Hayles uses notions from Saussure and Derrida to formulate ideas about code and how a computer handles signifiers and signifieds. The crux of her argument is that digital computers 'rectify' signifiers by virtue of their electronics - all noise between 0 and 5 volts is translated to either on or off, and thus signifiers in the digital world are absolute. To me this begs the question of what happens when we extend this reasoning to the function of the human brain as a computer? Rudimentary understanding of the brain is that of a neural network of synapses firing and neurons communicating - a system which can be viewed much like the communication of transistors within a digital computer; however, while noise in a digital computer is "rectified into unambiguous signals of one and zero before they enter the bit stream" (46), noise in an organic brain is a fundamental aspect of the communication. Synapse communication is analog, with a huge variety of information conveyed through frequency - thus data in the brain is not rectified, language communication is subject to noise, to subjectivity, to interpretation.
Another question this notion of analogue vs digital computing seems to lead to is one that Hayles also brings up when she mentions that "as the system builds up levels of programing laungages [...] they develop functionalities that permit increasingly greater ambiguities" (46) - i.e. even though the digital system is founded unambiguously, is the end result - the user level result - any different to the standard ambiguous world which Saussure lays out? A vinyl record is at it's root an infinitely analogue (ambiguous) store of data, and a CD fundamentally digital (unambiguous), yet after all the level of abstraction between encoding and listening, isn't the resultant experience equally ambiguous, equally plural?
If all of our actual uses, presentations, of digital code live in the real of the abstract, what does it matter that we can 'peer through to the source?' The end result is the same.