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Monday, 15 September 2008

Sience of the brain

Some interesting facts from our physiology.
The first one treats our olfactory sense. I won't comment it, both articles are not very commentable. But they are very informational.
For example, the first one explains why and to what extent, our nose rules our life. I personally find it little disgraceful how some people abandon their nose as a meaning of getting information. Of course, we cannot rule it our, since it's natural and quick, but they don't use it consciously. Which is wrong, since there is so much information and so many nuances you can get. For example, having a fever smells differently than not having. How about training your nose to discern your child's health? Isn't that useful? Well, I think it is. And I'm absolutely sure, you can train your nose to acquire a tremendous types of information. You just have to want it and to pay attention.
As for the other article, well, for me, it was interesting that the slow time when we're bored is connected with the 5% less energy that our brain uses while idle. Well, there are more points to it, but I think I'll leave them out for the moment. Let's just say that people tend to do crazy things out of boredom and the article might explain why. Or it might not. But in any case, the boredom is a natural condition that is connected with the conviction of the brain that there is nothing to be learnt from the current situation. Which mean that the "only" thing to do to reactivate the brain is to convince it, there's something interesting. Nothing new, but now-it's a science!

The Nose, an Emotional Time Machine

Published: August 5, 2008

Here is a fun and easy experiment that Rachel Herz of Brown University suggests you try at home. Buy a bag of assorted jelly beans of sufficiently high quality to qualify as “gourmet.” Then, sample all the flavors in the bag systematically until you are sure you appreciate just how distinctive each one is, because expertise is important.

Now pinch your nostrils shut and do the sampling routine again. Notice the differences? That’s right — now there are none. Every bean still tastes sweet, but absent a sense of smell you might as well be eating sugared pencil erasers. And if in midchew you unbind your nose, what then? At once the candy’s candid charms return, and you can tell your orange sherbet from a buttered popcorn.

We’ve all heard about the mysterious powers of smell and its importance in love, friendship and food. Yet a simple game like What’s My Bean shows that we don’t really grasp just how deep the nose goes. At the International Symposium on Olfaction and Taste held in San Francisco late last month, Dr. Herz and other researchers discussed the many ways our sense of smell stands alone. Olfaction is an ancient sense, the key by which our earliest forebears learned to approach or slink off. Yet the right aroma can evoke such vivid, whole body sensations that we feel life’s permanent newness, the grounding of now.

On the one hand, said Jay A. Gottfried of Northwestern University, olfaction is our slow sense, for it depends on messages carried not at the speed of light or of sound, but at the far statelier pace of a bypassing breeze, a pocket of air enriched with the sort of small, volatile molecules that our nasal-based odor receptors can read. Yet olfaction is our quickest sense. Whereas new signals detected by our eyes and our ears must first be assimilated by a structural way station called the thalamus before reaching the brain’s interpretive regions, odiferous messages barrel along dedicated pathways straight from the nose and right into the brain’s olfactory cortex, for instant processing.

Importantly, the olfactory cortex is embedded within the brain’s limbic system and amygdala, where emotions are born and emotional memories stored. That’s why smells, feelings and memories become so easily and intimately entangled.

Many mammals are clearly nosier than we. Consider that our olfactory epithelium, the yellowish mass of mucous membrane located some three inches up from our nostrils, holds about 20 million smell receptors designed to detect odor molecules delivered either frontally, when we, say, sniff a rose, or via the rear, the volatile aromas that come up through the back of the mouth and give each jelly bean meaning. The nasal membranes of a bloodhound, by contrast, sustain an olfactory army 220 million receptors strong.

Yet for all the meagerness of our hardware, we humans can become better nosehounds with startling ease. In one experiment, Dr. Gottfried said, subjects exposed to a single floral scent for just three and a half minutes markedly improved their ability to discriminate among whole families of flower odors. In another, participants soon learned to distinguish normally undetectable differences between one herbal smell and its mirror-image molecular twin if they were given mild electric shocks every time they guessed wrong.

Moreover, numerous studies have shown that smell memory is long and resilient, and that the earliest odor associations we make often stick.

In another presentation, Maria Larsson, an associate professor of psychology at Stockholm University, described the power of smell to serve as an almost magical time machine, with potential for treating dementia, depression, the grim fog of age. Johan Willander and others in her lab have sought to give firm empirical foundation to the old Proustian hypothesis, the idea that smells and aromas, like the famed taste of a madeleine dipped in tea, can help disinter the past.

