Tag: neuroscience

New research may help explain why curiosity promotes better memory

On By A.P.In aged brain, ageing, aging, brain, dopamine, hippocampus, Human Behavior, learning, LiveScience, Medicine, memory, mental concentration, MRI, Neurology, Neuron, Neuropsychiatric Disease, Neuroscience, neuroscientistLeave a comment

Everyone knows it’s easier to learn about a topic you’re curious about. Now, a new study reveals what’s going on in the brain during that process, revealing that such curiosity may give a person a memory boost.

When participants in the study were feeling curious, they were better at remembering information even about unrelated topics, and brain scans showed activity in areas linked to reward and memory.

The results, detailed October 2 in the journal Neuron, hint at ways to improve learning and memory in both healthy people and those with neurological disorders, the researchers said.

“Curiosity may put the brain in a state that allows it to learn and retain any kind of information, like a vortex that sucks in what you are motivated to learn, and also everything around it,” Matthias Gruber, a memory researcher at the University of California, Davis, said in a statement. “These findings suggest ways to enhance learning in the classroom and other settings.”

Gruber and his colleagues put people in a magnetic resonance imaging (MRI) scanner and showed them a series of trivia questions, asking them to rate their curiosity about the answers to those questions. Later, the participants were shown selected trivia questions, then a picture of a neutral face during a 14-second delay, followed by the answer. Afterward, the participants were given a surprise memory test of the faces, and then a memory test of the trivia answers.

Not surprisingly, the study researchers found that people remembered more information about the trivia when they were curious about the trivia answers. But unexpectedly, when the participants were curious, they were also better at remembering the faces, an entirely unrelated task. Participants who were curious were also more likley than others to remember both the trivia information and unrelated faces a day later, the researchers found.

The brain scans showed that, compared with when their curiosity wasn’t piqued, when people were curious, they showed more activation of brain circuits in the nucleus accumbens, an area involved in reward. These same circuits, mediated by the neurochemical messenger dopamine, are involved in forms of external motivation, such as food, sex or drug addiction.

Finally, being curious while learning seemed to produce a spike of activity in the hippocampus, an area involved in forming new memories, and strengthened the link between memory and reward brain circuits.

The study’s findings not only highlight the importance of curiosity for learning in healthy people, but could also give insight into neurological conditions. For example, as people age, their dopamine circuits tend to deteriorate, so understanding how curiosity affects these circuits could help scientists develop treatments for patients with memory disorders, the researchers said.

http://www.livescience.com/48121-curiosity-boosts-memory-learning.html

On/Off switch for consciousness in the human brain may have been discovered

On By A.P.In brain, Christof Koch, claustrum, consciousness, Epilepsy and Behavior, Francis Crick, Mohamad Koubeissi, NeuroscienceLeave a comment

ONE moment you’re conscious, the next you’re not. For the first time, researchers have switched off consciousness by electrically stimulating a single brain area.

Scientists have been probing individual regions of the brain for over a century, exploring their function by zapping them with electricity and temporarily putting them out of action. Despite this, they have never been able to turn off consciousness – until now.

Although only tested in one person, the discovery suggests that a single area – the claustrum – might be integral to combining disparate brain activity into a seamless package of thoughts, sensations and emotions. It takes us a step closer to answering a problem that has confounded scientists and philosophers for millennia – namely how our conscious awareness arises.

Many theories abound but most agree that consciousness has to involve the integration of activity from several brain networks, allowing us to perceive our surroundings as one single unifying experience rather than isolated sensory perceptions.

One proponent of this idea was Francis Crick, a pioneering neuroscientist who earlier in his career had identified the structure of DNA. Just days before he died in July 2004, Crick was working on a paper that suggested our consciousness needs something akin to an orchestra conductor to bind all of our different external and internal perceptions together.

With his colleague Christof Koch, at the Allen Institute for Brain Science in Seattle, he hypothesised that this conductor would need to rapidly integrate information across distinct regions of the brain and bind together information arriving at different times. For example, information about the smell and colour of a rose, its name, and a memory of its relevance, can be bound into one conscious experience of being handed a rose on Valentine’s day.

