So say Colorado-based researchers Sandy K. Wurtele and collegues in a new paper in the journal Sexual Abuse: Nearly 10% of males and 4% of females reported some likelihood of having sex with children or viewing child pornography. The study is an interesting attempt to probe the darkest depths of human nature, and raises questions […]The post Are One In Ten Men Sexually Attracted To Children? appeared first on Neuroskeptic.... Read more »
Wurtele SK, Simons D, & Moreno T. (2013) Sexual Interest in Children Among an Online Sample of Men and Women: Prevalence and Correlates. Sexual abuse : a journal of research and treatment. PMID: 24215791
Feeling smug because your normal brain doesn't insist on coloring all its 2's blue and M's purple? Not so fast: you might have been a child synesthete. Some elementary schoolers have associations between colors and letters or numbers that fade as they age. Others' associations expand to take over the whole alphabet, leading them toward a rainbow-hued adult life.Studying kids with synesthesia is tricky, because first you have to find them—and at a young age, kids don't know the word, or that their perceptions aren't standard. University of Edinburgh psychologist Julia Simner screened 615 kids for synesthesia back in 2009. Starting with six- and seven-year-olds, Simner and her coauthors sat the kids in front of a computer screen and told them to play a game: they'd see a letter or number next to a set of colors, as above, and should choose the "best" color for each one.After the computer ran through every letter and numeral in random order, it paused for several seconds, then did the entire test a second time. Forty-seven of the kids were significantly consistent in their choices between the two tests—which meant either that they were synesthetic, or that they had a good memory for colors they'd picked at random. The moment of truth came a year later, when those 47 kids sat down and took the test again. People with synesthesia should be consistent not only over a few minutes, but over years. That's because it's not really a test of memory for them; color is simply a quality that a letter or number has, like being even or a consonant. (For rarer types of synesthesia, people might experience colors with sounds, or tastes with words.)In 2009, Simner found eight girls and boys who passed her tests. For a new study published in Frontiers in Human Neuroscience, Simner and coauthor Angela Bain returned to these patient elementary schoolers—now 10 or 11 years old—and did the test a third time.They wondered whether any kids' synesthesia would have faded over the intervening years. Anecdotally, some adults say they remember having synesthesia as a child and growing out of it. The researchers started with not just their eight synesthetes, but 39 of the kids who had been classified as near misses in the first go-around—they had been consistent over 10 seconds, perhaps, but not over a year, or their performance had been just shy of statistically significant. Another 40 average kids served as controls.This time, six kids passed the test. They were consistent both within two trials and compared to their original tests four years earlier. On testing day, these synesthetes made consistent color choices for about 26 out of the 36 letters and numerals they saw. Non-synesthetes were consistent for only 6 or 7.Five of the children were from the original batch of synesthetes, and the sixth had been a near miss originally. The other three original synesthetes were no longer significantly outperforming their peers in choosing consistent colors. This may be evidence of "synesthetic demise," the authors write.Young synesthetes losing their colors over time would fit with a popular theory about synesthesia, which says that it comes from an overly connected brain. "All very young children have hyper-connected brains," Simner says; the neurons branch out indiscriminately between different areas. As we grow, the unneeded connections are pruned away, a process that continues throughout childhood. "It may be that synesthetes escape the pruning, so to speak," Simner says. All kids might start out with some degree of synesthesia, which fades away with normal development.It's also possible, Simner says, that the "near-miss" kids actually had synesthesia that was developing more slowly than their peers'. She found that synesthetes add more and more colored characters to their rosters as they age. When synesthetes were six or seven years old, they had consistent colors for only about a third of letters and numbers. In another year that number had risen to almost half, and at age 10 or 11 over 70% of letters and numbers had fixed colors. Adult synesthetes have consistent colors for 80 to 100% of letters and numbers.So for people who don't lose their synesthesia as they age, it becomes steadily more consistent. Now that Simner's subjects are 14 and 15 years old, she says, "we very much hope" to test them again. The teenagers may be happy to learn that at least one thing about their lives is becoming less chaotic.Image: Simner & Bain 2013.Julia Simner, & Angela E. Bain (2013). A longitudinal study of grapheme-color synesthesia in childhood: 6/7 years to 10/11 years. Frontiers in Human Neuroscience DOI: 10.3389/fnhum.2013.00603
