Archive for September, 2009
September 30th, 2009 by Mary
Time supposedly is nature’s way of keeping everything from happening at once. Consciousness may be the body’s way of keeping two contrary actions from being attempted at once. A recent study found that people reported higher levels of awareness when they felt the urge to carry out two contradictory actions simultaneously, compared with when they were planning an action about which no conflict existed or when the conflict did not involve the motions of muscles under conscious control. The implication is that consciousness tunes in when something happens that requires a decision about what muscles to move and how to move them. This press release from EurekAlert has more information.
September 28th, 2009 by Mary
Subliminal messages are presented so briefly that people do not register them consciously, but they can still influence emotions and perhaps behavior. New research indicates that subliminal messages are more easily registered if they involve negative emotions than if they are positive or neutral. If registering such a negative stimulus is linked to behavior, this might might make sense if you figure that a quick reaction to something bad heading our way is probably more essential than a quick reaction to something good. In the study, people were exposed very briefly to words that were emotionally positive, negative, or neutral, and then asked to identify whether the word was neutral or emotional. Even if they felt like they were just guessing, they made more correct identifications when they were shown negative words.
This press release on EurekAlert gives more information. It mentions possible applications in advertising and public service announcements. It’s not clear to me how effective subliminal advertising really is—that is, subliminal advertising in the strict sense of material presented too quickly to be consciously registered, as opposed to “hidden messages” in ice cubes in vodka ads and such. The latter could be manifestations of either crafty ad-makers or the human tendency to find patterns anywhere, in my opinion.
September 26th, 2009 by Mary
About a month ago I posted a link to a story about humans might have increased atmospheric carbon dioxide by enough to cause global climate change thousands of years before industrialization caused the current and ongoing spike in CO2 levels. The mechanism was believed to have been massive burning of forests to clear land for farming. A new paper, however, examines the factors contributing to the rise in CO2 over the last 7000 years. By examining the ratio of two isotopes of carbon in ancient air (trapped in bubbles in ice cores from Antarctica), researchers can figure out, in broad terms, the origin of atmospheric CO2. The results of a recent analysis of nearly 200 samples indicate that human land use played only a small part, and that the pre-industrial rise was mostly natural (due to a natural increase of vegetation after the ice age ended and the effect this had on ocean chemistry). This news story from Science magazine has the details.
This is particularly interesting in the context of a new framework for evaluating the impact of humans on their planet. A team of scientists published an article in Nature this week describing the environmental limits that mark out a “safe planetary operating space.” They identified nine factors (one of which is biological diversity, so at least it’s not entirely about a safe operating space for humans alone). Check out Nature’s Planetary Boundaries special feature. It looks like at least some of the content is available even to non-subscribers. However, in case that changes at some point, here’s a story from Science Daily.
And while we’re on the topic of the effect we have on our planet, this week New Scientist also published a series of articles on population, at least some of which appear to be available to all.
September 24th, 2009 by Mary
Natural History magazine has published an article by Frans de Waal that is excerpted from his recent book, The Age of Empathy. He discusses the bodily basis for feelings of empathy, from shared laughter, shared yawns, and other forms of physical synchrony across a variety of species. (The sequence of images of a yawning primate had me yawning too.) His focus is on the often instinctive and unconscious way that our bodies synch up with those of others, providing the basis for more conscious thoughts and feeling related to empathy.
September 23rd, 2009 by Mary
A gene called COMT has a mutation that is associated with better working memory and higher verbal IQ in those that possess two copies of it, compared with those who have only one copy of it or two copies of a different mutation. However, the mutation is also associated with emotional vulnerability and anxiety. In a recent study of about 800 Taiwanese students who took a high-stakes assessment exam that has a significant effect on their future education, those with two copies of the mutated gene scored lower than others, despite its effects on working memory and verbal IQ. This may indicate that the down side of the mutation outweighs the up side—at least in that particular population and those particular circumstances. This article from New Scientist has the details. Note that the sample size is rather small for such studies, so it’s not clear what exactly is going on. However, this does seem to make the point that pinpointing the effect of single genes on cognitive performance is a subtle business.
September 22nd, 2009 by Mary
As anyone who has suffered from it knows, depression would seem to have few or no good points; the only reasonable approach seems to be to find a way to make it stop, the sooner the better. Indeed, depression exacts a terrible toll in terms of lost time, lost energy, and even lost lives.
So why do people get depressed? With such unpleasant or even dire consequences to this illness, why was it not eliminated by natural selection long ago? It’s not a disease of aging, like most cancers, so that can’t be it. As unlikely as it seems, depression may be best viewed as an adaptation that offers the benefit of uninterrupted, highly analytical cogitation about complex problems. This article from Scientific American explains how the symptoms of depression might fit this interpretation, and offers some evidence that prolonged, productive contemplation of one’s problems might in fact help depressed people gain insight into their problems and thus be better able to resolve them.
