UCLA researchers have for the first time measured the activity of a brain region known to be involved in learning, memory and Alzheimer's disease during sleep. They discovered that this part of the brain behaves as if it's remembering something, even under anesthesia, a finding that counters conventional theories about memory consolidation during sleep.

The research team simultaneously measured the activity of single neurons from multiple parts of the brain involved in memory formation. The technique allowed them to determine which brain region was activating other areas of the brain and how that activation was spreading, said study senior author Mayank R. Mehta, a professor of neurophysics in UCLA's departments of neurology, neurobiology, physics and astronomy.

In particular, Mehta and his team looked at three connected brain regions in mice - the new brain or the neocortex, the old brain or the hippocampus, and the entorhinal cortex, an intermediate brain that connects the new and the old brains. While previous studies have suggested that the dialogue between the old and the new brain during sleep was critical for memory formation, researchers had not investigated the contribution of the entorhinal cortex to this conversation, which turned out to be a game changer, Mehta said. His team found that the entorhinal cortex showed what is called persistent activity, which is thought to mediate working memory during waking life, for example when people pay close attention to remember things temporarily, such as recalling a phone number or following directions.

"The big surprise here is that this kind of persistent activity is happening during sleep, pretty much all the time." Mehta said. "These results are entirely novel and surprising. In fact, this working memory-like persistent activity occurred in the entorhinal cortex even under anesthesia."

The study appears Oct. 7, 2012 in the early online edition of the journal Nature Neuroscience.

The findings are important, Mehta said, because humans spend one-third of their lives sleeping and a lack of sleep results in adverse effects on health, including learning and memory problems.

As a neurosurgeon, I did not believe in the phenomenon of near-death experiences. I grew up in a scientific world, the son of a neurosurgeon. I followed my father's path and became an academic neurosurgeon, teaching at Harvard Medical School and other universities. I understand what happens to the brain when people are near death, and I had always believed there were good scientific explanations for the heavenly out-of-body journeys described by those who narrowly escaped death.

The brain is an astonishingly sophisticated but extremely delicate mechanism. Reduce the amount of oxygen it receives by the smallest amount and it will react. It was no big surprise that people who had undergone severe trauma would return from their experiences with strange stories. But that didn't mean they had journeyed anywhere real.

Although I considered myself a faithful Christian, I was so more in name than in actual belief. I didn't begrudge those who wanted to believe that Jesus was more than simply a good man who had suffered at the hands of the world. I sympathized deeply with those who wanted to believe that there was a God somewhere out there who loved us unconditionally. In fact, I envied such people the security that those beliefs no doubt provided. But as a scientist, I simply knew better than to believe them myself.

In the fall of 2008, however, after seven days in a coma during which the human part of my brain, the neocortex, was inactivated, I experienced something so profound that it gave me a scientific reason to believe in consciousness after death.

I know how pronouncements like mine sound to skeptics, so I will tell my story with the logic and language of the scientist I am.

Very early one morning four years ago, I awoke with an extremely intense headache. Within hours, my entire cortex - the part of the brain that controls thought and emotion and that in essence makes us human - had shut down. Doctors at Lynchburg General Hospital in Virginia, a hospital where I myself worked as a neurosurgeon, determined that I had somehow contracted a very rare bacterial meningitis that mostly attacks newborns. E. coli bacteria had penetrated my cerebrospinal fluid and were eating my brain.

When I entered the emergency room that morning, my chances of survival in anything beyond a vegetative state were already low. They soon sank to near nonexistent. For seven days I lay in a deep coma, my body unresponsive, my higher-order brain functions totally offline.

Then, on the morning of my seventh day in the hospital, as my doctors weighed whether to discontinue treatment, my eyes popped open.

Swedish researchers at Uppsala University have, together with Brazilian collaborators, discovered a new group of nerve cells that regulate processes of learning and memory. These cells act as gatekeepers and carry a receptor for nicotine, which can explain our ability to remember and sort information.

The discovery of the gatekeeper cells, which are part of a memory network together with several other nerve cells in the hippocampus, reveal new fundamental knowledge about learning and memory. The study is published today in Nature Neuroscience.

The hippocampus is an area of the brain that is important for consolidation of information into memories and helps us to learn new things. The newly discovered gatekeeper nerve cells, also called OLM-alpha2 cells, provide an explanation to how the flow of information is controlled in the hippocampus.

