The Yale experience in first advancing fMRI

In 1992 during a period of only a few months functional brain mapping by MRI became an international research field. This paper gives background to the first studies performed at Yale University during April 1992 which examined the temporal characteristics of the BOLD response in the human visual cortex. For the first time it was shown that even brief visual stimuli could produce a BOLD response which was delayed (due to the hemodynamic response) and was detected by imaging some seconds (on average 1.5 s) after the stimuli was over. This observation was the first event-related scanning study by fMRI.