The pair suggested that the claustrum – a thin, sheet-like structure that lies hidden deep inside the brain – is perfectly suited to this job (Philosophical Transactions of The Royal Society B, doi.org/djjw5m).

It now looks as if Crick and Koch were on to something. In a study published last week, Mohamad Koubeissi at the George Washington University in Washington DC and his colleagues describe how they managed to switch a woman’s consciousness off and on by stimulating her claustrum. The woman has epilepsy so the team were using deep brain electrodes to record signals from different brain regions to work out where her seizures originate. One electrode was positioned next to the claustrum, an area that had never been stimulated before.

When the team zapped the area with high frequency electrical impulses, the woman lost consciousness. She stopped reading and stared blankly into space, she didn’t respond to auditory or visual commands and her breathing slowed. As soon as the stimulation stopped, she immediately regained consciousness with no memory of the event. The same thing happened every time the area was stimulated during two days of experiments (Epilepsy and Behavior, doi.org/tgn).
To confirm that they were affecting the woman’s consciousness rather than just her ability to speak or move, the team asked her to repeat the word “house” or snap her fingers before the stimulation began. If the stimulation was disrupting a brain region responsible for movement or language she would have stopped moving or talking almost immediately. Instead, she gradually spoke more quietly or moved less and less until she drifted into unconsciousness. Since there was no sign of epileptic brain activity during or after the stimulation, the team is sure that it wasn’t a side effect of a seizure.

Koubeissi thinks that the results do indeed suggest that the claustrum plays a vital role in triggering conscious experience. “I would liken it to a car,” he says. “A car on the road has many parts that facilitate its movement – the gas, the transmission, the engine – but there’s only one spot where you turn the key and it all switches on and works together. So while consciousness is a complicated process created via many structures and networks – we may have found the key.”

Counter-intuitively, Koubeissi’s team found that the woman’s loss of consciousness was associated with increased synchrony of electrical activity, or brainwaves, in the frontal and parietal regions of the brain that participate in conscious awareness. Although different areas of the brain are thought to synchronise activity to bind different aspects of an experience together, too much synchronisation seems to be bad. The brain can’t distinguish one aspect from another, stopping a cohesive experience emerging.

Since similar brainwaves occur during an epileptic seizure, Koubeissi’s team now plans to investigate whether lower frequency stimulation of the claustrum could jolt them back to normal. It may even be worth trying for people in a minimally conscious state, he says. “Perhaps we could try to stimulate this region in an attempt to push them out of this state.”

Anil Seth, who studies consciousness at the University of Sussex, UK, warns that we have to be cautious when interpreting behaviour from a single case study. The woman was missing part of her hippocampus, which was removed to treat her epilepsy, so she doesn’t represent a “normal” brain, he says.

However, he points out that the interesting thing about this study is that the person was still awake. “Normally when we look at conscious states we are looking at awake versus sleep, or coma versus vegetative state, or anaesthesia.” Most of these involve changes of wakefulness as well as consciousness but not this time, says Seth. “So even though it’s a single case study, it’s potentially quite informative about what’s happening when you selectively modulate consciousness alone.”

“Francis would have been pleased as punch,” says Koch, who was told by Crick’s wife that on his deathbed, Crick was hallucinating an argument with Koch about the claustrum and its connection to consciousness.

“Ultimately, if we know how consciousness is created and which parts of the brain are involved then we can understand who has it and who doesn’t,” says Koch. “Do robots have it? Do fetuses? Does a cat or dog or worm? This study is incredibly intriguing but it is one brick in a large edifice of consciousness that we’re trying to build.”

http://www.newscientist.com/article/mg22329762.700-consciousness-onoff-switch-discovered-deep-in-brain.html?full=true#.U7n7sI1dVC8

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.

