Theta, alpha and gamma traveling waves in a multi-item working memory model.

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.