February 28, 2007

End of rat parade

Well, today marked the end of my students' operant conditioning lab. Some of the rat groups really accomplished a lot over the two weeks, others not so much. But you really can't help it if you just got assigned to an unmotivated or anxious rat. Most of the time these guys will just sit in the corner and clean themselves or fall asleep.

Just for a little recap, we had 13 groups (two students per rat). Each group had to spend at least one hour each day with their rat for two weeks. For motivational purposes the rats needed to be brought down between 5 to 10 percent of their free-feeding weight. If the rat is not hungry, it will not be motivated enough to press a lever for a food reward. So, the students weighed their rats on the first day to get the estimate of it's free-feeding weight and from then on based what they feed them on the ideal weight that they were hoping to achieve. The students weighed their rats each day and weighed the amount of food to give them each day. They then recorded this information in their "rat journals," along with a rationale for why they were feeding them the amount of food that they gave.

They then brought their rats to the operant chambers (example to the left) and tried to shape a lever pressing behavior in their rat by reinforcing them with a small food pellet. When the rat was able to press the lever on its own, it would automatically receive a pellet. This is on a 1:1 ratio. After a rat learns the behavior and is able to press the lever without any reinforcement, the students were to switch to a higher ratio like a 2:1 ratio (rat presses the lever twice and gets one pellet). The goal was to get all the way up to a 10:1 ratio, but not all rat groups achieved this goal. Again, some groups just got stuck with rats that didn't want to do anything. Those with clever rats, or just plain hungry rats, were able to reach this goal and move on to more creative feats. Some tried extinction (not reinforcing the lever pressing behavior) for a day, and then trying the 1:1 ratio again on the next day to see how quickly the rat remembers. One activity that I thought was interesting was reinforcing the amount of time that the rat held the lever. One group did this. They shaped a behavior in the rat for pushing the lever down and holding it down. Eventually they would only give the rat a pellet if it held the lever down for 10 seconds. I thought that was pretty neat. Other groups utilized various variable rate ratios.

All in all the students really enjoyed their experience with the rat labs . . . or at least I think they did. Most seemed attached to their little rodents, and most gave them names. Oh well, it is all over now. Grading rat journals is what I have to look forward to for this weekend . . . sigh.


One of my favorite science blogs, pharyngula, has linked me to his blogroll list! YES! Hopefully this will mean more readers. like a lake is listed under blogs for the real world. Now I just have to make sure that I can actually keep this blog interesting enough for him to keep me on there.

February 23, 2007

Chimps hunting bushbabies

Mixing Memory has an interesting post about our closest relatives . . . the chimpanzees! Well, a journal article has recently been published that describes a case of tool use in chimps. But not just the normal, "stick a twig in a mound of dirt to gather termites" type of tool use. No, this is complex tool use that has not been witnessed in chimps or other non-human primates before. They use tools for hunting!

Now the creation and use of tools for hunting was thought to be uniquely human. Well, I guess that changes now:

"Chimpanzees made 26 different tools, and we were able to recover and analyze 12 of these. Tool construction entailed up to five steps, including trimming the tool tip to a point. Tools were used in the manner of a spear, rather than a probe or rousing tool. This new information on chimpanzee tool use has important implications for the evolution of tool use and construction for hunting in the earliest hominids, especially given our observations that females and immature chimpanzees exhibited this behavior more frequently than adult males."
Now, just what did these chimpanzees hunt with their "spears?" Why, bushbabies of course! You're not sure what a bushbaby is, are you? It's one of these little guys:

"In all observed cases, chimpanzees used one hand in a “power grip” [17] to jab the tool downward multiple times into the cavity. In the single instance in which a chimpanzee was observed to extract a bushbaby, it was unknown whether the prey was alive or dead after the use of the tool, but it made no attempts to escape, nor did it utter any vocalization."
Ouch! Kind of makes you feel a little sorry for the little buggers. In all, this seems to be a pretty important study into the chimp culture and perhaps has implications for the evolution of hunting. Some things that I would like to know is whether bushbabies are the only prey, for which they use these spears, or do they also hunt small rodents and what not. Is this a select incident or special case? Will we eventually find that this is a common trait among all chimps? I'm not really too familiar with the literature on chimpanzees, so perhaps I should look some of this stuff up?

