An EEG (electroencephalogram) is a painless test that uses small sensors placed on the scalp to measure the brain's electrical activity. It provides a real-time readout of brain "waves"—rhythms ...

"Blink and you'll miss it" isn't only for eyelids. The human brain also blinks, dropping a few frames of visual information here and there. Those lapses of attention come fast -- maybe just once every ...