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.
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.
University of Zurich researchers used transcranial magnetic stimulation, a noninvasive method of inhibiting activity in parts of the brain, to “turn off” people’s ability to control their impulses. They focused on the temporoparietal junction, an area of the brain thought to play an important role in moral decisions, empathy, and other social interactions. They hope […]
Are you jonesing for a dose of optimism and possibility? In the mood to contemplate the cosmos? Want to experience a musical message for extraterrestrials the way it was meant to be played? The Voyager Golden Record: 40th Anniversary Edition, a project I launched with Timothy Daly and Lawrence Azerrad, is a lavish vinyl box […]
In Rich do not rise early: spatio-temporal patterns in the mobility networks of different socio-economic classes, a group of transportation engineers analyze an open data-set about the commutes of people in the Colombian cities of Medellín and Manizales, concluding that the rich and the poor commute the furthest distances, but that the rich have much […]
This Python Mega Course will help you learn to code by teaching you to build 10 real-world apps that each highlight a unique use of Python.Job prospects for coders are still growing steadily—and with Python being one of the most popular coding languages out there today, it’s important for job seekers to demonstrate a widespread understanding of the […]
The Atmos R2 may be bigger than the brand’s previously-released vapes, but we argue that in this case it’s definitely a good thing. A bigger heating chamber means more room for packing it full. And the bigger battery means longer, more fulfilling vape sessions. In fact, you can use the Atmos R2 for up to about 25 […]
These days, there is huge demand for ethical hackers. Companies pay these professionals to identify and remedy security holes in their networks before malicious hackers find and exploit them. What’s great about this is that if you love hacking or think you may love hacking, you can do it for a living and not as […]