This idea is, frankly, a hard sell for me, because when I’m depressed, all I want is to feel better right now. However, I have encountered various books that suggest that depression sometimes has something to tell you, in roughly the same way that physical pain can alert you to a danger that you must address. As is almost always the case when I’m thinking about depression, I’m torn between the idea that depression is a sign that something is out of whack biochemically and needs to be set right, and the idea that it is a sign of emotional imbalance that needs to be explored and corrected. Both are probably true to differing degrees in different situations, so it’s worth looking into all the options available when you are depressed (medication, changes in diet and exercise, writing in a journal, counseling, and so on).
I’m also curious about the possible connection between depression and the typical diet in industrialized countries. I’ve been reading more about omega-3 fatty acids since I heard that talk last week about fats and the brain; the average American diet is seriously lacking in these necessary nutrients, which have been tentatively linked with depression. If depression is indeed an adaptation, I wonder if dietary deficiencies or other aspects of the way we live are inadvertently tripping the mechanism for this adaptation at times when it doesn’t actually do us any good. At any rate, it never hurts to nourish your brain well, both physically and emotionally.
September 21st, 2009 by Mary
Are we a naturally violent species or a naturally cooperative species? The answer may be “Yes,” meaning that both violence and cooperation are within our behavioral repertoire. However, the large-scale violence of warfare might be more a result of environmental conditions than anything to do with our genes. It might be human nature in the sense that it naturally appears in response to certain situations, but it’s not an inevitable component of human behavior. That, anyway, is the overall message of this article from New Scientist. (It’s from July; I’m finally getting the chance to follow up on some old bookmarks.)
The article explores the history of warfare and variations in the degree of warmongering over time and in different cultures. Part of this ties in to an article I linked to a couple of months ago about whether the move to agriculture was a bad idea in some ways; recent research suggests that warfare arose only with the advent of permanent human settlements and was often associated with agriculture. However, subsequent developments have led to far less violence in modern societies than in their earlier precursors, for a number of reasons, which the article also goes into.
If warfare occurs only in certain circumstances, what are the environmental factors that encourage or discourage its emergence? Crowding and resource scarcity have long been important. In today’s world, which is socially much “smaller” than any that humans have lived in previously, intolerance of differences, particularly religious differences, is another notable factor. The good news is that as we learn more about the roots of war, we know more about which environmental influences to manipulate to lessen the likelihood of war.
The bad news is that making some of these manipulations is not simple. For example, reducing population is crucial to decreasing both resource shortages and environmental degradation, but the topic is evidently something of a hot potato; I have seen very little about the importance of slowing and reversing population growth for concerns like global warming and looming freshwater shortages. (A recent report from the London School of Economics is getting some press lately, though, so maybe that will raise awareness a bit.) Anyway, knowing what to do and being able to do it are not the same thing, and current events indicate some disturbing trends toward the kind of environmental factors that are likely to trigger warfare.
However, balancing the good news and the bad news, it seems to me that there is room for hope in our growing knowledge of human nature and human behavior. Our collective capacity to understand and change the human social landscape is growing. Individually, it can be challenging, but I recently saw a William James quote that seems appropriate here: “Act as if what you do makes a difference. It does.”
September 20th, 2009 by Mary
Why are we the only primates with so little body hair? I thought this had been figured out, and that it had something to do with helping us shed body heat more quickly once we had moved out of the forest. But this article from New Scientist explains the shortcomings in that and various other explanations. The author, Elaine Morgan (ofAquatic Ape fame) also discusses current genetic research that may help resolve the question. Scientists are examining not only human genes but also those of lice, which evidently reveal a fair amount about their hosts. I love science.
September 19th, 2009 by Mary
Fans of the surreal, take heart. Recent research suggests that reading stories involving bizarre events that don’t necessarily make sense can temporarily enhance your ability to identify patterns that help you learn new material. Researchers did two studies to investigate the effects of exposure to a “meaning threat,” something that didn’t make sense or that upset typical notions.
In the first study, subjects read either a Kafka short story (The Country Doctor) pretty much as he wrote it, with its strange and inexplicable series of events, or a tidied-up version that was edited into a more conventional story line. In the second study, people were asked to think about aspects of their own past behavior that are contradictory—in other words, to consider the ways that identity is not as unified as we typically assume it is. After this, participants in both studies were shown strings of letters arranged in a strict but subtle pattern. Then they were given new letter strings and asked to identify the ones that conformed to the pattern.
