PET Imaging: The Real Positronic Brain?

In Isaac Asimov’s 1950 short story collection I, Robot, intelligent robots with positronic brains exist alongside humans. Unlike conventional computer hardware, the word positronic implies that electrical current is carried in the wires of these robots’ brains by  positrons, the antimatter counterpart of the familiar electron. Though the advantage of antimatter here is anyone’s guess, the stories of I, Robot may have introduced the positron to the public.  And as bizarre as Asimov’s fantasy sounds, neuroimaging has given the term “positronic brain” yet another meaning.

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The Slippery Slope of Dishonesty

A kid stealing candy in a convenience store grows up to be a convicted criminal. A husband who flirts with a coworker ends up as a serial cheater. A politician telling a few “white lies” to his or her constituents is eventually convicted of fraud. These are all extreme — but plausible — scenarios where dishonesty might escalate over time, resulting in dramatic and life-changing consequences. But how far does this slippery slope actually go? How can science help us answer this question?Continue reading

Why Dopamine Makes People More Impulsive

Over the past few decades, the neurochemical dopamine has earned the reputation of being the brain’s reward molecule.  This image is built on observations that when animals and humans experience surges of dopamine, they feel rewarded and motivated to pursue more of the experience or substance which triggered the dopamine release.  Researchers theorize that this neurochemical is at the root of an ancient system that evolved to make us feel gratified and thus more likely to approach situations and objects that might satisfy our needs — anything from nutrition to the more sophisticated desires for social approval or even money, a universal ticket for access to most resources.Continue reading

Surfing Brainwaves with EEG: A Classic Tool for Recording Temporal Brain Dynamics

Pictures are powerful tools for illustrating quantitative data and capturing public interest.  Each year, NASA releases many beautiful images of Martian dunes and distant nebulae which help win public funding.  Likewise, when it comes to grabbing headlines and commanding public attention, noninvasive studies of functional brain activity often do best when they beautifully illustrate said activity as colorful pixels dancing on the convoluted surface of the cerebral cortex.Continue reading