Octopuses are classified within the invertebrates in the mollusk family, and many mollusks, like clams, have no brain.

Only recently have scientists accorded chimpanzees, so closely related to humans we can share blood transfusions, the dignity of having a mind. But now, increasingly, researchers who study octopuses are convinced that these boneless, alien animals—creatures whose ancestors diverged from the lineage that would lead to ours roughly 500 to 700 million years ago—have developed intelligence, emotions, and individual personalities. Their findings are challenging our understanding of consciousness itself. (…)

Another measure of intelligence: you can count neurons. The common octopus has about 130 million of them in its brain. A human has 100 billion. But this is where things get weird. Three-fifths of an octopus’s neurons are not in the brain; they’re in its arms.

“It is as if each arm has a mind of its own,” says Peter Godfrey-Smith, a diver, professor of philosophy at the Graduate Center of the City University of New York, and an admirer of octopuses. For example, researchers who cut off an octopus’s arm (which the octopus can regrow) discovered that not only does the arm crawl away on its own, but if the arm meets a food item, it seizes it—and tries to pass it to where the mouth would be if the arm were still connected to its body.

{ Orion | Continue reading }

artwork { Hokusai, The Dream of the Fisherman’s Wife, 1814 }

Rather than being fixed over our lifespan, a person’s IQ can show both significant increases and decreases during their teenage years, new results suggest.

Reported in Nature today, the results reveal that verbal and non-verbal ability, as measured by IQ (Intelligence Quotient) tests, fluctuated over a period of three to four years during adolescence. They also showed that these changes correspond to specific structural changes in brain regions associated with speech and movement.

{ Cosmos | Continue reading }

{ With brain donation, unlike other types of organ donation, it’s important to have information about the donor and their mental functioning during life. | NewScientist | full story }

Both correlational and experimental evidence suggest that when people are sleep deprived, they feel more irritable, angry and hostile. Sleep loss is also associated with greater depressive mood. In addition, sleep deprivation seems to be associated with greater reactivity in that people who suffer from sleep loss are especially likely to react negatively when something doesn’t go well for them. For those of you interested in the brain – some research suggests that sleep deprivation enhances negative mood due to increased amygdale activity (a brain structure integral to experiences of negative emotions such as anger and rage) and a disconnect between the amygdale and the area of the brain that regulates its functions. In other words: increased negative mood, and decreased ability to regulate that anger.

{ Psych Your Mind | Continue reading }

Moody. Impulsive. Maddening. Why do teenagers act the way they do? Viewed through the eyes of evolution, their most exasperating traits may be the key to success as adults.

The first full series of scans of the developing adolescent brain showed that our brains undergo a massive reorganization between our 12th and 25th years. The brain doesn’t actually grow very much during this period. It has already reached 90 percent of its full size by the time a person is six, and a thickening skull accounts for most head growth afterward. But as we move through adolescence, the brain undergoes extensive remodeling, resembling a network and wiring upgrade. (…)

This process of maturation, once thought to be largely finished by elementary school, continues throughout adolescence. Imaging work done since the 1990s shows that these physical changes move in a slow wave from the brain’s rear to its front, from areas close to the brain stem that look after older and more behaviorally basic functions, such as vision, movement, and fundamental processing, to the evolutionarily newer and more complicated thinking areas up front. The corpus callosum, which connects the brain’s left and right hemispheres and carries traffic essential to many advanced brain functions, steadily thickens. Stronger links also develop between the hippocampus, a sort of memory directory, and frontal areas that set goals and weigh different agendas; as a result, we get better at integrating memory and experience into our decisions. At the same time, the frontal areas develop greater speed and richer connections, allowing us to generate and weigh far more variables and agendas than before.

When this development proceeds normally, we get better at balancing impulse, desire, goals, self-interest, rules, ethics, and even altruism, generating behavior that is more complex and, sometimes at least, more sensible. But at times, and especially at first, the brain does this work clumsily. It’s hard to get all those new cogs to mesh.

{ National Geographic | Continue reading }

painting { Gustav Klimt, Bildnis Helene Klimt, 1898 }

Every day we make thousands of tiny predictions — when the bus will arrive, who is knocking on the door, whether the dropped glass will break. Now, in one of the first studies of its kind, researchers at Washington University in St. Louis are beginning to unravel the process by which the brain makes these everyday prognostications. (…)

The researchers focused on the mid-brain dopamine system (MDS), an evolutionarily ancient system that provides signals to the rest of the brain when unexpected events occur. (…)

Zacks and his colleagues are building a theory of how predictive perception works. At the core of the theory is the belief that a good part of predicting the future is the maintenance of a mental model of what is happening now. Now and then, this model needs updating, especially when the environment changes unpredictably.