Well, if you are interested, the original journal article can be found here at Current Biology.

February 22, 2007

You only see what you want to see!

Well, not exactly. But one social psychologist has shown that what we perceive is sometimes guided by our unconscious desires.

Psychologist David Dunning, from Cornell University, is interested in social perception and the accuracy and illusion in human judgment and decision making. He studies the subjective perceptions of people's surroundings and investigates how it differs from objective reality. One phenomena, of which this post is about, is how wishful thinking often affects what people physically see.

In one clever experiment, he tells participants that a computer game will either assign them a letter or a number, which will then tell these participants to either drink a glass of orange juice or an intentionally disgusting, green smoothie. The image that was flashed in front of the participants was something like this "13," just the 1 and 3 were a little bit closer together. This way the image could either be mistaken for the number 13 or the letter B. Participants who were told that if they saw a letter, they could drink the orange juice, more often than not reported seeing the letter B. And as you may be able to guess, participants told to drink orange juice after seeing a number more often than not reported seeing 13. Lying was controlled for by the use of a hidden camera that recorded eye movements.

Interesting study . . . again, if you haven't already checked out the link, a video clip of the research can be found here, under 'Wishful Seeing,' as well as a host of other neat videos.

Sorry honey, not tonight . . . my mom had a headache 30 years ago!

There's some interesting research being done concerning the effect that aspirin taken during pregnancy has on the adult sex drive of males.

Researchers at University of Maryland's Medical School have found that young male rats, who were exposed to aspirin in the womb or through nursing, have a lower than normal sex drive as adults. During the trials, the mother rats were given low doses of aspirin in their drinking water during their last week of pregnancy and their first week of nursing. This low dose appears to frustrate the wiring of a region in the developing rat brain that regulates sexual behaviors. Sexual behaviors seem to be regulated by the same region of the human brain as well. Though a design with human participants has not yet been utilized, it is not a far-fetched idea that a similar effect would occur in human populations.

A video clip of the investigation can be viewed here under the name 'aspirin and sex drive.' There are a lot of other cool videos there, of which I will probably write one or two posts . . . enjoy!

February 21, 2007

too much work . . .

Image by Sam Brown, Explodingdog

Yeah, so I can't seem to sleep . . . I have sooo much reading to do! I'm starting to get behind in my reading for stats and my behavioral neuroscience class. I'm not at that point where there's no turning back yet though. I still have plenty of time to catch up . . . I just can't seem to get away from this computer though, haha. Oh bother!

Besides the little catching up that I need to do, school seems to be going very well this semester. I enjoy my classes, have the TA routine down and, most importantly I received IRB approval for my research, so I can start collecting my own data very soon. YEA!!!!

Oh well, back to work!!!!

February 20, 2007

Possible key to autism

Researchers at the University of Medicine and Dentistry of New Jersey have stumbled upon a clue in the detection of the biological risk factors of autism. They have found that children with autism are unable to metabolize certain fatty acids that help the body fight against inflammation, which damages the brain and other organs. The gene that is responsible for the metabolizing of these fats is called GSTM1, and appears to be missing in many autistic individuals.

Today, autism is diagnosed through a clinical assessment of behavioral symptoms, such as difficulties in social interaction and communication. Yet the researchers propose that future risk and diagnosis could be established through urine samples that check for those specific fatty acids or through blood tests that check for the missing gene.

Inferences from the investigators' findings also help create new avenues of research for a promising treatment/cure for autism:

"The potential treatment, members of the team say, is a kind of 'therapeutic cocktail' tailored to each child, which would give them a dose of a 'good' fatty acid that they are not able to make on their own. Team member Bernd Spur of UMDNJ-Stratford created the chemical process to replicate one of those good fatty acids."
This is very good news. The whole story can be found here.

February 19, 2007

Cool . . .