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Julia Simner, & Angela E. Bain. (2013) A longitudinal study of grapheme-color synesthesia in childhood: 6/7 years to 10/11 years. Frontiers in Human Neuroscience. DOI: 10.3389/fnhum.2013.00603
The professional musician who follows her dream of performing on the stage is greeted by an array of unusual occupational hazards. These are not limited to those late night hours spent in bars exposed to cigarette smoke and aggressive groupies but the risks of carpal tunnel, hoarseness, hearing loss, and the longterm effects of strange sleeping schedules as well. For those that provide their marching bands, funk joints, and jazz ensembles with that crucial brass sound, however, they may be at additional risk from a tiny threat hiding within their very own instrument.... Read more »
F Metzger et al. (2010) Hypersensitivity Pneumonitis Due to Molds in a Saxophone Player. . Chest. DOI: 10.3410/f.5396957.5351055
Newly found fossils suggest hominids are ‘breeds’ of the same species.... Read more »
Ann Gibbons. (2013) Stunning Skull Gives a Fresh Portrait of Early Humans. Science. DOI: 10.1126/science.342.6156.297
Richard Wrangham recently came and gave a talk as part of a four-field Anthropology colloquium here at Michigan. He presented an idea that's been gaining ground in biological anthropology in recent years - namely, that humans are adapted to consume a diet of cooked food. Having eaten my fair share of pizza recently (dissertation proposal grading = questionable nutritional decisions) I was inclined to agree with him. However, he didn't just appeal to the audience's craving for junk food. In fact, Wrangham's approach was particularly apropos for a four-field audience, as he focused on several different lines of evidence to make his argument:... Read more »
Boback SM, Cox CL, Ott BD, Carmody R, Wrangham RW, & Secor SM. (2007) Cooking and grinding reduces the cost of meat digestion. Comparative biochemistry and physiology. Part A, Molecular , 148(3), 651-6. PMID: 17827047
Henry AG, Brooks AS, & Piperno DR. (2011) Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium). Proceedings of the National Academy of Sciences of the United States of America, 108(2), 486-91. PMID: 21187393
Koebnick, C., Strassner, C., Hoffman, I., & Leitzmann, C. (1999) Consequences of a longterm raw food diet on body weight and menstruation: results of a questionnaire survey. Annals of Nutrition and Metabolism, 69-79. info:/
I like Twitter and I like scientific papers. So I like this new paper by University of the Philippines researchers Christian M. Alis and May T. Lim: Spatiotemporal variation of conversational utterances on Twitter Using Twitter’s API, they downloaded 229 million ‘conversational’ tweets from 2009-2012. They defined as ‘conversational’ any tweet starting with the character […]The post Why Are (Some) Tweets Getting Shorter? appeared first on Neuroskeptic.... Read more »
Alis CM, & Lim MT. (2013) Spatio-temporal variation of conversational utterances on twitter. PloS one, 8(10). PMID: 24204968
The image of an actor holding aloft a skull is a familiar cinematic and literary trope. Theatre scholars have noted that the representation is so powerful that it often stands in as a metonymic representation of acting itself (Williamson 2011; Monks 2012). The image is, of course, drawn from Hamlet, a representation of the protagonist's celebrated contemplation of the meaning of mortality in a Danish graveyard. On a recent visit to Stratford-upon-Avon, I was struck by the degree to which the familiar imagery of the skull permeated the town - it was plastered on baguette barges and sold as key rings and coffee mugs.... Read more »
Aebischer, P. (2001) Yorick's Skull: Hamlet's Improper Property. EnterText, 1(2), 206-225. info:/
Monks, Aoife. (2012) Human Remains: Acting, Objects, and Belief in Performance. Theater Journal, 64(3), 355-371. DOI: 10.1353/tj.2012.0082
High in the alpine forests of Wyoming, archaeologists have discovered more than a dozen villages dating back over 2,000 years, a find that could alter our understanding of the scope of human habitation in the ancient West, as well as the histories and migrations of the people who lived there.... Read more »
Matthew Stirn. (2014) Modeling site location patterns amongst late-prehistoric villages in the Wind River Range, Wyoming. Journal of Archaeological Science. DOI: 10.1016/j.jas.2013.09.018
Don't despair, left-handers who have just smeared the ink across your paper yet again. You have a true purpose in life, some scientists say—and it's walloping other people in the head. A flying elbow drop would work too. Researchers recently pored over video of hundreds of UFC fights to test the idea that lefties evolved with an edge in hand-to-hand combat.
Various other animals show a preference for one paw, or one swimming direction, over the other. But humans are notable for almost always preferring the right side. Only about 10 or 12 percent of us are lefties. Is this because there's a cost to being a left-handed human (aside from the ink thing)? Lefties are smaller in stature, and there's some evidence that they don't live as long. If these effects really add up to a raw evolutionary deal, perhaps the reason there are any lefties is that there's some advantage too.