"It is known that nicotine improves cognitive processes including learning and memory, but this is the first time that an identified nerve cell population is linked to the effects of nicotine", says Professor Klas Kullander at Scilifelab and Uppsala University.

Humans think, learn and memorize with the help of nerve cells sending signals between each other. Some nerve cells send signals far away to other areas of the brain, while other neurons send signals within the same area. Local nerve circuits in the hippocampus process impressions and turn some of them into memories. But how does this work? And how can nicotine improve this mechanism?

Do you think like a psychopath? It has been claimed that one quick way of telling is to read the following story and see what answer to its final question first pops into your head:

While attending her mother's funeral, a woman meets a man she's never seen before. She quickly believes him to be her soulmate and falls head over heels. But she forgets to ask for his number, and when the wake is over, try as she might, she can't track him down. A few days later she murders her sister. Why?

If the first answer that springs to your mind is some variation of jealousy and revenge - she discovers her sister has been seeing the man behind her back - then you are in the clear. But if your first response to this puzzle is "because she was hoping the man would turn up to her sister's funeral as well", then by some accounts you have the qualities that might qualify you to be a cold-blooded killer - or a captain of industry, a nerveless surgeon, a recruit for the SAS - or which may well make you a commission-rich salesman, a winning barrister, a charismatic clergyman or a red-top journalist. The little parable purports to reveal those qualities - an absence of emotion in decision making, a cold focus on outcomes, an extremely ruthless and egocentric logic - which tend to show up in disproportionate degrees in all those individuals.

Hate the Lakers? Do the Celtics make you want to hurl? Whether you like someone can affect how your brain processes their actions, according to new research from the Brain and Creativity Institute at USC.

Most of the time, watching someone else move causes a 'mirroring' effect - that is, the parts of our brains responsible for motor skills are activated by watching someone else in action.

But a study by USC researchers appearing Oct. 5 in PLOS ONE shows that whether or not you like the person you're watching can actually have an effect on brain activity related to motor actions and lead to "differential processing" - for example, thinking the person you dislike is moving more slowly than they actually are.

"We address the basic question of whether social factors influence our perception of simple actions," says Lisa Aziz-Zadeh, an assistant professor with the Brain and Creativity Institute at USC and the Division of Occupational Science. "These results indicate that an abstract sense of group membership, and not only differences in physical appearance, can affect basic sensory-motor processing."

Past research has shown that race or physical similarity can influence brain processes, and we tend to have more empathy for people who look more like us.

In recent years, educators have come to focus more and more on the importance of lab-based experimentation, hands-on participation, student-led inquiry, and the use of "manipulables" in the classroom. The underlying rationale seems to be that students are better able to learn when they can control the flow of their experience, or when their learning is "self-directed."

While the benefits of self-directed learning are widely acknowledged, the reasons why a sense of control leads to better acquisition of material are poorly understood.

Some researchers have highlighted the motivational component of self-directed learning, arguing that this kind of learning is effective because it makes students more willing and more motivated to learn. But few researchers have examined how self-directed learning might influence cognitive processes, such as those involved in attention and memory.

In an article published in Perspectives on Psychological Science, a journal of the Association for Psychological Science, researchers Todd Gureckis and Douglas Markant of New York University address this gap in understanding by examining the issue of self-directed learning from a cognitive and a computational perspective.

According to Gureckis and Markant, research from cognition offers several explanations that help to account for the advantages of self-directed learning. For example, self-directed learning helps us optimize our educational experience, allowing us to focus effort on useful information that we don't already possess and exposing us to information that we don't have access to through passive observation. The active nature of self-directed learning also helps us in encoding information and retaining it over time.

But we're not always optimal self-directed learners. The many cognitive biases and heuristics that we rely on to help us make decisions can also influence what information we pay attention to and, ultimately, learn.

A team of mind readers can now pinpoint exactly when a rat feels uncertain about its choices, simply by measuring its brain activity.

Doubt, they've discovered, creeps into the mind slowly. It starts with a few nerve cells near the front of the brain that get themselves into a tizzy. More and more cells join in, until a line is crossed and the mental maelstrom shakes up established patterns of brain activity -- allowing rats, and possibly humans as well, to question their old beliefs about the world and explore new options, researchers report in the October 5 issue of the journal Science.

