in vitro Petri Dish Model FEM model of an in vitro Petri Dish with a 30 mm diameter and height of 10 mm. The petri dish is filled with artificial CSF (similar electrical properties as real CSF). A grey matter tissue culture with the size of 2 X 1.5 X 0.3 mm (L X W X H) is placed at the center of the petri dish 8 mm above the bottom surface. IMPORTANT NOTE: For proper performance of SimNIBS, the top surface of the input FEM models needs to be assigned as a skin tissue (since it uses the skin for placing the coil), otherwise an error occurs. Because of this reason, the outer surface of this model is defined as skin. However, since we are interested in simulating the culture in a CSF volume, YOU SHOULD ASSIGN THE ELECTRICAL CONDUCTIVITY OF CSF TO SKIN TISSUE IN YOUR SIMULATION. This way the skin is treated as CSF in the simulation without actually defining a CSF volume in the FEM model.