The Secrets of Your Brain's Zoom Lens Notice that, even as you fixate on the screen in front of you, you can still shift your attention to different regions in your peripheries. For decades, cognitive scientists have conceptualized attention as akin to a shifting spotlight that “illuminates” regions it shines upon, or as a zoom lens, focusing on things so that we see them in finer detail. These metaphors are commonplace because they capture the intuition that attention illuminates or sharpens things, and thus, enhances our perception of them. Some of the important early studies to directly confirm this intuition were conducted by NYU psychologist Marisa Carrasco and colleagues, who showed that attention enhances the perceived sharpness of attended patterns. Subsequent studies by Carrasco’s group and others found that attention also enhances perception of other features – for example, color saturation , orientation , and speed . Are you a scientist who specializes in neuroscience, cognitive science, or psychology?
Everyday Stress Can Shut Down the Brain's Chief Command Center The entrance exam to medical school consists of a five-hour fusillade of hundreds of questions that, even with the best preparation, often leaves the test taker discombobulated and anxious. For some would-be physicians, the relentless pressure causes their reasoning abilities to slow and even shut down entirely. The experience—known variously as choking, brain freeze, nerves, jitters, folding, blanking out, the yips or a dozen other descriptive terms—is all too familiar to virtually anyone who has flubbed a speech, bumped up against writer’s block or struggled through a lengthy exam. For decades scientists thought they understood what happens in the brain during testing or a battlefront firefight. In recent years a different line of research has put the physiology of stress in an entirely new perspective. The response to stress is not just a primal reaction affecting parts of the brain that are common to a wide array of species ranging from salamanders to humans. Select an option below:
The Brain: A Body Fit for a Freaky-Big Brain | Mind & Brain Aiello and Wheeler noted that this dramatic increase in brain size would seem to have required a dramatic increase in metabolism—the same way that adding an air-conditioning system to a house would increase the electricity bill. Yet humans burn the same number of calories, scaled to size, as other primates. Somehow, Aiello and Wheeler argued, our ancestors found a way to balance their energy budget. As they expanded their brains, perhaps they slimmed down other organs. The scientists compared the sizes of organs in humans and other primates. Aiello and Wheeler christened their idea “the expensive tissue hypothesis.” Then William Leonard, a biological anthropologist at Northwestern University, put the expensive tissue hypothesis to a new test. This suggested that the gut-shrinking phenomenon within the primate groups was probably too subtle to explain our increase in brain size completely. Wray and his colleagues compared SLC2A1 in humans and other animals.
Personality Traits Correlate With Brain Activity Your personality says a lot about you. To categorize people by their disposition, psychologists have long relied on questionnaires. Now, however, researchers may be closing in on a tangible view of character in the brain. Even at rest, the brain hums with neural activity. Using functional MRI, the researchers monitored the resting state of 39 healthy participants and looked for regions that tended to activate together. Because the brain activity only correlated with the traits, Milham says it is too soon to tell whether the patterns reflect the neural embodiment of personality.
How mapping neurons could reveal how experiences affect mental wiring This article was taken from the July 2012 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online. No road, no trail can penetrate this forest. The long and delicate branches of its trees lie everywhere, choking space with their exuberant growth. No sunbeam can fly a path tortuous enough to navigate the narrow spaces between these entangled branches. This forest is majestic, but also comic and even tragic. You may be surprised to hear that it fits in a container less than 30 centimetres in diameter. In the 17th century, the French philosopher Blaise Pascal confessed that he was terrified by the vastness of the universe. As a neuroscientist I have come to know first-hand Pascal's dread. Studying an object as complex as the brain may seem almost futile. What's more, this standardised nervous system has been mapped completely. Differences fascinate us.
Making Sense of the World, Several Senses at a Time Our five senses–sight, hearing, touch, taste and smell–seem to operate independently, as five distinct modes of perceiving the world. In reality, however, they collaborate closely to enable the mind to better understand its surroundings. We can become aware of this collaboration under special circumstances. In some cases, a sense may covertly influence the one we think is dominant. Our senses must also regularly meet and greet in the brain to provide accurate impressions of the world. Seeing What You Hear We can usually differentiate the sights we see and the sounds we hear. Beep Baseball Blind baseball seems almost an oxymoron. Calling What You See Bats and whales, among other animals, emit sounds into their surroundings—not to communicate with other bats and whales—but to “see” what is around them. Let Your Fingers Do The Hearing People who are both deaf and blind are incredibly good at using other senses such as touch to navigate and understand the world. Do You Have Synesthesia?
Is the Purpose of Sleep to Let Our Brains “Defragment,” Like a Hard Drive? | The Crux Neuroskeptic is a neuroscientist who takes a skeptical look at his own field and beyond at the Neuroskeptic blog. Why do we sleep? We spend a third of our lives doing so, and all known animals with a nervous system either sleep, or show some kind of related behaviour. But scientists still don’t know what the point of it is. There are plenty of theories. But others argue that sleep has a restorative function—something about animal biology means that we need sleep to survive. Waking up after a good night’s sleep, you feel restored, and many studies have shown the benefits of sleep for learning, memory, and cognition. Recently, some neuroscientists have proposed that the function of sleep is to reorganize connections and “prune” synapses—the connections between brain cells. This illustration, taken from their paper, shows the basic idea: While we’re awake, your brain is forming memories. Yet this poses a problem for the brain. After heavy use, hard disks tend to get “fragmented.”
The Brain May Disassemble Itself in Sleep Compared with the hustle and bustle of waking life, sleep looks dull and unworkmanlike. Except for in its dreams, a sleeping brain doesn’t misbehave or find a job. It also doesn’t love, scheme, aspire or really do much we would be proud to take credit for. Yet during those quiet hours when our mind is on hold, our brain does the essential labor at the heart of all creative acts. It edits itself. And it may throw out a lot. In a provocative new theory about the purpose of sleep, neuroscientist Giulio Tononi of the University of Wisconsin–Madison has proposed that slumber, to cement what we have learned, must also spur the brain’s undoing. Select an option below: Customer Sign In *You must have purchased this issue or have a qualifying subscription to access this content