We’ve all been exposed to jazz at one time or another—whether it be the musings of an accomplished jazz pianist or the improvisational skills of a saxophone player, jazz is something that’s familiar to us. But, when enjoying such a piece of music, we may not have considered the effect it has on the musician’s brain.
Charles Limb, musician and researcher at Johns Hopkins University, is specifically interested in the workings of the brain during musical improvisation. In order to better understand these mechanisms, he studied the brains of accomplished jazz musicians playing music in an fMRI machine.
The two pillars of his study—playing music which has been memorized and over-learned, and playing music which has been entirely improvised—were designed to pinpoint which brain regions were most active in each situation, as well as to see how differing amounts of creativity play a role in brain activity. Limb asked participants to first play a memorized piece of music on a specially designed keyboard, and then to improvise based on the scale progression of the previous piece.
What he found was quite interesting.
In the studies, Limb observed that, compared to the fMRI of brains playing memorized music, those playing improvised music typically had a higher amount of activation in the medial prefrontal cortex, an area attributed to self-expression, and a lower amount of activation in the lateral prefrontal cortex, an area attributed to self-monitoring. He postulates that in order for an individual to be creative, they must exhibit a sort of dissociation in the frontal lobe by which the large part of the brain controlling self-monitoring is not inhibiting self-expression of new, free-flowing ideas.
More recently, Limb has been studying another form of improvisational music, which he believes serves a similar social function to that of jazz—hip-hop. To do this, he has recruited the talents of accomplished hip-hop artists from the Baltimore hip-hop scene and studied their brain activity while they rap. The structure of the study is similar to that of the jazz pianists in that it was separated into two parts—one to study brain activity while performing a memorized piece and one to study brain activity while improvising. The participants were asked first to rap a piece written by Limb (which they had not seen before), and then to improvise based on a guideline of periodically prompted words. Though the study is not yet complete and no conclusive results are available, what Limb has seen so far has been quite promising.
Outside of Limb’s unique research, no extensive work has been done yet to study these phenomena. However, these results prove to be very promising in that they can offer new ways to think about creativity and the brain. Perhaps sometime in the future, with more sophisticated methods of brain imaging, it will be possible to understand the workings of the brain in other creative realms, such as dance. These and many other questions are coming closer to having answers.
Charles Limb: Your Brain on Improv – Video on TED.com
TED Blog – Hip-hop, creativity and the brain: Q&A with Dr. Charles Limb
You are unique, just like everyone else.
Connectomics is the study of the structural and functional connections among brain cells; its product is the “connectome,” a detailed map of those connections. The idea is that such information will be monumental in our understanding of the healthy and diseased brain. Sebastian Seung thinks that a complete connectome of the human brain will be one of the great prizes in 21st-century neuroscience.
Efforts to construct brain connectomes are split into two categories: ones that use imaging techniques like MRI, PET, and DT, thus focusing on macroscopic connections or tracts; and those that use electron microscopy to map the tinniest of axons (0.2-20 microns in diameter) and individual synapses.
While this may sound daunting, it also seems the obvious thing to do in order to really understand how the brain works. After all, don’t all our memories, personalities, and behaviors dependent on the structure of the brain, down to the microscopic level? So why is connectomics so new? Because the three-pound enigma that can contemplate all things big and small – from protons and electrons, to planets and stars, to galaxies and the whole universe – contains more parts than anything we’ve ever studied before. The human brain, we’ve been told, holds 100 billion neurons, with close to one quadrillion synaptic connections total; storing all of that information in one brain would take one Exabyte of data (that’s one trillion Gigabytes).
Jeff Lichtman and colleages at Harvard remain hopeful. They are developing novel tools to automate the tedious task of scanning brain slices. They expect the connectome to reveal differences in the way healthy and diseased brains are wired.
The effort is laudable, considering its scope and ambition, but it begs the question: does all behavior, experience, perception, etc depend on the structure of synapses and connectivity of neurons? More pointedly, does structure determine all function – chemical and electrical? Sure, larger synapses or more dendritic spines make stronger connections and more efficient transmission of information, but a snap-shot connectome won’t take into account temporal dynamics and enzymatic processes, which play a big role in the active brain.
In his TED talk, Sebastian Seung says that to test the hypothesis that “I am my connectome,” we could try to read out memories from someone’s connectome. But memories are not just synaptic connections – they are also assemblies of neurons in time or firing sequence. The connectome does not take those into account. And Seung fails to explain how we could actually verify any of those personal memories, since current methods of constructing a connectome involve cutting the brain into thousands of 30-micron slices.
If we could devise some non-invasive methods to construct a human connectome at the synapse level, what ethical issues would we face? Could a personal connectome be the ultimate breach of privacy? Could it redefine or “undefine” what we consider to be normal brains/mental states?
Constructing a comprehensive human connectome is a great challenge. A bigger challenge would be to model the electrical dynamics of the 100 billion human neurons. But perhaps the most important quest for neuroscience isn’t building a connectome, but learning how neuronal activity creates experience.
Neurocartography – Narayanan Kasthuri and Jeff Lichtman via NIH Public Access
Sebastian Seung: I am my connectome – TED.com
Seeking the Connectome, a Mental Map, Slice by Slice – NYTimes.com
“We were hardwired to eat and eat—and particularly to eat fatty foods because we didn’t get them often,” says Sharman Russell, author of Hunger: An Unnatural History. So if you’re among the 200 million Americans who have surpassed their target weight, don’t feel so bad. Somewhere in your brain, there is a circuit for food.
