An abstraction node is anything that abstracts an information input. This means that lower animals can be abstraction nodes, and machines can also be abstraction nodes.
To see evidence of this in machines: see machine hallucinations of deep dreams.
NeoMemetic theory converges on the notion that biological organisms also use information in the form of memes to compete, survive and thrive. This has lead to evolution being bent around memetic processes—hence why you have biological processes adapting around and internalising abstraction processes.
Memes can then be made possible by abstraction processes. Another term could be "plant". 
From the paper, "Meme Machines and the Missing Link": "Let us return to the question of why no other animal seems to have our explosive growth of culture. If cultural evolution is a ‘natural’ process that happens relatively independently of slow, embodied processes, then why isn’t doesn’t it run so quickly for other species? Recent work in primatology tells us three interesting things. First, we know that apes and even monkeys do have culture (de Waal and Johanowicz, 1993; Whiten et al., 1999;Whiten, 2000; de Waal, 2001). That is, behavior is reliably and consistently transmitted between individuals by non-genetic means. So we know that the question is not 'why doesn’t it exist', but rather 'why isn’t it on the same scale?'"