What does the brain do when you're not doing anything in particular? That's when the brain's "default mode network" really kicks into gear. This series of connected regions in the brain is apparently a hot topic for cognitive neuroscientists. This week's issue of Science News surveys research on the default mode network, which apparently is responsible for allowing your mind to "wander." But it also seems to have a much more important role. From Science News:
Default brain settings may lead to daydreaming and mind-wandering, but the network also conducts serious business. Neuroscientists still hotly debate the network’s exact functions, however. Among its jobs may be running life simulations, providing a sense of self and maintaining crucial connections between brain cells. A few researchers doubt the network is anything special at all.
"You Are Who You Are by Default"
But evidence suggests that a malfunctioning default network is involved in diseases and disorders as diverse as Alzheimer’s disease, autism, depression, post-traumatic stress disorder, Tourette syndrome, amyotrophic lateral sclerosis, schizophrenia and attention-deficit/hyperactivity disorder.
Despite its laid-back name, which neuroscientist Marcus Raichle coined in a 2001 paper, the default mode network is one of the hardest-working systems in the brain. It was discovered accidentally by researchers watching the activity of brains at work on various tasks.
Neuroscientists use PET (short for positron emission tomography) and functional MRI scanners to image and gauge brain activity. To tell which areas of the brain become more active during a mental task, scientists compare brain activity during the task with activity when the person is at rest, either with eyes closed or while staring at a dot or cross. Raichle, of Washington University in St. Louis, and others saw that every time a person engaged in a mental activity such as memorizing a list of words, a collection of brain regions consistently decreased activity compared with their resting levels. Only when people recall autobiographical memories or imagine alternative situations is the network more active than it is at rest, scientists have since found. (In this context, “rest” refers to a state in which the brain is not engaged in a mental task but is still monitoring the body and the world around it.) Raichle hypothesized that the network is more active when the brain is at rest and has to dial back its activity to let people concentrate on specific tasks.
Artists Jeff Louviere and Vanessa Brown explore cymatics, the study of wave phenomena and how they are represented visually. Using black-colored water, a laptop computer, and a modified guitar amp, they captured “portraits” of the 12 notes in the chromatic scale. From my sister-in-law Heather Sparks’s profile of their project in Nautilus: In each (“portrait”), […]
Yesterday’s science-by-press-release announcement that a research team had made a “breakthrough” in treating ALS thanks to funds raised in last year’s viral ice-bucket challenge turns out to be vaporware: the gene identified was already known to be implicated in ALS, but only affects 3% of cases, and the new refinement in the research suggests some […]
New research on trends in adult human height over the last century confirm that, no surprise, humans are getting taller overall due to better nutrition and disease control. However according to the health science group Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC), the gain in adult height varies dramatically by country. From their paper, published in […]
Looks like all of your potential employers are hiring candidates with programming skills (which you don’t have). With all of the languages out there today, it’s tough to know where to start.With the Complete Front-End to Back-End Coding Bundle, you can beef your resume up in all the right places, no confusion necessary. This package of […]
Those of us who love music wish we could listen to it 24/7. But it’s impossible when we’re trying to converse with our friends, or when are swimming in the local pool.That is, until now. The KOAR Bone Conduction Bluetooth Headset, now 48% off, has changed the audio game.Made with lightweight titanium memory metal, this headset boasts patented bone conduction technology to transport sound […]
It’s one thing to enjoy dinner at home and a nice glass of Cabernet Sauvignon with your best friend, Netflix, but it’s another thing entirely to make that meal from scratch and get that wine delivered right to your doorstep.But what if we told you there’s a way to make this possible? To keep your social life, […]