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Exquisite Data: a Review of Cajal’s Butterflies of the Soul

[ 5 ] February 8, 2010

"Cajal’s Butterflies of the Soul" by Javier DeFelipe. Oxford University Press, 2010.

Long before fMRI and EEG, the light microscope was the only way to illuminate the world of the infinitely small that exists inside the brain.  In the nineteenth-century, pioneering investigators of the central nervous system had to compensate for primitive technology with extraordinary artistic talent.  These men produced drawings of their experimental slides in order to preserve the revelations therein.  Strange, complex, and utterly gorgeous, these figures are the inspiration for Cajal’s Butterflies of the Soul (2010) by Javier DeFelipe.  The book, published by Oxford University Press, contains two-hundred and eighty-two one-of-a-kind images, truly exquisite neuroscientific data.

But this is not merely a picture book; there is an abundance of valuable text.  The first part contains a detailed, well-told background and history of neuroscience and technology.  Like an art historian, DeFelipe separates the material into three periods: Benedictine, Black, and Colorful.  (“Black,” for example, refers to the revolutionary reazione nera, the chemical stain invented by Camilo Golgi that earned him a share, with Cajal, of the Nobel Prize in 1906).  I cannot imagine that a traditional textbook could do a better job of presenting this information.  The writing is approachable and engaging, and surely enhances the visual experience that follows in the second part.  After their introduction, the images become more than aesthetic stimulation; they acquire special meaning because they represent the seeds of early anatomical discovery that grew into the field of modern neuroscience.

Although the book includes the work of ninety-one scientists, Cajal’s Butterflies of the Soul is named for only one:  Santiago Ramón y Cajal, the Nobel Prize-winning “father of modern neuroscience” who compared himself to an entomologist and described pyramidal cells (neurons that he himself discovered) as “butterflies of the soul.”  Cajal, who said that “only artists are attracted to science,” originally wanted to be an artist.  He spent countless hours during his youth drawing natural scenes.  In the end he found aesthetic fulfillment in science, and his iconic figures are still used in textbooks.  Cajal is one of the greatest examples of a jointly artistic and scientific mind, one that could only have flourished in harmony.   (The book’s author, Javier DeFelipe, is a research professor at the Cajal Institute in Madrid).

Cajal’s Butterflies of the Soul, with big, glossy pages and a fancy silver place-holding ribbon, is expensive ($75—$60 on Amazon).  But I contend that it is worth the price.  I would rather not attempt to translate the unique images into descriptive approximations.  I prefer instead to use my words to urge the reader to see for his or herself. To me, the rest of the images found in the book images suggest an epic range of expressive styles; some figures resemble cave drawings, some remind of surrealism.  It all amounts to an affirmation of the fundamental beauty of this holy human organ, something to never forget.

These unique works surely belong in a museum.  Indeed, that is the opinion of DeFelipe.  I was fortunate to be present at a small release event for the book that took place at last year’s Society for Neuroscience conference in Chicago.  At the end of his engaging talk, DeFelipe showed slides of an imaginary museum that would display the astounding work we had all just seen through the projector and which appears in the pages of the book.  There were even, if I remember correctly, virtual ladies and gentlemen milling about the floor and admiring the featured art.  The small conference room was struck, I believe, by the normalcy of the scenario.  The message: this science is art.  And I will say that I, for one, look forward to the day when I can visit an exhibit in a real museum.

See the accompanying gallery of images from the book.

The Art and Brain Heavyweights

[ 6 ] January 27, 2010
Color-opponent cells in the primate visual cortex (Margaret Livingstone).

Color-opponent cells in the primate visual cortex (Margaret Livingstone).

In an essay I wrote to coincide with the first Beautiful Brain podcast, I discussed some of the current trends in neuroaesthetics research as presented at the 2009 Copenhagen Neuroaesthics Conference. I did not mention some of the heavyweights in the field who have shaped much of the current conversation between the arts and the brain sciences— figures whose work is alternatingly insightful and reductive, microcosms of where we currently stand in this attempt at Consilience.

