You have nothing to lose but your weariness! At any rate, that’s the gist of this article from Science Daily. In a recent study of normal sleepers, napping during the day improved cognitive performance on the following day without affecting night-time sleep. It’s not entirely clear from the article, but it sounds like the study participants were all over 60, so I’m not sure how much this applies to younger people. But by George, napping sure sounds good to me. This Science Daily article from 2002 discusses the role of napping and early-morning sleep in avoiding burnout and learning new skills, respectively. Also, napping might be part of our biological heritage from earlier humans. Human circadian rhythms include a dip in energy levels at some point in the afternoon, perhaps a reflection of an earlier bi-phasic sleep pattern that included a longer period of sleep at night and a shorter period during the day. Long live the siesta!
Painstaking studies of specific neurons in the prefrontal cortex of two rhesus monkeys revealed that the animals had neurons that responded to specific numbers, whether the numbers appeared as a pattern of dots or as an Arabic numeral. The monkeys were taught the numbers from one to four, and researchers subsequently found neurons (more than one neuron per number) that would each respond to a particular number. Monkeys may not have the words to talk about numbers, but they evidently can grasp the concepts. It’s possible human brains might have similarly tuned-in brain cells that fire for particular numbers, although it’s not clear how many numbers might have their own neuronal representation even in monkeys much less in humans (it’s probably not every single number, although it would be interesting to know whether it varies from person to person). You can read about it in this New Scientist article or if you’re really curious, check out the whole paper in PLoS Biology.
A recent study indicates that the difference between those who tend to solve problems in a moment of creative insight and those who solve them methodically may be evident in their brain activity even when they’re not solving problems at all. In fact, a person’s typical brain state might influence the type of problem solving style he or she uses.
In the study, volunteers rested quietly thinking of whatever they liked, and their EEGs were taken to get an idea of their baseline brain activity. Then they had to solve a series of anagrams (rearranging scrambled letters to make a word) and recorded whether each answer came to them in a single “Aha” moment or whether they attacked the problem step by step. The participants were divided into two groups, an “Aha” group and a methodical group, based on which strategy they used more often. The baseline EEGs of the two groups (taken, remember, before they were given any problems to solve or were even aware that they would be solving puzzles) were noticeably different.
The more creative group showed activity that indicated more diffuse visual attention and a greater tendency to make associations between remotely related concepts. This underscores the fact that particular skills are involved in thinking creatively. It’s also worth noting that they may not be the best skill set for every situation–creative thinking is perfect for situations that require you to cast a broader net and link peripherally related ideas, but being able to focus your attention on a known procedure has its place too. This article from Science Daily has more information.
Altruism toward community members who are not related to you, with its implications of kindness and generosity, may be intertwined in human history with hostility toward members of other communities. Researchers at the Santa Fe Institute have used game theory and computer simulations to demonstrate that under the conditions our late Pleistocene and early Holocene human ancestors probably faced, neither agression toward outsiders and generosity toward unrelated people (parochial altruism) are likely to have been viable strategies by themselves, but they could have been successful together. Each strategy is in some sense costly (benefitting others who don’t carry your genes, in the case of parochial altruism, and taking time and energy and risking death in the case of aggression toward outsiders). But if parochial altruism bound a community closely enough together that it was more likely to succeed in its attacks against outsiders, then the two strategies could work hand in hand. You can read more about the research in this press release from Science Daily.
Note that this is talking about the past, and not about conditions today. This dynamic may be alive and well in the human psyche today; to anyone who’s been on the outside of a close-knit community, this link between solidarity and hostility is not as counterintuitive as it may sound–being in, being “one of us”, is full of benefits, but if you in some way don’t fit the mold, you can in some cases quite easily become “one of them” and be ostracized or worse. But that doesn’t mean we have to live out this dynamic over and over. Not only do we have the power to understand and change our behavior, I think we may also find it imperative to do so in order to survive, in an age of nuclear and biological weapons and global problems that urgently require us to cooperate.
The morning dose of cough medicine with hydrocodone is starting to wear off and it’s not time for the evening dose yet, so maybe I’m awake enough to blog. So, how about a story about the antidepressant effects of cannabinoids? In lab animals, a synthetic cannabinoid at low doses appeared to act as an antidepressant and to increase activity in serotonin-producing neurons, but at higher doses had a completely opposite effect, bringing about a nasty drop in serotonin levels. This research is perhaps a step along the way toward developing cannabinoid therapy for mood disorders, and certainly provides an interesting look into the actions of cannabinoids in the brain. It also shows for the first time that cannabinoid CB1 receptors directly affect brain cells that produce serotonin. This press release from EurekAlert has more details.
I haven’t been sleeping all that well these days, but for some reason I find myself feeling an almost overwhelming urge to nap when I read the science section of the New York Times this week. Maybe it’s because there are so many articles about sleep and dreaming. This article talks about what goes on in the sleeping brain, and covers recent evidence that sleep seems to aid in the tasks of memory and learning. This one goes into nightmares and bad dreams. And this page features some good quotes about sleep and dreaming, from people ranging from poets to physicists (thanks to Tom for alerting me to this one).
If you’re interested in what the universe is made of and its long-term fate, you might want to go hear Neta Bahcall’s two Patten lectures at Indiana University in Bloomington this week. Tonight at 7:30 Bahcall, a cosmologist from Princeton, will talk about the composition of the universe–in particular, dark matter and dark energy–and at 7:30 on Thursday she will discuss whether the universe will expand forever or will collapse back upon itself. The talks are free and open to the public. For more information, see the news release from IU about the lectures.
When I was younger, I could bounce back more easily from sleep deprivation; now that I’m in my mid-40s, it’s harder to deal with a short night or worse yet, a series of short nights. My mind becomes muddy and my body feels sluggish. Studies have investigated the physical and cognitive effects of sleep deprivation, but not as much has been done to examine the emotional effects of sleep loss. A recent study looked at 26 healthy volunteers, some of whom kept a normal sleep/wake schedule and some of whom had to stay awake for 35 hours. Then, while their brains were scanned with fMRI, both groups were exposed to images that started out bland and became increasingly emotionally disturbing. The sleep-deprived group showed much more activity in areas of the brain involved in processing emotions (the press release doesn’t say specifically which areas) compared to the group who slept normally. The press release also doesn’t say if the people were monitored in any other way for the strength of the emotion they were feeling (self-reporting, respiration or heart rate, etc.). (I’d be particularly interested in correlations with what people reported they were feeling.) At this point there’s no telling why this should be the case or how sleep might buffer the effects of emotional stimuli, but this is an interesting start. This press release from EurekAlert has more information.