Greenspan and Shanker make it quite clear that they don't think artificial intelligence can have consciousness:
What is the necessary foundation for consciousness? Can computers be programmed to have it or any types of truly reflective intelligence? The answer is NO! Consciousness depends on affective experience (i.e. the experience of one's own emotional patterns). True affects and their near infinite variations can only arise from living biological systems and the developmental processes that we have been discussing.
Let's look at that logically. The first part of their argument is Consciousness (C) depends on Affective experience (A):
Let's go on the premise that this sentence is sound, even if it's not. Conscious AI can still be made even if this is true.
But the next part states Affective experience (A) depends on Biological systems (B) and Development processes (D).
Which means that Consciousness is, in turn, dependent on Biological systems and Development processes:
That's bad because it entails that if a system is not biological or if the system doesn't have proper development processes, that system cannot be conscious:
So the authors dramatically answer major questions of Strong AI in the negative with a deux ex machina of "true affect". The authors give no evidence or rationale for "true affect." Why would anybody assume that only living biological systems can experience emotional patterns? Biological organisms may have defined it, but that doesn't mean it can't be replicated in other substrates. Development is also a concept which can be implemented in an artificial system.
The authors spend most of a book talking about affect and development and how symbols are formed, and then full stop E brake when they get to the possibility of replicating those very architectural and dynamic system concepts they spent so much time trying to explain.
For those who think I may have taken this out of context, if they meant typical disembodied computers in comparison to embodied computers (e.g. robots), they would say so, and they don't. Simulated bodies are not considered either.
In conclusion, I still know no reasons that would prevent making conscious Strong AIs.