The names Ramachandran, Zeki, and Livingstone are among the top tier of art and brain researchers, each of whom have made and are continuing to make important contributions to the field from a variety of approaches. Harvard neurobiologist Margaret Livingstone’s achievements are in the realm of visual perception, based mostly on electrode recordings from primate visual cortex. Her work has demonstrated the building blocks of color perception—something we share with primates—where individual cells are tuned to fire action potentials in response to certain parts of the spectrum, and are organized in a system where color opposites, such as red and green, arise from the excitation and inhibition of these neighboring color-opponent cells.

The cellular basis of luminosity is another of Livingstone’s contributions to understanding our basic systems of visual perception; one of her favorite examples of the luminosity phenomenon is Monet’s “Impression Sunrise” of 1872.

Impression Sunrise, Claude Monet, 1872.

Impression Sunrise, Claude Monet, 1872.

In this painting, the orange sun seems to glow against the darker sky for two reasons: first, the orange-blue color-opponent nature of our visual system sets the sun and sky apart in our color perception; second, the lack of any change in luminance between the sun and the sky activates our perception of the orange of the sun more intensely, and we perceive this wonderful glowing of the sun (if the image were grayscale, as below, we could not see the sun as well—thus, with luminance almost the same between sun and sky, our visual system seizes on differences in color, and the sun seems to pop out).

Impression Sunrise, grayscale.

Impression Sunrise, grayscale.

Livingstone’s work presents some of the most exciting evidence we have for understanding the very basic phenomena of visual perception—yet because we’re talking about primates, it’s hard to get beyond these essential properties of color perception and optical illusions and move to an explanatory framework that could handle more of the complex subjectivity of human art. Knowing these visual basics can explain why Monet’s sun glows like it does, but this gets us only so far—the human brain quickly moves beyond base visual tricks and involves a much more subjective world of mood and memory.

V.S. Ramachandran is best known for both his work on synesthesia and his controversial “principles” to explain trends in art over millennia. While his synesthesia work is largely fMRI based, the “principles” combine fMRI data with predictions for what we may see on a cellular level during the perception of art. One of the principles Ramachandran most often uses as an example is that of the peak-shift phenomenon: he claims that across cultures and across art forms, pleasurable features of objects and figures are accentuated (such as the curves in a feminine figure) which target reward mechanisms in our brain, and could, in part, explain why we find certain art beautiful. In more modernist work, he argues that artists intuitively used techniques that played into the peak-shift phenomenon, such as Picasso’s faces, which present multiple perspectives of the same object to our visual system at the same moment, leading to a stronger activation of a category-specific “face cell” at the top of a hierarchy in the cortex, and thus a more pleasurable reaction. His principles feel exciting in their speculation into specific cellular mechanisms at hand during the perception of art, yet highly reductive in their lack of attention to the vast worlds of personal and cultural memory we bring to each viewing experience. As in Livingstone’s work, we can find starting points in these principles, but can never assume we are explaining the totality of the perceptive experience.

Lastly, Semir Zeki takes a similar bottom-up approach to cognitive science and aesthetics— studying, like Livingstone, the neural basis of color perception. His search has taken him from work on retinal cells to the visual cortex to the study of the neural correlates of the subjective states of love, beauty, and more recently, hate, mostly through fMRI work. “Perceiving something as ugly or beautiful involves activation of the medial orbito-frontal cortex,” he explained in a recent interview. “The [electrical] activity measured in these areas through scanning is much more pronounced when pictures considered to be beautiful are perceived.”

Zeki claims that artists are instinctive neuroscientists, innately understanding fundamental perceptual processes in the brain and exploring them in their art. Zeki’s writing gives much credit to artists who in reality, at the time they were working, had no idea of the actual physical properties of the brains they were using to create their art. This is neuro-revisionism, and it pervades much of the art/brain conversation in popular media—Virginia Woolf on consciousness, Monet on color processing, Stravinsky on cognitive dissonance—take your pick. Any art that anyone has ever produced can be mined for neuroscientific implications—it is more a product of the neuro-craze we live in at this juncture in the 21st century than any sort of real or even metaphorical “prediction” these artists had about future scientific findings. One will find predictions about what’s inside wherever you want to find them—humans have brains, and we use them for everything. Is it such a wonder that our art has reflected fundamental principles of the thing that made it?

