Brain and Behavior
dmunger | February 16, 2007Anyone who has tried to capture a fly or other insect can't help but marvel at their aeronautic prowess. Their reflexes are lightning-fast, and they seem to avoid obstacles before they are even perceptible. The brain of a fly or a honey bee is as little as a millionth the size of a human brain, with as few as a hundred thousand neurons compared to our hundred billion. How can such small computing power lead to such effective flight?
Yet flying insects also exhibit curious behavior. They land when flying into a headwind, and gain elevation with a tailwind. Some honey bees will land on the…
clock | February 15, 2007This is the last in the 16-post series of BIO101 lecture notes for a speed-course targeted at adults. As always, I welcome corrections and suggestions for improvement (June 17, 2006)...
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Last week we looked at the organ systems involved in regulation and control of body functions: the nervous, sensory, endocrine and circadian systems. This week, we will cover the organ systems that are regulated and controlled. Again, we will use the zebra-and-lion example to emphasize the way all organ systems work in concert to maintain the optimal internal…
purepedantry | February 15, 2007In light of the Lisa Nowak love triangle/kidnapping/nutness NASA is re-evaluating how it...well...evaluates astronauts for psychological fitness for space flights.
Part of the problem is one of sex frankly; astronauts are not allowed to have it while on duty.
NASA has been intransigent about the idea of the astronauts have intimate relations, justifying this policy because they would rather not deal with any of the associated problems on manned missions. On the other hand, for particularly long flights -- such as trips to Mars -- sex could be a stabilizing force. Anyway, an interesting…
purepedantry | February 14, 2007Restless Legs Syndrome is a neurological disorder, in spite of what you might think from the ridiculous ads on television. RLS is a syndrome where the individual has weird sensations in their legs while they are trying to relax. These sensations can be just unpleasant, or they can be quite painful. The result is that the individual has trouble sleeping -- leading to a marked reduction in their quality of life and ability to function.
RLS is treated with drugs similar to Parkinson's drugs -- drugs that function as dopamine agonists. It is known that a rare side effect of Parkinson's…
ddobbs | February 13, 2007
At this week's Mind Matters (the expert-written blog seminar I edit for sciam.com), Julie A. Markham of the University of Ililnois and Martha J. Farah of the University of Pennsylvania ponder how stimulating environments (read: better digs) and (of all things) fatherhood can build brains and make you smarter, at least if you're a marmoset.
The studies in question find that bigger, more interesting cages and fatherhood both spurred growth of dendritic spines -- the neuron's info receivers -- in marmosets. I was quite interested to read this, since two years ago I moved into a bigger, funner…
thusspakezuska | February 13, 2007This is the third of three discussion posts for Week 1 of Feminist Theory and the Joy of Science. You can find all posts for this course by going to the http://scienceblogs.com/thusspakezuska/archives.php>archives and clicking on "Joy of Science" under in the Category section.
This post deals with the readings by Hubbard, Spanier, and Keller, as well as the NSF report "Beyond Bias and Barriers".
Ruth Hubbard, Bonnie Spanier, and Evelyn Fox Keller each made the transition from practicing scientist to feminist critic of science. Hubbard addresses an issue that bothered me greatly when I…
developingintelligence | February 12, 2007Whereas yesteryear's artificial neural networks models were focused on achieving basic biological plausibility, today's cutting edge networks are modeling cognitive phenomena at the level of neurotransmitters. In a great example of this development, McClure, Gilzenrat & Cohen have an article in Advances in Neural Information Processing Systems where they propose a role for both dopamine and norepinephrine in switching behavior between modes of "exploration" and "exploitation."
First, a little background. In artificial intelligence circles, the "temporal difference" algorithm has been a…
clock | February 12, 2007
Yes, I was never a member of Boy Scouts (no such thing in Yugoslavia, of course), but I will gladly join the Order of the Science Scouts of Exemplary Repute and Above Average Physique, the brand new organization founded by the folks of World's Fair and the Science Creative Quarterly. Steve of Omni Brain and John Lynch have already signed up.
Above Average Physique? I am super-skinny. But OK, I am tall. And energetic. And have a deep bass voice. That should count...
So, of the possible badges, which ones apply to me? Let's see...
The first one is obligatory for all members:
The "…
omnibrain | February 11, 2007It's the end of an era (and also a lot of embarrassment for Princeton and scientists in general) for the Princeton Parapsychology lab.
From the NYT on Friday:
Over almost three decades, a small laboratory at Princeton University managed to embarrass university administrators, outrage Nobel laureates, entice the support of philanthropists and make headlines around the world with its efforts to prove that thoughts can alter the course of events.
