Colin Klein (Australian National University)
Biologically realistic models of neural spiking take into account spike timings, yet the relevance of spike timing beyond individual neurons is often unclear. In Izhikevich's (2006) model, spike timing plays a crucial role in allowing for the natural formation of polychronous circuits. These are firing patterns which are timedependent, but do not require synchronous firing of all neurons in an assembly. Further, individual elements can figure in a number of distinct polychronous assemblies, their role determined by the timing of their firing relative to other neurons. I argue that this reflects a distinct organisational principle from traditional notions of pluripotency, redundancy, or re-use, and argue that for the phenomenon to be understood properly requires a shift from a traditional static, capacity-based view of computation to a process-based one.
