Scientists at Wesleyan University have used electroencephalography to uncover differences in how the brains of Classical and Jazz musicians react to an unexpected chord progression.
Their new study, published in the journal Brain and Cognition, sheds new light on the nature of the creative process.
“I have been a classical musician for many years, and have always been inspired by the great jazz masters who can improvise beautiful performances on the spot,” explained study author Psyche Loui. “Whenever I tried to improvise I always felt inhibited and self-conscious, and this spurred my questions about jazz improvisation as a model for creativity more generally: What makes people creative improvisers, and what can this tell us about how we can all learn to be more creative?” [Continue reading…]
Open to the unexpected: Why jazz musicians are more creative than classical musicians
To improve memory, tune it like an orchestra
Anyone above a certain age who has drawn a blank on the name of a favorite uncle, a friend’s phone number or the location of a house key understands how fragile memory is. Its speed and accuracy begin to slip in one’s 20s and keep slipping. This is particularly true for working memory, the mental sketch pad that holds numbers, names and other facts temporarily in mind, allowing decisions to be made throughout the day.
On Monday, scientists reported that brief sessions of specialized brain stimulation could reverse this steady decline in working memory, at least temporarily. The stimulation targeted key regions in the brain and synchronized neural circuits in those areas, effectively tuning them to one another, as an orchestra conductor might tune the wind section to the strings.
The findings, reported in the journal Nature Neuroscience, provide the strongest support yet for a method called transcranial alternating current stimulation, or tACS, as a potential therapy for memory deficits, whether from age-related decline, brain injury or, perhaps, creeping dementia. [Continue reading…]
Can we get better at forgetting?
Whatever its other properties, memory is a reliable troublemaker, especially when navigating its stockpile of embarrassments and moral stumbles. Ten minutes into an important job interview and here come screenshots from a past disaster: the spilled latte, the painful attempt at humor. Two dates into a warming relationship and up come flashbacks of an earlier, abusive partner.
The bad timing is one thing. But why can’t those events be somehow submerged amid the brain’s many other dimming bad memories?
Emotions play a role. Scenes, sounds and sensations leave a deeper neural trace if they stir a strong emotional response; this helps you avoid those same experiences in the future. Memory is protective, holding on to red flags so they can be waved at you later, to guide your future behavior.
But forgetting is protective too. Most people find a way to bury, or at least reshape, the vast majority of their worst moments. Could that process be harnessed or somehow optimized?
Perhaps. In the past decade or so, brain scientists have begun to piece together how memory degrades and forgetting happens. A new study, published this month in the Journal of Neuroscience, suggests that some things can be intentionally relegated to oblivion, although the method for doing so is slightly counterintuitive.
For the longest time, forgetting was seen as a passive process of decay and the enemy of learning. But as it turns out, forgetting is a dynamic ability, crucial to memory retrieval, mental stability and maintaining one’s sense of identity.
That’s because remembering is a dynamic process. At a biochemical level, memories are not pulled from the shelf like stored videos but pieced together — reconstructed — by the brain. [Continue reading…]
How the brain links gestures, perception and meaning
The tendency to supplement communication with motion is universal, though the nuances of delivery vary slightly. In Papua New Guinea, for instance, people point with their noses and heads, while in Laos they sometimes use their lips. In Ghana, left-handed pointing can be taboo, while in Greece or Turkey forming a ring with your index finger and thumb to indicate everything is A-OK could get you in trouble.
Despite their variety, gestures can be loosely defined as movements used to reiterate or emphasize a message — whether that message is explicitly spoken or not. A gesture is a movement that “represents action,” but it can also convey abstract or metaphorical information. It is a tool we carry from a very young age, if not from birth; even children who are congenitally blind naturally gesture to some degree during speech. Everybody does it. And yet, few of us have stopped to give much thought to gesturing as a phenomenon — the neurobiology of it, its development, and its role in helping us understand others’ actions. As researchers delve further into our neural wiring, it’s becoming increasingly clear that gestures guide our perceptions just as perceptions guide our actions. [Continue reading…]
How the body and mind talk to one another to understand the world
By Sarah Garfinkel
Have you ever been startled by someone suddenly talking to you when you thought you were alone? Even when they apologise for surprising you, your heart goes on pounding in your chest. You are very aware of this sensation. But what kind of experience is it, and what can it tell us about relations between the heart and the brain?
