Saturday, July 21, 2012

The oldest skill

On the golf course, it is easy to spot a skilled player: they not only hit the ball so that it lands in the fairway along the path to the green, but they do so consistently.  That consistency is also at display when you watch a lumber jack use an ax to drop a tree, or a sculptor use a chisel and hammer to turn a rough piece of marble into a life-like statue.   

The degree of precision with which we can use a tool is roughly a measure of our skill, and our brain acquires skills through years of practice.  You need devotion and persistence to become skillful with a tool, whether that tool is a golf club, chisel, or a violin.  When did humans first exhibit this ability and desire to acquire a skill?

About 40,000 years ago, humans that were anatomically similar to us entered Europe and settled in the continent that was once populated by Neanderthals.  They arrived at a place in which mammoths, lions, and wild horses were plentiful.  In Swabia, in southwestern Germany, a few of these early explorers left behind pieces of work that for me represent the earliest examples of skillful tool use.

One particularly beautiful piece is a horse carved from mammoth ivory that dates to about 30-35K years ago.  It is about 5cm in length, and was found by Gustav Riek, a professor at University of Tubingen, in a 1931 excavation of the Vogelherd cave in Wolfstal valley.  Horses were not domesticated until about 6000 years ago, so the sculptor who created this piece was carving based on the memory of observing these animals in the wild.  The piece is made from ivory, which on its outer layer has a hard enamel, requiring sharp cutting tools to work through.  Its hallmark is a remarkably expressive curved neck.  Looking closely at it at Hohentubingen museum, I could see small engraved symbols, including cross marks and angular signs, on the back of the neck, as well as on the back and the left chest.  I thought it was astonishing that people in the Stone Age, facing hardships unimaginable to me, could find time to learn and perfect a motor skill that could produce something so beautiful. 

Another piece that exhibits exceptional craftsmanship is a female figurine also made of mammoth ivory.  This piece dates to about 35K years ago and was found by Nicholas Conrad in a nearby region in 2008.  It is 6cm in length.  Instead of a head, it has a carefully carved ring above the shoulders.  In the original paper that described the find, Conrad writes: “This ring, despite being weathered, preserves polish, suggesting that the figurine at times was suspended as a pendant.”   The arms end with two carefully carved hands, with the fingers resting on the stomach.  There are lines carved on the back and front, suggesting of clothing.  Conrad writes: “Microscopic images show that these incisions were created by repeatedly cutting along the same lines with sharp stone tools.  Such deep cuts into ivory are only possible with the application of significant force.”

The precision with which these pieces were made is among the earliest evidence of skillful use of tools.  This evidence suggests that despite the struggles of existence, humans of the Stone Age had the motivation to invest the years needed to acquire a motor skill, so that they could create things that today we call art.

NJ Conrad (2009) A female figurine from the basal Aurignacian of Hohle Fels Cave in southwestern Germany.  Nature 459:248-252.
NJ Conrad and M Bolus (2006) The Swabian Aurignacian and its place in European prehistory.  In: Bar-Yosef, O., Zilhao, J. (Eds.), Towards a Definition of the Aurignacian. Trabalhos de Arqueologia, 45. Instituto Portugueˆs de Arquologia, American School of Prehistoric Research, Lisboa, pp. 211–239. 
R. White (1992) Beyond Art: Toward an Understanding of the Origins of Material Representation in Europe.  Annual Review of Anthropology 21:537-564.

Saturday, July 14, 2012

Dear Mr. Porsche

Stuttgart is where they build Porsches.  There is a Porsche museum near one of the show rooms, and I imagined that this might be a fun place for a family visit.  We drove over one Wednesday morning.  

As we entered the under-ground parking lot, the asphalt and concrete floors disappeared and we were driving on something that was white and very shiny.  I felt a little embarrassed in our somewhat dirty rental car.  Elevator doors opened and the unusual furniture, glass, steel, and white everything, made me think that I was visiting the future, despite the fact that the museum was of course about the past: history of Porsche and automotive engineering. 

