Understanding the workings of our minds is one of science’s greatest challenges. With the help of flashing lights and materials used in diapers, we could find out what thoughts are made of.
Category: neuroscience – Page 808
When Stephen Hawking wanted to speak, he chose letters and words from a synthesiser screen controlled by twitches of a muscle in his cheek.
But the painstaking process the cosmologist used might soon be bound for the dustbin. With a radical new approach, doctors have found a way to extract a person’s speech directly from their brain.
The breakthrough is the first to demonstrate how a person’s intention to say specific words can be gleaned from brain signals and turned into text fast enough to keep pace with natural conversation.
New research, published today in Nature, reveals how increasing brain stiffness as we age causes brain stem cell dysfunction, and demonstrates new ways to reverse older stem cells to a younger, healthier state.
The results have far reaching implications for how we understand the ageing process, and how we might develop much-needed treatments for age-related brain diseases.
As our bodies age, muscles and joints can become stiff, making everyday movements more difficult. This study shows the same is true in our brains, and that age-related brain stiffening has a significant impact on the function of brain stem cells.
A long-standing controversy in neuroscience centers on a simple question: How do neurons in the brain share information? Sure, it’s well-known that neurons are wired together by synapses and that when one of them fires, it sends an electrical signal to other neurons connected to it. But that simple model leaves a lot of unanswered questions—for example, where exactly in neurons’ firing is information stored? Resolving these questions could help us understand the physical nature of a thought.
Two theories attempt to explain how neurons encode information: the rate code model and the temporal code model. In the rate code model, the rate at which neurons fire is the key feature. Count the number of spikes in a certain time interval, and that number gives you the information. In the temporal code model, the relative timing between firings matters more—information is stored in the specific pattern of intervals between spikes, vaguely like Morse code. But the temporal code model faces a difficult question: If a gap is “longer” or “shorter,” it has to be longer or shorter relative to something. For the temporal code model to work, the brain needs to have a kind of metronome, a steady beat to allow the gaps between firings to hold meaning.
Every computer has an internal clock to synchronize its activities across different chips. If the temporal code model is right, the brain should have something similar. Some neuroscientists posit that the clock is in the gamma rhythm, a semiregular oscillation of brain waves. But it doesn’t stay consistent. It can speed up or slow down depending on what a person experiences, such as a bright light. Such a fickle clock didn’t seem like the full story for how neurons synchronize their signals, leading to ardent disagreements in the field about whether the gamma rhythm meant anything at all.
S cientists are very careful about claiming that no one else has ever done something before — the last thing they need is some overlooked lab saying, um, right here! — but researchers at Massachusetts General Hospital are confident they’re on solid ground. Their high-resolution MRIs of a complete, intact human brain, they say, are “unprecedented.”
Other labs have sliced up brains and seen features down to 80 or even 50 microns. (One micron is a 10,000th of a centimeter, and 75 of them is about the width of a human hair.) The MGH team got 100-micron resolution in a whole brain, producing the most detailed three-dimensional images of an intact brain ever seen.
The scientists started with an MRI machine with a 7-tesla magnet, a significantly stronger magnetic field than the 0.5-to-3 teslas of most MRIs in clinical use, which optimized the signal-to-noise ratio. But they also built custom state-of-the-art software that, depending which physics parameters it directs the MRI to optimize, reveals particular features of the tissue, from tiny bleeds to swelling to white and gray matter.
With the rise of fad diets, “superfoods,” and a growing range of dietary supplement choices, it’s sometimes hard to know what to eat.
This can be particularly relevant as we grow older and are trying to make the best choices to minimize the risk of health problems such as high blood pressure, obesity, type 2 diabetes, and heart (cardiovascular) problems.
We now have evidence these health problems also all affect brain function: they increase nerve degeneration in the brain, leading to a higher risk of Alzheimer’s disease and other brain conditions including vascular dementia and Parkinson’s disease.
What is reality and how do we know? For many the answer is simple: What you see — hear, feel, touch, and taste — is what you get.
Your skin feels warm on a summer day because the sun exists. That apple you just tasted sweet and that left juices on your fingers, it must have existed. Our senses tell us that reality is there, and we use reason to fill in the blanks — that is, we know the sun doesn’t cease to exist at night even if we can’t see it.
But cognitive psychologist Donald Hoffman says we’re misunderstanding our relationship with objective reality. In fact, he argues that evolution has cloaked us in a perceptional virtual reality. For our own good.
The makers of the Argus II bionic eye are working on a new interface that sits directly on the user’s brain.
Our cells are more malleable than we thought – and by transforming them inside the body, we can mend broken hearts or even degenerating brains from within.
The Palm Beach Post
Posted in health, law enforcement, neuroscience
This article appears in Weekly Health Page July 31.
Researchers found that more than four out of five Ohio women who had been physically abused by their partners had suffered a head injury. A study that found domestic violence survivors had sustained staggering rates of head trauma and violent choking incidents suggests that many are left with ongoing health problems from “invisible injuries” to the brain.
But the effects of such injuries often go unrecognized by advocates, health care providers, law enforcement — even the victims themselves, researchers said.