“When we watch everyday activity unfold around us, we make predictions about what will happen a few seconds out,” Zacks says. “Most of the time, our predictions are right.

“Successfull predictions are associated with the subjective experience of a smooth stream of consciousness. But a few times a minute, our predictions come out wrong and then we perceive a break in the stream of consciousness, accompanied by an uptick in activity of primitive parts of the brain involved with the MDS that regulate attention and adaptation to unpredicted changes.”

{ ScienceDaily | Continue reading }

It’s email, it’s the Internet, it’s video games, then when texting comes along, it’s texting, and when social networking comes along, it’s social networking. So whatever the flavor of the month in terms of new technologies are, there’s research that comes out very quickly that shows how it causes our children to be asocial, distracted, bad in school, to have learning disorders, a whole litany of things.

And then the Pew Foundation and MacArthur Foundation started saying, about three or four years ago: “Wait, let’s not assume these things are hurting our kids. Let’s just look at how our kids are using media and stop with testing that’s set up from a pejorative or harmful point of view.” (…)

The phenomenon of attention blindness is real — when we pay attention to one thing, it means we’re not paying attention to something else. When we’re multitasking, what we’re actually really doing is what Linda Stone calls “continuous partial attention.” We’re not actually simultaneously paying equal attention to two things: One of the things that we’re doing is probably being done automatically, and we’re sort of cruising through that, and we’re paying more attention to the other thing. Or we’re moving back and forth between them. But any moment when there is a major new form of technology, people think it’s going to overwhelm the brain. In the 1930s there was legislation introduced to prevent Motorola from putting radios in dashboards, because it was thought that people couldn’t possibly cope with driving and listening to the radio. (…)

We used to think that as we get older we develop more neural pathways, but the opposite is actually the case. You and I have about 40 percent less neurons than a newborn infant does. (…) They are learning to process that kind of information faster. That which we experience shapes our pathways, so they’re going to be far less stressed by a certain kind of multitasking that you are or than I am, or people who may not have grown up with that.

{ Interview with Cathy N. Davidson | Salon | Continue reading }

illustration { Geneviève Gauckler }

All of us, at times, ruminate or brood on a problem in order to make the best possible decision in a complex situation. But sometimes, rumination becomes unproductive or even detrimental to making good life choices. Such is the case in depression, where non-productive ruminations are a common and distressing symptom of the disorder. In fact, individuals suffering from depression often ruminate about being depressed. This ruminative thinking can be either passive and maladaptive (i.e., worrying) or active and solution-focused (i.e., coping). New research by Stanford University researchers provides insights into how these types of rumination are represented in the brains of depressed persons.

{ EurekAlert | Continue reading }

photo { Erwin Blumenfeld }

At their most fundamental level, brains are made up of neurons. And those neurons collectively comprise the two main types of brain tissue: white matter is made up primarily of  axons, and grey matter is made up of  synapses, or the connections between neurons.

Grey matter exists as a thin, relatively flat sheet covering the rest of the brain, and is referred to as the cortex. When you compare the brains of different mammal species, you find that certain measurements of brain structure scale in similar ways. In other words, variables like grey matter volume, total number of synapses, white matter volume, number of neurons, surface area, axon diameter, and number of distinct cortical “areas” maintain common mathematical relationships with each other, whether you’re looking at the brains of mice, rabbits, dogs, cats, hyenas, kangaroos, bats, sloths, bonobos, or humans. (…)

Lots of networks have been compared to urban systems. (…) To what extent, though, might a brain be like a city? There’s the obvious analogy: neurons are like highways. Neurons are channels that carry information in the form of electric signals from one location within the brain to another, while highways are channels that transport people and materials from one location within a city to another. Cognitive scientists Mark Changizi and Marc Destefano think that the analogy goes deeper. (…) They argue that the organization of city highway networks is driven over time by political and economic forces, rather than explicitly planned based on principles of highway engineering – which means that city highway systems may be subject to a form of selection pressure similar to the selection pressure exerted on biological systems.

{ Scientific American | Continue reading }

photo { Keith Davis }

The projection of vagina, uterine cervix, and nipple to the sensory cortex in humans has not been reported.

The aim of this study was to map the sensory cortical fields of the clitoris, vagina, cervix, and nipple, toward an elucidation of the neural systems underlying sexual response.

Using functional magnetic resonance imaging (fMRI), we mapped sensory cortical responses to clitoral, vaginal, cervical, and nipple self-stimulation.

The genital sensory cortex, identified in the classical Penfield homunculus based on electrical stimulation of the brain only in men, was confirmed for the first time in the literature by the present study in women applying clitoral, vaginal, and cervical self-stimulation, and observing their regional brain responses using fMRI.

Activation of the genital sensory cortex by nipple self-stimulation was unexpected, but suggests a neurological basis for women’s reports of its erotogenic quality.

