Knowledge of the regular features about the spatiotemporal patterns of spiking behavior in an assembly could be used to recreate those patterns artificially and examine whether such synthetic assembly patterns evoke similar behaviors as the native ones (c.f., Cohen and Newsome, 2004). In principle, this approach could provide the long-waited mechanistic understanding of cell assembly organization (c.f., Luo et al., 2008; O’Connor et al., 2009). It may also help extract the essential features of assembly activity, such as the minimum assembly size, the required temporal precision and sequential recruitment effects. While this approach should be attempted, it may not always work effectively. A failure to elicit the desired effect may occur for various reasons. For example, the required assembly to be activated may reside in multiple structures and activation of neurons in a single structure may not be sufficient. Even if one manages to activate all neurons, the imposed synthetic pattern has to compete with an ongoing program because neuronal networks in the brain are spontaneously and perpetually active. The meaning of an artificial pattern for the same reader in
