Optimal Being

Theory has it yawning helps cool the brain—and it turns out animals with bigger brains do indeed tend to yawn longer. Christopher Intagliata reports. Not many scientific studies begin like this: "Many hours of watching YouTube clips. Trying to find as many yawns as possible." But for Andrew Gallup, an evolutionary psychologist who studies yawning at the State University of New York, it was all in a day's work. Gallup says yawns have traditionally been known as a sign of sleepiness, or boredom. "But recent evidence suggests that yawning may function to promote brain cooling." The idea being, when you breathe in deeply, the incoming air slightly cools the brain. And stretching the jaw increases blood flow to the brain too--another cooling factor. Reason we do it at night? "At night time when we're about to go to sleep our brain and body temperatures are at their highest point throughout the day." And so Gallup and his colleagues found themselves hunt...

Subjects suffering insomnia got more wrong answers in a face-matching task—but they were paradoxically more confident of their responses. Christopher Intagliata reports. Standing in line at passport control isn't the most relaxing experience. The officer looks at your passport… at you… back at your passport… back at you. Kind of nerve wracking. But put yourself in their shoes. They're trying to figure out if your face is actually the same one as that little thumbnail image on the page. Not the easiest task. "People are often surprised at how poor they are." David White, a cognitive psychologist at the University of New South Wales in Australia. He's even tested  Australian passport agents at the task. "Their performance was no better than a group of untrained university students." In his latest study, White and his colleagues investigated how poor sleep--less than six and a half hours a night--might affect facial recognition. Turns out, bad sleep did lea...

N eural responses decline after repeated acts of dishonesty, research suggests. As the U.S. presidential campaign has highlighted, the more a person lies, the easier it seems to become. But politics is not the only realm where dishonesty abounds. In 1996 Bernard Bradstreet, co-chief executive of the technology company Kurzweil Applied Intelligence was sentenced to jail for fraud. His initial transgressions were relatively minor: To boost quarterly accounts he allowed sales that had not quite been closed to go on the books. But before long customers' signatures were being forged, documents altered and millions of dollars in fake sales reported—allowing the company to show profits when it was losing money while investors paid millions for company stocks. Similar tales emerged after the Enron scandal, one of the largest bankruptcy cases in U.S. history. Anecdotal reports of dishonesty escalating over time are common, so a team of researchers from University College London (U.C.L.) and...

In search of answers, a neurobiologist looks to rodents. One minute you’re enjoying a nice buzz, the next your brain stops recording events that are taking place. The result can mean having vague or no memory of a time period ranging anywhere from a few minutes up to several hours. Scary—isn’t it? Unfortunately, alcohol-induced blackouts aren’t a rarity, either. A 2015 survey of English teenagers who drank showed 30 percent of 15-year-olds and 75 percent of 19-year-olds suffered alcohol-induced blackouts. In medical terms this memory loss is a form of temporary anterograde amnesia, a condition where the ability to form new memories is, for a limited time, impaired. That means you can’t remember a stretch of time because your brain was unable to record and store memories in the first place. Neuroscientists do not fully understand how blackouts occur. Researchers long assumed alcohol impairs memory because it kills brain cells. Indeed, long-standing alcohol abuse can damage nerve cells a...

A structure known as the cerebellum acts as a brake on consumption People with a rare genetic disorder known as Prader-Willi syndrome never feel full, and this insatiable hunger can lead to life-threatening obesity. Scientists studying the problem have now found that the fist-shaped structure known as the cerebellum—which had not previously been linked to hunger—is key to regulating satiation in those with this condition. This finding is the latest in a series of discoveries revealing that the cerebellum, long thought to be primarily involved in motor coordination, also plays a broad role in cognition, emotion and behavior. “We’ve opened up a whole field of cerebellar control of food intake,” says Albert Chen, a neuroscientist at the Scintillon Institute in California. The project began with a serendipitous observation: Chen and his team noticed they could make mice stop eating by activating small pockets of neurons in regions known as the anterior deep cerebellar nuclei (aDCN), wi...

Several recent studies point to a small, long-overlooked structure in the brain stem as a crucial gatekeeper for the body’s signals Imagine you are playing the guitar. You’re seated, supporting the instrument’s weight across your lap. One hand strums; the other presses strings against the guitar’s neck to play chords. Your vision tracks sheet music on a page, and your hearing lets you listen to the sound. In addition, two other senses make playing this instrument possible. One of them, touch, tells you about your interactions with the guitar. Another, proprioception, tells you about your arms’ and hands’ positions and movements as you play. Together, these two capacities combine into what scientists call somatosensation, or body perception. Our skin and muscles have millions of sensors that contribute to somatosensation. Yet our brain does not become overwhelmed by the barrage of these inputs—or from any of our other senses, for that matter. You’re not distracted by the pinch of your s...

Animals learn especially well from surprising events, and the hormone noradrenaline may be one reason why. You reach over a stove to pick up a pot. What you didn’t realize was that the burner was still on. Ouch! That painful accident probably taught you a lesson. It’s adaptive to learn from unexpected events so that we don’t repeat our mistakes. Our brain may be primed to pay extra attention when we are surprised. In a recent  Nature  study, researchers at the Massachusetts Institute of Technology found evidence that a hormone, noradrenaline,  alters brain activity —and an animal’s subsequent behavior—in these startling moments. Noradrenaline is one of several chemicals that can flood the brain with powerful signals. Past research shows that noradrenaline is involved when we are feeling excited, anxious or alert and that it contributes to learning. But the new research shows it plays a strong role in responses to the unexpected. The M.I.T. team used a method called optoge...

 Working memories have long been thought to be maintained by persistent spiking. However, mounting evidence from multiple-electrode recording (and single-trial analyses) shows that the underlying spiking is better characterized by intermittent bursts of activity. A counterargument suggested this intermittent activity is at odds with observations that spike-time variability reduces during task performance. However, this counterargument rests on assumptions, such as randomness in the timing of the bursts, which may not be correct. Thus, we analyzed spiking and LFPs from monkeys’ prefrontal cortex (PFC) to determine if task-related reductions in variability can co-exist with intermittent spiking. We found that it does because both spiking and associated gamma bursts were task-modulated, not random. In fact, the task-related reduction in spike variability could largely be explained by a related reduction in gamma burst variability. Our results provide further support for the intermitte...