In both cases, the people who were exposed to the meaning threat (the original Kafka story, the idea of a somewhat fragmented identity) not only selected more strings as adhering to the pattern, but were also correct more often than the respective control group. The researchers explain this by suggesting that it’s uncomfortable to have our common-sense expectations violated, and to compensate when that happens, people are more motivated to make sense of what’s going on around them.
It would be interesting to know if this extends to other media such as music or visual art. It’s also kind of interesting to me that one of the problems with the human cognitive apparatus is that we often make connections too easily, through various cognitive biases such as confirmation bias. Finding associations between seemingly unrelated things or events is a source of creativity, and uniting disparate phenomena under a single comprehensive explanation is often a goal of science. On the other hand, finding patterns where none exist (the supposed face on Mars is a classic example) is a less agreeable manifestation of our hunger for meaning. Like so many things about human thought, perhaps pattern-seeking deserves a “Handle with care” label. Goo goo g’joob.
This article from ScienceDaily describes the research in more detail. The paper appears in Psychological Science:
Connections From Kafka: Exposure to Meaning Threats Improves Implicit Learning of an Artificial Grammar, Travis Proulx and Steven J. Heine. Psychological Science, 20 (9), 1125–1131.
September 17th, 2009 by Mary
I went to an interesting talk today, one of Indiana University’s themester activities. Steven Gaulin of UC Santa Barbara spoke about work he has done with William Lassek on the relationship between human brain size and sex differences in fat distribution. It’s a fascinating story. We women are fattier overall than men, and we tend to carry our fat in different places. One thing the sexes have in common, however, is that fat is vital to the brain, the dry weight of which is mostly fat. Could the differences and the similarity be linked?
Gaulin presented several lines of evidence suggesting that fat deposited on women’s hips and thighs provides the material needed to build the unusually big brains (as primate brains go) of their offspring. He also suggested that a link between lower-body fat and cognitive ability in one’s offspring might have driven male preference and thus sexual selection for a low waist-hip ratio (WHR, i.e., the bottom half of an hourglass figure with small waist and large hips).
Among the things he discussed is something called maternal depletion, evident in hunter-gatherers but also more subtly observable in American women, in which the amount of hip/thigh fat decreases as women bear more children. Another factor is a link between WHR in women and cognitive ability (the data they used showed a link between lower WHR—i.e., more lower-body fat—and higher cognitive abilities in their offspring). Menarche (the onset of menstruation in young girls) appears to be related not to the amount of body fat but to its distribution (specifically, a greater amount of it on the hips).
Other lines of evidence include the fact that hip/thigh fat is very hard to get rid of; the body seriously taps into it only during the last trimester of pregnancy and during lactation. Also, hip/thigh fat and abdominal fat (the kind men are more prone to carry around) have opposite effects on the body’s supply of two long-chain polyunsaturated fatty acids that are crucial to brain development, docosahexaenoic acid (DHA) and arachidonic acid (AA). As best I could understand it—I’m not a biochemist, so I’m speaking fairly broadly here—the former promotes and the latter hinders the synthesis of these two fats.
I can’t possibly do justice to the entire talk here. In a nutshell, the shape of women’s bodies could be intimately connected, in interesting ways, with the need to nurture the development in babies of these unusually large brains we have. You can check out Gaulin’s web page for more information, including links to papers about the maternal depletion and menarche research.
September 16th, 2009 by Mary
Seed has posted an article about optical and tactile illusions. Such illusions, enjoyable and mind-boggling as they can be, are more than just curiosities; they can help us figure out how the brain processes reality. The article provides some interesting examples, with links to more information.
September 14th, 2009 by Mary
Yes, the blog looks a little peculiar today. The software was just upgraded, and over the next few days I will be tweaking and twiddling to drag Thinking Meat kicking and screaming into–oh, the mid-2000s, anyway, in terms of design. Meanwhile, I ask your patience as I re-learn the exciting world of CSS and so forth. (If you have any suggestions for layout or appearance, by the way, or something has always bugged you about navigating the site, please let me know! I can’t promise to incorporate all suggestions, but I’d like to hear them.)
September 9th, 2009 by Mary
This is a bit off topic, but worth passing on: They Might Be Giants has released a new CD/DVD set for kids called Here Comes Science. Here’s a video of one song, Science Is Real. This set looks like an excellent gift for any budding young minds you might be fortunate enough to have in your life.
September 3rd, 2009 by Mary
Those of you in Bloomington might be interested in some of the events associated with Indiana University’s “themester” (I don’t like the word but the concept is great). The theme this semester is Evolution, Diversity, and Change. Many of the lecture series and speakers will cover Thinking Meat sorts of topics; here’s a complete list. Richard Dawkins will be speaking here October 12, and Judge John E. Jones III (who ruled in the Dover-Kitzmiller trial about the teaching of intelligent design as an alternative to evolution) will be speaking on December 4. There are lots of other interesting talks coming up as well.
