Scientists report that they have mapped the physical architecture of intelligence in the brain. Theirs is one of the largest and most comprehensive analyses so far of the brain structures vital to general intelligence and to specific aspects of intellectual functioning, such as verbal comprehension and working memory. (…)

“We found that general intelligence depends on a remarkably circumscribed neural system,” Barbey said. “Several brain regions, and the connections between them, were most important for general intelligence.”



These structures are located primarily within the left prefrontal cortex (behind the forehead), left temporal cortex (behind the ear) and left parietal cortex (at the top rear of the head) and in “white matter association tracts” that connect them.

The researchers also found that brain regions for planning, self-control and other aspects of executive function overlap to a significant extent with regions vital to general intelligence.

The study provides new evidence that intelligence relies not on one brain region or even the brain as a whole, Barbey said, but involves specific brain areas working together in a coordinated fashion.

{ University of Illinois | Continue reading }

It’s a debate that’s been running since at least the days of Sigmund Freud: Can women climax from vaginal stimulation alone? And is there any difference between so-called clitoral and vaginal orgasms?

Now, a new series of essays lays out the evidence that vaginal and clitoral orgasms are, in fact, separate phenomena, activating different areas of the brain and perhaps revealing key psychological differences between women.  (…)

Arguably, unraveling the mystery of whether vaginal orgasms exist should be simple: Ask women if they have them. But in practice, it’s a bit harder to tease out the exact sexual stimulation that leads to orgasm. French gynecologist Odile Buisson argues in her Journal of Sexual Medicine essay, for example, that the front wall of the vagina is inextricably linked with the internal parts of the clitoris; stimulating the vagina without activating the clitoris may be next to impossible.

Other research, however, would tend to suggest two distinct types of female orgasm. Barry Komisaruk of Rutgers University has conducted multiple studies in which women masturbate while having their brains scanned with a functional magnetic resonance imaging (fMRI) machine. The results show which sensory brain areas activate in response to stimulation. (…)

Most provocatively, some research links vaginal-only orgasms with both physical and mental health. The research is correlational, so it’s not entirely clear whether healthier women are prone to vaginal orgasms, whether vaginal orgasms somehow promote health, or whether some unknown factor links the two.

{ LiveScience | Continue reading }

One of the great challenges in cosmology is understanding the nature of the universe’s so-called missing mass.

Astronomers have long known that galaxies are held together by gravity, a force that depends on the amount of mass a galaxy contains. Galaxies also spin, generating a force that tends to cause this mass to fly apart.

The galaxies astronomers can see are not being torn apart as they rotate, presumably because they are generating enough gravity to prevent this.

But that raises a conundrum. Astronomers can see how much visible mass there is in a galaxy and when they add it all up, there isn’t anywhere enough for the required amount of gravity.  So something else must be generating this force. 

One idea is that gravity is stronger on the galactic scale and so naturally provides the extra force to glue galaxies together.

Another is that the galaxies must be filled with matter that astronomers can’t see, the so-called dark matter.

{ The Physics arXiv Blog | Continue reading }

photo { Bela Borsodi }

Robert Provine found that babies laugh 300 times a day, while adults laugh only 20 times. (…)

He’s actually proved that laughter is contagious. Consider the case of the “laugh epidemic” that swept through what’s now Tanzania in 1962. In the small town of Kashasha, three girls started giggling. Soon, the snickers rippled outward to 95 students, lasting for hours before dying down, then erupting again—for three months straight. The school closed down, briefly reopened, then shut down again after the laugh bug reinfected 57 students. Within ten days, laugh attacks plagued 217 kids in the nearby town of Nshamba, then 48 more in Bukoba. It continued to spread, closing 14 schools and afflicting about 1,000 people, before quarantines were put in place. A year and a half passed before this laughathon tailed off.

{ Mental Floss | Continue reading }

One by one, pillars of classical logic have fallen by the wayside as science progressed in the 20th century, from Einstein’s realization that measurements of space and time were not absolute but observer-dependent, to quantum mechanics, which not only put fundamental limits on what we can empirically know but also demonstrated that elementary particles and the atoms they form are doing a million seemingly impossible things at once. (…)

Eighty-seven years ago, as far as we knew, the universe consisted of a single galaxy, our Milky Way, surrounded by an eternal, static, empty void. Now we know that there are more than 100 billion galaxies in the observable universe. (…)

Combining the ideas of general relativity and quantum mechanics, we can understand how it is possible that the entire universe, matter, radiation and even space itself could arise spontaneously out of nothing, without explicit divine intervention. (…)

Perhaps most remarkable of all, not only is it now plausible, in a scientific sense, that our universe came from nothing, if we ask what properties a universe created from nothing would have, it appears that these properties resemble precisely the universe we live in.

