March 31, 2007

Zimbardo on the Daily Show

I just found out over on Edge that Philip Zimbardo was interviewed by John Stewart on the Daily Show. Here's the link!

The interview was pretty cool. He mainly talks about his new book, The Lucifer Effect.

If you have ever taken an Introductory Psychology course, then you have probably heard of Dr. Zimbardo. He is basically one of the biggest, if not the biggest, figurehead in social psychology. Zimbardo is mostly known for his Stanford Prison Experiement. You can go to the website for extra details, but basically his study showed how ordinary, good people can be outrageously cruel. His study, along with others in social psychology (such as Milgram's obedience study), showed that people don't necessarily do bad things because they are just plain evil. Instead his study emphasizes the power of the situation. Anyone can be persuaded to hurt others, if one encounters the situational forces that provoke that behavior. At the same time, it seems that anyone can be an angel under circumstances that provoke that behavior.

Anyways, the interview was good, so check it out!

March 28, 2007

are we more violent now?

You may be quick to assume that violence is increasing around you. Heck, these are the days of the Iraq War and routine terrorist attacks right? Violence seems to be everywhere in our news, music, movies and games. Violence in the media might even be the problem. You might hold the view that men are naturally born peaceful and are corrupted by modern society (the Noble Savage). This also seems to be a popular view among many politicians and academics. But is this true?

Steven Pinker has written an excellent essay on this topic, which is featured on the Edge website. In it, he argues that violence has actually been decreasing as time has gone by, and, in fact, humans have become "kinder and gentler." He presents evidence from recent anthropological studies to support his argument:

"It is true that raids and battles killed a tiny percentage of the numbers that die in modern warfare. But, in tribal violence, the clashes are more frequent, the percentage of men in the population who fight is greater, and the rates of death per battle are higher. According to anthropologists like Lawrence Keeley, Stephen LeBlanc, Phillip Walker, and Bruce Knauft, these factors combine to yield population-wide rates of death in tribal warfare that dwarf those of modern times. If the wars of the twentieth century had killed the same proportion of the population that die in the wars of a typical tribal society, there would have been two billion deaths, not 100 million."
He also explains why many people think that modern times are more violent, even though the evidence points to the contrary. This actually has a lot to do with Tversky's availability heuristic that I wrote about the other day. Again, the availability heuristic is a cognitive illusion that makes us think an event is likely to occur just because we can easily recall similar events happening before. So, people might think that we are more violent today, just because it's easy to remember the mugging that was reported in the news last night.

Lastly he presents four possible theories for why humans are becoming less violent. To sum them up real quick: 1) we can't take the law into our own hands anymore, we have centralized governments for that, 2) as technology improves our lives, we put more value on living, 3) the importance of cooperation in trading goods and dividing labor leads us to the idea that our neighbors are more valuable alive than dead and finally 4) we evolved a sense of empathy that only applied to family members, but over time our moral circles slowly encompassed whole tribes, nations, both sexes, the various ethnicities and even animals . . . in other words, our moral circles are getting bigger and bigger.

I liked his essay and I think that I got a lot out of it, for instance I didn't know that the favorite pass-tiime of 16th century Paris was cat-burning:
"In sixteenth-century Paris, a popular form of entertainment was cat-burning, in which a cat was hoisted in a sling on a stage and slowly lowered into a fire. According to historian Norman Davies, '[T]he spectators, including kings and queens, shrieked with laughter as the animals, howling with pain, were singed, roasted, and finally carbonized.'"
That's pretty sadistic. I'm sure there's some variability around the world as far as human and animal rights are concerned, but I can't imagine anyone wanting to do that today. I mean, no one's ever had to tell me that burning a cat was wrong. I've always kind of just assumed that cats had the right not to be burned alive and all. Well, anyways, if you are interested in the topic of the history of violence in humanity, definitely check out Pinker's essay!

March 25, 2007

what a week . . .

Okay, so I have been slacking on the blog lately. What can I say? I guess my only defense is that this past week has just been really crazy for me. Most of my time has been devoted to finishing a big cognitive paper that was due on Thursday. And Friday I had to finish a Statistics mid-term. So I thought those tasks were a little bit more important than the blog. However, I don't have so many deadlines to make this coming week, so everything should go back to normal, somewhat anyways.

My cognitive paper was on the topic of the ability to perceive and work with numbers. It was really cool, and I learned a lot. So if I can find access to electronic articles that are open to the public, then I'll probably write a post or two on that topic. But right now it's awesome outside, so I'm going to enjoy the weather a little bit.

photo by explodingdog

March 16, 2007

Today in the history of psychology

The great Amos Tversky was born today in 1937.

