system based on selection. The most famous of these is, of course, Darwin’s magnificent theory of the origin of species by natural selection—or evolution. But we have discovered that the immune system also operates by selection, not by using only the genetic mechanisms of evolution over eons of time to adapt to novelty. Instead it uses analogous biological mechanisms for selection and amplifying effective variations in a population of antibodies that adapt to novel antigens over somatic time, the lifetime of the organism.

SS: Dancers are deeply aware that movement creates meaning in our consciousness. It is full of emotional expression and sensation, even if it can’t be verbalized. Movement seems to be an essential component in any structuring process. All living things inherently express their vitality in movement and movement seems to fuel their morphogenesis. Why is movement so important to under‐ stand as a contributor to brain function and development?

DR. E.: There are many reasons that movement is fundamental to an organism’s development and survival. In the case of the organ‐ ism’s brain and mind, it is crucial to remember as I have said, that the brain is embodied and the body is embedded in the world. In general, perception both depends on and leads to action. Movement is the way that the brain and body sample the environment. It is through movement that the brain is stimulated to interpret and adapt to both the internal and external world, and thereby to learn and thrive. The dynamic structure of the brain is maintained, refreshed, and altered by continual motor activity and rehearsal. And some of that motor activity may be called improvisational.

SS: Another capacity of dance improvisers relates to embodiment or the mapping of gestural, rhythmic and dynamic information in the body by experimenting with movement gestures and shapes. There are many, many ways to jump, to lift an arm and to turn on one leg. Each of these variations on the same shape instantiated in the body can create a memory of learned responses that can emerge in the future without a script. This allows endless variation on similar movements, preventing repetitive injury while exploring an aesthetic functionality. Does your theory of degeneracy that goes beyond redundancy in the neuronal mapping in the brain relate to this ability in dance improvisation?

DR. E.: The meaning of degeneracy in the context of biology is that it is possible to generate the same performance or outcome in different ways. Like selection, degeneracy provides yet another layer, another dimension to the dynamics and complexity of our biology. The entire world opens up to fresh ways of thinking as one contemplates again and again in setting after setting the idea that the way living things might work is not through getting it exactly right, not through the strictness of logic or the precision of hard wiring. Rather: there are “a number of ways to skin a cat,” and in the case of the human brain, an unparalleled order of flexibility and plasticity may well be the spectacular accomplishment of evolution rather than some refinements of hardware or the workings of virtual machines.

SS: Listening to your descriptions, I can imagine that an improvising dancer works with some essential capacities that are shared with the brain. One capacity relates to the ability of dance improvisers using their senses and perceptual information to create coherence in their interactions, tracking the forms through developmental arcs while allowing new movements to enter, creating new patterns. This ability resonates with my understanding of your concept of integration and differentiation in the brain. Dance improvisers can sense that fine balance between holding a pattern together while openness for new information to enter their composition. Do you think this capacity relates to your theory about reentrant signaling in the brain?

DR. E.: Allowing new information to enter and modify existing patterns and arrangements is essential for the working brain. The dense interconnectivity in the brain across so many levels and kinds of organization looks and acts more like a jungle or a rain forest than an instance of logical planning and most certainly than anything resembling a computer. It works because of a capacity for continuous communication, called “reentrant signaling” among active groups of neurons, not unlike the continuous back and forth communication required among improvising dancers. It is helpful to remember that even though it is not evident to us, the brain is working non-stop at an unimaginable level of activity. And it is not as if the world presents us with well-ordered and labeled clusters of stimuli. The visual system alone has more than 30 different elements of sensation that separately stimulate neuronal maps — some for color, some for movement, some for shape, and so on. Reentry is the mechanism that enables the brain to create a unitary scene out of the bombarding stimuli of everyday life, correlating light, color, sound, taste, smell, touch, proprioception, feelings, temperatures, and other internal and external states on a continuous and ongoing basis.

SS: Would it be right to say that a major focus of your work is to discover how it is that our bodies and our brains give rise to our minds—our imaginative selves?

DR. E.: Since the beginnings of abstract thought, philosophers have asked, as have Darwin, Freud and William James, what is it about our material selves that enables us to learn, to plan, to dance, to dream, to make music, to use language, to create and attach meaning, to imagine things that don’t exist. Unlike most of his scientific contemporaries, Darwin was certain that human minds sprang from our bodies, from human morphology. He believed that one day we would discover how emotions and intelligence emerged over evolutionary time and how bodies and brains produce feelings and ideas in somatic time. We are at long last beginning to cross the great divide between the body and the mind, the material and the immaterial. I am completely persuaded that every perception is not a decoding of the world, but an act of creation. And every memory is not an act of retrieval, but, to some degree, an act of imagination.