7 Very Bizarre (and Very Rare) Psychotic Hallucinations

On By A.P.In Alice-in-Wonderland syndrome, Anxiety, bipolar disorder, brain, Capgras delusion, Caro Lippman, Charles Bonnet syndrome, Clinical lycanthropy, Cotard's Syndrome, delusional infestations, delusional parasitosis, Dementia, Depression, Drugs, Ekbom's syndrome, epilepsy, John Todd, Jules Cotard, Medicine, mental health, mental illness, migraine, multiple sclerosis, neural activity, neurologist, Neurology, Neuropsychiatric Disease, Neuroscience, neuroscientist, Othello syndrome, post-traumatic stress disorder, psychiatrist, Psychiatry, Psychosis, seizure, stroke, traumatic brain injury, Walking Corpse SyndromeLeave a comment

brain

The many documented cases of strange delusions and neurological syndromes can offer a window into how bizarre the brain can be.

It may seem that hallucinations are random images that appear to some individuals, or that delusions are thoughts that arise without purpose. However, in some cases, a specific brain pathway may create a particular image or delusion, and different people may experience the same hallucination.

In recent decades, with advances in brain science, researchers have started to unravel the causes of some of these conditions, while others have remained a mystery.

Here is a look at seven odd hallucinations, which show that anything is possible when the brain takes a break from reality.

1. Alice-in-Wonderland syndrome
This neurological syndrome is characterized by bizarre, distorted perceptions of time and space, similar to what Alice experienced in Lewis Carroll’s “Alice’s Adventures in Wonderland.”

Patients with Alice-in-Wonderland syndrome describe seeing objects or parts of their bodies as smaller or bigger than their actual sizes, or in an altered shape. These individuals may also perceive time differently.

The rare syndrome seems to be caused by some viral infections, epilepsy, migraine headaches and brain tumors. Studies have also suggested that abnormal activity in parts of the visual cortex that handle information about the shape and size of objects might cause the hallucinations.

It’s also been suggested that Carroll himself experienced the condition during migraine headaches and used them as inspiration for writing the tale of Alice’s strange dream.

English psychiatrist John Todd first described the condition in an article published in the Canadian Medical Association Journal in 1955, and that’s why the condition is also called Todd’s syndrome. However, an earlier reference to the condition appears in a 1952 article by American neurologist Caro Lippman. The doctor describes a patient who reported feeling short and wide as she walked, and referenced “Alice’s Adventures in Wonderland” to explain her body image illusions.

2. Walking Corpse Syndrome
This delusion, also called Cotard’s Syndrome, is a rare mental illness in which patients believe they are dead, are dying or have lost their internal organs.

French neurologist Jules Cotard first described the condition in 1880, finding it in a woman who had depression and also symptoms of psychosis. The patient believed she didn’t have a brain or intestines, and didn’t need to eat. She died of starvation.

Other cases of Cotard’s syndrome have been reported in people with a range of psychiatric and neurological problems, including schizophrenia, traumatic brain injury and multiple sclerosis.

In a recent case report of Cotard’s syndrome, researchers described a previously healthy 73-year-old woman who went to the emergency room insisting that she was “going to die and going to hell.” Eventually, doctors found the patient had bleeding in her brain due to a stroke. After she received treatment in the hospital, her delusion resolved within a week, according to the report published in January 2014 in the journal of Neuropsychiatry.

3. Charles Bonnet syndrome
People who have lost their sight may develop Charles Bonnet syndrome, which involves having vivid, complex visual hallucinations of things that aren’t really there.

People with this syndrome usually hallucinate people’s faces, cartoons, colored patterns and objects. It is thought the condition occurs because the brain’s visual system is no longer receiving visual information from the eye or part of the retina, and begins making up its own images.

Charles Bonnet syndrome occurs in between 10 and 40% of older adults who have significant vision loss, according to studies.

4. Clinical lycanthropy
In this extremely rare psychiatric condition, patients believe they are turning into wolves or other animals. They may perceive their own bodies differently, and insist they are growing the fur, sharp teeth and claws of a wolf.

Cases have also been reported of people with delusional beliefs about turning into dogs, pigs, frogs and snakes.