Enter the so-called fighting hypothesis, which says that lefties have persisted at low numbers because they have the element of surprise in a fight.
In order for this theory to make sense, you have to imagine that sometime after our ancestors came down from the trees but before they built weapons, punching each other became very important to their survival. And that despite our squishy outer coverings, valuable dextrous hands, and vulnerable heads, we are a species built for combat. It's a speculative theory. A recent review paper about the fighting hypothesis—which shared an author with the current paper—called evidence for the idea "not particularly strong."
Nevertheless, a group of researchers in the Netherlands chose to explore the theory using mixed martial arts fighters. The UFC "seemed like a very interesting arena to test this hypothesis," says lead author Thomas Pollet, "pun intended." Pollet is a psychologist at VU University Amsterdam. Since the UFC is "a fierce fighting sport hardly constrained by rules," the authors write, it might be a good representation of humans scrapping in an ancestral state.
Pollet studies handedness but didn't have a particular interest in the Ultimate Fighting Championship when he began the study. To get perspective from a fan, I wrote to my friend Ryan, who happens to love watching MMA fighting. He's also a lefty. "A left-handed fighter will lead with their right foot, jab with their right, and cross with their left," Ryan explained. This is all unexpected to an opponent who mainly fights righties. "The speedy jab will come from the opposite side, and the lefty fighter will naturally circle the ring in the opposite direction as well."
Studying recordings of 210 UFC fights, Pollet found that lefties were significantly more common than in the general population. More than 20 percent of the 246 fighters were left-handed. (You can tell by checking their feet; the back leg corresponds to the dominant hand. "UFC fighters only rarely switch between stances within or between fights unless their lead leg is...severely injured," the authors write.)
To look for a left-handed advantage, Pollet analyzed all the fights between a lefty and a righty. The results were an exact tie. A computer simulation in which the fighters' handedness was randomized led to the same conclusion: left-handers had no advantage over righties.
This alone might not disprove the fighting hypothesis. That's because the UFC represents the cream of the lawless-brawling crop. "A fighter must go through a minor league promotion in their home town before making it to the big stage," Ryan told me. On their way to the professional level, left-handed fighters might have an advantage, which would explain why there are so many of them in the UFC. But once they become more common—and face more opponents who are experienced at fighting lefties—their edge might disappear.
"I think it is a very attractive hypothesis," Pollet says. The advantage of being left-handed in a fight may depend on how many other lefties are around, but "testing frequency dependence can be hard," he says. He's hoping to compare results in the UFC to other competitions that include more amateurs.
Currently, Pollet and his colleagues are working on a meta-analysis of lefties in different sports. In tennis, for example, being left-handed can give players a boost. (My friend Ryan, who just happens to also play tennis, said that being a lefty gave him "a great advantage growing up." A lefty cross-court forehand shot, he explained, forces your right-handed opponent to return the ball with a weaker backhand.)
In addition to the UFC, left-handedness is especially common among badminton players, cricketers, and recent U.S. presidents. Maybe lefties can look to those areas to find their evolutionary reason for being. If they still feel existential angst, they can always go out and punch someone.
Image: by Krajten (via Wikimedia Commons)
Thomas V. Pollet, Gert Stulp, & Ton G.G. Groothuis (2013). Born to win? Testing the fighting hypothesis in realistic fights: left-handedness in the Ultimate Fighting Championship. Animal Behaviour DOI: 10.1016/j.anbehav.2013.07.026
Thanks to Ryan Sponseller for his thoughtful comments on handedness and punching dudes.
