Category: Brain Science

Jyutika Mehta, Texas Woman’s University

Imagine never again forgetting where you parked your car, or that last item you had on your grocery list, or why you walked into this room anyway. If you trust media stories about research currently under way at Defense Advanced Research Projects Agency (DARPA) to build an implantable device to restore memory, you might not have to worry about these memory lapses in the future.

Many neuroscientists share the dream of neuroprosthetic technology that could help damaged brains function. Many such devices are in various stages of experimentation. Beyond helping those with impaired memories, the next step could conceivably be implantable “brain chips” that would improve the memories of the rest of us, ensuring that in the future we never forget anything.

But what would it really mean if we were able to remember every single thing?

How brains remember

Since the early neurological work on memory in the 1950s and 1960s, studies have demonstrated that memories are not stored in just one part of the brain. They’re widely distributed across the whole brain, particularly in an area called the cortex.

 

Contrary to the popular notion, our memories are not stored in our brains like books on shelves in specific categories. They’re actively reconstructed from elements scattered throughout various areas of the cortex by a process called encoding.

As we experience the world through our eyes, ears and so on, various groups of neurons in the cortex fire together to form a neural pathway from each of these senses and encode these patterns into memories. That’s why the aroma of cornbread may trigger a Thanksgiving dinner memory at grandmother’s house many years ago, or the sound of a car backfiring may trigger a panic attack in a war veteran.

A structure called the hippocampus, located within the cerebral cortex, plays a vital role in memory. We find the hippocampus is damaged in conditions that affect memory such as Alzheimer’s disease.

Forgetting, then, is an inability (either temporary or permanent) to retrieve part of the neural pathway that’s been encoded in the brain. Increasing forgetfulness is a normal part of the aging process, as the neurons start to lose their connections and pathways start to wither off. Ultimately the brain shrinks and becomes less effective at remembering. The hippocampus is one of the first areas of the brain to deteriorate with age.

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If you spoke Chinese or some other language as a young child but don’t speak it now, you probably assume you’ve forgotten it. But a recent study suggests your brain hasn’t.

In fact that “forgotten” first language could have a lot to do with what goes on in your brain when you speak today.

Researchers say the finding is important because it not only shows how the brain becomes wired for language, but also how that hard-wiring can change and adapt over time in response to new language environments. The research has implications for understanding how brain plasticity functions, and could also be important when creating educational practices geared to different types of learners.

For a new study, three groups of children (aged 10-17) with very different linguistic backgrounds were asked to perform a task that involved identifying French pseudo-words (such as vapagne and chansette).

One group was born and raised in unilingual French-speaking families. Children in the second group were adopted from China into a French-speaking family before age three, stopped speaking Chinese, and from that point on heard and used only French. Children in the third group were fluently bilingual in Chinese and French.

As the children responded to the words they heard, researchers used functional magnetic resonance imaging (fMRI) to look at which parts of their brains were activated.

Although all groups performed the tasks equally well, the areas of the brain that were activated differed between the groups. In monolingual French children with no exposure to Chinese, areas of the brain, notably the left inferior frontal gyrus and anterior insula, expected to be involved in processing of language-associated sounds were activated.

However, among both the children who were bilingual (Chinese/French) and those who had been exposed to Chinese as young infants and had then stopped speaking it, additional areas of the brain, particularly the right middle frontal gyrus, left medial frontal cortex, and bilateral superior temporal gyrus were also activated.

Chinese children who had been adopted into unilingual French families and no longer spoke Chinese (and so were functionally unilingual at the time of testing) still had brains that processed language in a way that is similar to bilingual children.

“During the first year of life, as a first step in language development, infants’ brains are highly tuned to collect and store information about the sounds that are relevant and important to the language they hear around them,” says Lara Pierce, a doctoral student and first author of the study.

“What we discovered when we tested the children who had  been adopted into French-language families and no longer spoke Chinese, was that, like children who were bilingual, the areas of the brain known to be involved in working memory and general attention were activated when they were asked to perform tests involving language. These results suggest that children exposed to Chinese as infants process French in a different manner to monolingual French children.”

The findings, published in the journal Nature Communications, speak to the unique and lasting influence of early language experience on later brain organization, as well as to the brain’s ability to adapt to new language environments in order to gain proficiency in a new language, the researchers say.

“The adopted children we tested have an interesting background because they were exposed to one language from birth, but completely discontinued that language at a young age when they were adopted into families who speak a different language,” Pierce says. “This is very interesting from a language development perspective because it allows us to look at the influence of just that very early period of language development on later language processing, separately from the effects of ongoing exposure to one or more languages.”

