331 posts tagged Brain
Woman of 24 found to have no cerebellum in her brain
DON’T mind the gap. A woman has reached the age of 24 without anyone realising she was missing a large part of her brain. The case highlights just how adaptable the organ is. The discovery was made when the woman was admitted to the Chinese PLA General Hospital of Jinan Military Area Command in Shandong Province complaining of dizziness and nausea. She told doctors she’d had problems walking steadily for most of her life, and her mother reported that she hadn’t walked until she was 7 and that her speech only became intelligible at the age of 6. Doctors did a CAT scan and immediately identified the source of the problem – her entire cerebellum was missing (see scan, below left). The space where it should be was empty of tissue. Instead it was filled with cerebrospinal fluid, which cushions the brain and provides defence against disease. The cerebellum – sometimes known as the “little brain” – is located underneath the two hemispheres. It looks different from the rest of the brain because it consists of much smaller and more compact folds of tissue. It represents about 10 per cent of the brain’s total volume but contains 50 per cent of its neurons. Although it is not unheard of to have part of your brain missing, either congenitally or from surgery, the woman joins an elite club of just nine people who are known to have lived without their entire cerebellum. A detailed description of how the disorder affects a living adult is almost non-existent, say doctors from the Chinese hospital, because most people with the condition die at a young age and the problem is only discovered on autopsy (Brain, doi.org/vh7). (via Woman of 24 found to have no cerebellum in her brain - health - 10 September 2014 - New Scientist)
So a team of neuroscientists sent a message from the brain of one person in India, to the brains of three people in France, using brainwave-reading equipment and the Internet. Yes, really. The process is slow and cumbersome. It also doesn’t make use of any bleeding-edge technology. Instead, it puts together neurorobotics software and hardware that have been developed by several labs in recent years. We’re not predicting that this will have practical applications, or society-changing implications, any time soon. Still, it’s pretty amusing that somebody did this, and we’re here to give you the step-by-step instructions on how. To wit: The emitter—we’re using the vocab and italics from the original paper because they are awesome—wears an EEG cap on her scalp that records the electrical activity in her brain. The cap communicates wirelessly with a laptop that shows, on its screen, a white circle on a black background. The emitter translates the message she wants to send into an obscure five-bit binary system called Bacon’s cipher, which is more compact than the binary code that computers use. The emitter now has to enter that binary string into the laptop using her thoughts. She does this by using her thoughts to move the white circle on-screen to different corners of the screen. (Upper right corner for “1,” bottom right corner for “0.”) This part of the process takes advantage of technology that several labs have developed, to allow people with paralysis to control computer cursors or robot arms. The emitter’s binary message gets sent over the Internet, yay. The receivers sit inside a transcranial magnetic stimulation machine that’s able to send electromagnetic pulses through people’s skulls. The pulses make the receivers see flashes of light in their peripheral vision that aren’t actually there. In addition, the machine has a robotic arm that’s able to aim at different places on the receivers’ skulls. The results are phantom flashes (called phosphenes) that seem to show up in different positions in the air, which is not spooky at all, no. As soon as the receivers’ machine gets the emitter’s binary message over the Internet, the machine gets to work. It moves its robotic arm around, sending phosphenes to the receivers at different positions on their skulls. Flashes appearing in one position correspond to 1s in the emitter’s message, while flashes appearing in another position correspond to 0s. We don’t know how the receivers keep track of all that flashing. Perhaps they take notes using a pen and paper. Whew, that’s a lot of work to give your friends a holler. The research team, including neuroscientists and engineers from universities and startups in Europe and the U.S., understandably sent only two messages in this manner: “hola” and “ciao.” Imagine trying to send “bonjour” or “good morning.”
Neuroscientists test the theory that your body shapes your ideas
The player kicked the ball.
The patient kicked the habit.
The villain kicked the bucket.
The verbs are the same.
The syntax is identical.
Does the brain notice, or care, that the first is literal, the second metaphorical, the third idiomatic?
It sounds like a question that only a linguist could love. But neuroscientists have been trying to answer it using exotic brain-scanning technologies. Their findings have varied wildly, in some cases contradicting one another. If they make progress, the payoff will be big. Their findings will enrich a theory that aims to explain how wet masses of neurons can understand anything at all. And they may drive a stake into the widespread assumption that computers will inevitably become conscious in a humanlike way. The hypothesis driving their work is that metaphor is central to language. Metaphor used to be thought of as merely poetic ornamentation, aesthetically pretty but otherwise irrelevant. “Love is a rose, but you better not pick it,” sang Neil Young in 1977, riffing on the timeworn comparison between a sexual partner and a pollinating perennial. For centuries, metaphor was just the place where poets went to show off. But in their 1980 book, Metaphors We Live By, the linguist George Lakoff (at the University of California at Berkeley) and the philosopher Mark Johnson (now at the University of Oregon) revolutionized linguistics by showing that metaphor is actually a fundamental constituent of language. For example, they showed that in the seemingly literal statement “He’s out of sight,” the visual field is metaphorized as a container that holds things. The visual field isn’t really a container, of course; one simply sees objects or not. But the container metaphor is so ubiquitous that it wasn’t even recognized as a metaphor until Lakoff and Johnson pointed it out. From such examples they argued that ordinary language is saturated with metaphors. Our eyes point to where we’re going, so we tend to speak of future time as being “ahead” of us. When things increase, they tend to go up relative to us, so we tend to speak of stocks “rising” instead of getting more expensive. “Our ordinary conceptual system is fundamentally metaphorical in nature,” they wrote.
Monkey leaders and followers have ‘specialised brains’
Monkeys at the top and bottom of the social pecking order have physically different brains, research has found.
A particular network of brain areas was bigger in dominant animals, while other regions were bigger in subordinates. The study suggests that primate brains, including ours, can be specialised for life at either end of the hierarchy. The differences might reflect inherited tendencies toward leading or following, or the brain adapting to an animal’s role in life - or a little of both. Neuroscientists made the discovery, which appears in the journal Plos Biology, by comparing brain scans from 25 macaque monkeys that were already “on file” as part of ongoing research at the University of Oxford. “We were also looking at learning and memory and decision-making, and the changes that are going on in your brain when you’re doing those things,” explained Dr MaryAnn Noonan, the study’s first author. The decision to look at the animals’ social status produced an unexpectedly clear result, Dr Noonan said. “It was surprising. All our monkeys were of different ages and different genders - but with fMRI (functional magnetic resonance imaging) you can control for all of that. And we were consistently seeing these same networks coming out.” The monkeys live in groups of up to five, so the team identified their social status by watching their behaviour, then compared it to different aspects of the brain data. In monkeys at the top of their social group, three particular bits of the brain tended to be larger (specifically the amygdala, the hypothalamus and the raphe nucleus). In subordinate monkeys, the tendency was for a different cluster of regions to be bigger (all within the striatum). (via BBC News - Monkey leaders and followers have ‘specialised brains’)