Since consciousness refers to self-awareness, there is belief that unless there is a language-processing mechanism and the ability to express yourself through some form of communication, then one does not have consciousness.
This can be seen through simple experiments of whether animals that don't possess language skills can recognize themselves in a mirror. Cats and dogs cannot; monkeys can. Monkeys also have their way of communicating within the species. Dolphins are also said to be able to recognize themselves as well, and they have their own form of communication. Elephants are also among a select few of species that can recognize themselves, and they have their own form of sign language, according to this article on National Geographic (http://newswatch.nationalgeographic.com/2013/04/24/elephants-communicate-in-sophisticated-sign-language-researchers-say/).
Now, just because a cat or dog is not aware of themselves and able to eloquently express themselves doesn't mean they don't exist. At least, this is the conversation we debated in our classroom with our professors recently.
I am not sure if I have entirely understood your question. However, you may find my own work of interest.
The Fractal Catalytic Model of living processes suggests that the brain is a catalyst and as such the theory does not treat the brain as an 'epistemological engine' or symbolic processor. It is treated more as an 'ontological lens'.
The FCM argues that all living processes (including the brain) maintain their organisation as a direct consequence of the way in which transitions are mediated in their respective environments. Implicated in this process are quantum coherent solitonic wave functions. It is argued that these coherent wave functions are truly 'ontological' in that they exist and persist as a direct consequence of their internal dynamic relationships. All non-living objects and phenomena are only deemed to be implicit in the pattern of evens in space and time.
Within the FCM consciousness is correlated with a macroscopic solitonic coherent wave function. The implication of the theory is that the evolution of life is the evolution of catalysis. And also, the evolution of life is the evolution of consciousness.
http://www.psy.cmu.edu/~davia/mbc/
Davia, C.J (June 2006), "Life, Catalysis and Excitable Media: A Dynamic Systems Approach to Metabolism and Cognition", in Tuszynski, J.A, The Emerging Physics of Consciousness (The Frontiers Collection), Springer, pp. 255–292, ISBN 978-3540238904
Consciousness is the faculty of awareness but awareness has to be aware of something, namely, existence-cs. cannot be cs. of nothing--self cs. is only possible after one becomes aware of something-putting cs before existence is a disastrous error (Decsartes' blunder).