Scientists Lior Appelbaum and David Zada in Israel publish new proof that sleep serves to help our brains repair damage. Read the rest
Although scientists already believed that drinking coffee could possibly reduce the risk of neurodegenerative conditions such as Alzheimer's disease, a new study by Krembil Brain Institute in Toronto, Canada suggests that the kind of roast you drink might determine how much protection your cup of joe might actually give you. Read the rest
There's a lot of text out about how, for better or worse, playing computer games will mess with your brains. Instead of adding to the pile of words already scrawled on the subject, WIRED's Peter Rubin took it upon himself to work up a video that examines how gaming messes with his brain in particular. Read the rest
Neuroscientist Nicho Hatsopoulous and his team taught monkeys that lost limbs through accidents how to control a robotic arm. The work has profound implications on what they call the brain-machine interface.
“That's the novel aspect to this study, seeing that chronic, long-term amputees can learn to control a robotic limb,” said Nicho Hatsopoulos, PhD, professor of organismal biology and anatomy at UChicago and senior author of the study. “But what was also interesting was the brain’s plasticity over long-term exposure, and seeing what happened to the connectivity of the network as they learned to control the device.”
Here's the basic setup in a similar lab with non-amputee monkeys. The monkey gets juice or some other treat for successfully completing the tasks.
Here's a detailed lecture on the current work in the field:
Can you "hear" motion or light flashes? If so, according to new research from City University London, you may be experiencing a not-so-rare form of synaesthesia. Synesthesia is the fascinating neurological phenomenon whereby stimulation of one sense involuntarily triggers another sensory pathway. For example, a synesthete might taste sounds or hear colors. (In this study, 8 out of 40 participants, a very high percentage, were considered to have hearing-motion synaesthesia.) Here is their test for you to take yourself. From The Guardian:
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(This new study) suggests that many more of us experience a less intrusive version of (synesthesia) in which visual movements or flashes are accompanied by an internal soundtrack of hums, buzzes or swooshes. Since movements are very frequently accompanied by sounds in everyday life, the effect is likely to be barely discernible.
When tested under laboratory conditions, the “hearing motion” effect appeared to enhance a person’s ability to interpret fine visual movements, but also interfered with the ability to hear real sounds when visual and audio signals were mis-matched.
“These internal sounds seem to be perceptually real enough to interfere with the detection of externally-generated sounds,” said Freeman. “The finding that this ‘hearing-motion’ phenomenon seems to be much more prevalent compared to other synaesthesias might occur due to the strength of the natural connection between sound and vision.”
In a separate study, the team tested for the phenomenon in trained musicians and found that it was much more common in the group. It is not clear if this is due to a natural disposition to link sounds and visual cues or whether thousands of hours of training might have strengthened the neural circuitry behind the effect.
Annoying song stuck in your head? This BrainCraft video explains that listening to it from beginning to end may free you from its burden. It's a technique based on the Zeigarnik effect, the tendency we have to remember things which are uncompleted.
To try it yourself, listen to this first:
In a curious study, researchers at the University of California, Los Angeles showed that transcranial magnetic stimulation (TMS) -- altering brain activity by zapping specific regions with magnetic pulses -- can apparently increase people's libido, at least briefly. Neuroscientist Nicole Prause and her colleagues targeted the left dorsolateral prefrontal cortex (at the left temple), a region involved in reward-seeking. New Scientist explains the curious protocol used by the researchers:
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...A vibrator was either connected to a sheath that the penis goes in or a small hood that fits over the clitoris. Electrodes on each participant’s head measured the strength of their brain’s alpha waves, which are weaker when people are more sexually aroused.
During the experiment, 20 people were given TMS for about two minutes, designed to either excite or inhibit the dorsolateral prefrontal cortex. Next, each volunteer was taken to a room where the EEG electrodes were placed on their head. They were then left to attach the vibrator themselves.
Finally, each participant carried out a task that involved pressing a button as fast as possible when shapes appeared on a screen. Depending on how quick they were, they were given a genital buzz lasting between half a second and five seconds – but only after a pause.
Their brainwaves were recorded during this waiting period. “They know they’re about to be sexually stimulated, but it hasn’t actually happened yet,” says Prause. It is the closest analogue for measuring desire in the lab, she adds.
As predicted, after excitatory TMS, participants’ alpha waves were weaker – suggesting they were more sexually aroused – than after inhibitory TMS.
