Do you think that the only way to define computational model of consciousness is based on an action of an individual neuron?
It's not a definition, it's a description, an explanation. If you connect a large number of computational units so that they work together, the output(s) is/are the result of computation - because the system is computational, and the brain can be seen as such; an information processing, connectionist (networked) computational system.
Some contributors may be querying whether, in a computational system that, for example, emits a hum of varying frequency when in operation, that hum should be considered computational; IOW, if consciousness is a non-computational side-effect of computational brain activity, perhaps analogous to resonance, we should probably not expect to reproduce it by emulating only the computations that gave rise to it.
My response would be that despite extensive study of brain function on many scales, there is no physical evidence of such an effect, nor any likely physical mechanism for it in that context. The brain appears to be constructed of a large number of computational elements that are fairly well understood - to the extent of functional emulation of significant networks of them; consciousness itself is fairly resilient to minor physical damage, and it's impairments when damaged are typically directly related to the damage in the relevant functional areas of the brain. IOW, it doesn't behave like a serendipitous non-computational side-effect. But it remains an unevidenced possibility.
It seems to me that no-one will be able to demonstrate that consciousness is computational until a computational machine is built that all parties agree exhibits consciousness - and judging by the debate in this thread, that agreement seems unlikely, even if the machine were to pen a heart-rending suicide note and creatively destroy its own power supply out of sheer boredom.
In the meantime, as far as I know, we have no evidence that the brain doesn't function in a computational way, and a great deal of evidence that it does. Consciousness is, beyond reasonable doubt, a result of the normal functioning of the brain, and if that functioning is computational, then it seems reasonable to assume (with the side-effect caveat above) that consciousness is computational - until we have evidence to the contrary. YMMV
