Frontoparietal cortical networks revealed by Structural Equation modeling and high resolution EEG during a short term memory task

We addressed questions related to the cortical sources involved in the spatial short term memory in humans. Such sources were estimated from non-invasive EEG recordings by using linear inverse procedure in a group of 9 normal healthy subjects. Analyzed neural activations from EEG recordings were obtained in regions of interest (ROIs) of few squared cm at the cortical level. Structural equation modeling (SEM) technique was then used to assess effective connectivity between cortical ROIs. Results showed an increase of connectivity of cortical prefrontal and premotor areas during the task phase in which an image has to be held in the memory before an appropriate decision has to be made by the subjects.