Using the analogy of a musical assembly, in which the tempo of one member can be reasonably predicted from the activity of the other members of the orchestra, the spike occurrence of a neuron taking part in a cell assembly should be reliably predicted from the activity of its peer neurons. To illustrate such assembly cooperation, I draw an example from the hippocampus (for neocortex, see Truccolo et al., 2010).5 Spike timing of hippocampal pyramidal cells can be related to the position of the animal (O’Keefe and Nadel, 1978), to the phase of the local field potential (LFP) theta cycle (O’Keefe and Recce, 1993) and the spiking of other neurons. Each of these variables is correlated with the spiking activity of single neurons but with different temporal resolutions. Since spiking activity refers to events that occur in time, the best prediction of spike timing from the other variables should have an optimum time window. By varying the analysis window experimentally, the best prediction of the spike timing of single hippocampal neurons from the activity of other neurons was found when