The researchers are interested in knowing whether similar areas of the brain would be activated if the languages that had been “lost” and “gained” through adoption were closer together than Chinese and French, such as French and Spanish for example.

The Natural Sciences and Engineering Research Council of Canada, the Social Sciences and Humanities Research Council of Canada, and the Fonds de recherches sur la société et culture, the G.W. Stairs Foundation, and the Centre for Research on Brain Language and Music contributed to the work.

 

Republished from Futurity.org  under the Creative Commons Attribution 4.0 International license with a new headline and some links to other articles removed. Original article posted to Futurity by  Katherine Gombay-McGill.

Featured Photo Credit: David Woo via flickr, CC BY-ND 2.0

Believe it or not, there is science – brain science, to be exact – to kissing, and to making your kisses count. As silly as this might seem, if you’re on the dating scene and you want to make an impression (so to speak), then this video’s scientific advice might just make the difference between a hot night or yet another “don’t call me, I’ll call you” date…

Our thanks to BuzzFeedBlue for this very insightful video.

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Neuroscientists can make a sleeping mouse start dreaming at the flip of a switch.

The researchers inserted an optogenetic switch into a group of nerve cells located in the ancient part of the brain called the medulla, allowing them to activate or inactivate the neurons with laser light.

When the neurons were activated, sleeping mice entered REM sleep within seconds. REM sleep, characterized by rapid eye movements, is the dream state in mammals accompanied by activation of the cortex and total paralysis of the skeletal muscles, presumably so that we don’t act out the dreams flashing through our mind.

Inactivating the neurons reduced or even eliminated a mouse’s ability to enter REM sleep.

“People used to think that this region of the medulla was only involved in the paralysis of skeletal muscles during REM sleep,” says lead author Yang Dan, a professor of molecular and cell biology at the University of California, Berkeley, and a Howard Hughes Medical Institute Investigator.

“What we showed is that these neurons triggered all aspects of REM sleep, including muscle paralysis and the typical cortical activation that makes the brain look more awake than in non-REM sleep.”

While other types of neurons in the brainstem and hypothalamus have been shown to influence REM sleep, Dan says, “Because of the strong induction of REM sleep—in 94 percent of the recorded trials our mice entered REM sleep within seconds of activating the neurons—we think this might be a critical node of a relatively small network that makes the decision whether you go into dream sleep or not.”

STOP-AND-GO DREAMING

The discovery, reported in Nature, will not only help researchers better understand the complex control of sleep and dreaming in the brain, the researchers say, but also will allow scientists to stop and start dreaming at will in mice to learn why we dream.

“Many psychiatric disorders, especially mood disorders, are correlated with changes in REM sleep, and some widely used drugs affect REM sleep, so it seems to be a sensitive indicator of mental and emotional health,” says first author Franz Weber, a postdoctoral fellow.

“We are hoping that studying the sleep circuit might lead us to new insights into these disorders as well as neurological diseases that affect sleep, like Parkinson’s and Alzheimer’s diseases.”

THE OPPOSITE OF STRESS NEURONS?

The researchers also found that activating these brain cells while the mice were awake had no effect on wakefulness, but did make them eat more. In normal mice, these neurons—a subset of nerve cells that release the neurotransmitter gamma-amino butyric acid (GABA), and so are called GABAergic neurons—are most active during waking periods when the mice are eating or grooming, two highly pleasurable activities.

Dan suspects that these GABAergic neurons in the medulla have the opposite effect of stress neurons, such as the noradrenergic neurons in the pons, another ancient part of the brain. Noradrenergic neurons release the transmitter noradrenalin, a cousin of adrenalin.

“Other people have found that noradrenergic neurons, which are active when you are running, shut down when eating or grooming. So it seems like when you are relaxed and enjoying yourself, the noradrenergic neurons switch off and these GABAergic neurons in the medulla turn on,” she says.

The GABAergic neurons project from the ventral part of the medulla, which sits at the top of the spinal cord, into many regions of the brainstem and hypothalamus, and thus are able to affect many bodily functions. These regions—more primitive than the brain’s cortex, the center of thinking and reasoning—are the seat of emotions and many innate behaviors as well as the control centers for muscles and automatic functions such as breathing.

TURNING NEURONS ON AND OFF

Dan, Weber, and their colleagues chose a powerful technique called optogenetics to study these REM-related GABAergic neurons in the medulla. The technique involves inserting a light-sensitive ion channel into specific types of neurons by means of a virus.