Tversky was a Stanford cognitive psychologist who did fundamental work in the realm of judgment and decision making. He, along with collaborator Daniel Kahneman, have identified and explained 11 different "cognitive illusions" often found in the making of human judgments. He explained that people often use various heuristics (simple rules of thumb) when making decisions. But these simple rules can bias our decisions, especially decisions made under pressure, risk or uncertainty, which leads to errors in judgment.

One such heuristic was the availability heuristic. This is basically the notion that people base their prediction of an outcome on the emotional or cognitive closeness of prior experiences rather than the actual probability of it occurring. In other words, if a person can recall an instance of an event occurring, then he/she will give this event a higher probability of occurring in the future than other events for which they cannot recall instances. For example, a person may say that the chance of a plane crash is higher than a car crash, just because plane crashes are reported in the news more often.

Tversky's ideas have had a considerable impact in the field of economics for challenging the wide-held belief that people behave rationally to maximize their own welfare and minimize costs. He showed that, in fact, this is not always the case. People often act irrationally against their own welfare. His and Kahneman's overarching theory became known as Prospect Theory.

Prospect theory describes how people choose among alternatives when risk is involved. Basically, people assign probabilities of all possible outcomes of a decision based on a heuristic, then they set a reference point with values being assigned to gains and losses rather than final assets. They then choose between two alternatives, the one with the higher utility. There is a whole mathematical formula that describes these types of decisions. I'm not going to really get into that, but the function sort of looks like this:

Essentially, Tversky and Kahneman found that people favor gains that are certain over gains of the same value that are less certain. But even more so, people will avoid losses that are certain over losses that are less certain, even if this means taking more risks. You can look up "prospect theory" in any search engine for a deeper understanding, but I thought the example that I found here was nice:
"Tversky and Kahneman told people to assume there was disease affecting 600 people and they had two choices:
  • Program A, where 200 of the 600 people will be saved .
  • Program B, where there is 33% chance that all 600 people will be saved, and 66% chance that nobody will be saved.

The majority of people selected A, showing a preference for certainty. They then offered them another choice:

  • Program C, where 400 people will die.
  • Program D, where there is a 33% chance that nobody will die, and 66% chance that all 600 people will die.

Most people now selected D, seeking to avoid the loss of 400 people.
Notice how the framing makes the difference. A and C are the same, and B and D are the same."

This work in judgment making is what eventually led Kahneman to receiving the Nobel Prize in Economics in 2002. Tversky would have been there right beside him, and would have received the prize, but sadly he died in 1996 of skin cancer. But his influence lives on!

Happy Birthday Amos Tversky!

March 15, 2007

omega-3s are great!

Here's a press release concerning Omega-3 fish oils and it's relationship with our brain.

Scientists from the University of Pittsburgh have found that consumption of fatty fish, such as Salmon, may increase grey matter volume in the brain, particularly in areas connected to mood.

"Researchers interviewed 55 healthy adult participants to determine their average intake of long-chain omega-3 fatty acids. Grey matter volume was evaluated using high-resolution structural MRI. The researchers discovered that participants who had high levels of long-chain omega-3 fatty acid intake had higher volumes of grey matter in areas of the brain associated with emotional arousal and regulation – the bilateral anterior cingulate cortex, the right amygdala and the right hippocampus."
This is an interesting finding and may help explain the observation that Omega-3 fatty acids obtained from fish help alleviate symptoms of depression.

Reading this press release is also a coincidence for me, since one of my fellow graduate students gave a presentation on fish oil and depression in our Behavioral Neuroscience class last week.

From what I remember, it seems that fish oil really does alleviate the symptoms of depression. But only the EPA omega-3 fatty acid is accounting for the decrease in depressive symptoms. The other omega-3 found in fish oil, DHA, doesn't seem to have an effect. Also, the effect is not cumulative. Instead, the effect seems to go away as one increases the dosage of fish oil.

On another note, administration of a fish oil supplement seems to be a good treatment for postpartum depression. Fish oil seems to be one of the few supplements safe to take while pregnant or breast feeding, unlike other medications. In fact, taking a fish oil supplement while pregnant may be a good thing to do whether suffering from depression or not. The fatty acids found in these fish oils are essential to development and are only obtained through the diet. If a mother-to-be is not taking in a lot of these Omega-3s, the growing fetus may deplete her own source, because it needs these fats. Nonetheless, you should consult a physician before taking any supplements while pregnant!

Yea fish oil!

