14 December 2008

Riding a bike

I was 5 when I learned to ride a bike. I remember the place - a thin strip of asphalt surrounded by very green grass, just beside a small patch of forest - where I first managed to ride it for a stretch without dad holding it steady and without falling over. Imagine my brain at the time. Imagine two pulsating groups of active neurons in each prefrontal cortex, slowly circling each other. One, oscillating slowly, projecting to the motor cortex right at the top of my head and down between the lobes, driving the oscillating contractions of leg and foot on the pedal. The other, pulsating a seemingly patternless pattern to the motor cortex below the upper sides of the skull, constantly adjusting the handle bar with a cramped grip, keeping the whole circus upright. Both groups, closely connected to eachother and to their mirror images in the opposite lobe, receiving a constant barrage of input: sight from the back of the brain and the colliculus, balance from the inner ear, kinetics from the spinal cord. Both groups constantly adjusting their output to maximize the flow of reinforcing dopamine from their respective midbrains. And that's why I remember it so well, that moment when the groups finally got the output right, for a time, and were showered with dopamine as all regions of the brain reported success. The dopamine reinforced them, and with them every other process that was active in my frontal lobes at the time - the location, the weather, the color of the grass.

After that of course, I've kept on biking, for years and years and years, milking those two groups for all the dopamine they were worth, until they were neat and trimmed and refined to a point where almost all the oscillation and rotation and complex feedback loops have been moved over to small, dedicated central pattern generators in my motor cortex and spinal cord.

12 December 2008

Morphine - A good woman is hard to find



She painted a bull's eye on my mind.
No matter how I moved her aim was never high.
I guess that was what I needed at the time.

A good woman is hard to find. A good woman is hard to find.
A good woman is hard to find. A good woman is hard to find.

She was heavy, on the back beat. See played me just like a tambourine.
Well, she took me to church, prayed till it hurt.

A good woman is hard to find. A good woman is hard to find.
I'll live to love another one more time. A good woman is hard to find.

She was a helluva woman, from a helluva town.
She took me all the way, it was a long way down.
She makes me wonder, wonder, all day long.
Can a good woman, ever be found? Can a good woman, never be found?

She was beauty and adventure. She seemed so glad to be alive.
I want to be happy, but not all the time.

A good woman is hard to find. A good woman is hard to find.
I'll live to love another one more time. A good woman is hard to find.

She wrapped me up. Saved me for later.
Left me no way to penetrate her. Guess that was what I needed at the time.

A good woman is hard to find. A good woman is hard to find.
I'll live to love another one more time. A good woman is hard to find.

(Happy birthday Chris)

09 December 2008

How compliant do we want our children to be?

Deep tip of the hat to Laura for sharing this seminal paper, due to appear in Nature on Dec 11.

Greely, Shakain, Harris, Kessler, Gazzaniga, Campbel & Farah (2008) Towards responsible use of cognitive-enhancing drugs by the healthy. Nature.

I'm obviously thrilled to see a paper like this in such a high-impact journal and with such distinguished authors. Few things seem as capable of speeding up scientific development and the spread of a modern, progressive mind-set as does the prospect of widespread brain enhancement. But I want us to acknowledge how enormous this transition will be. Many social norms will not survive the change and many others will need to be updated.

One issue I'm baffled by is how we will think about the use of drugs to make school-children more attentive and compliant. The authors in the current paper call for policy to prevent coercive use of cognitive enhancers in children. But at the end of the day the fact is that teachers are already doing everything they can (often unsuccessfully) to focus the attention of their pupils. A drug that enhances attention seems like a natural next step. Would it damage creative thinking in children if they went through school on Adderall? I guess that's one of the topics the authors call for more research on, but it's also a social or existential issue: how compliant do we want our children to be? I was a hell-raiser in school; I would have been VERY different on Adderall and would be a different person now. But maybe this is just our first shaky step into a new era of responsibe, neuroscientific design of children; maybe the next generations of Ritalin, Adderall and Modafinil will be designed specifically to enhance creative thinking and brain growth (BDNF anyone?).

Anyway, it's a great paper, I strongly recomended it.
"The new methods of cognitive enhancement are 'disruptive technologies' that could have a profound effect on human life in the twenty-first century. A laissez-faire approach to these methods will leave us at the mercy of powerful market forces that are bound to be unleashed by the promise of increased productivity and competitive advantage. The concerns about safety, freedom and fairness, just reviewed, may well seem less important than the attractions of enhancement, for sellers and users alike...

We call for a programme of research into the use and impacts of cognitive-enhancing drugs by healthy individuals...

We call for physicians, educators, regulators and others to collaborate in developing policies that address the use of cognitive-enhancing drugs by healthy individuals...

We call for information to be broadly disseminated concerning the risks, benefits and alternatives to pharmaceutical cognitive enhancement...

We call for careful and limited legislative action to channel cognitive-enhancement technologies into useful paths..."


The basic amphetamine (Adderall) molecule. Click to interact (requires Java).

04 December 2008

West Bank evictions: Israeli police does the right thing

Thoughts on forks

Whenever there is purposeful, goal-directed behavior going on, dopamine is involved. Without dopamine, there is no purposeful behavior. At 1% of normal dopamine concentrations even feeding and drinking stops. In Parkinson's disease the parts of the brain most intimately involved with purposeful movement (as opposed to thinking) are deprived of dopamine, and at 20% of normal concentrations it becomes hard to move. Dopamine is key to organized behavior and motivation: it reinforces activity in brain tissue and strengthens synapses.

So whenever you see purposeful behavior going on you might ask yourself "where is the dopamine coming from?". Only rarely do we see humans engaged in behavior that directly activates dopamine neurons. Eating comes to mind: sensory neurons in the mouth detect the presence of good food and immediately activate dopamine neurons in an attempt, if you will, to reinforce whatever behavior brought the food there. But that behavior, the movement of the fork or the chop-sticks, was learnt at some point. Suckling is the only form of eating we know from the start. We suckled the breast and the milk was warm and sweet and we stopped crying. We suckled the twig and it was cold and hard and we cried. When suckling brought warmth and sugar, dopamine was released and the neuronal ensembles generating the behavior and remembering the context were reinforced. Later we learned a bottle works almost as well. We learned to hold the bottle. And a few years and millions of dopaminergic learning experiences later we learned to use the fork.