To target the virus to GABAergic neurons, the researchers used a genetically engineered mouse line that expresses a marker protein in these specific neurons only. Once present, the ion channel can turn on the activity of neurons when stimulated by laser light through an optical fiber inserted in the brain. Alternatively, inserting an inhibitory ion pump into the GABAergic neurons allowed the researchers to turn off the activity of these neurons through laser stimulation.

Using this genetically engineered strain of mice, the researchers mapped the activity of these neurons in the medulla and then recorded how activating or inactivating the neurons for brief periods affected sleep and waking behavior.

They also used a drug to inactivate the same set of neurons and found a reduction of REM sleep, though not as immediate and lasting for a longer period of time, since the drug required about half an hour to take effect and wore off slowly.

They also inserted the light-sensitive ion channels into a different set of neurons in the medulla: glutamatergic neurons, which release the neurotransmitter glutamate. Activating these neurons immediately awakened the animals, the opposite effect of activating the GABAergic neurons.

Dan is continuing her studies of the neurons that affect not only REM sleep, but also non-REM sleep.

Weber’s postdoctoral fellowships from the European Molecular Biology Organization and the Human Frontier Science Program supported the work. Additional authors are Shinjae Chung and Min Xu of UC Berkeley and Kevin Beier and Liqun Luo of Stanford University.

 

Republished from Futurity.org under the Creative Commons Attribution 4.0 International license with a new headline and additional article links removed. Original article posted on Futurity by  Robert Sanders-UC Berkeley.

Featured Photo Credit: Motorito/Flickr 

 

Researchers have figured out how brain rhythms help process music.

The study, which appears in the Proceedings of the National Academy of Sciences, points to a newfound role the brain’s cortical oscillations play in the detection of musical sequences. The findings also suggest musical training can enhance the functional role of brain rhythms.

“We’ve isolated the rhythms in the brain that match rhythms in music,” explains lead author Keith Doelling, a PhD student at New York University. “Specifically, our findings show that the presence of these rhythms enhances our perception of music and of pitch changes.”

Not surprisingly, the study found that musicians have more potent oscillatory mechanisms than do non-musicians—but this discovery’s importance goes beyond the value of musical instruction.

“What this shows is we can be trained, in effect, to make more efficient use of our auditory-detection systems,” observes study coauthor David Poeppel, a professor in psychology department and Center for Neural Science and director of the Max Planck Institute for Empirical Aesthetics in Frankfurt.

“Musicians, through their experience, are simply better at this type of processing.”

Previous research has shown that brain rhythms very precisely synchronize with speech, enabling us to parse continuous streams of speech—in other words, how we can isolate syllables, words, and phrases from speech, which is not, when we hear it, marked by spaces or punctuation.

However, it has not been clear what role such cortical brain rhythms, or oscillations, play in processing other types of natural and complex sounds, such as music.

To address these questions, the researchers conducted three experiments using magnetoencephalography (MEG), which allows measurements of the tiny magnetic fields generated by brain activity. The study’s subjects were asked to detect short pitch distortions in 13-second clips of classical piano music (by Bach, Beethoven, Brahms) that varied in tempo—from half a note to eight notes per second.

The study’s authors divided the subjects into musicians (those with at least six years of musical training and who were currently practicing music) and non-musicians (those with two or fewer years of musical training and who were no longer involved in it).

For music that is faster than one note per second, both musicians and non-musicians showed cortical oscillations that synchronized with the note rate of the clips—in other words, these oscillations were effectively employed by everyone to process the sounds they heard, although musicians’ brains synchronized more to the musical rhythms. Only musicians, however, showed oscillations that synchronized with unusually slow clips.

This difference, the researchers say, may suggest that non-musicians are unable to process the music as a continuous melody rather than as individual notes. Moreover, musicians much more accurately detected pitch distortions—as evidenced by corresponding cortical oscillations.

Brain rhythms, they add, therefore appear to play a role in parsing and grouping sound streams into “chunks” that are then analyzed as speech or music.

The National Institutes of Health and the National Science Foundation supported the work.

 

Source: Reproduced from Futurity.org as a derivative work under the Attribution 4.0 International license. Original article posted by James Devitt-NYU

Featured Photo Credit: danbruell/Flickr

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Gene E Robinson, University of Illinois at Urbana-Champaign

It’s not headline news that our brains are the seat of our thoughts and feelings. The brain is a body’s decision-maker, the pilot of its actions and the engineer that keeps all systems going. The brain suits the body’s actions to its surroundings, taking in sensory details and sending out appropriate and timely responses. We’ve long attributed the marvelous workings of the brain to the intricate structures formed by its highly specialized cells, neurons. These structures constitute the hardware of the brain.