While eating is vital to life, it’s a voluntary action. But nature has made eating irresistible. So what is the science behind this irresistibility? Over the course of a year, the average adult male consumes about 900,000 calories, yet his weight doesn’t fluctuate by more than a pound. It takes a lot of effort from your internal systems to keep this balance, and an important substance behind this is a hormone called ghrelin.
Ghrelin, identified in 1999, is produced in the gut in response to meal schedules. Its purpose is to give the empty feeling we know as the need to eat. When ghrelin hits the brain, it affects three specific areas: the hindbrain, the hypothalamus, and the mesolimbic reward center. The hindbrain controls the body’s automatic and unconscious processes. It is responsible for the sensation of hunger. For the purposes of eating and digesting, the hypothalamus governs the rates of metabolism. And at the center of the midbrain lies the mesolimbic reward center, where the feelings of pleasure and satisfaction are processed. This is what motivates us to eat and keep eating.
Of course, other substances in our body govern our appetite as well as ghrelin. Even as ghrelin continues to arouse our appetite, other systems are standing by to slow down the process. The most basic such step occurs in the stomach and intestines. Distension sends a signal to the brain to stop eating. That message is then reinforced by a peptide called cholecystokinin (CCK) and two hormones called PYY and GLP-1. They all send complex chemical messages that literally tell the brain to stop eating. And, in the case that food consumption continues, the body has a last resort appetite-supressing hormone called leptin. Discovered in 1994, leptin affects the hypothalamus where it inhibits a pair of neuropeptides known to stimulate appetite.
So with all these measures in place to stop the body from eating, why do we overeat? Studies have shown that ghrelin hits the mesolimbic reward region very powerfully. It has been shown that this part of obese people’s brains activate very similarly to how the brains of drug addicts activate when exposed to their preferred substance. While the causes of over eating are very obvious, the real question is: how can we control it? Diet and exercise are often the recommendations (and should be followed), but the minds who discovered leptin, ghrelin, and all the other appetite-related peptides and hormones are also looking for ways to harness the power so we can take better control of it on our own.
Hunger: An Unnatural History – Sharman Russell
- Are you aging and senile?
- Do you find yourself frequently forgetting facts and misplacing objects?
- Are you simply dissatisfied with your cognitive strength?
The Posit Science Brain Fitness Program might be right for you!
As we age, our brains age with us, slowly deteriorating over time. For the fast-paced lives we now lead however, having mediocre cognitive abilities just doesn’t cut it. Famed neuroscientist, brain-plasticity connoisseur, and new businessman Michael Merzenich has engineered a series of “brain fitness” activities that are claimed to help individuals keep their minds in tip-top shape.
Merzenich’s Posit Science program is based on neuroplasticity, the ability of the brain to reorganize itself. While cortical reorganization is a remarkable asset of the brain to adapt to change, it may also be detrimental when the brain is not utilized to its full potential. Dr. Merzenich asserts that in order to maintain neurological skill throughout adulthood, individuals must continue to train the various cognitive-sensory facets of the mind.
The clinically supported Posit Science program offers a multi-modal, total brain training package composed of both an auditory skill and a visual skill program. This training includes a series of six computer-based programs specifically designed to improve the brain’s auditory-visual processing and perceptive abilities.
Currently, Posit Science is looking to broaden the applicability of its products by venturing into the world of social networking. The company has recently developed and launched a networking site called “Brain Odyssey,” through which individuals can work together to solve mysteries and virtually explore cities throughout the world, all while collaborating on cognitive training tasks.
In addition to offering a mental fitness program, the company website also features several brain games as well as a few “brain tests” as an informal way of testing one’s cognitive prowess, free of charge.
Click here to get your cognitive fitness on today!
A “better brains” collective launches to improve cognition of the masses – Scientific American
Any dog lovers out there? Have you ever wanted to refute someone who claimed “dogs can’t really understand you?” PBS program Dogs Decoded: NOVA asserts the idea that dogs are able to communicate with and understand humans better than any other animal that we know of.
When humans express an emotion, the right and left sides of their face show very different pictures. The right half is more expressive than the left when displaying all emotions, from happiness to anger to guilt. Therefore, humans have developed something called a “natural left gaze.” This means whenever we are presented with a face, we automatically look to our left to view the right side of their face to see a better display of their emotion. Recent studies with dogs have shown that they use this same mechanism when presented with a human’s face. Yet, when presented with a picture of another dog’s face, Fido treats it as if it is a picture of an object and randomly assesses the picture with no determined natural gaze. Dogs are the only animals known to display a natural left gaze when presented with a human face, suggesting that they have evolved to understand our facial expressions. Scientists are becoming more convinced that dogs are able to interpret our emotions better than many people think.
There are a few unique communication tools that only humans possess, such as eye gaze. Humans have almond-shaped eyes with white sclera surrounding the pupil so others are able to follow the direction of one’s gaze. We also use pointing as another communication tool that many other species are not able to utilize or comprehend. Cognitive psychologist Dr. Juliane Kaminski has been performing experiments with both chimps and dogs studying these two communication tactics. When a chimp is presented with two cups upside down and Kaminski points at the cup containing a reinforcer (such as a food treat), the chimp is not able follow her point nor gaze to pick up the correct cup. Instead, Kaminski notes that chimps tend to make a decision before she even points, supporting the idea that they are not wired to comprehend human gestures. Yet Kaminski performs this same task with dogs and they are able to follow to where her finger is pointing and retrieve a reinforcer. Even when presented with only a gaze at the correct cup, dogs are often able to determine which one Kaminski is urging them to choose.
It’s interesting to think that dogs have evolved to advance the way they communicate with the species that has domesticated them.
Dogs Decoded: Nova – PBS special via Netflix