March 14, 2007

synapse again . . .

In continuing with the topic of neuronal communication, here's a recent press release about research that exposes a possible flaw in our understanding of neuron activity.

Okay, so again, our current understanding is that neurons communicate with each other through synaptic transmission of neurotransmitters. Well, recent research suggests that neurotransmitter release is not in fact exclusively synaptic.

Instead, researchers at the University of Bonn claim that neurons release neurotransmitters all along the length of the axon, thereby exciting neighboring cells. This seems to have been demonstrated in their research concerning the "white matter" of rat brains. The white matter consists of only axons and ancillary cells. There are no dendrites or synapses present. Since there are no synapses present, one would expect not to find neurotransmitters in this matter. Well, as it turns out, they do observe the presence of a neurotransmitter here:

"Yet it is in the white matter that the scientists have made a remarkable discovery. As soon as an electrical impulse runs through an axon cable, tiny bubbles containing glutamate travel to the axon membrane and release their content into the brain. Glutamate is one of the most important neurotransmitters, being released when signal transmission occurs at synapses. The researchers were able to demonstrate that certain cells in the white matter react to glutamate: the precursor to what are known as oligodendrocytes. Oligodendrocytes are the brain's 'insulating cells'. They produce the myelin, a sort of fatty layer that surrounds the axons and ensures rapid retransmission of signals. 'It is likely that insulating cells are guided by the glutamate to locate axons and envelope them in a layer of myelin,' says Dirk Dietrich."
"As soon as the axons leave the white 'cable duct' they enter the brain's grey matter where they encounter their receptor dendrites. Here, the information is passed on at the synapses to the receptor cells. 'We think, however, that on their way though the grey matter the axons probably release glutamate at other points apart from the synapses,' Dietrich speculates. 'Nerve cells and dendrites are closely packed together here. So the axon could not only excite the actual receptor but also numerous other nerve cells.'"
If their speculation turns out to be correct, it will show that neuronal communication in the brain is a lot more chaotic than what was originally thought. Our original understanding will have to be revised to include non-synaptic transmission of neurotransmitters. Interesting stuff.

communication of neurons

Well, we're in the middle of spring break right now. I have been out of town for a couple of days, visiting some family and what not, so I haven't really had time to update my blog. But finally today I have some interesting stuff to write about and the free time to do it!

Today I'm going to describe a couple of press releases that I have been meaning to post about, which concern the neuron. Neurons are the cells that make up the nervous system (brain, spinal cord, peripheral nerves) and they process and transmit information throughout the body. At the moment, we are going to be concerned with how these neurons communicate.

The current accepted view of how neurons transmit information is by synaptic transmission through a electrochemical process. Here is my very brief and general description of such transmission: Basically, neurons receive chemical messages (neurotransmitters) from other neurons through receptors, which are located on their dendrites (tree branch looking extensions from cell body). Once dendrites receive the message, an electrical impulse is generated that travels down to the soma (cell body) and along the axon (another extension from the soma in opposite direction of the dendrites). At the end of the axon are terminals that contain vesicles that release a neurotransmitter to the next receiving neuron. The neurotransmitter is released into a synapse, which is a microspace between the terminals of the preceding neuron (presynaptic terminals) and dendrites of the following neuron (postsynaptic dendrites). So neuron communication in real basic terms: neighbor neuron releases chemical, chemical is received and causes electrical impulse in next neuron who then releases another chemical to it's next neighbor and so on. All chemical transmission is done through the synapse, hence the name "synaptic transmission." There, now that wasn't too bad I guess . . .

Well, a group of physicists from Copenhagen University are not really too satisfied with this explanation of nerve cell communication. Reasoning? Electrical impulses should produce heat, such heat has not been observed in the neuron, therefore electrical impulses are not generated along the axons. Instead, they propose that neurons transmit impulses of sound.

"Heimburg and Jackson theorize that sound propagation is a much more likely explanation. Although sound waves usually weaken as they spread out, a medium with the right physical properties could create a special kind of sound pulse or "soliton" that can propagate without spreading or losing strength. The physicists say because the nerve membrane is made of a material similar to olive oil that can change from liquid to solid through temperature variations, they can freeze and propagate the solitons."
This seems to be mostly theoretical work, the news article doesn't describe any of the research that the group has done on the topic. I'm not willing to buy into it, not at the moment anyways. They have a lot of work to do if they want to stand against the decades of research on the electrical activity of neurons. By the by, how in the world would we be able to measure the electrical activity in the brain through EEG if neurons did not generate electricity? Just not ready to give up the electro-chemical explanation I guess.