Check out this quick read. It's about how scientists are working to help the blind to see:

"The retinal implants communicate with an external camera and computer. The person who receives the implant has a pair of glasses which include a video camera. Visual data from the camera is processed by a computer, the processed data is then sent to the implant - all this is done wirelessly. The electrodes in the implant turn the data into electrical impulses which are sent into the brain, which in turn interprets the visual data."
Pretty cool.

chocolate helps memory?

Scientists delivered a symposium on the neurobiology of chocolate at this year's meeting of the American Association for the Advancement of Science. There they presented the findings of their research, namely that the flavanols in chocolate help out the brain:

"The beneficial brain effects appear to stem from flavanols' impact on the blood system. In essence, the chemicals stimulate an increase of blood flow to the brain, particularly in areas that light up during tasks that require alertness. Experiments suggest this neurovascular activity is distinct from the well-known stimulant effects of caffeine."
The downside is that most chocolates lose their beneficial flavanols during processing. You can read about it all here.

February 18, 2007

Brain repair

BBC news has a recent article about a certain type of brain cell that has been found to continuously regenerate itself in humans. We have known about this phenomenon in rats and mice for over a decade, but the recent findings published in Science show for the first time the effect in a human sample.
"This opens another direction by which we may discover ways to repair human brains that are damaged from injury or diseases, and underscores the importance of animal research in guiding biomedical research in humans," says Dr. Mark Baxter from the Welcome Trust of Oxford University.
It's a short article. You can check it out here.

February 12, 2007

today in science history . . .

"We must acknowledge, as it seems to me, that man with all his noble qualities, with sympathy which feels for the most debased, with benevolence which extends not only to other men but to the humblest living creature, with his god-like intellect which had penetrated into the movements and constitution of the solar system -- with all these exalted powers. Man still bears in his bodily frame the indelible stamp of his lowly origin."

-Charles Darwin, The Descent of Man

Charles Darwin was born today! Well this day in 1809. Most know of him as an important figure of science in general, but his ideas about natural selection have an enormous influence on the field of psychology. Darwin's ideas gave us a tool, by which we can scientifically investigate traits that were once thought uniquely human, such as emotion, intelligence, ability to learn and self-awareness.

The idea that the law of evolution through natural selection applied to all organisms opened up new doors in experimental psychology. For one, it gave rise to comparative psychology, which is the study of the behavior and mental life of animals. Basically, comparative psychologists conduct studies on animals across different species to see what behaviors are similar and what's different, and how different. They also look at which principles of behavior are applicable to human beings.

Developmental psychology is another field that has a pronounced influence from Darwin. Developmental psychology is essentially the study of the progressive changes in behavior as human beings age. They are also interested in how innate certain behaviors are and how these behaviors are impacted by various social backgrounds. Some also look at what behaviors are experienced across the human species and what behaviors are specific to certain cultures.

And of course we wouldn't even have evolutionary psychology without the idea of evolution through natural selection. Evolutionary Psychology is the theoretical approach to psychology that looks at the psychological mechanisms that we now possess as adaptations to the environmental context through which our species evolved. For instance, we have a 'need to belong' and psychological mechanisms by which we can detect the likelihood of being socially accepted or excluded. Well, this most likely developed because working in groups was often times a matter of life and death in early hunter/gatherer societies. People who were better at being accepted into their group and better at avoiding ostracism would be more likely to survive and pass on their genes.

Darwin's ideas about evolution have had an enormous impact on many other fields of psychological inquiry, social psychology, behavioral neuroscience, clinical psychology, etc. . . . but I have a lot of work to do at the moment so I can't write anymore!


February 10, 2007


Now this is pretty cool! A wheel chair controlled by your thoughts!

I think I'm satisfied with this result . . .

I think I see it.

Your results:
You are Riddler

The Joker
Dark Phoenix
Mr. Freeze
Dr. Doom
Lex Luthor
Poison Ivy
Green Goblin
Riddle me that, riddle me this, who is obsessed with having a battle of wits??
Click here to take the "Which Super Villain are you?" quiz...

February 8, 2007

future looks bright . . .

for Evolutionary Psychology and it's influence on Social and Personality Psych.

