Saturday, October 11, 2014

Review of The Selfish Gene by Richard Dawkins

I can't remember how but when I was 16 I came across this book and it changed my life. The title of Dawkins biography is "An appetite for wonder", and this appetite is no where more apparent than in this book (I have read most of his books). It is a wonderful introduction to the theory of evolution by natural (and sexual) selection, behavioral ecology, and the wonders of nature. At the same time it serves as a terrific example of first rate scientific reasoning. The writing is clear and fluid and extremely elegant. In his autobiography Dawkins admits that every sentence has been rewritten multiple times. Those that have survived this selection process really deliver. Every sentence seem to fill a purpose and yet, rarely does one feel that information is in some way lacking. This book, when it came out in the late seventies, influenced the general public and academics alike. It changed how academics thought about genes and evolution, and it introduced the meme, which has subsequently entered our dictionaries.

As I have said elsewhere, this book really is a literary masterpiece. The fact that it also teaches science to the reader is an added benefit that makes this book one of the best and most important ever written.

The book has a very good structure. At no point does it feel as if new concepts are introduced inappropriately. Dawkins begins by slowly and carefully introducing the replicator concept. In the widest sense a replicator is, as the name implies, something that replicates itself. This can be a mineral shape, a computer virus or a molecule such as RNA or DNA. It is inevitable that a replicator that produce more copies or copies that are more durable will become more prominent in the population. And so it is with our genes. The genes that exist in humans that are alive today are descendents of a very long series of genes that outperformed other genes. To achieve this success the genes have used many different tricks. Primary among these is cooperation with other genes to construct vehicles such as a plant or an animal that can both protect the genes and pass them on. Humans are thus "merely" vehicles created by genes for the benefit of genes (though in another sense we are of course much more than that).

Dawkins carefully builds from this starting point and reaches startling conclusions about many different aspects of nature and evolution. Why did sex evolve and why do the different sexes differ to a greater or a lesser extent in different species? Why are males in general more aggressive? Why do we cooperate? Does altruism exist? How did sterile ants evolve? Whatever he is discussing, Dawkins always provides illustrative examples from nature and when he use metaphors he is (unlike many others) always careful to translate those metaphors back into the language of replicators. The Selfish Gene also derives some of its fame from the fact that it introduced the meme concept. A meme, Dawkins suggested is like a gene in that it can replicate itself, typically via language or imitation. Successful memes (think viral youtube clips) will spread throughout population of less successful memes in the same way that successful genes spread, however, for memes the sexual reproduction of its host matters little. Rather, the success of a meme is determined by its ability to make its host share the idea with others. The meme concept is now in most dictionaries.

Throughout the book Dawkins is careful to point out that even though we are products of evolution and as a result have many instincts that are not always very noble, that does not mean that it is in anyway good or moral to follow ones evolutionary inclinations. Indeed if we understand human instincts we may be better able to construct societies that combat our caveman instincts.

Friday, October 3, 2014

New research from our lab shows that individual neurons can produce timed responses

Previously, when I have blogged I have mostly written about other people's research. Yet sometimes our research group in Lund also publishes first class, revolutionary research. This monday (sep 29th 2014), Fredrik Johansson and colleagues (of which I am one), published a study that I believe will have a huge impact, not only within our own field of research (we study the cellular mechanisms underlying classical conditioning), but for neuroscience at large.

To understand the findings a little background is necessary. Since the 80s we have known that the cerebellum is required for the acquisition of conditioned eye-blink responses. If a subject repeatedly hears a tone and then, right after the tone, is hit with an air-puff on the eye, then eventually that subject will learn to blink in response to the tone. However, if one removes the cerebellum, subjects can no longer acquire these conditioned blink responses. Removing the cortex as well as the mid brain, on the other hand, has little effect on this type of learning.

An important feature of the conditioned blink response is that it is adaptively timed. This means that even if a very long tone precedes the air-puff, the subject will still blink just before the air-puff arrives. This may not seem particularly interesting however, no one know how the brain can produce such delayed responses. Neurons communicate with each other using action potentials which propagate at certain speeds, however, they never slow down anywhere near as much as would be necessary to achieve the type of delay seen during eyeblink conditioning (>100 milliseconds). This means that somewhere within the brain there must be a delay or a memory trace that essentially keeps track of time, thus allowing the subject to execute a certain action at the appropriate time. Such delays are not only seen following eyeblink conditioning, but in pretty much any type of behavior. If you move your lips 10-20 milliseconds too early or too late then your speech will no longer be comprehensible, and when Cristiano Ronaldo runs up to score a free kick, even minor timing errors will cause the ball to hit the stands instead of the net...

Recent research have shown that during eye-blink conditioning, Purkinje cells in the cerebellum acquire conditioned pause responses which are directly linked to the conditioned blink responses. These pauses are, just like the eye-blinks, delayed with respect to the tone, meaning that if we can understand how the delayed pause responses are generated then we may also be able to understand how delays in general appear. The long standing assumption has been that there are so called "delay lines" somewhere along the signal pathway that transmit information about the tone to the Purkinje cells. The tone activates sensory cells in the cochlea which activates cells in the brainstem which in turn passes the signal on to the cerebellum. If one cell type along this pathway maintain a change in its firing rate following this input, then this could explain how the delayed responses arise. However, Fredrik have now shown that this cannot be the case...

