A selection of facts and conjectures about the cerebral cortex inspired by the theory of cell assemblies

This chapter presents a selection of facts and conjectures about the cerebral cortex inspired by the theory of cell assemblies. The cortex is essentially a system of pyramidal cells (Py-cells), coupled by short range and long range connections. Pyramidal cells are excitatory. There is great convergence and divergence in this system. The amount of excitation transmitted by one Py-cell to another is small compared to the threshold. It takes a number of active Py-cells to activate other Py-cells. The elements of the representation of things and events are sets of cortical Py-cells coupled by above average excitatory connections. Sets such as Hebb's cell assemblies ignite upon partial activation and stay active for some time. Besides the relation of belonging to the same cell assembly, which is reciprocal, cortical neurons or cell assemblies can also be tied by the asymmetrical relation of one follows the other