The placebo response as a form of classical conditioning

I have already written a few posts about the pros and cons of The placebo effect. The placebo effect can loosely be defined as the effects you get when you think you are receiving medical care, be it psychological counselling or an injection of some substance.

I have also written previously about classical conditioning (see for example Learning described at the cellular level: Finding from our laboratory in Lund). Classical conditioning is a type of learning in which you pair a neutral stimuli such as a tone, a light, a touch, a picture, a thought or something else with another stimulus that has an associated reflex such as a puff of air in the eye (causes you to blink), a punch in the face (also causes you to blink), an electrical shock (causes fear and pain), or a shot of morphine (causes you to enter heaven for a short while).

If you present a neutral stimulus to someone and then, directly afterwards a reflex eliciting stimulus to the same person, and then repeat this procedure many times, then you will eventually notice that merely presenting the neutral stimulus can cause the person to perform the reflexive behavior that was formerly associated only with the second stimulus.

For example, play a tone just before giving an air-puff to the eye of your participant, over and over again, and you will eventually see that the participant blinks when he or she hears the tone. Show someone a picture just before you give that person an injection of morphine, and eventually (after a number of repetitions), that person will feel as if he or she was in heaven just from looking at the picture.

I don't know whether the relationship between the placebo effect and classical conditioning has become obvious to you yet, but if not, let me spell it out. Say that you have a spinal injury causing permanent and intensive pain. In some cases the only available therapy is regular morphine injections. You go to your doctors, enter the hospital, the doctor takes out an injection needle, and sticks it through your arm into a vein and injects a fluid which contains morphine. Notice that all these experiences leading to up the injection of the morphine can work as a neutral stimuli that is consistently associated with an injection of morphine. In other word, it is likely that one of these neutral stimuli such as seeing the injection needle (just like seeing a nice steak will cause an increased saliva production (at least for me)), will start processes in your body similar to the ones you experience when you get the actual morphine injection.

This was a hypothetical example for which I have no reference, however, you can find examples in the scientific literature which quite strongly supports the idea that placebo's sometimes are a form of classical conditioning.

For example it has been shown that people who are allergic to pollen, can get allergic reactions just from seeing a flower, even if it is made of plastic and therefore has no pollen.

In a more extreme example, a boy was getting chemotherapy to treat his cancer. The chemotherapy was paired with a specific taste and smell. Later on, the boy was presented with only the taste and smell and surprisingly (or not), the doctors observed the same effects as during the "real" chemotherapy...

These results have all but convinced me that there is indeed many parallells between the placebo effect and classical conditioning. Further these findings do suggest that you can help patients quite a lot without actually giving them "real" medicine. However, I also think it is wise not to go to far with this (see again: The placebo effect).

At the very least, this is a truly fascinating subjects that I, for one, will continue to follow.

See also my post on Complementary and alternative medicine - Spontaneous recovery from disease

Lund University Blog Portal

My university (see picture) has recently started a blog portal on the web.

If anyone out there would like to read what other employees at my University think you should check out this page:

nyheter.blogg.lu.se

Our tiny planet in our huge Universe

I have always been fascinated by astronomy and before I decided to go into neuroscience to study our amazing brain I had dreams about studying astronomy. I personally cannot understand how people can avoid being overwhelmed by our universe.

Our earth is a pretty big place, yet planets such as Saturn and Uranus are much bigger. Jupiter, however, is larger than all the other planets in our solar system combined into one planet - now that is big. Compare Jupiter to our sun and Jupiter looks like a pea next to
football, put another way - the sun is huge and massive! Still, our sun, which we rely on so intimately, is one of a hundred billion stars in our massive galaxy "the milky way". The Milky Way is a hundred thousand light years across - meaning that it takes light 100.000
years to reach us from the other end of the galaxy (yet the light can whizz around the earth 7 times in one second). Our sun, which is huge, is not even close to one light year across - rather it is about one light minute...

Our huge Milky Way galaxy containing a hundred billion stars and with a diameter of about 100.000 light years is small compared to the local cluster of galaxies (a small cluster of half a dusin galaxies), which measured millions of light years across.

I think you see where this is going... Our local cluster, which is absolutely humungous, is tiny compared to the observable universe. The most distant galaxies that can be seen are about 14 billion (that's 14.000.000.000) light years away - suggesting that the observable universe has a diameter of maybe 28 billion light years. Our local cluster of galaxies is tiny in comparison...

Still, theory suggests that our 28 billion light year observable universe is just a small fraction of the true size of the universe (we cannot see the whole universe because galaxies far away may be travelling away from us faster than the speed of light in which case their light will never reach us). Maybe the observable universe is just "one billionth" of the size of our true universe.

At last - many theorists believe that our universe, in which we are much smaller than a grain of sand in the Sahara dessert, is but one out of a large number of universes...