March 6, 2007

tomorrow night!

If you happen to be in Norfolk tomorrow, go see my best buddy Dustin (the guy next to me in my profile picture) play at The Boot. He's awesome! If you like stuff like old-school Bob Dylan or Woodie Guthrie, then you will probably enjoy hearing him play.

The show starts at 10:00pm and the address is:

123 W. 21st St., Norfolk, VA 23517

Go check it out! You won't regret it!

busy, busy, busy!

I haven't been neglecting my blog . . . I promise! I've just been really busy lately with grading papers and catching up with my own work. Things should be straight after Thursday morning. I have several posts that I have been formulating in my mind, I just have to find the time to post them . . . which I don't have right now. But soon!

March 3, 2007

another funny colbert interview!

J. Craig Venter, one of the leading scientists who completely sequenced the human genome, was interviewed on the Colbert Report on Feb. 27th. It's a little shorter than the Pinker interview, but it's still pretty funny. Check it out!

March 1, 2007


The American Psychological Association has just put out a press release today describing a policy that the group has adopted that opposes the teaching of intelligent design as a SCIENTIFIC THEORY.

"WASHINGTON, DC—The Council of Representatives of the American Psychological Association (APA) has adopted a resolution opposing the teaching of intelligent design as scientific theory and stating that teaching intelligent design as science undermines the quality of both science education and science literacy. The APA Council released the following statement after adopting the resolution:

'While we are respectful of religion and individuals’ right to their own religious beliefs, we also recognize that science and religion are separate and distinct. For a theory to be taught as science it must be testable, supported by empirical evidence and subject to disconfirmation. Thus, intelligent design lacks a basis in science.'

In adopting the resolution, APA reaffirmed its 1982 Resolution on Creationism which stated that “creationism does not conform to the criteria of science.” In adopting the current resolution, APA joins a number of other science and education organizations that have taken similar positions including the American Association for the Advancement of Science, the Federation of American Societies for Experimental Biology and the National Association of Biology Teachers."

This is great news!

Now they did not say that ID could not be taught as a religious theory. But parading it in a science classroom as if it was of the same caliber as that of genuine empirical observations is really just nonsense. Why waste the students' time with this when schools have trouble just teaching the basics? Teaching students an idea, which is based upon no empirical evidence, as a generally accepted scientific theory will severely hold these students back when they decide to go to college. Not only will they be lacking in biological knowledge, but they really won't know what science is. There's already too much to keep up with in college, why hinder the learning process by trying to relearn biology and reconstruct your concept of what scientific standards are at the same time?

I think this is the big issue here. Science is not just about curiosity and creativity. Those are definitely major components, but science is also based upon rigorous logic, experimentation, replication and peer review (all four being rigorous, not just the logic part). These criteria are here for a reason. We can't just say something is a scientific theory because it makes us feel better. Science is about being able to make predictable generalizations about how the world works. That's why it's useful. If your theory can't predict anything about the world around us, well then it's worthless. Saying that we were designed (because you can't find a good, natural explanation for how we came about) is not useful, not to mention intellectually lazy. It doesn't predict anything. How is this type of explanation going to be a driving force for medical science? It's not.

Now besides holding the principles of science up to the highest degree of integrity, there is also another reason why this APA policy adoption is a good idea. And that is because the knowledge of evolution through natural selection intersects a variety of scientific disciplines. For example, it is important for the discipline of psychology. And I'm not just talking about whether one accepts contemporary evolutionary psychology or not. But to be an intellectually honest psychologist, one must accept that our brains and minds, as well as our bodies, have evolved by the process of natural selection. This has numerous implications for psychology as a discipline. For instance, evolution is important for the study of developmental psychology. Developmental psychologists study the stages by which humans develop across the lifespan. We don't just pop out with the ability to speak and think abstractly. All this comes in stages. I mean, if we want to know how a human being develops and interacts with his/her environment, we at the very least should understand the concept of inheritance. We should be comfortable with the idea that genes have a certain influence on our behavior.

Another example that helps illustrate how evolution is the crux of psychology is the development of psychoactive medications. Most, if not all, the drugs we use (for mental and physiological illnesses) have been developed under animal models. Animal models of behavior are ubiquitous in neuroscience, pharmacy, cognitive psychology, you name it. There would be no reason to use these animal models if it weren't for the idea of evolution through natural selection. Why should we expect medicines developed through these models to work?

Oh well . . . needless to say, I'm pretty happy about the press release. The only question I have is why did it take so long?

The complete APA resolution can be found here.