When Big Data is Bad Data

You've heard of MRI machines for diagnostic imaging: big machines where the subject slides into the center of a noisy donut-shaped machine while a powerful magnetic field and radio waves create a picture of their insides. There are many types of MRI scans. Functional MRI (fMRI) looks at how different parts of the brain respond to stimuli. A common fMRI use is for Alzheimers neuro-imaging. Some 40,000 published papers have used fMRI to delve into the human brain over the last 25 years.