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 their research could help inform our understanding of addiction and self-discipline. From Scientific American:
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In their study, subjects underwent 40 seconds of disruptive transcranial magnetic stimulation (TMS)—in which a magnetic coil placed near the skull produced small electric currents in the brain that inhibited activity of the posterior TPJ—then spent 30 minutes completing a task. To rule out a placebo effect, a control group received TMS in a different area of the brain. In one task, subjects made a choice between a reward (ranging between 75 and 155 Swiss francs) for themselves or one that was shared equally between themselves and another person, who ranged from their closest confidante to a stranger on the street. In another task subjects were offered an immediate reward of between zero and 160 Swiss francs or a guarantee of 160 Swiss francs after waiting three to 18 months. In a final task, subjects were instructed to take the perspective of an avatar and indicate the number of red dots on a ball that the avatar would see.
Subjects with an inhibited TPJ were less likely to share the money and were more likely to take the money up front rather than delay gratification and wait for a larger prize.
According to Stanford University researchers, a primary circuit in the brain's reward involving the chemical "feel-good" chemical dopamine, is also essential for controlling our sleep-wake cycles.
“Insomnia, a multibillion-dollar market for pharmaceutical companies, has traditionally been treated with drugs such as benzodiazepines that nonspecifically shut down the entire brain," says psychiatry and behavior science professor Luis de Lecea "Now we see the possibility of developing therapies that, by narrowly targeting this newly identified circuit, could induce much higher-quality sleep.”
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It makes intuitive sense that the reward system, which motivates goal-directed behaviors such as fleeing from predators or looking for food, and our sleep-wake cycle would coordinate with one another at some point. You can’t seek food in your sleep, unless you’re an adept sleepwalker. Conversely, getting out of bed is a lot easier when you’re excited about the day ahead of you...
The reward system’s circuitry is similar in all vertebrates, from fish, frogs and falcons to fishermen and fashion models. A chemical called dopamine plays a crucial role in firing up this circuitry.
Neuroscientists know that a particular brain structure, the ventral tegmental area, or VTA, is the origin of numerous dopamine-secreting nerve fibers that run in discrete tracts to many different parts of the brain. A plurality of these fibers go to the nucleus accumbens, a forebrain structure particularly implicated in generating feelings of pleasure in anticipation of, or response to, obtaining a desired objective.
“Since many reward-circuit-activating drugs such as amphetamines that work by stimulating dopamine secretion also keep users awake, it’s natural to ask if dopamine plays a key role in the sleep-wake cycle as well as in reward,” Eban-Rothschild said.
The narrator uses a near-parody of the "youtube voice" to explain what happens when the bundle of neural fibers (corpus callosum) connecting the left and right hemispheres of a person's brain is severed. The hemispheres will operate independently of each other, sometimes in an adversarial way. For example, when the right brain (which is less verbal than the left brain) is given a written instruction, the person reacts appropriately, but the left brain won't know why the person followed the instruction, and will make up a reason for performing the action.
Here's a video about a man who had his corpus callosum severed to treat his epilepsy. He said he doesn't feel different but experiments reveal unusual behavior. Read the rest
This is Edgar Latulip of southwestern Ontario. The developmentally disabled man has been missing since 1986 but was just found about 120 kilometers from his hometown. Or rather, he found himself. Latulip had lost his memory due to a head injury after he disappeared and had created a new identity. Last month, he realized he wasn't who he thought he was. From CBC:
On Jan. 7, Latulip met with a social worker and told her he thought he was somebody else, Gavin said. The social worker found his missing persons case file and police were then called in. Latulip volunteered to have a DNA test done and on Monday, the results came back indicating he was Latulip.
Gavin said it is an unusual, but happy resolution to the case.
"When someone goes missing for an extended period of time, they don't want to be found and they're off the grid and we don't find them," Gavin said. "Or the other option, sadly, is sometimes people are deceased. I've never heard of something like this where someone's memory has come back and their identity is recovered.
"It is absolutely a good news story," Gavin added. "I try not to only think about his mother's side, but also Mr. Latulip's side where for 30 years you've learned a certain way and someone tells you and confirms to you that's not who you are. That's a lot to take in, personally, right, so there's interesting pieces for him as well."
My friend Stanford neuroscientist Melina Uncapher and her colleagues are piloting a new public project called mymntr meant to create a "user guide for your brain" through brain tests for self-knowledge, interviews with fascinating creative folks to get a sense of the minds behind the madness, and lots of other cool stuff at the intersection of science and culture. Read the rest