But at the end of the month, the Princeton Engineering Anomalies Research laboratory, or PEAR, will close, not because of controversy but because, its…
retrospectacle | February 10, 2007Huffing, or inhalant abuse, is a significant problem among young people and the homeless due to the habit being cheap and easily accessible legally. It involves the concentration and inhalation of chemicals that are found in many household cleaners, solvents, glue, paint, etc, which result in the person feeling inebriated or "high." At higher concentrations these chemicals can induce nausea, psychosis, memory loss, emotional disturbances, or violent behavior. One of the most common ingredients in abused inhalants is toluene (think the smell of paint thinner), an aromatic hydrocarbon which…
razib | February 9, 2007The "domestic" cat, Felis silvestris catus, has been with us for nearly 10,000 years. Recently, a 9,500 year old burial of a human and their companion cat was discovered on Cyprus. Cats are not indigenous to the island, so it seems that the presence of this cat must be owed to human intervention in some manner. Though we are used to thinking about how humans shaped cats through selective breeding the recent data on Toxoplasma gondii suggests that cats might have an impact on human behavior that could explain cultural differences! Some intellectuals have posited that the selection of…
clock | February 9, 2007Children's Sleep Problems Can Lead To School Problems:
It is obvious that young children who have difficulties sleeping are likely to have problems in school. A new study shows that African-American children and children from lower socioeconomic backgrounds fare worse than their counterparts when their sleep is disrupted. The study offers one of the first demonstrations that the relationship between children's performance and sleep may differ among children of different backgrounds. Conducted by researchers at Auburn University and Notre Dame University, it is published in the January/…
clock | February 8, 2007
The penultimate installment of lecture notes in the BIO101 series. Help me make it better - point out errors of fact and suggest improvements:
It is impossible to cover all organ systems in detail over the course of just two lectures. Thus, we will stick only to the basics. Still, I want to emphasize how much organ systems work together, in concert, to maintain the homeostasis (and rheostasis) of the body. I'd also like to emphasize how fuzzy are the boundaries between organ systems - many organs are, both anatomically and functionally, simultaneously parts of two or more organ systems…
developingintelligence | February 6, 2007Humans are notoriously finicky decision makers, and new research is beginning to elucidate the neural networks that are responsible. For example, we are exquisitely sensitive to framing effects regardless of whether two decisions have mathematically equivalent value - a previous post reviews how this framing effect may arise in the brain. Another famous example is delay of gratification: often we are willing to accept less of something now rather than wait for more of it later. Today's post summarizes a recent article that begins to explain why.
In their 2004 article, authors McClure,…
bushwells | February 6, 2007There's a little corner of the Internet which I stumbled across several weeks ago, a personal blog in which a young writer, her educational background in biopsychology, recently dissected an expansive and bizarre post-modern Milgram-esque experiment which occurred at fast-food chain restaurants throughout the United States during the span of 2000 through 2004, at which time a suspect was arrested, and the hoaxes ceased. The story, as reported originally in the Louisville KY Courier-Journal, A hoax most cruel in October 2005, outlines the history and consequences of a series of abuse by an…
clock | February 6, 2007Slow-wave Activity During Sleep Affected By Quality, Intensity Of Wakefulness:
A study published in the February 1st issue of the journal SLEEP provides a first direct demonstration that the "quality" and "intensity" of wakefulness can affect slow-wave activity (SWA) during subsequent sleep.
According to Chiara Cirelli, MD, PhD, of the University of Wisconsin-Madison, one of the authors of the study, the importance and novelty of the paper lies in the demonstration that the crucial factor linking physiological waking activity to sleep SWA is synaptic plasticity, notably synaptic potentiation…
pharyngula | February 6, 2007Sometimes I do get strange requests in email. For instance, I was asked if the claim in this article was true:
When an orgasm has been achieved through sex, you can measure theta waves. These are also said to cause the "running high" feeling of euphoria experienced sometimes by marathon runners. If theta waves are taken as a criterion, the entire brain emits theta waves when women reach an orgasm that are close on 10 times stronger than when men climax. So, if theta waves are an indication of an orgasm's strength, then women experience an orgasm that is physically impossible for men to go…
developingintelligence | February 5, 2007What cognitive processes make up consciousness? One way of answering this question is to identify conscious processes as those involved in controlled but not in automatic behaviors. For example, if you see a bright dot appear in your field of vision, your eyes will automatically orient to that location in space. In contrast, if I have told you to look away from any bright dots that appear in your field of view, you will be able to do this - but only because you possess consciousness in the form of "cognitive control." So, what computations support "cognitive control"?
Cognitive control is…
clock | February 5, 2007
Last week I asked if you would be interested in my take on this paper, since it is in Serbian (and one commenter said Yes, so here it is - I am easy to persuade):
Stankovic Miodrag, Zdravkovic Jezdimir A., and Trajanovic Ljiljana,Comparative analysis of sexual dreams of male and female students (PDF). Psihijatrija danas 2000, Vol. 32, No. 4, pp. 227-242
Here is the English-language Abstract:
The subject of research is analysis of connection between sexuality as instinctive function and dreams with sexual content as cognitive function. The sample consisted of 656 students, 245 males and 411…
developingintelligence | February 3, 2007My favorites from the last two weeks in brain blogging:
First off, a new blog: Robots Will Take Over!
Neural networks in silicon, and progress in brain-computer interfaces.
Lifestyle improvements, brought to you by your friends at DARPA
Is machine learning really any different from statistics? (One of my pet peeves, incidentally).
A critical view of simulation's role in science
Thank the military for cockroaches that are even harder to kill: tomorrow's robotic insects
Sequelae of Octopus Intelligence? Senescence and depression in cephalopods.
Bird Grammar: Recursive center-embedding in…