{ Lawrence M. Krauss/LA Times | Continue reading }

artwork { Ellsworth Kelly, White curve I (black curve I), 1973 }

The study, reported in The Journal of Neuroscience [2007], provides the first direct evidence that humans, like rats, moths and butterflies, secrete a scent that affects the physiology of the opposite sex. (…)

He found that the chemical androstadienone — a compound found in male sweat and an additive in perfumes and colognes — changed mood, sexual arousal, physiological arousal and brain activation in women.

Yet, contrary to perfume company advertisements, there is no hard evidence that humans respond to the smell of androstadienone or any other chemical in a subliminal or instinctual way similar to the way many mammals and even insects respond to pheromones, Wyart said. Though some humans exhibit a small patch inside their nose resembling the vomeronasal organ in rats that detects pheromones, it appears to be vestigial, with no nerve connection to the brain.

“Many people argue that human pheromones don’t exist, because humans don’t exhibit stereotyped behavior. Nonetheless, this male chemical signal, androstadienone, does cause hormonal as well as physiological and psychological changes in women.” (…)

Sweat has been the main focus of research on human pheromones, and in fact, male underarm sweat has been shown to improve women’s moods and affect their secretion of luteinizing hormone, which is normally involved in stimulating ovulation.

Other studies have shown that when female sweat is applied to the upper lip of other women, these women respond by shifting their menstrual cycles toward synchrony with the cycle of the woman from whom the sweat was obtained.

{ ScienceDaily | Continue reading }

A general continuum theory for the distribution of hairs in a bundle is developed, treating individual fibers as elastic filaments with random intrinsic curvatures. Applying this formalism to the iconic problem of the ponytail, the combined effects of bending elasticity, gravity, and orientational disorder are recast as a differential equation for the envelope of the bundle, in which the compressibility enters through an ‘equation of state’. From this, we identify the balance of forces in various regions of the ponytail, extract a remarkably simple equation of state from laboratory measurements of human ponytails, and relate the pressure to the measured random curvatures of individual hairs.

{ arXiv | Continue reading }

painting { Botticelli, Portrait of Simonetta Vespucci, c.1476 }

How to actually be good at rote memorization. A group of psychologists decided to help the kids out by examining the optimal duration for studying a particular item. (…)

Subjects who avoided the longest (16s) and shortest (1s) durations retained more information when testeed after 5 minutes and when tested after 2 days. (…)

Performance was much better for intermediate (e.g., 4 s) presentation durations.

I bring up this study not because it’s crucial for our education system, but because in the future every part of our lives will be designed based on this type of research. Advertisements, online dating profiles, and all manner of printed instructions will be optimized for the perfect exposure length.

{ peer-reviewed by my neurons | Continue reading }

Red seems to affect us in a way that other colors don’t. (…)

Johns and colleagues test an hypothesis for why red on women looks so attractive to me. The hypothesis is that red is sexy because it reminds men of… lady parts. (…) One version of the hypothesis is that as females are approaching ovulation, the vulva becomes more red than is is at other points in the cycle.

If this “red is code for female sex organs” hypothesis is true, you might predict that men would judge female genitals as more attractive as they became more red.

Explicit images of anatomically normal, un-retouched, nonpornographic, similarly-orientated female genitals were surprisingly difficult to obtain… We selected photographs that … did not contain other, potentially distracting, objects (fingers, sex toys, piercings etc.) and were hairless to account for current fashion.

They showed their pictures to 40 males. Most of the men were in their 20s. (…) They rated the attractiveness of each image.

The ratings of attractiveness were the exact opposite of those predicted by the signalling hypothesis. The reddest images were rated the least attractive.

The authors are then tasked to come up with an hypothesis as to why redness is less attractive. Their suggestion is that red is suggestive of menstrual blood.

{ NeuroDojo | Continue reading }

The researchers in charge of performing psychometric testing recently made an interesting observation: if they wear a white coat when interacting with the participants (and their parents), they receive more respect.

According to a study by Hajo Adam and Adam Galinsky of Norwestern University, it’s possible that our psych testers not only look more professional, but subconsciously feel more professional. In other words, the clothes may literally make the man (or woman).

{ Gaines, on brains | Continue reading }

images { 1 | 2 }

{ We show that if a car stops at a stop sign, an observer, e.g., a police officer, located at a certain distance perpendicular to the car trajectory, must have an illusion that the car does not stop, if the following three conditions are satisfied: (1) the observer measures not the linear but angular speed of the car; (2) the car decelerates and subsequently accelerates relatively fast; and (3) there is a short-time obstruction of the observer’s view of the car by an external object, e.g., another car, at the moment when both cars are near the stop sign. | Dmitri Krioukov/arXiv | PDF }

Under the transgender umbrella, a distinct subset of “Bigender” individuals report blending or alternating gender states. It came to our attention that many (perhaps most) bigender individuals experience involuntary alternation between male and female states, or between male, female, and additional androgynous or othergendered identities (”Multigender”). (…)

A survey of the transgender community by the San Francisco Department of Public Health found that about 3% of genetic males and 8% of genetically female transgendered individuals identified as bigender. To our knowledge, however, no scientific literature has attempted to explain or even describe bigenderism.

