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Neuroscientist debunks one of the most popular myths about the brain


At some point in your life, you’ve probably been labeled a “right-brain thinker” (you’re so creative!) or a “left-brain thinker” (you’re so logical). Maybe this has shaped the way you see yourself or view the world.

Well, either way it’s bogus science, says Sarah-Jayne Blakemore, a University College London professor of cognitive science, in the latest episode of the Freakonomics Radio Podcast.

“This is an idea that makes no physiological sense,” she says.

The popular “right brain-left brain” theory for explaining people’s personalities is not actually backed by science.

Blakemore believes that the concept of “logical, analytical, and accurate” thinkers favoring their left hemisphere and “creative, intuitive, and emotional” thinkers favoring their right hemisphere is the misinterpretation of valuable science. She thinks it entered pop culture because it makes for snappy self-help books. And of course people love categorizing themselves.

In the ’60s, ’70s, and ’80s, the renowned cognitive neuroscientist Michael Gazzaniga led breakthrough studies on how the brain works. He studied patients who — and here’s the key — lacked a corpus callosum, the tract that connect the brain’s hemispheres. During this time doctors had experimented on patients suffering from constant seizures due to intractable epilepsy by disconnecting the hemispheres.

Gazzaniga could thus determine the origins in the brain of certain cognitive and motor functions by monitoring the brains of these patients.

He found, for example, that a part of the left brain he dubbed “The Interpreter” handled the process of explaining actions that may have begun in the right brain.

He discovered “that each hemisphere played a role in different tasks and different cognitive functions, and that normally one hemisphere dominated over the other,” Blakemore explains.

This was breakthrough research on how parts of the brain worked. But in a normal human being, the corpus callosum is constantly transmitting information between both halves. It’s physically impossible to favor one side.

Blakemore thinks that this misinterpretation of the research is actually harmful, because the dichotomous labels convince people that their way of thinking is genetically fixed on a large scale.

“I mean, there are huge individual differences in cognitive strengths,” Blakemore says. “Some people are more creative; others are more analytical than others. But the idea that this has something to do with being left-brained or right-brained is completely untrue and needs to be retired.”

You can listen to Blakemore and many other experts taking down their least favorite ideas in the Freakonomics Radio episode “This Idea Must Die,” hosted by “Freakonomics” co-author Stephen J. Dubner.

The above story is reprinted from materials provided by BusinessInsider.

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Why Do We Think Better after We Exercise?


Why is it that we seem to think better when we walk or exercise?

Justin Rhodes, an associate professor of psychology at the University of Illinois at Urbana-Champaign, responds:

After being cooped up inside all day, your afternoon stroll may leave you feeling clearheaded. This sensation is not just in your mind. A growing body of evidence suggests we think and learn better when we walk or do another form of exercise. The reason for this phenomenon, however, is not completely understood.

Part of the reason exercise enhances cognition has to do with blood flow. Research shows that when we exercise, blood pressure and blood flow increase everywhere in the body, including the brain. More blood means more energy and oxygen, which makes our brain perform better.

Another explanation for why working up a sweat enhances our mental capacity is that the hippocampus, a part of the brain critical for learning and memory, is highly active during exercise. When the neurons in this structure rev up, research shows that our cognitive function improves. For instance, studies in mice have revealed that running enhances spatial learning. Other recent work indicates that aerobic exercise can actually reverse hippocampal shrinkage, which occurs naturally with age, and consequently boost memory in older adults. Yet another study found that students who exercise perform better on tests than their less athletic peers.

The big question of why we evolved to get a mental boost from a trip to the gym, however, remains unanswered. When our ancestors worked up a sweat, they were probably fleeing a predator or chasing their next meal. During such emergencies, extra blood flow to the brain could have helped them react quickly and cleverly to an impending threat or kill prey that was critical to their survival.

So if you are having a mental block, go for a jog or hike. The exercise might help pull you out of your funk.

Story Source:

The above story is reprinted from materials provided by ScientificAmerican magazine.

An Old Illusion


The Monkey Business Illusion


“Imagine you are asked to watch a short video (above) in which six people-three in white shirts and three in black shirts-pass basketballs around. While you watch, you must keep a silent count of the number of passes made by the people in white shirts. At some point, a gorilla strolls into the middle of the action, faces the camera and thumps its chest, and then leaves, spending nine seconds on screen. Would you see the gorilla?

Almost everyone has the intuition that the answer is “yes, of course I would.” How could something so obvious go completely unnoticed? But when we did this experiment at Harvard University several years ago, we found that half of the people who watched the video and counted the passes missed the gorilla. It was as though the gorilla was invisible.

This experiment reveals two things: that we are missing a lot of what goes on around us, and that we have no idea that we are missing so much. To our surprise, it has become one of the best-known experiments in psychology. It is described in most introductory textbooks and is featured in more than a dozen science museums. It has been used by everyone from preachers and teachers to corporate trainers and terrorist hunters, not to mention characters on the TV show C.S.I., to help explain what we see and what we don’t see. And it got us thinking that many other intuitive beliefs that we have about our own minds might be just as wrong. We wrote The Invisible Gorilla to explore the limits of human intuition and what they mean for ourselves and our world. We hope you read it, and if you do, we would love to hear what you think.”

-Christopher Chabris and Daniel Simons

www.theinvisiblegorilla.com