Neuroscientists Have Been Misreading Brain Scans for Decades

Neuroscientists have long assumed that when a brain region becomes more active, more blood flows to it. That assumption is the entire basis of functional magnetic resonance imaging. A new paper now says it's wrong for about 40% of the signals, and it isn't the only recent study to find that a lot of what we thought we knew about the brain rests on bad measurements. Let's take a look.