  Brain oscillations are believed to be involved in the different operations
necessary to manipulate information during working memory tasks. We propose a
modular variant of the Lisman-Idiart model for short-term memory, where theta,
alpha and gamma oscillations are traveling waves. Using this model we show that
the interactions between theta and gamma determine the allocation of multiple
information in distinct modules, while the interference between theta and alpha
disrupts the maintenance of current stored information. The effect of alpha in
erasing or blocking storage is robust and seems fairly independent of the
frequency, as long as it stays within the alpha range. The model help us to
understand why the alpha and theta oscillations, which have close frequency
bands, could have opposite roles in working memory.