Fredrik, instead of using a tone (or equivalent), for conditioning, used stimulation of parallel fibers. These tiny fibers project directly to the Purkinje cell dendrites meaning that there is no possibility of any delay lines. We wanted to see whether the Purkinje cells would still have a delayed response when using parallel fiber stimulation. The results convincingly showed that this was the case. That is, even when stimulating the fibers right next to the Purkinje cells, we still got delayed responses. The implications of this finding are huge. The results show that individual neurons can produce delayed responses to a certain input. In neuroscience this is represents a paradigm shift because previously it has been assumed that we can understand the brain if map all connections between cells as well as the strength of those connections. This study shows that there is much more to the story than this. Unknown processes within the cells evidently play a key role in determining the firing pattern... Johansson F, Jirenhed DA, Rasmussen A, Zucca R, & Hesslow G (2014). Memory trace and timing mechanism localized to cerebellar Purkinje cells. Proceedings of the National Academy of Sciences of the United States of America PMID: 25267641

Friday, April 18, 2014

Being against vaccines is like being against seatbelts

I sometimes try to come up with analogies that can help people understand the benefit of vaccination. One that I believe ought to used more often is the seat belt analogy. Although most parents in Sweden do vaccinate their children according to the national program there are some who believe that the potential risks of vaccination outweigh the benefits.

Admittedly, un-vaccinated children usually do fine in Sweden, thanks to good compliance with the vaccination programs in the past. There are in essence not so many viruses left in Sweden and therefore it is unlikely that you get vaccine preventable disease even if you decide not to vaccinate. It does happen however, that children get for instance measles. (It is extra common in Järna where I grew up due to the widespread false and silly belief that it aids the childs mental development .) However, because our health care system is relatively good it is also very uncommon that children die or get permanent disabilities as a result of measles. Rather, most parents come away with a feeling that measles is really not that bad... Ok, so un-vaccinated children are unlikely to get sick and even if they do get sick it is unlikely that the disease will have any severe consequences. So why vaccinate at all?

The simple answer is that not vaccinating is a huge risk compared to vaccinating which is associated with almost zero risk, and this is where the analogy comes in. Would you accept the argument that we should stop wearing seatbelts. After all, most people have tried this and nothing happened to them. It might even be that on rare occasions the seatbelt prevented a person from exiting a burning car or the metal thing at the end of the seat belt caused a burn on a child... I'm sure

Shouldn't we stop using seat belts? This argument is I believe almost perfectly analogous to the vaccination argument. Of course, as most people realize in the seat belt situation (but not in the vaccination situation), an anti-seat-belt policy would cause many thousands of deaths because even though most people manage fine without seatbelts. This is because the small proportion of people who actually would have been saved by vaccination, I mean seatbelts, adds up to hundreds of thousands of people.

Just to really drive home this message, think of the many people oppose the relatively new HPV vaccine. The HPV virus, which the vaccine protects against, is responsible for approximately 200.000 mortal cases (from twice as many cases), of cervical cancer per year. The vaccine meanwhile have been tested repeatedly with no adverse effects discovered to date. How many years should we keep on testing before we decide that the evidence is sufficient to go ahead and save 200.000 lives per year?

Tuesday, March 25, 2014

Review of Quiet by Susan Cain - A confidence booster for introverts and parents of introvert children.

I thought long about whether I should give this book 4 or 5 stars because there were certain aspect of the book that I did not like. Some central assertions were based almost entirely on anecdotes. I realize that it is a powerful way to drive home your message, but it can also be disingenuous - appealing to people’s emotion. I was also not very pleased with Cain’s description of the neuroscience. She made it seem as though the almond sized amygdala was all there was in the brain and that whether or not this part of the brain lit up under certain circumstances was all important. Yes, yes, I am a cerebellar scientist and am therefore probably overreacting here, but I would have preferred that the neuroscience was left out instead of receiving this very biased account.

Ok, enough of the bad stuff. I did after all give this book 5 stars (which is rare for me). The reason for this is that this book is one of few books I have read in my life that really made me see things, especially myself, in a new light. While I consider myself to be a rather social person who gets along with others I also have many introvert traits. During my time at University I really did not like the weekends because I felt that I had to go out and drink and dance not to be considered strange. I have also always been a little bit ashamed that I can be a “coward”. At least that is how I would have described it to myself before reading this book. Now I prefer to use the terms cautious. I am also a highly adaptable person and I can to some extent transform my behavior based on the circumstances. Again, before reading this book I saw this as being a disingenuous person. After all, you should be who you are and stand up for your ideals no matter what the circumstances, right? While I used to think this I do not anymore. It would be absolutely terrible if everyone spoke their mind all the time. The world needs people who can work in different circumstances, people like me. I guess what I am trying to say in this paragraph is that before I read this book I had consciously and unconsciously bought the extrovert ideal that is so prevalent in our society. I had seen all my introvert traits as weaknesses that I had to combat and conceal. This book made me see that these traits can work to my advantage and it helped me find the proper middle ground where I can better assess my own personality, my strengths and my weaknesses. If you are also an introvert or have introvert kids I really really think you should read this book!