Studying groups of Swedes whose average age was 75, the researchers offered three different sets of the same 20 memory cues — the cue as a word, as a picture and as a smell. The scientists found that while the word and visual cues elicited associations largely from subjects’ adolescence and young adulthood, the smell cues evoked thoughts of early childhood, under the age of 10.

And despite the comparative antiquity of such memories, Dr. Larsson said, people described them in exceptionally rich and emotional terms, and they were much likelier to report the sudden sensation of being brought back in time.

Dr. Larsson attributes the youthfulness of smell memories to the fact that our olfaction is the first of our senses to mature and only later cedes cognitive primacy to vision and words, while the cortical link between olfaction and emotion ensures that those early sensations keep their bloom all life long. source


You’re Bored, but Your Brain Is Tuned In


Published: August 5, 2008

Even the most fabulous, high-flying lives hit pockets of dead air, periods when the sails go slack.

Scientists know plenty about boredom, too, though more as a result of poring through thickets of meaningless data than from studying the mental state itself. Much of the research on the topic has focused on the bad company it tends to keep, from depression and overeating to smoking and drug use.

Yet boredom is more than a mere flagging of interest or a precursor to mischief. Some experts say that people tune things out for good reasons, and that over time boredom becomes a tool for sorting information — an increasingly sensitive spam filter. In various fields including neuroscience and education, research suggests that falling into a numbed trance allows the brain to recast the outside world in ways that can be productive and creative at least as often as they are disruptive.

In a recent paper in The Cambridge Journal of Education, Teresa Belton and Esther Priyadharshini of East Anglia University in England reviewed decades of research and theory on boredom, and concluded that it’s time that boredom “be recognized as a legitimate human emotion that can be central to learning and creativity.”

Psychologists have most often studied boredom using a 28-item questionnaire that asks people to rate how closely a list of sentences applies to them: “Time always seems to be passing too slowly,” for instance.

High scores in these tests tend to correlate with high scores on measures of depression and impulsivity. But it is not clear which comes first — proneness to boredom, or the mood and behavior problems. “It’s the difference between the sort of person who can look at a pool of mud and find something interesting, and someone who has a hard time getting absorbed in anything,” said Stephen J. Vodanovich, a psychologist at University of West Florida in Pensacola.

Boredom as a temporary state is another matter, and in part reflects the obvious: that the brain has concluded there is nothing new or useful it can learn from an environment, a person, an event, a paragraph. But it is far from a passive neural shrug. Using brain-imaging technology, neuroscientists have found that the brain is highly active when disengaged, consuming only about 5 percent less energy in its resting “default state” than when involved in routine tasks, according to Dr. Mark Mintun, a professor of radiology at Washington University in St. Louis.

That slight reduction can make a big difference in terms of time perception. The seconds usually seem to pass more slowly when the brain is idling than when it is absorbed. And those stretched seconds are not the live-in-the-moment, meditative variety, either. They are frustrated, restless moments. That combination, psychologists argue, makes boredom a state that demands relief — if not from a catnap or a conversation, then from some mental game.

Some evidence for this can be seen in semiconscious behaviors, like doodling during a dull class, braiding strands of hair, folding notebook paper into odd shapes. Daydreaming too can be a kind of constructive self-entertainment, psychologists say, especially if the mind is turning over a problem. In experiments in the 1970s, psychiatrists showed that participants completing word-association tasks quickly tired of the job once obvious answers were given; granted more time, they began trying much more creative solutions, as if the boredom “had the power to exert pressure on individuals to stretch their inventive capacity,” Dr. Belton said.

In the past few years, a team of Canadian doctors had the courage to examine the fog of boredom as it thickened before their (drooping) eyes. While attending lectures on dementia, the doctors, Kenneth Rockwood, David B. Hogan and Christopher J. Patterson, kept track of the number of attendees who nodded off during the talks. They found that in an hourlong lecture attended by about 100 doctors, an average of 16 audience members nodded off. “We chose this method because counting is scientific,” the authors wrote in their seminal 2004 article in The Canadian Medical Association Journal.

The investigators analyzed the presentations themselves and found that a monotonous tone was most strongly associated with “nod-off episodes per lecture (NOELs),” followed by the sight of a tweed jacket on the lecturer. source

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