But new genomic research reveals that, at an even deeper level, emotions and behavior are also shaped by a second layer of organization in the brain, one that we only recently created the tools to see. This one relies on genes.

We are beginning to appreciate how genes and neurons work together, like software and hardware, to make brain function possible. Learning to understand this two-layer system can help us understand how the environment affects behavior, and how to hack the system to improve mental health.

It is time to fully recognize gene activity not as the background utility of the brain, but as an integral part of its operation.

Neurons in the driver’s seat

The sheer complexity of the human brain became apparent in the late 19th century, when two skilled anatomists, Camillo Golgi of Italy and Santiago Ramón y Cajal of Spain, invented tissue-staining techniques that revealed intricate microscopic networks of neural cells.

We now know that about 100 billion neurons connect with each other in a human brain to form complex circuits that carry electrical and chemical messages to make memories and govern behavior. This physical structure, the one that yielded itself to the scientific tools of the time, constitutes the hardware of our neural control system, which is uniquely rewireable by experience.

Throughout the 20th century, scores of scientists characterized the sugars, lipids, proteins and myriad other molecules that build, run and repair our brains. These molecules seemed to stay out of the limelight; they appeared to play a supporting role to the neurons that ostensibly controlled our behavior.

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Some very astounding news from the world of neuroscience research shows that brain scans can predict intelligence, bringing the science fiction scenarios of movies like Divergent or the Minority Report that much closer to reality. A great article on WIRED’s website reports the details from a new study in the journal Nature, and also explores the ethical ramifications of the research:

But now that neuroscientists have used maps of people’s brains to accurately predict intelligence, reality creeps ever so much closer to fiction.

By intelligence, in this case, the scientists mean abstract reasoning ability, which they inferred by mapping and analyzing the connections within people’s brains. But the study, published today in Nature, is compelling because it gets at a fundamental and very uncomfortable truth: Some brains are better than others at certain things, simply because of the way they’re wired. And now, scientists are closer to being able to determine precisely which brains those are, and how they got that way.

Richard Haier, an intelligence researcher at the University of California, Irvine, has some more serious, non-journalistic applications in mind: Eventually, he hopes, schools could scan children to see what sort of educational environment they’d thrive in, or determine who’s more prone to addiction, or screen prison inmates to figure out whether they’re violent or not. Two researchers brought up Minority Report as a salient example.

Figuring out if little Timmy’s a visual or auditory learner is great and all, but that other data—if you’re prone to addiction, or violence, or predisposed to having delusions—is much touchier. “It’s a double-edged sword,” says Laura Cabrera, a neuroethicist at Michigan State University. Schools could use the data to guide admissions decisions, companies could hire based on mental aptitude, insurance companies could base coverage on cognitive predispositions. Predictive brain scanning could lead to a whole new form of neurodiscrimination.

In this study, the researchers predicted how well people would do on a cognitive test by analyzing fMRI scans of 126 subjects in the Human Connectome Project, a five-year initiative to map how areas of the human brain communicate with each other. The subjects performed motor, memory, and intelligence tests, including a pattern completion test that measured abstract reasoning—what neuroscientists call fluid intelligence.

Their connectomes, it turned out, had a lot to do with how well they scored. “The more certain regions are talking to one another, the better you’re able to process information quickly and make inferences,” says Emily Finn, a grad student at Yale and another author of the study. A strong connection between the frontal and parietal lobes, especially, meant a high fluid intelligence score. Both regions are involved in high-level mental function, Finn says, which makes sense: “They kind of underpin all of the sophisticated stuff that makes us humans to begin with.”

According to the WIRED article, each person’s connectome is unique, making it essentially a brain fingerprint. You can read more details about this amazing research and it’s ethical considerations in the excellent article on the WIRED site.

 

Source: WIRED.com – “Scientists Can Now Predict Intelligence From Brain Activity“

Featured Image Credit: Emily Finn

George Tsoulas, University of York

Music is what penetrates most deeply into the recesses of the soul, according to Plato. Language has been held by thinkers from Locke to Leibniz and Mill to Chomsky as a mirror or a window to the mind. As American psychologist Aniruddh Pattel writes:
“Language and music define us as humans”.

The two are facets of a single cognitive system. Under the brain’s hood there is a simple computational operation, taking basic elements like words or simple sounds, combining them in a step-by-step manner and producing a larger structured object such as a flowing sentence or a melodious musical phrase.

This is all just in the mind, but needs to happen before language is “externalised” as speech or writing and music is expressed through performance or by the simple act of tapping your foot to a rhythm.