"When your environment changes, you want to be able to reevaluate the world," said Alla Karpova, a neuroscientist at the Howard Hughes Medical Institute's Janelia Farm campus in Ashburn, Va. "We have seen an abrupt change in neural activity at a moment when an animal seems to abandon a previously held belief."

Karpova studies the medial prefrontal cortex, a brain region that's thought to guide decisions by weighing the good and bad outcomes of past choices. Levels of activity in a probably analogous part of the human brain can predict how well people do at games that require learning from past experiences, one group of researchers reported in 2007. Macaque monkeys with brain damage in this area can still use their most recent mistakes to guide their choices. But they can't draw on lots of choices made over time, an ability that's important for picking the best places to search for food in the wild.

Uncertainty plays an important role in making such decisions, helping to balance beliefs drawn from previous experiences against changing conditions. A fisherman who never doubts a favorite spot that has yielded good results in the past may miss the fact that the fish have moved on, for instance.

Not everyone is able to be hypnotized, and new research from the Stanford University School of Medicine shows how the brains of such people differ from those who can easily be.

The study, published in the October issue of Archives of General Psychiatry, uses data from functional and structural magnetic resonance imaging to identify how the areas of the brain associated with executive control and attention tend to have less activity in people who cannot be put into a hypnotic trance.

"There's never been a brain signature of being hypnotized, and we're on the verge of identifying one," said David Spiegel, MD, the paper's senior author and a professor of psychiatry and behavioral sciences. Such an advance would enable scientists to understand better the mechanisms underlying hypnosis and how it can be used more widely and effectively in clinical settings, added Spiegel, who also directs the Stanford Center for Integrative Medicine.

Spiegel estimates that one-quarter of the patients he sees cannot be hypnotized, though a person's hypnotizability is not linked with any specific personality trait. "There's got to be something going on in the brain," he said.

Hypnosis is described as a trance-like state during which a person has a heightened focus and concentration. It has been shown to help with brain control over sensation and behavior, and has been used clinically to help patients manage pain, control stress and anxiety and combat phobias.

Not everyone is able to be hypnotized, and new research from the Stanford University School of Medicine shows how the brains of such people differ from those who can easily be.

The study, published in the October issue of Archives of General Psychiatry, uses data from functional and structural magnetic resonance imaging to identify how the areas of the brain associated with executive control and attention tend to have less activity in people who cannot be put into a hypnotic trance.

"There's never been a brain signature of being hypnotized, and we're on the verge of identifying one," said David Spiegel, MD, the paper's senior author and a professor of psychiatry and behavioral sciences. Such an advance would enable scientists to understand better the mechanisms underlying hypnosis and how it can be used more widely and effectively in clinical settings, added Spiegel, who also directs the Stanford Center for Integrative Medicine.

Spiegel estimates that one-quarter of the patients he sees cannot be hypnotized, though a person's hypnotizability is not linked with any specific personality trait. "There's got to be something going on in the brain," he said.

Hypnosis is described as a trance-like state during which a person has a heightened focus and concentration. It has been shown to help with brain control over sensation and behavior, and has been used clinically to help patients manage pain, control stress and anxiety and combat phobias.

A compassion-based meditation program can significantly improve a person's ability to read the facial expressions of others, finds a study published by Social Cognitive and Affective Neuroscience. This boost in empathic accuracy was detected through both behavioral testing of the study participants and through functional magnetic resonance imaging (fMRI) scans of their brain activity.

"It's an intriguing result, suggesting that a behavioral intervention could enhance a key aspect of empathy," says lead author Jennifer Mascaro, a post-doctoral fellow in anthropology at Emory University. "Previous research has shown that both children and adults who are better at reading the emotional expressions of others have better relationships."

The meditation protocol, known as Cognitively-Based Compassion Training, or CBCT, was developed at Emory by study co-author Lobsang Tenzin Negi, director of the Emory-Tibet Partnership. Although derived from ancient Tibetan Buddhist practices, the CBCT program is secular in content and presentation.

The research team also included senior author Charles Raison, formerly a psychiatrist at Emory's School of Medicine and currently at the University of Arizona, and Emory anthropologist James Rilling.