This Week in Neuroblunders: fMRI Edition

My entire body of work has been called into question!And what a fine week for technical neurogaffes it is. First was the threat that many trendy and important studies of neural circuits may need to be replicated using old-fashioned lesion methods, because of “off-target” effects:Where do we go from here? Most acute manipulation studies that use optogenetics confirm, and so add valuable support to, existing hypotheses that were established in earlier studies. But for those studies that have proposed new circuit functions, it may be advisable to re-evaluate the conclusions using independent approaches.1 Up next we have....fMRI Neuroblunders in Brief  The most notable one of late is a new paper by Eklund et al. (2015), which demonstrated that common statistical tests used to analyze fMRI data can give wildly inflated false positive rates of up to 60%, as illustrated in the top figure.“What they found is shocking”!While voxel-wise error rates were valid, nearly all cluster-based parametric methods (except for FSL’s FLAME 1) have greatly inflated familywise Type I error rates. This inflation was worst for analyses using lower cluster-forming thresholds (e.g. p=0.01) compared to higher thresholds, but even with higher thresholds there was serious inflation. This should be a sobering wake-up call for fMRI researchers, as it suggests that the methods used in a large number of previous publications suffer from exceedingly high false positive rates (sometimes grea...
Source: The Neurocritic - Category: Neuroscience Authors: Source Type: blogs