Craig Bennett(of Prefrontal.org) and Michael Miller, of dead fish brain scan fame, have a new paper out: How reliable are the results from functional magnetic resonance imaging?
Tal over at the [citation needed] blog has an excellent in-depth discussion of the paper, and Mind Hacks has a good summary, but here's my take on what it all means in practical terms.
Suppose you scan someone's brain while they're looking at a picture of a cat. You find that certain parts of their brain are activated to a certain degree by looking at the cat, compared to when they're just lying there with no picture. You happily publish your results as showing The Neural Correlates of Cat Perception.
If you then scanned that person again while they were looking at the same cat, you'd presumably hope that exact same parts of the brain would light up to the same degree as ...