{ The Journal of Sexual Medicine | Continue reading }

photo { Richard Kern }

Perls proposed that in all relationships people could be either toxic or nourishing towards one another. It is not necessarily true that the same person will be toxic or nourishing in every relationship, but the combination of any two people in a relationship produces toxic or nourishing consequences. And the important thing that I can tell you is that there is a test to determine whether someone is toxic or nourishing in your relationship with them. Here is the test: You have spent some time with this person, either you have a drink or go for dinner or you go to a ball game. It doesn’t matter very much but at the end of that time you observe whether you are more energised or less energised. Whether you are tired or whether you are exhilarated. If you are more tired then you have been poisoned. If you have more energy you have been nourished. The test is almost infallible. (…)

I have a friend named Gerald Edelman who was a great scholar of brain studies and he says that the analogy of the brain to a computer is pathetic. The brain is actually more like an overgrown garden that is constantly growing and throwing off seeds, regenerating and so on. And he believes that the brain is susceptible, in a way that we are not fully conscious of, to almost every experience of our life and every encounter we have. I was fascinated by a story in a newspaper a few years ago about the search for perfect pitch. A group of scientists decided that they were going to find out why certain people have perfect pitch. You know certain people hear a note precisely and are able to replicate it at exactly the right pitch. Some people have relevant pitch; perfect pitch is rare even among musicians. The scientists discovered – I don’t know how - that among people with perfect pitch the brain was different. Certain lobes of the brain had undergone some change or deformation that was always present with those who had perfect pitch. This was interesting enough in itself. But then they discovered something even more fascinating. If you took a bunch of kids and taught them to play the violin at the age of 4 or 5 after a couple of years some of them developed perfect pitch, and in all of those cases their brain structure had changed. Well what could that mean for the rest of us? We tend to believe that the mind affects the body and the body affects the mind, although we do not generally believe that everything we do affects the brain.

{ Milton Glaser | Continue reading }

images { 1 | 2 }

Phineas Gage is famous for having an iron bar being blown through his frontal lobes. Although his case is usually described as the first of its kind, this month’s edition of The Psychologist has a surprising article on many lesser known cases from the 1800s, usually due to mishaps with early firearms.

The piece is packed with amazing case vignettes of people who have suffered serious frontal lobe injury but were described as relatively unaffected.

{ MindHacks | Continue reading }

related { Have humans reached the physical limits of how complex our brain can be? }

Regardless of how wisely we may use our brains, there’s no disputing that they are extraordinarily big. The average human brain weighs in at about three pounds, or 1,350 grams. Our closest living relatives, the chimpanzees, have less than one-third as much brain—just 384 grams. And if you compare the relative size of brains to bodies, our brains are even more impressive.

As a general rule, mammal species with big bodies tend to have big brains. If you know the weight of a mammal’s body, you can make a fairly good guess about how large its brain will be. As far as scientists can tell, this rule derives from the fact that the more body there is, the more neurons needed to control it. But this body-to-brain rule isn’t perfect. Some species deviate a little from it. A few deviate a lot. We humans are particularly spectacular rule breakers. If we were an ordinary mammal species, our brains would be about one-sixth their actual size.

Competing theories seek to explain the value of a big brain. One idea, championed by psychologist Robin Dunbar of the University of Oxford, is that complicated social lives require big brains. A relatively large-brained baboon can make a dozen alliances while holding grudges against several rivals. Humans maintain far more, and more complicated, relationships.

{ Discover | Continue reading }

In 2006, archaeologists exhumed the remains of the legendary 18th century castrato, Carlo Maria Broschi, better known as Farinelli.

As a boy, Farinelli showed talent as an opera singer and, when their father died young, his elder brother Riccardo made the decision to have Farinelli castrated, an illegal operation at the time, in order to preserve his voice.  Farinelli became quite famous by the 1720s and sang daily until his death at the age of 78.

An analysis of the bones has just been published in the Journal of Anatomy, with the most salient finding being that Farinelli’s castration led to hormonal changes that likely caused him to develop internal frontal hyperostosis (or hyperostosis frontalis interna, depending on what side of the Atlantic you’re from), a thickening of the frontal bone in the cranial vault that is found almost exclusively in postmenopausal women.

{ Kristina Killgrove | Continue reading }

This was in Japan, so the major breakfast staples were white rice and white bread. (…)

The kids who had rice for breakfast showed higher grey matter volumes than those who had bread. The authors of the study related this to cognitive performance, and said that the rice group had higher IQ scores and POI scores compared to the bread group. (…)

I’ve got a few issues with this paper.

