Functional MRI (fMRI) imaging has been a powerful tool for visualizing processing of information in the brain. This technique is based on the observation that the MRI signal changes with changes in the amount of blood flowing to a particular region of the brain, which correlates with the activity of that brain region. This is a very sophisticated technique that relies on complicated computer algorithms and this is where the problem lies.
A review of the three most popular software processing packages suggested that false-positive results are present in up to 70% of studies, which means up to 40,000 published trials may provide erroneous results. This review was published in the Proceedings of the National Academy of Sciences.
fMRI reports often provide tantalizing details about the effect of emotions, thoughts, drugs, etc on the brain. I searched through my posts and found three “Expect relief and you will get it“, “Botox helps headaches, makes you happier“, and “Science of acupuncture“.
This is not to say that all of this research is worthless. However, I would be skeptical of studies that involve a small number of subjects and from centers not known for rigorous scientific research.