The condition usually occurs in combination with another disorder, such as schizophrenia, bipolar disorder or severe depression, according to a review study published in the March issue of the journal History of Psychiatry in 2014.

5. Capgras delusion
Patients with Capgras delusion believe that an imposter has replaced a person they feel close to, such as a friend or spouse. The delusion has been reported in patients with schizophrenia, Alzheimer’s disease, advanced Parkinson’s disease, dementia and brain lesions.

One brain imaging study suggested the condition may involve reduced neural activity in the brain system that processes information about faces and emotional responses.

6. Othello syndrome
Named after Shakespeare’s character, Othello syndrome involves a paranoid belief that the sufferer’s partner is cheating. People with this condition experience strong obsessive thoughts and may show aggression and violence.

In one recent case report, doctors described a 46-year-old married man in the African country Burkina Faso who had a stroke, which left him unable to communicate and paralyzed in half of his body. The patient gradually recovered from his paralysis and speaking problems, but developed a persistent delusional jealousy and aggression toward his wife, accusing her of cheating with an unidentified man.

7. Ekbom’s syndrome
Patients with Ekbom’s syndrome, also known as delusional parasitosis or delusional infestations, strongly believe they are infested with parasites that are crawling under their skin. Patients report sensations of itching and being bitten, and sometimes, in an effort to get rid of the pathogens, they may hurt themselves, which can result in wounds and actual infections.

It’s unknown what causes these delusions, but studies have linked the condition with structural changes in the brain, and some patients have improved when treated with antipsychotic medications.

http://www.livescience.com/46477-oddest-hallucinations.html

Brain tumor causes uncontrollable laughter

On By A.P.In Bolivia, brain tumor, Burgos Zuleta, hamartoma, laughter, LiveScience, Medicine, Michael Moore, neurologist, Neurology, Neuroscience, neurosurgeon, neurosurgery, seizureLeave a comment

They say laughter is the best medicine. But what if laughter is the disease?

For a 6-year-old girl in Bolivia who suffered from uncontrollable and inappropriate bouts of giggles, laughter was a symptom of a serious brain problem. But doctors initially diagnosed the child with “misbehavior.”

“She was considered spoiled, crazy — even devil-possessed,” Dr. José Liders Burgos Zuleta, ofAdvanced Medical Image Centre, in Bolivia, said in a statement.

But Burgos Zuleta discovered that the true cause of the girl’s laughing seizures, medically called gelastic seizures, was a brain tumor.

After the girl underwent a brain scan, the doctors discovered a hamartoma, a small, benign tumor that was pressing against her brain’s temporal lobe.The doctors surgically removed the tumor, and the girl is now healthy, the doctors said.

The girl stopped having the uncontrollable attacks of laughter and now only laughs normally, the doctors said.

Gelastic seizures are a form of epilepsy that is relatively rare, said Dr. Solomon Moshé, a pediatric neurologist at Albert Einstein College of Medicine in New York. The word comes from the Greek word for laughter, “gelos.”

“It’s not necessarily ‘hahaha’ laughing,” Moshé told Live Science. “There’s no happiness in this. Some of the kids may be very scared,” he added.

The seizures are most often caused by tumors in the hypothalamus, especially in kids, although they can also come from tumors in other parts of brain, Moshé said. Although laughter is the main symptom, patients may also have outbursts of crying.

These tumors can cause growth abnormalities if they affect the pituitary gland, he said.

The surgery to remove such brain tumors used to be difficult and dangerous, but a new surgical technique developed within the last 10 years allows doctors to remove them effectively without great risk, Moshé said.

The doctors who treated the girl said their report of her case could raise awareness of the strange condition, so doctors in Latin America can diagnose the true cause of some children’s “behavioral” problems, and refer them to a neurologist.

The case report was published June 16 in the journal ecancermedicalscience.