The artist as a portal (and only a portal—none living before modern neuroscience truly predicted any cellular findings) is an interesting way to approach brain science, especially for those unfamiliar with the science of cells and synapses. But it is dangerous in the evolution of this conversation between art and neuroscience because it has stopped, for the time being, in the aforementioned fMRI studies of individuals’ brains while they create and perceive art. These studies have lent important insights into the locations and role of brain regions, and could thus be used to generate hypotheses for future research at the cellular level—but because of the need to remain noninvasive with human subjects, we may be working with fMRI data combined with primate-based cellular speculation for many years to come. One hope to move beyond the delayed magnetic traces of blood-transported iron that fMRI machines detect is a modeling endeavor such as The Blue Brain Project, which seeks to simulate an entire human brain on IBM supercomputers, neuron by neuron, within ten years. If we have a functioning model of a brain, filled out with a life’s worth of experience, then perhaps we could really see what is happening in the dark jungle when art is made or seen.

We’re approaching a time in modern neuroscience where we can move beyond the fascination in correlating artistic output with cognitive neuroscience, beyond the loose association of an artist’s work with a modern fMRI study about a function of the brain that happens to have something to do with the art at hand. As some scientists—such as Livingstone and Ramachandran—have already began, we can start talking about cells and synapses, the most fundamental language we have, and appreciate the beauty of the brain by tracking the movement of a work of art through its dense networks that feedforward, feedback, and always associate, beginning to populate our understanding of art in the brain with higher and higher degrees of complexity.

The Neuroscience of Avatar

[ 9 ] January 5, 2010
The Tree of Life. Gustav Kilmt, 1909.The Tree of Life. Gustav Klimt, 1909.

“An animal’s behaviour tends to maximize the survival of the genes ‘for’ that behaviour, whether or not those genes happen to be in the body of the particular animal performing it.”

– Richard Dawkins, The Extended Phenotype

When a mainstream movie explores even the slightest hint of a contemporary scientific concept there is reason for excitement. Too often the world of science seems like an estranged sibling of the mainstream entertainment industry, the quiet cousin nobody is interested in talking to at the family gathering. And that is why, all other critical responses aside, one cannot help but feel joy for the central role of the nervous system in Avatar.

Gaps in logic also aside—and there are some significant ones—the biological world of Pandora in James Cameron’s film is modeled as a planet-wide neural network with animals living in it that can literally plug into one another’s nervous system. In one of the first examples of this animal-to-animal interface in the film, Neytiri, one of the indigenous Na’vi inhabiting Pandora, leads our protagonist to the top of a rocky outcropping and demonstrates her bond with an Ikran, a dragon-like bird. Neytiri extends her ponytail to reveal a cluster of nerve-like filaments at the tip, which she touches to a similar bundle on the Ikran. The filaments fuse, and we watch as she mounts the beast and is able to exert directional control over it. At first quite menacing and flapping about, the Ikran now becomes calm and controlled by means of the symbiotic bond achieved through the fusion of their nervous systems.

Another neuroscientific theme is presented when we learn that the neural interfaces extend beyond the level of the paired individual organisms and include the entire planet’s ecosystem, which is primarily composed of trees with roots that connect to one another and exchange electrochemical information like neurons in a brain. At various points we witness the Na’vi plugging into this tree network and hearing voices of their ancestors, as if their memories had been uploaded this planet-wide neural net to be accessed at a later date. During religious ceremonies, we see the Na’vi plugged into the forest floor around the central Tree of Souls, waving in unison.

The last ripple to the neuroscience of Pandora is the presence of a spirit in the planet’s nervous system, called Eywa, which suggests that the entire system has some sort of emergent sentience—but to investigate this line of deduction any further would only be to peek into one of the ultimately blurred logical systems in Cameron’s para-scientific world. The science works for the story: it gives us enough sense of an all-encompassing, all-connected life force to assuage the spiritualists but at the same time grounds this force in filaments and neuro-talk to keep things rooted in the physical world. To try to unify these forces into a logical, scientifically sound system or to explain how much intelligence the planet really has were tasks Cameron probably didn’t have time to fully develop, nor is it our concern here.

