The model evolves as we learn more about brain physiology. Computer programmers are allowed the freedom to build almost any kind of computing model as long as it performs the computation efficiently. Until then, we may need to create models of neural circuits which approximate, or guess at, computation in the natural brain since we have no concrete way to measure thoughts arising from neural synapses. However, we know that thought processes are naturally wrapped or packaged in language. Language elements such as words, sentences, and the associations these language elements make up in the minds exists because, maybe, the mind's architecture is built to accomodate language intrinsically.
Language exists because of how the mind is built.
Spoken and written language enables us to associate or connect sequences of word elements together. Spoken language in particular places special meaning on the temporal sequence of words. Images are composed of picture elements which are meaningful to each other in terms of the spatial relationship they have to each other. Both verbal and visual language elements can be described by sequences of words or picture elements, and our brain processes this information by associating these elements together in a temporal or spatial sequence. A thought is created by the orderly synapse of neurons in a sequence.