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Thomas V. Pollet, Gert Stulp, & Ton G.G. Groothuis. (2013) Born to win? Testing the fighting hypothesis in realistic fights: left-handedness in the Ultimate Fighting Championship. Animal Behaviour. DOI: 10.1016/j.anbehav.2013.07.026
I recently finished reading Living the Sky: The Cosmos of the American Indian by Ray Williamson. This is a classic work on the archaeoastronomy of North America, and it’s the best introduction to the subject I’ve found. (Granted, there aren’t many out there.) Although it was written in the 1980s, the research it discusses is […]... Read more »
In honor of Halloween, I was going to post something about the new morbid terminology- necropants. However, this is a site about bones, burials, and bodies- so I’ll let you read that at Huffington Post. For Halloween, we’re going to be exploring the burials of witches. Like many other of the ‘deviant’ burials we’ve discussed … Continue reading »... Read more »
Jerome Handler. (1996) A Prone Burial from a Plantation Slave Cemetery in Barbados West Indies: Possible Evidence for an African-type Witch or Other Negatively Viewed Person . Historical Archaeology, 30(3), 76-86. info:/
Procrastination is a fact of academic life, particularly during the PhD period, as every academic supervisor knows. However, judging from ever-increasing institutional efforts to control procrastination or from the many self-help guides intended to cure procrastination, it would seem that … Continue reading →... Read more »
Paola Villani. (1990) Documenti saussuriani conservati a Lipsia e a Berlino. Cahiers Ferdinand de Saussure, 3-33. info:/
First, a big thanks to everybody for being engaged in what I thought was just a simple map to visualize relationships …Continue reading »... Read more »
Bouchard-Côté A, Hall D, Griffiths TL, & Klein D. (2013) Automated reconstruction of ancient languages using probabilistic models of sound change. Proceedings of the National Academy of Sciences of the United States of America, 110(11), 4224-9. PMID: 23401532
Atkinson, Q.D. (2013) The descent of words. PNAS, 4159-4160. info:/10.1073/pnas.1300397110
Gray RD, Drummond AJ, & Greenhill SJ. (2009) Language phylogenies reveal expansion pulses and pauses in Pacific settlement. Science (New York, N.Y.), 323(5913), 479-83. PMID: 19164742
Does your workweek schedule dig you into an ever-deepening hole of sleep deprivation? Do you sleep in on the weekends to try to boost yourself back out? You're in good company. But even if you feel recovered by the following week, your brainpower might be suffering.
In a survey by the National Sleep Foundation, 40 percent of respondents said they try to "catch up" on sleep during the weekend. Pennsylvania State University professor and physician Alexandros Vgontzas, along with a group of colleagues, recruited 30 subjects to study how well this catching up really works. The subjects were healthy men and women between 18 and 34 (who didn't mind the prospect of sleeping with a catheter in their arm).
For two weeks before the study, researchers made sure subjects got 7.5 to 8 hours of sleep every night. Then the subjects came into the sleep lab. The experiment began with three "baseline" nights of 8 hours' sleep. For the next five nights, their sleep was restricted to just 6 hours, mimicking a full workweek of uncomfortably early rising. Then subjects had two "recovery" nights where they were left sleeping for 10 hours.
During most days of the experiment, subjects were allowed to go home and follow their normal routine—though monitors on their wrists made sure they followed strict no-napping instructions. At night, they returned to the lab. And after each phase of the experiment, subjects spent a full 24 hours undergoing tests: researchers tracked the levels of hormones circulating in their blood and gave them cognitive tests. They also asked subjects to rate how sleepy they felt. To measure their actual sleepiness, researchers had subjects lie down to nap, recorded how long it took them to conk out, and woke them up again—six times a day.
Predictably, subjects were sleepier during their week of sleep deprivation. It took them less time to fall asleep during the day, and the easiest time for them to nap was 9:00 in the morning (as opposed to 3:00 in the afternoon during the baseline period). After their two recovery days, subjects' sleepiness returned to normal.
One hormone the scientists monitored was IL-6, a marker of inflammation in the body. They found that IL-6 increased when subjects lost sleep. This fits with what earlier studies have found, and suggests one way sleep deprivation is bad for your health. IL-6 levels dropped back to normal after the two nights of recovery sleep.
The only measurement that didn't go back to normal was performance on a test called the psychomotor vigilance task (PVT). Subjects did this test every two hours during their lab days. In it, they watched a screen for ten minutes and pressed a button every time a certain number appeared. It's a test that measures a person's ability to sustain attention; astronauts on the International Space Station do a similar test on themselves to check for fatigue.
Subjects in the sleep study did worse on the PVT after their sleep-deprived week, and continued to do poorly even after two nights of catch-up sleep. Vgontzas says he doesn't know why this is. But apparently some function in people's brains hadn't recovered fully by the end of the experiment, even though they felt well rested.
It's worth noting that because there was a 24-hour testing period after each stage of the experiment, subjects actually had a sixth night of poor sleep before their "weekend." And some champion snooze-button users can sleep well past 10 hours on their real makeup days. Still, Vgontzas's findings suggest our brains are slow to catch up after losing sleep—specifically, our ability to pay attention suffers—and we might not know when we're mentally fatigued.
Vgontzas also doesn't know what the cumulative effect might be of living this way every week. On average, he writes, we need seven hours of sleep a night. (Though if you really can't sleep any later, a nap during the day will also help you recover.)
