Working memory and spontaneous activity of cell assemblies. A biologically motivated computational model

Many cognitive tasks require the ability to maintain and manipulate simultaneously several chunks of information. Numerous neurobiological observations have reported that this ability, known as the working memory, is strongly associated with the activity of the prefrontal cortex. Furthermore, during resting state, the spontaneous activity of the cortex exhibits exquisite spatiotemporal patterns sharing similar features with the ones observed during specific memory tasks. Here, we propose a computational model of the prefrontal cortex within the framework of the cell assembly theory. In that framework, 'a chunk of information' refers to an associative memory and consists of an ensemble of neurons which activates coherently due to their strong inter-connections. Our model consists of a recurrent network of cells whose dynamics results from the interplay between the membrane potential and the theta local field potential.