When considering the senses, we tend to think of sight and sound, taste, touch and smell. However, these are classified as exteroceptive senses, that is, they tell us something about the outside world. In contrast, interoception is a sense that informs us about our internal bodily sensations, such as the pounding of our heart, the flutter of butterflies in our stomach or feelings of hunger.
The brain represents, integrates and prioritises interoceptive information from the internal body. These are communicated through a set of distinct neural and humoural (ie, blood-borne) pathways. This sensing of internal states of the body is part of the interplay between body and brain: it maintains homeostasis, the physiological stability necessary for survival; it provides key motivational drivers such as hunger and thirst; it explicitly represents bodily sensations, such as bladder distension. But that is not all, and herein lies the beauty of interoception, as our feelings, thoughts and perceptions are also influenced by the dynamic interaction between body and brain.
Evidence mounts that gut bacteria can influence mood, prevent depression
Of all the many ways the teeming ecosystem of microbes in a person’s gut and other tissues might affect health, its potential influences on the brain may be the most provocative. Now, a study of two large groups of Europeans has found several species of gut bacteria are missing in people with depression. The researchers can’t say whether the absence is a cause or an effect of the illness, but they showed that many gut bacteria could make substances that affect nerve cell function—and maybe mood.
“It’s the first real stab at tracking how” a microbe’s chemicals might affect mood in humans, says John Cryan, a neuroscientist at University College Cork in Ireland who has been one of the most vocal proponents of a microbiome-brain connection. The study “really pushes the field from where it’s been” with small studies of depressed people or animal experiments. Interventions based on the gut microbiome are now under investigation: The University of Basel in Switzerland, for example, is planning a trial of fecal transplants, which can restore or alter the gut microbiome, in depressed people.
Several studies in mice had indicated that gut microbes can affect behavior, and small studies of people suggested this microbial repertoire is altered in depression. To test the link in a larger group, Jeroen Raes, a microbiologist at the Catholic University of Leuven in Belgium, and his colleagues took a closer look at 1054 Belgians they had recruited to assess a “normal” microbiome. Some in the group—173 in total—had been diagnosed with depression or had done poorly on a quality of life survey, and the team compared their microbiomes with those other participants. Two kinds of microbes, Coprococcus and Dialister, were missing from the microbiomes of the depressed subjects, but not from those with a high quality of life. The finding held up when the researchers allowed for factors such as age, sex, or antidepressant use, all of which influence the microbiome, the team reports today in Nature Microbiology. They also found the depressed people had an increase in bacteria implicated in Crohn disease, suggesting inflammation may be at fault. [Continue reading…]
The cerebellum is your ‘little brain’ — and it does some pretty big things
For the longest time the cerebellum, a dense, fist-size formation located at the base of the brain, never got much respect from neuroscientists.
For about two centuries the scientific community believed the cerebellum (Latin for “little brain”), which contains approximately half of the brain’s neurons, was dedicated solely to the control of movement. In recent decades, however, the tide has started to turn, as researchers have revealed details of the structure’s role in cognition, emotional processing and social behavior.
The longstanding interest in the cerebellum can be seen in the work of French physiologist Marie Jean Pierre Flourens—(1794–1867). Flourens removed the cerebella of pigeons and found the birds became unbalanced, although they could still move. Based on these observations, he concluded the cerebellum was responsible for coordinating movements. “[This] set the dogma that the cerebellum was involved in motor coordination,” says Kamran Khodakhah, a neuroscientist at Albert Einstein College of Medicine, adding: “For many years, we ignored the signs that suggested it was involved in other things.”
One of the strongest pieces of evidence for the cerebellum’s broader repertoire emerged around two decades ago, when Jeremy Schmahmann, a neurologist at Massachusetts General Hospital, described cerebellar cognitive affective syndrome after discovering behavioral changes such as impairments in abstract reasoning and regulating emotion in individuals whose cerebella had been damaged. Since then this line of study has expanded. There has been human neuroimaging work showing the cerebellum is involved in cognitive processing and emotional control—and investigations in animals have revealed, among other things, that the structure is important for the normal development of social and cognitive capacities. Researchers have also linked altered cerebellar function to addiction, autism and schizophrenia.
