I suggest an alternative strategy to the representational approach of neuronal assembly identification. The main hypothesis is that the cell assembly concept is most useful from the point of view of downstream ‘observer-reader-classifier-integrator’ mechanisms (referred to as readers hereafter) because the biological relevance of a particular constellation of active neurons (i.e., a presumed cell assembly or assembly sequence) can only be judged from the perspective of explicit outputs. An elementary classifier mechanism is the action potential of a reader neuron, which reflects the integration of the activity of an upstream assembly. The action potential is caused by the assembly activity. At the most complex level, such ‘caused’ effects may be motor outputs, decisions, plans, recalls and thoughts.