Image: by Phae (via Flickr)
Pejovic S, Basta M, Vgontzas AN, Kritikou I, Shaffer ML, Tsaoussoglou M, Stiffler D, Stefanakis Z, Bixler EO, & Chrousos GP (2013). Effects of recovery sleep after one work week of mild sleep restriction on interleukin-6 and cortisol secretion and daytime sleepiness and performance. American journal of physiology. Endocrinology and metabolism, 305 (7) PMID: 23941878
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Pejovic S, Basta M, Vgontzas AN, Kritikou I, Shaffer ML, Tsaoussoglou M, Stiffler D, Stefanakis Z, Bixler EO, & Chrousos GP. (2013) Effects of recovery sleep after one work week of mild sleep restriction on interleukin-6 and cortisol secretion and daytime sleepiness and performance. American journal of physiology. Endocrinology and metabolism, 305(7). PMID: 23941878
BLOOMINGTON, Ind. — The search for a common ancestor linking modern humans with the Neanderthals who lived in Europe thousands of years ago has been a compelling subject for research. But a new study suggests the quest isn’t nearly complete.... Read more »
Gómez-Robles A, Bermúdez de Castro JM, Arsuaga JL, Carbonell E, & Polly PD. (2013) No known hominin species matches the expected dental morphology of the last common ancestor of Neanderthals and modern humans. Proceedings of the National Academy of Sciences of the United States of America. PMID: 24145426
The latest SAT and ACT data show record declines for men, whites, and Native Americans. Analysis of state SAT data suggests that family income does not significantly affect scores when controlled for parents’ education and race.... Read more »
Anonymous. (1998) Why Family Income Differences Don't Explain the Racial Gap in SAT Scores. The Journal of Blacks in Higher Education, 6-8. DOI: 10.2307/2999198
Anonymous. (2008) Why Family Income Differences Don't Explain the Racial Gap in SAT Scores. The Journal of Blacks in Higher Education, 10-12. info:/
The skull of an early Homo individual, discovered in Georgia in 2005 and presented on October 18 in the scientific journal Science, is truly a wonderful find. Not only was it recovered relatively intact and complete, but together with four … Continue reading →... Read more »
Lordkipanidze D, Ponce de León MS, Margvelashvili A, Rak Y, Rightmire GP, Vekua A, & Zollikofer CP. (2013) A complete skull from Dmanisi, Georgia, and the evolutionary biology of early Homo. Science (New York, N.Y.), 342(6156), 326-31. PMID: 24136960
Changes in gene regulation have been used to study the evolutionary chasm that exists between humans and chimpanzees despite their largely identical DNA.
However, scientists from the University of Chicago have discovered that mRNA expression levels, long considered a barometer for differences in gene regulation, often do not reflect differences in protein expression — and, therefore, biological function — between humans and chimpanzees. The work was published Oct. 17 in Science.... Read more »
Khan Z, Ford MJ, Cusanovich DA, Mitrano A, Pritchard JK, & Gilad Y. (2013) Primate Transcript and Protein Expression Levels Evolve under Compensatory Selection Pressures. Science (New York, N.Y.). PMID: 24136357
When cells are put under stress (e.g. UV light, ionising radiation, reactive oxygen species) they undergo a process known as cellular senescence in which cell division (mitosis) is arrested. This is thought to contribute to ageing. In their 2013 paper Naylor and colleagues outline a strategy to selectively remove in vivo senescent cells expressing p16Ink4A .... Read more »
Naylor RM, Baker DJ, & van Deursen JM. (2013) Senescent cells: a novel therapeutic target for aging and age-related diseases . Clinical Pharmacology . DOI: 10.1038/clpt.2012.193
Paleoanthropologists from the University of Zurich have uncovered the intact skull of an early Homo individual in Dmanisi, Georgia. This find is forcing a change in perspective in the field of paleoanthropology: human species diversity two million years ago was much smaller than presumed thus far. However, diversity within the «Homo erectus», the first global species of human, was as great as in humans today.... Read more »
David Lordkipanidze, Marcia S. Ponce de León, Ann Margvelashvili, Yoel Rak, G. Philip Rightmire, Abesalom Vekua, & Christoph P. E. Zollikofer. (2013) A Complete Skull from Dmanisi, Georgia, and the Evolutionary Biology of Early Homo. Science AAAS. DOI: 10.1126/science.1238484
Margvelashvili A, Zollikofer CP, Lordkipanidze D, Peltomäki T, & Ponce de León MS. (2013) Tooth wear and dentoalveolar remodeling are key factors of morphological variation in the Dmanisi mandibles. Proceedings of the National Academy of Sciences of the United States of America. PMID: 24101504
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