Although many of these findings suggested the cerebellum played an important part both in reward-related and social behavior, a clear neural mechanism to explain this link was lacking. New research, published this week in Science, demonstrates that a pathway directly tying the cerebellum to the ventral tegmental area (VTA)—one of the brain’s key pleasure centers—can control these two processes. [Continue reading…]
The brain maps out ideas and memories on spacial form of representation
We humans have always experienced an odd — and oddly deep — connection between the mental worlds and physical worlds we inhabit, especially when it comes to memory. We’re good at remembering landmarks and settings, and if we give our memories a location for context, hanging on to them becomes easier. To remember long speeches, ancient Greek and Roman orators imagined wandering through “memory palaces” full of reminders. Modern memory contest champions still use that technique to “place” long lists of numbers, names and other pieces of information.
As the philosopher Immanuel Kant put it, the concept of space serves as the organizing principle by which we perceive and interpret the world, even in abstract ways. “Our language is riddled with spatial metaphors for reasoning, and for memory in general,” said Kim Stachenfeld, a neuroscientist at the British artificial intelligence company DeepMind.
In the past few decades, research has shown that for at least two of our faculties, memory and navigation, those metaphors may have a physical basis in the brain. A small seahorse-shaped structure, the hippocampus, is essential to both those functions, and evidence has started to suggest that the same coding scheme — a grid-based form of representation — may underlie them. Recent insights have prompted some researchers to propose that this same coding scheme can help us navigate other kinds of information, including sights, sounds and abstract concepts. The most ambitious suggestions even venture that these grid codes could be the key to understanding how the brain processes all details of general knowledge, perception and memory. [Continue reading…]
How new data is transforming our understanding of the brain’s navigational place cells
The first pieces of the brain’s “inner GPS” started coming to light in 1970. In the laboratories of University College London, John O’Keefe and his student Jonathan Dostrovsky recorded the electrical activity of neurons in the hippocampus of freely moving rats. They found a group of neurons that increased their activity only when a rat found itself in a particular location. They called them “place cells.”
Building on these early findings, O’Keefe and his colleague Lynn Nadel proposed that the hippocampus contains an invariant representation of space that does not depend on mood or desire. They called this representation the “cognitive map.” In their view, all of the brain’s place cells together represent the entirety of an animal’s environment, and whichever place cell is active indicates its current location. In other words, the hippocampus is like a GPS. It tells you where you are on a map and that map remains the same whether you are hungry and looking for food or sleepy and looking for a bed. O’Keefe and Nadel suggested that the absolute position represented in the hippocampal place cells provides a mental framework that can be used by an animal to find its way in any situation—be that to find food or a bed.
Over the next 40 years, other researchers—including the husband and wife duo of Edvard and May-Britt Moser—produced support for the idea that the brain’s hippocampal circuitry acts like an inner GPS. In recognition of their pioneering work, O’Keefe and the Mosers were awarded the 2014 Nobel Prize in physiology or medicine. You’d think that this would mean that the role of the hippocampus in guiding an animal through space was solved.
But studying the brain is never that straightforward. Like a match lighting a fuse, the 2014 Nobel Prize set off an explosion of experiments and ideas, some of which have pushed back against O’Keefe and Nadel’s early interpretation. This new work has suggested that when it comes to spatial navigation, the hippocampal circuit represents location information that is relative and malleable by experience rather than absolute. The study of the hippocampus seems to have stumbled into an age-old philosophical argument. [Continue reading…]
The battle over whether new nerve cells can develop in adult brains intensifies
Just a generation ago, common wisdom held that once a person reaches adulthood, the brain stops producing new nerve cells. Scientists countered that depressing prospect 20 years ago with signs that a grown-up brain can in fact replenish itself. The implications were huge: Maybe that process would offer a way to fight disorders such as depression and Alzheimer’s disease.
This year, though, several pieces of contradictory evidence surfaced and a heated debate once again flared up. Today, we still don’t know whether the fully grown brain churns out new nerve cells.This year’s opening shot came March 7 in a controversial report in Nature. Contradicting several landmark findings that had convinced the scientific community that adults can make new nerve cells, researchers described an utter lack of dividing nerve cells, or neurons, in adult postmortem brain tissue (SN Online: 3/8/18). A return volley came a month later, when a different research group described loads of newborn neurons in postmortem brains, in an April 5 paper in Cell Stem Cell (SN: 5/12/18, p. 10). Scientific whiplash ensued when a third group found no new neurons in postmortem brains, describing the results in the July Cerebral Cortex. Still more neuroscientists jumped into the fray with commentaries and perspective articles.
This ping-ponging over the rejuvenating powers of the brain is the most recent iteration of a question that still hasn’t been answered. [Continue reading…]