The kids had a blast posing with and sitting in the fancy cars, but I thought the most interesting thing was the small exhibit that they had made to honor Ferdinand Alexander Porsche, the grandson of the original Ferdinand Porsche (who designed not only Porsches, but also the first Volkswagen Beetle).  The grandson died about two months ago and his major work was the design of Porsche 911.  In this exhibit there was a young lady attending a couple of imposingly large books bound in black leather.  Curious, I walked over and she told me that the books were there for visitors to sign.  I opened one and started reading.  I was surprised to read so many emotional comments.  The authors, just ordinary visitors to the museum, were from all over the world, but they were writing to the deceased man as if he was their friend, often thanking Ferdinand for the passion that he had brought to their lives.  One said: "Your car helped me when I was in a difficult period in my life".  Another said: "The design of the 911 was an inspiration to me when I needed an example of a passionate design."

I imagined that the people who had left these notes had driven one of his cars (or maybe just appreciated looking at one of his cars), and felt joy.  It’s like when I read a good book, and feel that I have gotten to know the author a bit.  When the author teaches me a few things, I feel grateful.  I had never thought about feeling this way about a car, and its designer.  It is good to see that engineers can leave such a positive impression on people who use their designs.

Tuesday, July 10, 2012

Simple and complex spikes

During my visit to Germany, I wake up early most mornings to walk to the lab.  I share a small office with some of the graduate students.  In one of those early morning, I walked in and surprised a graduate student from a neighboring office who was on the phone.  I think she felt a little embarrassed, and so afterwards she sat down to tell me that she comes in early to call her dad.  

She is from Poland, finished medical school 3 years ago, and decided to go into neuroscience and is now recording from the cerebellum.  She mentioned how important it was for her to talk to her dad each day, as the science was going slowly and things were not always so great. 

Over on her desk she has a piece of paper taped to her computer.  It's something that an earlier student made for her.  It shows a recording from a Purkinje cell.  The top part of the paper shows the raw voltage trace, where you can clearly see the simple and complex spikes in fantastic isolation.  On the bottom of the paper is the spike-sorting waveform that is used for online sorting of the simple and complex spikes.

The note on the paper says: "Motivation screen shot.  These cells exist and you can find them!"

Saturday, July 7, 2012

Revolutionary teenager

During a visit to University of Tubingen, I met a young neurologist who is the lead postdoc in the lab.  I see him talking to the students each day and helping them with their recordings and data analysis.  His is originally from East Germany, town of Leipzig.  In 1989, he was 14, living with his little brother, his dad (an engineer), and mom (a physician).  His parents had wanted to leave the country, and had finally gotten the courage to put in the paper work to get an exit visa. This was a brave thing, because in earlier years people who put in an application were usually arrested.  But there was a feeling that things might become easier, and there might be a window of opportunity now.  A family friend was so desperate that they bought a plane ticket to Cuba, and chose a flight that had a layover in Canada. Once there, they escaped from the transit area and asked for asylum.   He explains that his dad felt that his father had once had a chance to leave for the West, but had hesitated, and ended up living his life under communism.  Not wanting to make the same mistake, they put in for an exit visa and sold their house.

People who were in a similar situation met on Monday evenings in a Lutheran church in Leipzig named Nikolaikirche.  In summer of 1989, they would just meet in the evening and say a few prayers and then go home.  But in September of that year, a few people stayed after the meeting and went to the front of the church and just stood there for a while before going home.  This gathering at the church attracted other people who were dissatisfied with the East German regime, resulting in weekly “prayer for peace” meetings, held first at the courtyard of the church and soon in the streets surrounding it, with the meetings always culminating in standing outside.  He was there among them as the weekly meetings became larger, growing rapidly and within weeks including 70000 people (out of a city population of 500000).  The most famous chant became “We are the people”, referring to the government who used a similar phrase to describe itself.

The East German police showed restraint, and by October of 1989, the weekly meeting had more than 300000 people.  The news spread, as did the demonstrations in other cities, and the chant began to change from "We are the people" to "We are one people".  By November the Berlin wall was brought down.

He describes driving over to the west and being greeted by West Germans.  They had organized hotels for the immigrants, free of charge.  Within a few months they had a place of their own.  Within a year the two countries were united.

They settled in a small village outside of Stuttgart.  As he tells it, his life in the West turned out to be less than he had hoped for (at least at the beginning).  It was hard to be a participant in a revolution that toppled a regime and brought unification to two countries, and now just being an ordinary high school student.  He thinks he might have had the peak of his career at 14.  Half jokingly, we talked about how his experience might help people in other places who are striving for freedom.  He had thought of going to Syria to see if he could help organize demonstrations.  For now, he is a neurologist who sees patients one day a week and spends the rest of his time searching for mirror neurons in the premotor cortex.