Every person thinks and acts a little differently than the other 7 billion on the planet. Scientists now say that variations in brain connections account for much of this individuality, and they’ve narrowed it down to a few specific regions of the brain. This might help us better understand the evolution of the human brain as well as its development in individuals.
Each human brain has a unique connectome—the network of neural pathways that tie all of its parts together. Like a fingerprint, every person’s connectome is unique. To find out where these individual connectomes differed the most, researchers used an MRI scanning technique to take cross-sectional pictures of 23 people’s brains at rest.
Thanks to NASA and emerging commercial space flight companies, there will likely be more astronauts in the future, and they’ll be traveling farther and more frequently into space. Space travel has known risks for bones, eyesight and other bodily systems, but a new study is the first to show that space travel could lead to Alzheimer’s disease l
ater in life.
Outside the protection of the Earth’s magnetic field, astronauts are exposed to cosmic radiation. These high-mass, highly-charged particles can penetrate solid objects—spaceships, astronauts and brains included.
For the New Caledonian crow, birdbrain is a misnomer: These members of the corvid family have proved their problem-solving and tool-wielding abilities again and again. The birds may have yet another impressive cognitive capacity, a new study suggests: causal reasoning. The ability to link an event with the mechanism that caused it, even if that mechanism is hidden, is the basis of modern science—and our most basic knowledge of the world around us. If New Caledonian crows are capable of causal reasoning as well, we can better trace and understand the evolution of this ability.
Young children need attention—and not just to keep them from wandering off or yelling their lungs out. Social interactions actually help their developing brains. We know about this from studying children and animals raised in relative isolation: Neglected children, like those raised in Romanian orphanages, suffer from behavioral and cognitive deficits as adults, and isolated young monkeys grow up to have weaker memory and learning abilities than their socialized peers. Just what is happening in the brain to trigger these mental problems?
According to a new paper in the journal Science, it’s all about the fatty tissue myelin, and the cells that produce it. Babies are born with very little myelin in the brain—as they develop, specialized cells called oligodendrocytes wrap insulating myelin sheaths around the long, rod-like sections of certain neurons. These myelin coatings help electrical signals travel more quickly through children’s brains. Read More
So. Tired. From reading email.
A day of hard mental labor—writing emails, taking the SAT, competing in the national crossword competition—can leave you beat. But how, exactly, is that possible? You haven’t done any heavy lifting, at least not with your muscles.
Ferris Jabr at Scientific American MIND takes a crack at investigating this phenomenon, exploring the science on whether thinking really hard burns calories, or whether the exhaustion is coming from something else. He writes:
Although the average adult human brain weighs about 1.4 kilograms, only 2 percent of total body weight, it demands 20 percent of our resting metabolic rate (RMR)—the total amount of energy our bodies expend in one very lazy day of no activity.RMR varies from person to person depending on age, gender, size and health. If we assume an average resting metabolic rate of 1,300 calories, then the brain consumes 260 of those calories just to keep things in order. That’s 10.8 calories every hour or 0.18 calories each minute. (For comparison’s sake, see Harvard’s table of calories burned during different activities). With a little math, we can convert that number into a measure of power.
Doctors long believed that patients who remained in a coma weeks or more after a brain injury would never regain consciousness. But recent research has shown that consciousness isn’t a binary, awake-or-not state; it’s a spectrum. While some brain injury patients are in a vegetative state, without any conscious awareness, others are in what’s called a minimally conscious state, still partially aware of—and at times even able to respond to—their surroundings. From the outside, it can be difficult to tell the two apart, though new methods, such as EEGs that pick up on subtle differences in brain waves, are starting to help clinicians gauge a patient’s level of consciousness.
From these hinterlands of consciousness comes another astounding—and mysterious—discovery: Ambien, the prescription sleep medication, and zolpidem, the drug’s generic form, can help some minimally conscious patients wake up. Jeneen Interlandi delves deep into this seemingly paradoxical treatment in the New York Times magazine:
A twice-daily dose of insulin, sprayed deep in the nose for easy transit to the brain, may slow or stop the progression of Alzheimer’s disease, according to a new pilot study. The researchers gave 104 patients with mild to moderate Alzheimer’s disease or pre-Alzheimer’s cognitive impairment one of three nasal sprays for four months. One group of patients got a nasal spray with a moderate dose of insulin twice a day, one group got a higher dose, and the third got a squirt of saline solution, as a placebo. The memory, cognitive abilities, and day-to-day functioning of patients given insulin stayed constant or improved slightly—particularly for those given the moderate dose of insulin rather than the high dose—while the abilities and memory of patients given the placebo declined.
What’s the News: While most people think of dyslexia as primarily a problem with reading, people with dyslexia seem to have trouble processing the spoken language, as well. A new study published last week Science found that people with dyslexia have a harder time recognizing voices than other people do.
Luis Populin never meant to study whether monkeys recognize themselves in the mirror. As DISCOVER blogger Carl Zimmer notes at the Loom, Populin’s team was working on a different project that required putting mirrors in monkey cages to stimulate their brains. Quite by accident, he noticed that monkeys with electrodes attached by the researchers spent an awful long time gawking at themselves in the mirrors.
The researchers published their findings this week in PLoS One, in which they write:
We hypothesize that the head implant, a most salient mark, prompted the monkeys to overcome gaze aversion inhibition or lack of interest in order to look and examine themselves in front of the mirror. The results of this study demonstrate that rhesus monkeys do recognize themselves in the mirror and, therefore, have some form of self-awareness.
For a video of a monkey checking itself out in the mirror, as well as much more detail about the study, its implications, and other primatologists’ doubts about it, check out Zimmer’s post.
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Image: Populin et. al.