Working memory is the capacity to store and manipulate items in mind. There are many neuroimaging methods that provide with information about its neural underpinnings. In our case we are using magnetoencephalography (MEG), a technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring in the brain. One of the advantages of MEG is the temporal resolution, which can be as fine as 1000 Hz. Thus, it produces an enormous amount of data. In this project we intend to compute the synchronicity of the different brain regions by using tools from the field of signal theory. Then, we will apply tools from graph theory to assess how brain regions behave under high cognitive demands.