Thanks to Michael Moore for sharing this with the It’s Interesting community.

http://www.cbsnews.com/news/girls-uncontrollable-laughter-caused-by-brain-tumor/

Study Finds Pedophiles’ Brains Wired to Find Children Attractive

On By A.P.In biology, Biology Letters, child abuse, Crime, crime prediction, Human Behavior, James Cantor, Jorge Ponseti, magnetic resonance imaging, MRI, neurologist, Neurology, Neuroscience, neuroscientist, pedophilia, psychiatrist, Psychiatry, Psychological Medicine, Psychological Science, psychology, Science, sex, sexuality, The Brain, The Future, University of Toronto1 Comment

Pedophiles’ brains are “abnormally tuned” to find young children attractive, according to a new study published this week. The research, led by Jorge Ponseti at Germany’s University of Kiel, means that it may be possible to diagnose pedophiles in the future before they are able to offend.

The findings, published in scientific journal Biology Letters, discovered that pedophiles have the same neurological reaction to images of those they find attractive as those of people with ordinary sexual predilections, but that all the relevant cerebral areas become engaged when they see children, as opposed to fellow adults. The occipital areas, prefrontal cortex, putamen, and nucleus caudatus become engaged whenever a person finds another attractive, but the subject of this desire is inverted for pedophiles.

While studies into the cognitive wiring of sex offenders have long been a source of debate, this latest research offers some fairly conclusive proof that there is a neural pattern behind their behavior.

The paper explains: “The human brain contains networks that are tuned to face processing, and these networks appear to activate different processing streams of the reproductive domain selectively: nurturing processing in the case of child faces and sexual processing in the case of sexually preferred adult faces. This implies that the brain extracts age-related face cues of the preferred sex that inform appropriate response selection in the reproductive domains: nurturing in the case of child faces and mating in the case of adult faces.”

Usually children’s faces elicit feelings of caregiving from both sexes, whereas those of adults provide stimuli in choosing a mate. But among pedophiles, this trend is skewed, with sexual, as opposed to nurturing, emotions burgeoning.

The study analyzed the MRI scans of 56 male participants, a group that included 13 homosexual pedophiles and 11 heterosexual pedophiles, exposing them to “high arousing” images of men, women, boys, and girls. Participants then ranked each photo for attractiveness, leading researchers to their conclusion that the brain network of pedophiles is activated by sexual immaturity.

The critical new finding is that face processing is also tuned to face cues revealing the developmental stage that is sexually preferred,” the paper reads.

Dr. James Cantor, associate professor at the University of Toronto’s Faculty of Medicine, said he was “delighted” by the study’s results. “I have previously described pedophilia as a ‘cross-wiring’ of sexual and nurturing instincts, and this data neatly verifies that interpretation.”

Cantor has undertaken extensive research into the area, previously finding that pedophiles are more likely to be left-handed, 2.3 cm shorter than the average male, and 10 to 15 IQ points lower than the norm.

He continued: “This [new] study is definitely a step in the right direction, and I hope other researchers repeat this kind of work. There still exist many contradictions among scientists’ observations, especially in identifying exactly which areas of the brain are the most central to pedophilia. Because financial support for these kinds of studies is quite small, these studies have been quite small, permitting them to achieve only incremental progress. Truly definitive studies about what in the brain causes pedophilia, what might detect it, and what might prevent it require much more significant support.”

Ponseti said that he hoped to investigate this area further by examining whether findings could be emulated when images of children’s faces are the sole ones used. This could lead to gauging a person’s predisposition to pedophilia far more simply than any means currently in place. “We could start to look at the onset of pedophilia, which is probably in puberty at about 12 or 14 years [old],” he told The Independent.

While Cantor is correct in citing the less than abundant size of the study, the research is certainly significant in providing scope for future practicable testing that could reduce the number of pedophilic crimes committed. By being able to run these tests and examine a person’s tendency toward being sexually attracted to underage children, rehabilitative care and necessary precautions could be taken to safeguard children and ensure that those at risk of committing a crime of this ilk would not be able to do so.

http://www.thedailybeast.com/articles/2014/05/23/study-finds-pedophiles-brains-wired-to-find-children-attractive.html#