June 28, 2009

Open scientists have more and more early "Aha!" moments

Why I am an open scientist
The other day, I wrote about developing public understanding of science, now I came across the somehow interlinked concept of being an open scientist: scientists shall engage in making their work as transparent as possible. And no, not just writing about completed projects to peers and public, but about the scientific work in progress. For example, an experimentalist could keep a public lab notebook.

Challenges are to be discussed, but I immediately felt that the idea is straight forward and the rewards would outweigh risks. Traditionally, you had a lab notebook holding your unpublished work, until the data is transformed into results presented in a journal article. Nowadays that could be, and should be if possible, an open access journal, so why not starting with making also your lab notebook open. So far the straightforwardness: open access to information, maybe not entirely so, but at least during all stages to a certain degree. I guess, I do not need to mention the risks. What about the rewards?

What came as a reward into my mind was the early creation of "Aha!" moments. An "Aha!" moment or event indicates a change in the cognitive state. I first heard about this concept from Frank Ohl and Henning Scheich, former colleagues, but recently also found it in the Wall Street Journal: A Wandering Mind Heads Straight Toward Insight, which serves as a better introduction. These moments need an environment in which they can flourish. As far as my moments are concerned, they come—surprisingly—reliably but only if I write about my work with the reader in mind. Most of my articles changed quite dramatically in the process of writing, although I used to start writing, only when I thought the creative work is seemingly finished. I learned nothing could be more wrong. So for me being engaged in making my work more transparent by writing about it at an earlier stage, while it is still in progress, is nothing less than forcing insight.

June 12, 2009

Seeing zigzags

You can literally see how your brain works during a migraine with aura and learn first hand about cortical organization

In the article that starts with the question "Does the migraine aura reflect cortical organization?", published in the European Journal of Neuroscience, I considered the old idea that flickering zigzag patterns seen during migraine with aura reflect properties of our neurons. Let me explain this briefly.

It is well known that neurons fire much more frequently if the condition they are tuned for is met. For example, one of your neurons may only fire if you see a vertical line at a specific location in your visual field. We know very well how such neurons are organized on the surface of your brain. This is called cortical organization. In general, this concept denotes how sensory conditions that must be met for neurons to fire—such as edge orientation, but also color or any other feature of the outside world—are spatially organized on the surface of your brain. Sometimes, this is also called a cortical feature map.

It seems natural to suggest that hallucinatory zigzag patterns seen during migraine with visual aura reflect the organization in the visual cortex representing the feature edge orientation. What other than a pattern of edges is a zigzag? That migraine aura reflects cortical organization was proposed by many scientists, but how to prove or at least support this hypothesis?

My idea was to translate our current knowledge of both cortical organization and migraine pathophysiology into a neural network model. I should then be able to reconstruct the flickering zigzag patterns seen during migraine in a computer simulation. The result is displayed on the right. In fact, the actual computer simulation is animated, but I chose a still image. Otherwise this blog would become unreadable for those who suffer from migraine. Flickering patterns can trigger migraine. For an animated version, please see my scholarpedia article Models of cortical spreading depression. We now have sample movies that can be compared with the zigzags seen during migraine, like we measure tinnitus by sample noise.

June 11, 2009

Public Understanding of Science

One half scientific lobbying to increase the understanding of the value of science to society, the other half engaging the public in science to increase knowledge

For good or bad, public understanding of science becomes more and more an essential prerequisite for both getting adequate funding of research activities and finding a permanent faculty position. To my mind this is actually a good thing because the rapidly expanding Internet technology allows scientist to easily reach out to the public. (blogs in particular: it took 10 minutes to figure out how to create my own blog and here am I. The web still amazes me.)

To call for developing PUS as a task for scientists is quite different from the controversial concept of "publish or perish", a common advice how to sustain a career in academia. I admit, I like rather spending time developing my original research than writing papers. But once a paper is published, why not writing three short paragraphs to explain to the public what I did or maybe only why I did this research? I am doing both basic research carried out to increase our understanding of fundamental principles and applied research. Not always is an immediate benefit to the society obvious. But I can answer questions like: What has driven my curiosity to do this research. Why do I think this is a fundamental principle? What is my vision?

Do I spend much time pondering about these questions? Yes and no. Yes, I spent a large fraction of my time on thinking about the general significance of my work. Where will I go next, and why? This is part of my job. I will not spend much time for writing this blog. Frankly, in many cases I will just copy and paste text from my research proposals. There, I have to provide a clear flow of thoughts starting from the broadest scope of my research. Moreover, I get e-mails very other week from people asking about their migraines and what I think. So, I hope, this blog will actually safe me time for I can now refer to it.

June 5, 2009

Seeing your brain anatomy without fMRI scan

Migraine sufferer literally sees his brain surface being curved
In the article entitled "Migraine Aura: Retracting Particle-Like Waves in Weakly Susceptible Cortex", published in the open-access journal PLoS ONE, my colleague, Nouchine Hadjikhani, and I uncovered in a rather unconventional manner the spatial form and temporal evolution of pathological activity patterns in human cortex during migraine with aura. We compared symptom reports of visual field defects with the topographic representation of these symptoms on the cortical surface obtained by non-invasive functional magnetic resonance imaging (fMRI).

Migraine maps and other maps

A keen engineer provided us with fascinating data. He marked the progression of his visual disturbances with a pencil on a sheet of paper. For about half an hour, every minute he newly outlined the location of his visual field disturbance while keeping his gaze fixed on a cross that he had drawn on the paper when the attack started. So we got many drawings, he called them migraine aura maps, each with about thirty lines.

Nouchine recorded then another map from his cortical surface—called retinotopy—using fMRI. In this map, positions in visual field are marked on the cortical surface, for example with a color code ranging from cyan (lower hemimeridian, 6 o'clock position) via blue (horizontal hemimeridian, that would be 3 o'clock) to red (upper hemimeridian, you got it). Let us first use this color code in the picture above, voilĂ .

What you see below is a 3D picture of the primary visual cortex with the same color code as used for azimuthal positions in the visual field.

The primary visual cortex is a credit card-size large area in the brain receiving visual information from the eyes. The cross with the 4 letters c,r,d,v mark anatomical directions and cuneus, lingual gyrus, CS, and occitipal pole are just names for anatomical landmarks known to the specialist. Important is that the primary visual cortex is organized retinotopic, that is, neighboring points in the cortex process information from neighboring points in the visual field. Without retinotopic organization, the picture would be not smoothly colored but randomly.

This retinotopic mapping allowed me to reconstruct the spatial patterns that correspond on the cortical surface to the engineer's lines in the aura map. I compared the aura map with his typical anatomical landmarks and we uncovered that the engineer actually saw his curved brain from within because there where remarkable correlations between his aura map drawing and the curved shape of his primary visual cortex.

Towards novel therapeutic methods using chaos control

These patterns revealed valuable information about the self-organization principles behind migraine pathophysiology. The gained knowledge, namely the confined location of the activity, opens up entirely new therapeutic methods based on chaos control. I work currently on intelligent neuronavigated transcraniel stimulation techniques that can be used in combination with biofeedback training via a brain-computer interface to persistently decrease susceptibility to this pathological activity in exactly the right location. My hope is that location is the key to non-pharmaceutical medical therapies using biomedically engineered approaches.

Suggested further reading:
Chaos and Migraine.