Many fMRI studies could be giving false-positive results according to an important new paper from Anders Eklund and colleagues:
Does parametric fMRI analysis with SPM yield valid results?—An empirical study of 1484 rest datasets.
The authors examined the SPM8 software package, probably the most popular tool for analyzing neuroimaging data.
Their approach was beautifully simple. They wanted to check how often conventional analysis of fMRI would "find" a signal when there wasn't really anything happening. So they took data from nearly 1,500 people who were scanned when they were just resting, and saw what would happen if you looked for "task related" activations in those scans, even though there was in fact no task. It's a very clever use of the resting state data.
Eklund et al ran the analysis many thousands of times, under various different conditions. This is the key finding:
This shows the proportion of analyses which ...