Rats again

So we had the class demonstration of operant conditioning today. I think it went well. "Number 3" (the severely anxious rat) was a lot calmer than expected. He didn't even make a chirp or squeak. I was pleasantly surprised. Of course I have been handling him for about a week. I know that he has gotten used to me, I just didn't know what to expect with in a room of 30 psych. students. He did very well though. He's our 'middle' performing rat at the moment. Number 1 is our top performer and 2 is our slowest learner. As soon as you put 1 in a skinner box, he goes straight for the lever and will press it and keep pressing it until you take him out. 2 will just sit by the food tray and occasionally walk near the lever hoping to get a pellet. Then he gets tired and sleeps in the corner. 3 is somewhere in the middle. He is very good at pressing the lever, but you sometimes have to remind him that it's there. Sometimes he'll just clean himself in the corner, but if you press the reinforcement button and he hears that food pellet make a clink in the dish, he goes to work.

Next week the students will be assigned to their own rats, well actually 1 rat per two people. So students will be working with their rat in groups of two and for about two weeks everyday on their own time. They are supposed to keep record of their interactions in a journal, which they later hand in to me. At the end of the two weeks they bring in their rats and we have a sort of "Rat Parade." They just talk about working with the rat and show us what he/she can do. The students usually enjoy the experience, and I don't think this group will be any different . . .they seemed pretty excited about it today anyways.

Stephen Colbert interviews Steven Pinker!

If you have been reading likealake lately, you might have noticed that I have been making numerous posts about Steven Pinker. Well, can't help it. He has just been in the public eye a lot recently. Not to mention that he's the MAN! And I mean that in all seriousness. He's an important figure in cognitive science and has done a hell of a lot to popularize the field of Evolutionary Psychology. Pinker is one of those celebrity-status academics who kind of just take hold of your attention.

So, without further ado, here's an awesome video of Stephen Colbert interviewing Steven Pinker on the Colbert Report. It's pretty funny. The video is broken up into 2 parts. Of course Colbert had to make the hair joke, but other than that it seems Pinker endured the interview unscathed. It's really good so check it out!

February 2, 2007

Rats . . .

I am the teaching assistant for Dr. Langholtz's psychology research methods course this semester, and his course happens to be unique from other research methods courses in that the students actually get to work with rats for about two weeks to learn operant conditioning. It's pretty interesting.

So, about a week before the "rat labs," I work with three rats to get them ready for a class demonstration. It's not too bad, I got the hang of it now. But I was also his TA last semester, and before coming to W&M I haven't ever worked with rats (it was never a part of my research method courses at VCU). So when he told me that I would be in control of the rat labs I was pretty freaked out about it. I remember the first day of handling the rats, man that was horrible. I didn't know how to hold them . . . I thought I was going to squish them or they would bite me or something. But by the end of the week I felt like a pro. It was actually a good experience, and the students last semester really enjoyed the lab.

Well, today I started working with my rats . . . oh joy. Can you tell the hint of sarcasm? It's really not that bad actually. Rats are just time consuming when using them in research. You have to weigh them, feed them and then clean up after them before, during and after you complete your tasks for the day. I have three males this go round (last semester I had three females). At the moment two are really passive and don't really care what I do to them. But the other one is really aggressive and stubborn. He cries loudly and really tries to force himself out of my hands. Not to mention the control of his bowels that he happens to lose while I'm grabbing him. But I think he'll get used to me after a few days.

As a side-note, all students in the lab have to take a short "animals in research" ethics certification before they are allowed to proceed with the lab. Also, all that we are teaching them is operant conditioning stuff. No real intrusive procedures such as injections and what not. Just putting the rats in a skinner box and seeing if we can get them to press a lever for a food pellet. It's pretty easy and the rats catch on quick. We usually do the lab in fixed ratio schedules. In the beginning, the rats must learn that after every lever press a food pellet will come. Once that is mastered, then we go on to the next level, which is two lever presses before receiving a pellet and so on and so on up to a fixed ratio schedule of ten. After that students can try what they want, extinction (not killing the rat, but getting him/her to unlearn the behavior), variable ratio schedules, light discrimination schedules . . . whatever. They'll enjoy it.

We'll see how it goes I guess!