Interoception: EGG and fMRI experiments
The stomach-brain axis
Interest has grown in recent years in how the internal organs and the brain interact, and in how those interactions shape perception and emotion. The lab focuses specifically on the stomach-brain axis and the dynamic relationship between gastric electrical activity and large-scale brain networks, measured using EGG (electrogastrogram) and fMRI. The work examines which brain regions synchronise with the stomach's intrinsic electrical rhythm, and how strongly those regions are functionally connected. The broader goal is to understand what shapes this coordination, including gastric filling, visual food stimuli, and individual traits such as bodily awareness and psychological well-being.
Two directions of investigation
This line of work approaches the gut-brain relationship from two complementary directions. One is bottom-up, manipulating the gut from the body rather than the brain. Earlier studies in the lab used water ingestion for this, producing meaningful changes in gastric activity that were closely tied to the amount of water consumed.
The other direction is top-down, asking whether the electrical signals of the stomach and their interaction with the brain can be modulated from the brain downward. This stage, currently underway, presents participants with different categories of food images, including appetising and disgusting ones, while gastric and neural activity are recorded simultaneously using EGG and fMRI. The study also includes questionnaires assessing bodily awareness, anxiety, and well-being.
What the experiment involves
The experiment assesses neural connectivity between the stomach and the brain and is conducted in two stages. In the first stage, gastric activity is recorded by placing electrodes on the lower abdomen to capture the stomach's electrical signals. This part takes place in the research lab at Ben-Gurion University.
In the second stage, gastric activity is recorded again while the participant lies inside the MRI scanner. This part is conducted at the Imaging Institute at Soroka Medical Center. All recordings are performed while lying still, and between sessions participants may be asked to drink or eat.
Participation requirements
Participants must fast for three hours before the experiment. Male participants are asked to shave abdominal hair to allow proper electrode placement.
