Using electrogastrography to measure signals from the stomach non-invasively in the fMRI scanner

COEX 

The stomach continuously produces a 0.05 Hz electrical oscillation (i.e. 1 cycle every 20 seconds), which serves to pace the stomach contractions necessary for digestion. This so-called gastric rhythm can be measured non-invasively by placing electrodes over the abdomen, a technique known as the electrogastrogram. This electrophysiological technique can be safely incorporated during fMRI recordings by using MRI-compatible electrodes and amplifiers of the same type used to measure electrocardiography or electromyography. While common in the field of gastroenterology, electrogastrography has yet to gain wider adoption in the field of cognitive neuroscience. The objective of this educational talk is thus to introduce the electrogastrography technique, as well as its potential applications for cognitive neuroscience. During the talk, I will review the physiological basis of the gastric rhythm, and provide an overview of brain-stomach anatomical pathways. I will then present the standard practices to acquire, analyze and interpret the electrogastrogram inside the fMRI scanner.