Overall the book is well structures, easy to read and of a good length. Cain starts out by describing the extrovert ideal. To drive this message home (though I think it is a fairly obvious point) she describes a day at a Tony Robbins event where everyone is dancing, speaking with deep confident voices, doing high fives and walking on coal etc. Cain, who is an introvert feels awkward under these circumstances (as would I), and she is not ashamed of it. She states what should be obvious but strangely isn’t, that the world needs people with different qualities. Indeed, under certain circumstances it is better to be more quiet and less assertive. According to studies Cain describes bosses with highly skilled employees are better of if they are introverts, probably because being more quiet allows them to better harvest the qualities and ideas of the employees. Cain also talks about the power of working alone. As one illustrative example, take brainstorming which is normally done in small groups. Actually studies show that you get a better brainstorm if people are allowed to come up with ideas on their own which are later pooled. In certain situations, a group of people can be a constraint rather than a benefit. She also brings up several examples which have been founded by introverts such as Apple, Microsoft, and Google. Though these are huge companies it is hard to tell whether these examples are representative of the overall picture. Nevertheless, there can be little doubt that qualities such as cautiousness, empathy and conscientiousness can be very good qualities to have in some companies. Cain suggests that in some cases introverts can even hold aggressive stances in negotiations because they are less likely to antagonize the other part the way an extrovert outspoken person might.

In the remainder of the book Cain writes about the nature nurture debate (it bothered me that she seems to presume that free will exists, but I forgive her), and about different examples where temperament mattered (ex Wall street crash). The last three chapters serve as a type of guide to introverts and to parents of introverts. What types of conflicts tend to happen between introverts and extroverts and how should these be solved? What strategies can introverts use to avoid falling off the earth altogether? To what extent do you push your introvert child to do extrovert things such as hold presentations? Cain suggest sensible answers to all of these questions and I think that many people would benefit from reading this, and they are genuinely encouraging to introverts and parents of introvert children. I found it encouraging for instance that introvert children are influenced by their parents more than extrovert children. Thus introvert children will benefit more from good parenting than extrovert children (which is nice to know if you are indeed a good parent).

Friday, February 28, 2014

Free will debate, Sam Harris vs Daniel Dennett

Skepticism is very different from religion. One way in which it is that there is basically just one thing everyone agrees on, which is that arguments should be based on reason and empirical data. If you adhere to this then it is ok to question everything else. Free will is one issue on which there are different opinion within the skeptical community and in the past few weeks Sam Harris, author of the book "Free will" have had a feisty written exchange with another heavy weight in the skeptical/atheist community, namely Daniel Dennett.

The exchange started with Sam Harris book where he basically argues that Free will is an illusion, and that when we feel as if we have done something freely it is really just the "conscious" parts of the brain that takes credit after the fact... Daniel Dennett do not agree with this view and eventually wrote a long response to Sam Harris which was supposed to put him straight. I have read this response and would love to tell you what Dennett says but unfortunately I must admit that I did not really understand the objections Dennett makes. Is there a Dennett for dummies book somewhere out there, cause I need one...

Anyway, the most recent development is that Sam Harris have written a response to Dennett's response. Again, I find Sam Harris writing to be much easier to understand, and perhaps for this reason I tend to agree with Sam Harris. I just see no way around the conclusions that he makes.

Anyway, I do recommend following the discussion. Everything can be found on Sam Harris blog:

Sunday, January 5, 2014

Review of All Hell Let Loose by Max Hastings

There are many alternatives if you are looking for books about WW2. I recently read the not so creatively named "second world war" by Anthony Beevor, a thousand page book that gives the reader a comprehensive account of the entire war.

All hell breaks loose is in many ways similar to Beevors book, however, it did not seem to put as much emphasis on covering all aspects of the war. Instead this book frequently quoted personal correspondence from people who were involved in the war. Indeed I think that this is the primary reason why someone should choose rather than some other book.

You often read or hear about wars and the number of fatalities and how many starved etc etc, however, it is very hard to take the perspective of the individuals involved. The letters and diaries in this book takes you one step closer. Upon reading such material you can easily feel a bit ill (unless you are a complete psychopath), but at least for me the stronger feeling is one of gratitude that you have not been caught up in a war...

Reviewing my notes on this book I realized that it also contained quite a bit of information that was new to me, things that I had not considered important before. For example, the author convincingly argues that had Germany not attacked England with their airforce, England would not have been able to maintain the moral of their army and the political climate would probably have swayed towards peace with Hitler.

Another slightly comical story relates to Italy's inability to do, well, anything at all. As a part of a propaganda stunt meant to demonstrate the superiority of the Italians, a boxing fight was arranged between a famous boxer and an African man woo had never boxed before. Much to Mussolini dismay, the African man knocked the professional Italian boxer unconscious...

All in all, this book is kind of average if you are looking to get an overview of the war, however if you want to understand better what it was like for the soldiers and civilians who were actually involved in the war, this book is a sound choice.