{ Medical Hypotheses | via Neuroskeptic | Continue reading }

We all know the story: Every few years, millions of lemmings, driven by a deep-seated urge, run and leap off a cliff only to be dashed on the rocks below and eventually drowned in the raging sea. Stupid lemmings. It’s a story with staying power: short, not-so-sweet, and to the rocky point.

But it is a lie.

{ The Scorpion and the frog | Continue reading }

This experiment is designed to test the efficiency of the intuition, that is, the capacity to acquire information that does not require conscious control and intentional mental activity of the person. In this experiment your implicit intuition will be observed by measuring your pupil dilation. (…)

This study investigates the prediction accuracy of anticipatory pupil dilation responses in humans prior to the random presentation of alerting or neutral sounds. The aim of this study was to test the hypothesis that the autonomous nervous system may react prior to the presentation of random stimuli. A total of 80 participants, who were matched according to gender to take into account individual differences, were asked to listen to a random sequence of 10 neutral and 10 alerting sounds. Their pupil dilation was continuously recorded and the diameter of their pupils was used to predict the category of sound, alerting, or neutral. The pupil dilation of both males and females predicted alerting sounds approximately 10% more accurately than would be expected by chance, whereas neutral sounds were predicted at the chance level.

{ SSRN | Continue reading }

photo { Delaney Allen }

There is no shortage of advice on how to recover from a bad break-up: keep busy, don’t contact your ex, go out with friends. (…) But according to a new study, something important is missing from this list. (…)

“It is just something that happens these days.” (…) This statement expresses a sense of common humanity, or recognition that suffering is part of the human experience, which is considered a fundamental part of self-compassion. (…)

“It was all my fault. (…) I know I did it all wrong.” In contrast to the first statement, this one includes a high degree of self-judgment, with no evidence of self-kindness. (…)

Results indicated that participants who were judged to be higher in self-compassion showed less distress at the beginning of the study and at the nine-month mark, while those low in self-compassion showed a greater increase in distress between six and nine months.

{ Psych Your Mind | Continue reading }

photo { Sam Haskins }

Multiple viral diseases are spread through vectors, like ticks and mosquitoes, that result in massive health care issues and epidemics worldwide – my question has always been, if the vectors are infected with the virus, are they getting a disease? And, what is in it for the organism? Or, what is driving the vector to spread the viral infection?

George Dimopoulous’ group at Johns Hopkins University shed light on these questions in their latest publication on Dengue virus and the effect on its main vector, mosquito species Aedes aegypti.

{ Smaller Questions | Continue reading }

Math can be a fun, logic puzzle for some people. But for others, doing math is a headache-inducing experience. Scientists at the Stanford University School of Medicine have recently shown that people who experience math anxiety may have brains that are wired a little differently from those who don’t, and this difference in brain activity may be what’s making people sweat over equations.

{ APS | Continue reading }

Imagine that you have a big box of sand in which you bury a tiny model of a footstool. A few seconds later, you reach into the box and pull out a full-size footstool: The sand has assembled itself into a large-scale replica of the model.

That may sound like a scene from a Harry Potter novel, but it’s the vision animating a research project at the Distributed Robotics Laboratory (DRL) at MIT’s Computer Science and Artificial Intelligence Laboratory.

At the IEEE International Conference on Robotics and Automation in May — the world’s premier robotics conference — DRL researchers will present a paper describing algorithms that could enable such “smart sand.”

{ MIT News | Continue reading }

A variety of studies suggest that 10% of the world population is left-handed. (…)

In his book Right-Hand, Left-Hand, Chris McManus of University College London argues that the proportion of left-handers is increasing and left-handed people as a group have historically produced an above-average quota of high achievers. He says that left-handers’ brains are structured differently in a way that increases their range of abilities, and the genes that determine left-handedness also govern development of the language centres of the brain.

In a 2006 U.S. study, researchers from Lafayette College and Johns Hopkins University concluded that there was no scientifically significant correlation between handedness and earnings for the general population, but among college-educated people, left-handers earned 10 to 15 % more than their right-handed counterparts.

{ Wikipedia | Continue reading }

illustration { Sauer Kids }

Six studies demonstrate the “pot calling the kettle black” phenomenon whereby people are guilty of the very fault they identify in others. Recalling an undeniable ethical failure, people experience ethical dissonance between their moral values and their behavioral misconduct. Our findings indicate that to reduce ethical dissonance, individuals use a double-distancing mechanism. Using an overcompensating ethical code, they judge others more harshly and present themselves as more virtuous and ethical.

{ Journal of Experimental Psychology: General | PDF | via Overcoming Bias }

related { Psychological projection is a psychological defense mechanism where a person subconsciously denies his or her own attributes, thoughts, and emotions, which are then ascribed to the outside world, usually to other people. | Wikipedia }