But there are further questions to ask about the relationship between music and language, such as whether musical education and expertise influence our way with language or if it makes us better learners of a second or third language. On the other side, it would be great to know if fluency in more than one language makes it easier for us to learn an instrument. And if people who are bilingual, trilingual or quadrilingual listen to music in a different way.

Benefits of bilingualism

Several studies have shown that both bilingualism and musical training and practice appear to protect people against the onset of dementia and other cognitive decline in later life. As Canadian psychologists Ellen Bialystok and Anne-Marie DePape pointed out in a 2009 article, the mechanisms responsible for these effects are rather poorly understood, more so in music than in language. But they do point at some interesting possibilities.

Several of the studies reviewed in a 2011 paper by Finnish music and education researcher Riia Milovanov and her colleagues, showed that mastery of more than one language as well as mastery of music involves higher levels of executive control. These are the mechanisms responsible for overall management of cognitive resources and processes – including attention shifts, working memory, reasoning, and switching between tasks.

Less daunting if you play piano?
Foreign languages via f9photos/Shutterstock

Other studies reviewed in the same article showed that musical training correlates with better language-learning skills. Learners with a musical background were found to be better at pronouncing the sounds of a second language and at perceiving the relevant contrasts between sounds in that new language.

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Researchers at the University of Washington in Seattle have discovered that they can connect two people’s brains over the internet using specially designed skull caps. Once connected, study participants played a question and answer game where the person responding had the correct answer 72% of the time.

A fantastic article on Science Daily’s website provides the details:

University of Washington researchers recently used a direct brain-to-brain connection to enable pairs of participants to play a question-and-answer game by transmitting signals from one brain to the other over the Internet. The experiment, detailed today in PLOS ONE, is thought to be the first to show that two brains can be directly linked to allow one person to accurately guess what’s on another person’s mind.

“This is the most complex brain-to-brain experiment, I think, that’s been done to date in humans,” said lead author Andrea Stocco, an assistant professor of psychology and a researcher at UW’s Institute for Learning & Brain Sciences.

“It uses conscious experiences through signals that are experienced visually, and it requires two people to collaborate,” Stocco said.

Here’s how it works: The first participant, or “respondent,” wears a cap connected to an electroencephalography (EEG) machine that records electrical brain activity. The respondent is shown an object (for example, a dog) on a computer screen, and the second participant, or “inquirer,” sees a list of possible objects and associated questions. With the click of a mouse, the inquirer sends a question and the respondent answers “yes” or “no” by focusing on one of two flashing LED lights attached to the monitor, which flash at different frequencies.

A “no” or “yes” answer both send a signal to the inquirer via the Internet and activate a magnetic coil positioned behind the inquirer’s head. But only a “yes” answer generates a response intense enough to stimulate the visual cortex and cause the inquirer to see a flash of light known as a “phosphene.” The phosphene — which might look like a blob, waves or a thin line — is created through a brief disruption in the visual field and tells the inquirer the answer is yes. Through answers to these simple yes or no questions, the inquirer identifies the correct item.

The experiment was carried out in dark rooms in two UW labs located almost a mile apart and involved five pairs of participants, who played 20 rounds of the question-and-answer game. Each game had eight objects and three questions that would solve the game if answered correctly. The sessions were a random mixture of 10 real games and 10 control games that were structured the same way.

But how did the researchers make sure that study participants weren’t gaming the system somehow? We answer that question on the next page…

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Richard Gunderman, Indiana University-Purdue University Indianapolis

Oliver Sacks, the celebrated neurologic storyteller who died at the end of August at age 82, once described himself as “strongly atheist by disposition.”

Sacks could write sensitively about religion, including a recent article on the role of the Sabbath in his own life, but in writing about mystical experiences, he typically repaired to his professional lexicon, referring to them as hallucinations – seemingly authentic visual and auditory experiences traceable not to any external reality, but only to the brain itself. Sacks had witnessed in many of his patients the depths of human longing, including a deep hunger for God, but to him they revealed truths only about our own psyches.

Oliver Sacks.
Steve Jurvetson/Flickr, CC BY

The notion that God represents but a chimera, a projection of inner human needs, goes back at least to the 19th-century philosopher Ludwig Feuerbach, who wrote that our longing for God reveals nothing more than a desire to make gods of ourselves.

More recently, some philosophers and scientists have suggested that belief in God is nothing more than a delusion that springs from our need to discern patterns and even intentions in otherwise purposeless events taking place around us. Belief in God, they say, offers a refuge from the world’s cold incomprehensibility.

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