I don't know about you, but these numbers make my heart beat faster. I feel small and improbable, but also grand, lucky and inspired - it turns all my daily woes into experiences - I feel lucky for having experienced what it feels like to be sad, angry or happy - I feel
lucky for being able to study all the grand aspects of nature - from our huge universe to our fantastic brains.

Monkey's sacrifice their juice to watch "porn"

It is no news that porn cosumption on the internet is huge. When researchers in Montreal wanted to compare students who did cosume porn on the internet with students who did not consume the same, they were unable to find and male heterosexual students who had not looked at porn on the internet at all. The average age at which these students first saw porn was ten(!). Recent, unconfirmed estimates in Sweden suggests that more around 80-90% of male students consume porn over the internet.

There are also some interesting "cultural differences" this article (in Swedish) claims that the mormon dense state of Utah, consumes much more porn than for instance Montana. Perhaps most amazingly, when a county in Sweden investigated how their employees used their work computers they found that to a large extent they were used for activities such as file sharing and pornography. One employee actually spent 75% of his working hours looking at porn...

Now, it turns out that getting excited by 2D depictions of the other sex is not one of the uniqly human traits. Monkey apparently like porn too. In fact this scientific article shows that monkeys are willing to give up some juice (which they like alot) if they then get to watch pictures of the perineal area of female monkeys (perineal area is scientific name for the anus and vagina area.

Thiomersal

To vaccinate or not to vaccinate, that is the question. At least in Sweden, an intense debate has been going on recently due to the new influenza H1N1. Here I will not discuss whether or not it is a good idea to take the vaccination, rather I would like drive home another message - Thiomersal, which can be found in the H1N1 vaccine is not dangerous.

Thiomersal is an ingredient in the new swine flu vaccine. Thiomersal contains 50% mercury - a substance that is indeed very toxic. Drink a 10 grams of mercury and you will die from mercury poisoning. Unless you have a deathwish it is not normal for people to drink 10 grams of mercury, however, some traditional chinese medicines contains a few grams of mercury and taking these regularly might give you mercury poisoning. Indeed, a recent study found that for 64% of a sample of different traditional chinese medicines, taking the recommended weekly dose would result in mercury or arsenic intake significantly above the safety limit. What is the safety limit for mercury? It is around 1700 micrograms weekly.

Ironically this means that taking these so called "natural" chinese medicines can give you mercury poisoning. How much mercury is there in a shot of swine flu vaccine? Judging from the number of articles this issue has produced it has to be alot right? Five micrograms is the answer! In other words, take the natural medicine and you will get more than 1700 micrograms of mercury, take the highly controversial vaccine and you get 5 micrograms... By the way, fish is allowed to have as much as 500 micrograms of mercury per kilogram. So eating a fish will give you much more mercury than taking a shot of the vaccine.

I talk to a lot of people who are extremely skeptical towards the medical industry, WHO, and doctors in general. Fair enough, the medical industry wants to make money, and the WHO propably have some sort of agenda and perhaps they do not want to put focus on potential side effects on a vaccine that can potentially save a lot of lives. Doctors, well maybe they are to some extent indoctrinated by the medical industry and WHO. My advice is don't trust the expert, but trust the evidence and take the numbers I have just presented into account. Everything is toxic if you get too much of it, but small amounts of something (even mercury), is rarely dangerous...

What should you believe in? Shermers Baloney detection kit

When someone makes a claim, how do you decide whether to believe in that or not? If you believe everything anyone has told you, then you will soon have many many contradictory beliefs. Even if you only listen to people around you, you will still get contradictory information - all claims cannot be true. So how do you decide who to believe in?

Micheal Shermer, a famous sceptic suggests that we ask ourselves the following questions when we decide whether to believe in something. Why should you trust Shermer? Don't! You should question him just like everyone else, he is certainly a man with an agenda, so listen to someone who does not agree with Shermer and decide for yourself. Anyway here is what Shermer suggests you ask yourself when you hear a claim.

1. How reliable is the source?
2. Does the source often make similar claims?
3. Has the claim been confirmed elsewhere?
4. Does the claim fit with the way the world works?
5. Has anyone tried to falsify the claim?
6. What does the majority of the evidence point to?
7. Is the source basing their claim on science?
8. Is there positive evidence in favour of the theory (or is it only negative evidence)?
9. Does the new theory account for as many phenomenon as the old theory?
10. Are personal beliefs or ideologies drive the claim?

Carcinogens in natural foods - the Ames test

I have previously written about the difference between natural foods and "unnatural foods" in terms of how much carcinogens they contain. I did one post on "Irrational fear of pesticides", and another post that I called "natural foods contain more carcinogens than unnatural foods".

Just now I found a video clip from Physics for Future Presidents, a UC Berkeley lecture series that you can watch for free online, in which Richard Muller, an entertaining physicist explains what this is all about. Watch and enjoy.