What Avatar does raise are some fascinating possibilities—and potential limitations—of brains, as we consider both the future of our own species and the potential of discovering a planet like Pandora with a highly interconnected, global nervous system. After a conversation with re:COGNITION author and sharp evolutionary biologist Sam McDougle, I began to think about many of the neuroscientific concepts in Avatar in terms of Richard Dawkins’ theory of the extended phenotype, which argues that we should look beyond the neat segregations of genomes into their “replicator vehicles” (the organisms themselves) and to instead try to see a broad biological community with extensive interaction between organisms and their environment. Examples abound in Dawkins’ text of animals whose genes lead them to create or scavenge for artifacts—shells, burrows, or perhaps a cathedral mound, in the case of the termite

Termite Cathedral Mound

Termite Cathedral Mound

—that end up playing a role in their fitness and reproductive success. Dawkins’ reasoning leads to the conclusion that the phenotype of animals should include objects that, like their heart or any other vital organ, become integral to their survival.

Taking Dawkins’ idea of the extended phenotype and applying it to a more neurocentric approach in Avatar, we can begin to detect some contemporary scientific work, such as modern brain-computer interface research and Ramachandran’s infamous phantom limb experiments that parallel some of the Avatar concepts of extended neural networks (and thus extended phenotypes) and “plugging in” to external banks of senses and memories. Ramachandran’s unveiling of the phantom limb phenomenon, in which a patient who has lost a limb is tricked through their visual system into feeling touch sensations being acted upon another individual’s hand as if it were their own, demonstrated that our nervous system is not a fully contained, self-centered purist—it can be tricked, perhaps through the activation of the always trendy “mirror neuron” systems which seem to fire while we observe someone else in action, into integrating the experience of another organism into our first-person experience, with activation seen in the same regions of cortex as the amputee’s “phantom” hand was being touched– a case of one sensory modality receiving foreign input but still making its way into conscious feeling. Likewise, in Avatar, as Jake mounts one of the horses on Pandora for the first time and plugs in his filaments, he feels the “heartbeat,” “muscles,” and “breathing” of the beast—then uses his own executive system to guide it through the landscape. Perhaps the future will bring more instances, building on Ramachandran’s experiments, where we more directly interface with the brains of other individuals (or even other animals) to receive sensory input and thereby extend our phenotype. In a way this has already started, albeit digitally: one of the most active fields of neuroscientific research around the world is that of brain-computer interfaces, where electrodes in pre-motor cortex can drive the action of a prosthetic hand, which can provide sensory input back into the cortex. These interfaces will undoubtedly yield some of the most remarkable developments in this century of scientific research.

Yet we are still on the level of the individual—what does modern neuroscience tell us about the possibility of a vast network of biologically stored memory in the trees of Pandora? Though we are still blind to the translation of cellular firing into subjective perceptions, researchers are already beginning to manipulate and understand small segments of neural tissue that can store patterns of activation. If larger and larger models are created and we can begin to correlate subjective memory retrieval in an organism to the precise patterns of spatiotemporal firing of neurons, then perhaps we will move closer to bridging the explanatory gap (massive modeling initiatives such as the Blue Brain Project could do just that). The question lingers of whether we could achieve anywhere near the kind of biological unity of the Na’vi in Avatar. Cameron may be right– our future could, whether we like it or not, consist of a lot of laying on our backs under a piece of machinery that takes us somewhere else and less of moving our actual physical body through space.

Even if our future is all digital, researchers are still attempting to unlock the biological secrets of how coalitions of neurons encode and store memories– we’ll need this information before we can hope to truly interface our nervous systems with another entity, be it biological or otherwise. Phillip Larimer and Ben Strowbridge of Case Western Reserve University published a study in this month’s edition of Nature Neuroscience in which they were able to store short patterns of activation in rat hippocampal slices that persisted after the removal of the original stimulus. Such studies mark the beginning of engineering memory into a neural network such as that on Pandora—if we can scale up our models and correlate subjective perceptions with cellular activity, it may be possible to offload—or at least digitally simulate and record—one’s own memories in an external network for safe keeping. Yet there are deep fissures in our understanding of what is possible when it comes to accessing another individual’s patterns of neuronal activity and the memory encoded therein: one can easily argue that you’d need to live an entire life of sensory experience in another person’s shoes in order to have access to the nuances of their memory, or even to see a color the way they do. Whether humans can ever have something like the Na’vi’s vast biological information network (not the Internet) in which the first-person memories of ancestors are stored and accessed will remain a question of science fiction for some time. Until then, long live the memoir.

