Sentience is the present participle of the Latin verb sentire –‘to feel’- but what is it? What does it imply? Consciousness? Thought? Or merely some form of awareness of the surroundings, however indistinct and vague? Is avoidance of a noxious stimulus enough to establish sentience, or does it have to involve an understanding that it is harmful?
How about pain itself, then? What kind of a nervous system can feel pain -not just avoid damage, you understand, but feel it? Because surely feeling pain assumes some sort of an I who perceives it as pain rather than simply moves away reflexively… Are we back to consciousness again?
I suppose it’s easy to posit sentience in something like a dog, or a wary squirrel in whose eyes one can easily see that there is something/someone behind them looking out at the world. It’s more difficult as you move down the phylogenetic chain (if one even can, or should, assign direction or rank to changing phyla): easier with, say, lizards or crocodiles; more difficult with flies and mosquitoes; and impossible -for me, at least- with, oh, tapeworms or amoebae and their ilk.
Yes, and then there are the plants which react to stimuli, often in a purposive fashion -what do we do with them? What constitutes a feeling of pain -especially since they do not have what most of us would consider a nervous system (although their root structures and associated symbiotic fungal networks might qualify). Do plants feel some sort of proto-pain -and if they do, so what? The buck, if I may be allowed to paraphrase the sign on the previous American president Harry Truman’s desk, has to stop somewhere…
So where do we draw the line with sentience? Is it entirely subjective (ours, at any rate)? Should it be confined to those things we would not think of stepping on or swatting? Or is it enough to be alive to merit consideration -different from a rock, for example?
I don’t know why I worry about such things, but I obviously do -especially when I come across essays like the one in Aeon written by Brandon Keim. https://aeon.co/essays/do-cyborg-cockroaches-dream-of-electric-trash
It was entitled I, cockroach, and delved into whether insects felt pain, or were conscious. The question occurred to him after reading about Backyard Brains, ‘a Kickstarter-funded neuroscience education company.’ The company’s flagship product is apparently RoboRoach, a ‘bundle of Bluetooth signal-processing microelectronics that’s glued to the back of a living cockroach and wired into the stumps of its cut-off antennae. Cockroaches use their antennae to detect objects; they react to electrical pulses sent through these nerves as though they have bumped into something, allowing children to remote‑control them with smartphones.’
I have to admit that I am appalled at this -although I suppose I would think little of swatting a cockroach crawling across the kitchen floor. The difference, I suspect, is somewhat akin to what Keim discusses: using a living creature as a tool in what might be -for the cockroach, at any rate- similar to some higher being wiring us up for whatever questionable purpose to change and study our behaviour and -who knows?- maybe change our reality. It’s hard not to sound overly anthropomorphic in describing my feelings about this, but there you have it.
‘A note on the company’s website does reassure customers that, though it’s unknown if insects feel pain, anaesthesia is used during procedures on cockroaches, and also on earthworms and grasshoppers involved in other experiments.’ But as I’ve already mentioned, and as Keim discusses, ‘You can’t experience pain unless there’s a you — a sense of self, an interior dialogue beyond the interplay of stimulus and involuntary response, elevating mechanics to consciousness. [And] such sentience is quite unlikely in a bug, says Backyard Brains.’ Really?
Even the likes of Darwin wondered about cognitive states in ‘lower’ creatures. In his final book, The Formation of Vegetable Mould Through the Action of Worms, with Observations on Their Habits (1881), he describes in great detail ‘how earthworms plug the entrance to their burrows with precisely chosen and arranged leaf fragments, and how instinct alone doesn’t plausibly explain that. ‘One alternative alone is left, namely, that worms, although standing low in the scale of organisation, possess some degree of intelligence.’
And no, as the more observant of my readers will no doubt have noted, worms are not cockroaches. Then how about honey bees as insect stand-ins for roaches? How about their waggle dances: ‘the complicated sequence of gestures by which honeybees convey the location and quality of food to hive-mates’? As Keim notes, ‘scientists have assembled a portrait of extraordinary cognitive richness, so rich that honeybees now serve as model organisms for understanding the neurobiology of basic cognition. Honeybees have a sense of time and of space; they have both short- and long-term memories. These memories combine sight and smell, and are available to bees independent of their immediate environments. In other words, they have internal representations of their worlds. They can learn to recognise patterns, and also concepts: above and below, same or different. They have simple emotions and beliefs, and apply those memories and concepts to their decisions. They likely recognise individuals.’
In fact, ‘Cognition is only one facet of mental activity, and not a stand-in for rich inner experience, but underlying honeybee cognition is [a] small but sophisticated brain, with structures that effectively perform similar functions as the mammalian cortex and thalamus — systems considered fundamental to human consciousness.’
I don’t want to take this too far. Thomas Nagel, the American philosopher, in his 1974 essay What is it like to be a bat? argued that ‘an organism has conscious mental states, “if and only if there is something that it is like to be that organism—something it is like for the organism to be itself.” (A fascinating paper, by the way, and well worth the read). But, coming back to cockroaches, as Keim writes, ‘The nature of their consciousness is difficult to ascertain, but we can at least imagine that it feels like something to be a bee or a cockroach or a cricket. That something is intertwined with their life histories, modes of perception, and neurological organisation’ -however impoverished that something might seem in comparison to our own perceptions. Indeed, maybe it would be something like our state of awareness in doing ‘mindless’ tasks like walking down stairs, or picking up a cup of coffee -both purposive, and yet likely unremarked consciously…
There’s even some evidence that cockroaches have a richer social life than most of us might have imagined. According to ethologist Mathieu Lihoreau in his 2012 article for the journal Insectes Sociaux, ‘one can think of them as living in herds. Groups decide collectively on where to feed and shelter, and there’s evidence of sophisticated communication, via chemical signals rather than dances. When kept in isolation, individual roaches develop behavioural disorders; they possess rich spatial memories, which they use to navigate; and they might even recognise group members on an individual basis.’
Maybe the famous English biologist J.B.S. Haldane got it right when, in 1927, he wrote that ‘the universe is not only queerer than we suppose, but queerer than we can suppose’. Then again, I suspect we tend to view things as peculiar or even alien if we feel no connection to them -feel that, as humans, we are not really a part of their world. But remember the words of Gloucester as he stumbles around the moor after being blinded by Regan and Cornwall in Shakespeare’s King Lear: ‘As flies to wanton boys are we to the gods; they kill us for their sport‘.
Who’s world are we in, exactly…?