Although a flying pig doesn't exist in the real world, our brains use what we know about pigs and birds — and superheroes — to create one in our mind's eye when we hear or read those words. iStockphoto.com hide caption

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A window into dreams may now be opening. Silver Screen Collection/Getty Images hide caption

itoggle caption Silver Screen Collection/Getty Images

This image shows a human glial cell (green) among normal mouse glial cells (red). The human cell is larger, sends out more fibers and has more connections than do mouse cells. Mice with this type of human cell implanted in their brains perform better on learning and memory tests than do typical mice. Courtesy of Steven Goldman hide caption

itoggle caption Courtesy of Steven Goldman

Movies like The Shining frighten most of us, but some brain-damaged people feel no fear when they watch a scary film. However, an unseen threat — air with a high level of carbon dioxide — produces a surprising result. Warner Bros./Photofest hide caption

itoggle caption Warner Bros./Photofest

Chances are they already speak more languages than you: children from Papua New Guinea's Andai tribe of hunter-gatherers wait for their parents to vote in the village of Kaiam. Over 800 languages are spoken in PNG, a country of about six million people. Torsten Blackwood/AFP/Getty Images hide caption

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A visitor to the Wellcome Collection's 2012 exhibition "Brains: The mind as matter" looks at a functional magnetic resonance image (fMRI) showing a human brain as it listens to Stravinsky's "Rite of Spring" and Kant's third Critique. Miguel Medina/AFP/Getty Images hide caption

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The warmer orange colors show parts of the brain most active during improvisational rap. The blue regions are most active when rappers performed a memorized piece. NIDCD hide caption

itoggle caption NIDCD

Matt Langione, a subject in the study, reads Jane Austen's Mansfield Park. Results from the study suggest that blood flow in the brain differs during leisurely and critical reading activities. L.A. Cicero/Stanford University hide caption

itoggle caption L.A. Cicero/Stanford University

Researchers are using MRI scans to learn more about the brains of people with extraordinary memory. iStockphoto.com hide caption

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Megan Lutz, left, and Justin Chun react to amateur comedian Robert Lynch at the Metropolitan Room in Manhattan, N.Y. Lynch is an anthropologist researching what laughing reveals about us. Melanie Burford for NPR hide caption

itoggle caption Melanie Burford for NPR