In the end what is rewarding about the inklings of neuroscience in a film like Avatar is the fact that it will reach millions of viewers who may otherwise have had no exposure to these concepts. There is plenty of pseudo-science to be nitpicked, but the fact remains that physical neuroscience gets its share of the spotlight in the film, from the filaments that bond creatures together to the unveiling of the planet as a network of trees “communicating like neurons in a brain.” The tree is a fitting visual analogy– one with roots in the classic work of Santiago Ramon y Cajal, the father of modern neuroscience, who turned a childhood fascination with the branches above him into a lifelong investigation of the branches within him. And now it could be the very analogy that excites millions more to take interest in the scientific field that will define the 21st century.

Science Mentioned:

Related Articles:

  • Pophumanism post on Pandora as a planetary immune system.
  • Jonah Lehrer on Clement Greenberg and the visual ingenuity of Avatar.
  • OpEdNews piece: Avatar’s tantalizing possibilities laced with disappointment.
  • Andy McKenzie on the possibility of uploading a brain.

Jung’s Red Book Unveiled in Manhattan

[ 3 ] December 16, 2009
A page from Jung's Red Book, publicly exhibited for the first time at the Rubin Museum of Art.

A page from Jung's Red Book, publicly exhibited for the first time at the Rubin Museum of Art.

C.G. Jung’s Red Book, publicly exhibited for the first time at the Rubin Museum of Art in Manhattan through February 2010, is as electrifying a trip into the unconscious as one could hope to find. Not much knowledge of the rest of Jung’s work as a psychologist—or even his place in the history of psychology—is required to connect with the brilliant presentation at the Rubin.  Jung’s ultimate text is a rich postcard from a world spawned by the active imagination—the inquisitive and fearless plunge into the land of symbols, abstractions, and dim connections that reside below our conscious awareness. The magic in this exhibit is in its reminder to the contemporary viewer of the powers of introspection, the sense that there are vast worlds within each of us that await the curious traveler.

The work is considered Jung’s hidden masterpiece, a crucial anchor for his entire oeuvre and the embodiment of his deepest and most profound thoughts on the self. In the Red Book, Jung was weaving his own myth, mining his own experience and imagination for all their offerings in this epic quest. We gaze at these images of foreign lands, mandalas, and intricate cosmological symbols, and we marvel at the capacity of the human imagination.

For me, it was an example of a fascinating interaction between art and science. For here is a man who, in plumbing his brain for these words and images, is combing through the grand record of his own existence in the world. By moving through the world with his senses from the moment he became a conscious being, Jung allowed the raw data for the Red Book to begin brewing in the depths of his unconscious. The great scientific art here is Jung’s active quest back into this world that most of us leave untouched, and the product transcends a work of art and verges on an as empirical a document we could hope to find of one man’s active imagination and the unconscious it has mined.

The role of the unconscious has been the subject of several recent neuroscientific studies, and though such work does not handle the complexity of an introspective journey such as the Red Book, the empirical data only affirms the presence and power of the deep ocean of thought beneath our conscious awareness. A study published in Nature Neuroscience in February of 2009 by Ken Paller of Northwestern University demonstrated that the visual system can work “offline” in simple memory tasks, storing information for accurate retrieval even while the subject is distracted during the original presentation of the image. According to Paller, “The novel results show that when people try to remember, they can know more than they think they know. This suggests that we also need to develop our intuitive nature and creativity. Intuition may have an important role in finding answers to all sorts of problems.”

The Red Book reminds us that in moving through the world each day, thinking privately, acting publicly, and absorbing it all, we are all artists of our own brain, rewiring, reshaping, and retrieving. We study for an exam, deliberately painting our neural landscape with information we want to remember. Or we walk through the woods, harping on one concern in our conscious thought while the physical landscape around us washes into our memory, trickling into the dim corners of our unconscious. No matter how actively or passively we have painted, built, sculpted and composed our own brains, journeying back into the depths of this constructed world can be painful—tantamount to an artist cringing at a first viewing of his own work—yet in doing so we may hope to know ourselves and the world we have been moving through in new and perhaps deeper ways. What better source for artistic inspiration could there be?

The Red Book of C.G. Jung: Creation of a New Cosmology will be on exhibit at the Rubin Museum of Art in New York City, 17th Street and 7th Avenue, through February 15, 2010.

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