209 posts tagged neuroscience
The recent release of Susan Greenfield’s new book and the film Lucy, both of which are dependent on tired misconceptions or dubious theories about the brain, suggest one worrying conclusion: we are running out of myths about the brain. So here are some new ones, to keep things ‘mysterious’
One of the best things about being a neuroscientist used to be the aura of mystery around it. It was once so mysterious that some people didn’t even know it was a thing. When I first went to university and people asked what I studied, they thought I was saying I was a “Euroscientist”, which is presumably someone who studies the science of Europe. I’d get weird questions such as “what do you think of Belgium?” and I’d have to admit that, in all honesty, I never think of Belgium. That’s how mysterious neuroscience was, once. Of course, you could say this confusion was due to my dense Welsh accent, or the fact that I only had the confidence to talk to strangers after consuming a fair amount of alcohol, but I prefer to go with the mystery. It’s not like that any more. Neuroscience is “mainstream” now, to the point where the press coverage of it can be studied extensively. When there’s such a thing as Neuromarketing (well, there isn’t actually such a thing, but there’s a whole industry that would claim otherwise), it’s impossible to maintain that neuroscience is “cool” or “edgy”. It’s a bad time for us neurohipsters (which are the same as regular hipsters, except the designer beards are on the frontal lobes rather than the jaw-line). One way that we professional neuroscientists could maintain our superiority was by correcting misconceptions about the brain, but lately even that avenue looks to be closing to us. The recent film Lucy is based on the most classic brain misconception: that we only use 10% of our brain. But it’s had a considerable amount of flack for this already, suggesting that many people are wise to this myth. We also saw the recent release of Susan Greenfield’s new book Mind Change, all about how technology is changing (damaging?) our brains. This is a worryingly evidence-free but very common claim by Greenfield. Depressingly common, as this blog has pointed out many times. But now even the non-neuroscientist reviewers aren’t buying her claims.
Neurons reveal the brain’s learning limit
Carnegie Mellon University, Stanford University, University of Pittsburgh Original Study
Scientists have discovered a fundamental constraint in the brain that may explain why it’s easier to learn a skill that’s related to an ability you already have. For example, a trained pianist can learn a new melody easier than learning how to hit a tennis serve. As reported in Nature, the researchers found for the first time that there are limitations on how adaptable the brain is during learning and that these restrictions are a key determinant for whether a new skill will be easy or difficult to learn. Understanding how the brain’s activity can be “flexed” during learning could eventually be used to develop better treatments for stroke and other brain injuries. Lead author Patrick T. Sadtler, a Ph.D. candidate in the University of Pittsburgh department of bioengineering, compared the study’s findings to cooking. “Suppose you have flour, sugar, baking soda, eggs, salt, and milk. You can combine them to make different items—bread, pancakes, and cookies—but it would be difficult to make hamburger patties with the existing ingredients,” Sadtler says. “We found that the brain works in a similar way during learning. We found that subjects were able to more readily recombine familiar activity patterns in new ways relative to creating entirely novel patterns.” (via Neurons reveal the brain’s learning limit - Futurity)
Mouse memories ‘flipped’ from fearful to cheerful
By artificially activating circuits in the brain, scientists have turned negative memories into positive ones. They gave mice bad memories of a place, then made them good - or vice versa - without ever returning to that place. Neurons storing the “place” memory were re-activated in a different emotional context, modifying the association. Although unlikely to be applied in humans with traumatic memories, the work sheds new light on the details of how emotional memories form and change. The research is is published in the journal Nature. (via BBC News - Mouse memories ‘flipped’ from fearful to cheerful)
read of the day: This Is Your Brain on Silence
Contrary to popular belief, peace and quiet is all about the noise in your head.
One icy night in March 2010, 100 marketing experts piled into the Sea Horse Restaurant in Helsinki, with the modest goal of making a remote and medium-sized country a world-famous tourist destination. The problem was that Finland was known as a rather quiet country, and since 2008, the Country Brand Delegation had been looking for a national brand that would make some noise. Over drinks at the Sea Horse, the experts puzzled over the various strengths of their nation. Here was a country with exceptional teachers, an abundance of wild berries and mushrooms, and a vibrant cultural capital the size of Nashville, Tennessee. These things fell a bit short of a compelling national identity. Someone jokingly suggested that nudity could be named a national theme—it would emphasize the honesty of Finns. Someone else, less jokingly, proposed that perhaps quiet wasn’t such a bad thing. That got them thinking. A few months later, the delegation issued a slick “Country Brand Report.” It highlighted a host of marketable themes, including Finland’s renowned educational system and school of functional design. One key theme was brand new: silence. As the report explained, modern society often seems intolerably loud and busy. “Silence is a resource,” it said. It could be marketed just like clean water or wild mushrooms. “In the future, people will be prepared to pay for the experience of silence.” People already do. In a loud world, silence sells. Noise-canceling headphones retail for hundreds of dollars; the cost of some weeklong silent meditation courses can run into the thousands. Finland saw that it was possible to quite literally make something out of nothing.
(via This Is Your Brain on Silence - Issue 16: Nothingness - Nautilus)
If we want to understand what’s happening in the brain when people ‘hear voices’, we first need to understand what happens during ordinary inner speech
Most of us will be familiar with the experience of silently talking to ourselves in our head. Perhaps you’re at the supermarket and realise that you’ve forgotten to pick up something you needed. “Milk!” you might say to yourself. Or maybe you’ve got an important meeting with your boss later in the day, and you’re simulating – silently in your head – how you think the conversation might go, possibly hearing both your own voice and your boss’s voice responding. This is the phenomenon that psychologists call “inner speech”, and they’ve been trying to study it pretty much since the dawn of psychology as a scientific discipline. In the 1930s, the Russian psychologist Lev Vygotsky argued that inner speech developed through the internalisation of “external”, out-loud speech. If this is true, does inner speech use the same mechanisms in the brain as when we speak out loud? We have known for about a century that inner speech is accompanied by tiny muscular movements in the larynx, detectable by a technique known as electromyography. In the 1990s, neuroscientists used functional neuroimaging to demonstrate that areas such as the left inferior frontal gyrus (Broca’s area), which are active when we speak out loud, are also active during inner speech. Furthermore, disrupting the activity of this region using brain stimulation techniques can interrupt both “outer” and inner speech. So the evidence that inner speech and speaking out loud share similar brain mechanisms seems pretty convincing. One worry, though, is whether the inner speech we get people to do in experiments is the same as our everyday experience of inner speech. As you might imagine, it’s quite hard to study inner speech in a controlled, scientific manner, because it is an inherently private act.
Bjorklund and Kipp (1996) provide an evolutionary framework predicting that there is a female advantage in inhibition and self-regulation due to differing selection pressures placed on males and females. The majority of the present review will summarize sex differences in self-regulation at the behavioral level. The neural and hormonal underpinnings of this potential sexual dimorphism will also be investigated and the results of the experiments summarized will be related to the hypothesis advanced by Bjorklund and Kipp (1996). Paradoxically, sex differences in self-regulation are more consistently reported in children prior to the onset of puberty. In adult cohorts, the results of studies examining sex differences in self-regulation are mixed. A few recent experiments suggesting that females are less impulsive than males only during fertile stages of the menstrual cycle will be reviewed. A brief discussion of an evolutionary framework proposing that it is adaptive for females to employ a self-regulatory behavioral strategy when fertile will follow.