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.
Apple released this lovely new commercial featuring Carl Sagan reading from his magnificent 1994 book Pale Blue Dot: A Vision of the Human Future in Space, now available as an audiobook. This surprising partnership spurred Adweek to interview my friend Ann Druyan, Sagan’s wife, collaborator, and creative director of the Voyager Golden Record, about being […]
The Action Lab took a maglev gyroscope and placed it inside a sealed chamber to see what happens to a levitating gyroscope in a vacuum. A lot of people took issue with the experiment’s setup and explanation, but it’s interesting nonetheless. He responded to those concerns: Hi everyone! I see a lot of comments that […]
Shocking footage, taken from a nearby aircraft, shows a jetliner spraying its appalling chemical payload into our skies. Traffic 12 o'clock pic.twitter.com/g5QjlQ5v8z— Airplane Pictures ✈ (@iLove_Aviation) June 19, 2017
Although flagship smartphones are unlikely to adopt heavy-duty outer casing anytime soon, you can always prepare your device for the outdoors with a beefy case and and an external battery like this Nomad Tile Trackable PowerPack, available in the Boing Boing Store for $119.95.The Nomad Tile can fully recharge an iPhone 7 over three times […]
Even though credit cards now feature an EMV chip for securing transactions, they still have to include the magnetic strip for compatibility with older point of sale systems. Because of this, there’s no way for the chip’s new security capabilities to protect against card skimmers in the wild.How do you protect yourself from legacy-technology-induced fraud? […]
As the old saying goes, “You should sit in meditation for 30 minutes every day. Unless you are too busy, in which case you should meditate for an hour.” Since most of us have an endless list of things to do and people to see, carving out quiet time can feel impossible, especially when most […]