Discover, August 19, 2014

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The long battle between humans and infectious microbes has left its marks all over us. It shows up most obviously in the way our bodies are constructed. The thousands of species of bacteria that swarm over us cannot penetrate our multilayered skin. Entry points, such as the eyes and the nose, are bathed in moisture to help flush out pathogens. The lining of our lungs releases bacteria-killing compounds. Viruses that manage to infect cells are greeted by proteins that attempt to shred them into genetic confetti. Any pathogen that sneaks past all these defenses then faces an army of immune cells, which can devour and destroy the invaders. Immune cells can also manufacture antibodies, which allow them to launch swift attacks if they encounter the same infection elsewhere in the body.

Continue reading “Germs on the Brain”

Discover, August 19, 2014

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Numbers make modern life possible. “In a world without numbers,” University of Rochester neuroscientist Jessica Cantlon and her colleagues observed in the journal Trends in Cognitive Sciences, “we would be unable to build a skyscraper, hold a national election, plan a wedding, or pay for a chicken at the market.”

The central role of numbers in our world testifies to the brain’s uncanny ability to recognize and understand them—and Cantlon is among the researchers trying to find out exactly how that skill works.

Continue reading “A Calculating Mind”

Discover, August 19, 2014

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One day in 2005, a retired building surveyor in Edinburgh visited his doctor with a strange complaint: His mind’s eye had suddenly gone blind.

The surveyor, referred to as MX by his doctors, was 65 at the time. He had always felt that he possessed an exceptional talent for picturing things in his mind. The skill had come in handy in his job, allowing MX to recall the fine details of the buildings he surveyed. Just before drifting off to sleep, he enjoyed running through recent events as if he were watching a movie. He could picture his family, his friends, and even characters in the books he read.

Continue reading “Inner Visions”

Discover, August 19, 2014

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There is nothing more humbling or more perception-changing than holding a human brain in your hands. I discovered this recently at a brain-cutting lesson given by Jean Paul Vonsattel, a neuropathologist at Columbia University. These lessons take place every month in a cold, windowless room deep within the university’s College of Physicians and Surgeons. On the day I visited, there were half a dozen brains sitting on a table. Vonsattel began by passing them around so the medical students could take a closer look. When a brain came my way, I cradled it and found myself puzzling over its mirror symmetry. It was as if someone had glued two smaller brains together to make a bigger one.

Continue reading “Doublethink”

I’ve been on something of a microbial jag recently. For my past two columns for the New York Times I’ve explored the creepy biochemical sophistication of bacteria.

First, I took a look at the outbreak of toxic bacteria that shut down Toledo’s water supply a couple weeks ago. A lot of people don’t realize it, but those microbes have been spewing out these toxins for about three billion years–for reasons that scientists are still trying to figure out.

Then I wrote about the chemicals that our own microbiome releases, and the ways they can affect our behavior. Some scientists don’t think those changes are just random side effects. Instead, our microbes may be trying to manipulate us for their own benefit, eating certain foods or getting close to other people (also known as hosts).