A popular method for detecting abnormalities in the shape and size of individual brains is seriously flawed, and is almost guaranteed to find 'differences' even in normal people.
So say Italian neuroscientists Scarpazza and colleagues in an important new report: Very high false positive rates in single case Voxel Based Morphometry.
Voxel Based Morphometry (VBM) is a way of analyzing brain scans to detect structural differences. It's most commonly used to compare groups of brains to find average differences, but some neuroscientists have started using VBM to check for abnormalities in a single brain. Scarpazza et al list 34 pieces of research about that, including 13 since 2010.
So it would suck if there were a problem with individual VBM... but there is. This pic tells the tale:
The authors took 200 normal brains and compared each one of them in turn to a control group of 16 normal brains. ...