{ Scientopia | Continue reading }

photo { Thatcher Keats }

Almost everyone has experienced one memory triggering another, but explanations for that phenomenon have proved elusive. Now, University of Pennsylvania researchers have provided the first neurobiological evidence that memories formed in the same context become linked, the foundation of the theory of episodic memory. (…)

“Theories of episodic memory suggest that when I remember an event, I retrieve its earlier context and make it part of my present context,” Kahana said.  “When I remember my grandmother, for example, I pull back all sorts of associations of a different time and place in my life; I’m also remembering living in Detroit and her Hungarian cooking. It’s like mental time travel. I jump back in time to the past, but I’m still grounded in the present.” (…)

“By examining the patterns of brain activity recorded from the implanted electrodes,” Manning said, “we can measure when the brain’s activity is similar to a previously recorded pattern. When a patient recalls a word, their brain activity is similar to when they studied the same word.   In addition, the patterns at recall contained traces of other words that were studied prior to the recalled word.”

“What seems to be happening is that when patients recall a word, they bring back not only the thoughts associated with the word itself but also remnants of thoughts associated with other words they studied nearby in time,” he said.

{ Penn News | Continue reading }

artwork { Cy Twombly, Poems to the Sea, 1959 }

Memory includes both learning and then some sort of recollection. (…) Each time something is remembered it is actually recreated. The problem is that each time a memory is recreated it can be changed — dramatically or subtly. This occurs more often than we might think. (…)

This leads into point 2 — memory is unreliable. (…) These type of memories are called flashbulb memories. While they can be quite accurate, researchers have shown that they are often affected by news coverage after the fact or discussions with others. Further, how confident people are about these types of memories does not strongly relate to how accurate the memories are. (…)

This leads into point 3 — false memories are common. (…) False memories are often strongly emotional. While emotion can help strengthen memories, it also sets them up to potentially be more unreliable because emotions change over time, which changes can affect connected memories.

{ BrainBlogger | Continue reading }

There is this fountain of youth inside the adult brain that actively makes new neurons. Yet we don’t know how this fountain is constructed or maintained.

{ EurekAlert | Continue reading }

photo { Allan Macintyre }

At some point, the Mongol military leader Kublai Khan (1215–1294) realized that his empire had grown so vast that he would never be able to see what it contained. To remedy this, he commissioned emissaries to travel to the empire’s distant reaches and convey back news of what he owned. Since his messengers returned with information from different distances and traveled at different rates (depending on weather, conflicts, and their fitness), the messages arrived at different times. Although no historians have addressed this issue, I imagine that the Great Khan was constantly forced to solve the same problem a human brain has to solve: what events in the empire occurred in which order?

Your brain, after all, is encased in darkness and silence in the vault of the skull. Its only contact with the outside world is via the electrical signals exiting and entering along the super-highways of nerve bundles. Because different types of sensory information (hearing, seeing, touch, and so on) are processed at different speeds by different neural architectures, your brain faces an enormous challenge: what is the best story that can be constructed about the outside world?

The days of thinking of time as a river—evenly flowing, always advancing—are over. Time perception, just like vision, is a construction of the brain and is shockingly easy to manipulate experimentally. We all know about optical illusions, in which things appear different from how they really are; less well known is the world of temporal illusions. When you begin to look for temporal illusions, they appear everywhere.

{ David M. Eagleman/Edge | Continue reading }

photos { Henri Cartier-Bresson | Ruben Natal-San Miguel }

Scientists have traced chronic pain to a defect in one enzyme in a single region of the brain. Could this be a decisive turn in the battle against pain? (…)

As neuroscientists learn more about the biological basis of pain, the situation is finally beginning to change. Most remarkably, unfolding research shows that chronic pain can cause concrete, physiological changes in the brain. After several months of chronic pain, a person’s brain begins to shrink. The longer people suffer, the more gray matter they lose. (…)

Normally, pain is triggered by a set of danger-sensing neurons, called nociceptors, that extend into the organs, muscles, and skin. Different types of nociceptors respond to different stimuli, including heat, cold, pressure, inflammation, and exposure to chemicals like cigarette smoke and teargas. Nociceptors can notify us of danger with fine-tuned precision. Heat nociceptors, for example, send out an alarm only when they’re heated to between 45 and 50 degrees Celsius (about 115 to 125 degrees Fahrenheit), the temperature at which some proteins start to coagulate and cause damage to cells and tissues.

For all that precision, we don’t automatically feel the signals as pain; often the information from nociceptors is parsed by the nervous system along the way. For instance, nociceptors starting in the skin extend through the body to swellings along the spinal cord. They relay their signals to other neurons in those swellings, called dorsal horns, which then deliver signals up to the brain stem. But dorsal horns also contain neurons coming down from the brain that can boost or squelch the signals. As a result, pain in one part of the body can block pain signals from another. If you stick your foot in cold water, touching a hot surface with your hand will hurt less.

{ Discovery | Continue reading }