Masters of their fates?

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.

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…?


Seeing is believing, my mother used to say when she saw I hadn’t finished the spinach on my plate despite my protestations to the contrary. But what if the belief were to persist in the absence of visual corroboration? Suppose I simply closed my eyes and pointed at the plate? My mother, no solipsist, would merely laugh and tell me it would still be there if I ever chose to open my eyes again. I could never win at that –her open eyes trumped my temporarily closed ones every time. I tried that ruse so many times, I got so I could actually see the spinach and the plate even with my eyes firmly clamped shut.

Perhaps I was a slow child, but it did make me wonder about what seeing actually meant. Was it something that could continue even when I tried to turn it off? In the bedroom at night when the blinds were drawn and the room was black, I could still navigate fairly well -and if I did bump into something, I could usually sense it just before the collision.

People talked about noticing things out of the corners of their eyes –meaning when they weren’t looking at them, I guess- and when I grew older, I learned about the sensitivities and image resolution of different cells in the retina. The cone cells in the macula –which you use when you are actually looking at something- were good for colour discrimination and fine resolution, whereas the rod cells, peripheral to that, were more sensitive to light, but not at resolution.

That weird sensation of thinking someone is looking at you, I assumed, was something detected in that peripheral part of the retina by the rod cells –noticed, but not readily identified, and maybe, therefore, not consciously processed until you turned to focus your cones cells on it. It made sense, but every so often I am thrilled to find others who continue to be intrigued by the process:

I had assumed that it was fairly straightforward –light hits the retinal cells in the eyes, the signal travels to the visual cortex in the brain, and then it makes us conscious of what the signal means. But, of course, it’s not quite as simple as that. ‘Once information leaves our eyes it travels to at least 10 distinct brain areas, each with their own specialised functions. […] The visual cortex supports our conscious vision, processing colour and fine detail to help produce the rich impression of the world we enjoy. But other parts of our brain are also processing different pieces of information, and these can be working away even when we don’t – or can’t – consciously perceive something.’

So what would happen if your visual cortex were destroyed by a stroke or trauma of some sort? You’d lose your conscious vision –your cortical vision… but ‘cortically blind is only mostly blind – the non-cortical visual areas can still operate. Although you can’t have the subjective impression of seeing anything without a visual cortex, you can respond to things captured by your eyes that are processed by these other brain areas’ –Blindsight, as a researcher name Larry Weiskrantz called it.

The BBC article reported on a study of a man with just such a condition. They were able to do a functional MRI to watch his brain while faces were presented to his ‘blind’ eyes. ‘The scanning results showed that our brains can be sensitive to what our conscious awareness isn’t. An area called the amygdala, thought to be responsible for processing emotions and information about faces, was more active when TD [the patient] was looking at the faces with direct, rather than averted, gaze. When TD was being watched, his amygdala responded, even though he didn’t know it.’

Exciting stuff. ‘[…]research like this shows that certain functions are simpler and maybe more fundamental to survival, and exist separately from our conscious visual awareness. Specifically, this study showed that we can detect that people are looking at us within our field of view – perhaps in the corner of our eye – even if we haven’t consciously noticed. It shows the brain basis for that subtle feeling that tells us we are being watched.’

The article reminded me of something that happened long ago in my gynaecology practice. At the time it seemed a rather trivial incident, but I suppose the fact that I can even remember it suggests that I found it intriguing nevertheless.

Prisha –I think that was her name- was a young woman whose baby I had delivered, a few years before. She returned every two or three years for her pap smear but I remember being surprised to see her again only a few months after her last visit. A tall, beautiful woman with what seemed to me to be an exquisite taste in saris, it was hard not to notice her in the waiting room whenever she visited. Long black hair that never managed to hide the large gold earrings, and the red bindi in the middle of her forehead marked her as an immediate attraction for whatever children happened to be playing on the carpet with their toys.

That day, however, their attention seemed to be focused on an older lady sitting beside her like a queen. Regal in bearing and bolt upright in posture, she was wearing a dark blue sari with gold trim, and as I recall her snow white hair was tucked away under a lighter blue scarf. I suppose what drew my attention to it was that she sat beside her daughter with her eyes closed even when she talked. A tow-headed little boy with large, blue, curious eyes was standing a few feet away staring at her. He would have been too young to have been Prisha’s son, so I assumed he was just fascinated, as I always was with the saris that Prisha wore. But it was more the older lady that had captured his eyes. As soon as I walked across the room to greet them, the little boy ran back to his mother who was sitting beside the window, but he continued to watch from the corner.

I was welcomed by a big smile as I approached Prisha. “I’m so happy to see you again, doctor,” she said, “but this time it’s my mother, Lakshmi, who needs your help.”

Her mother pursed her lips, but didn’t extend her hand to shake mine as I had expected. Her mouth drooped slightly on one side, but a smile broke through nonetheless.

“She is blind,” Prisha explained, “So I have come to help her, if that is alright with you. She only speaks Hindi, though, so I will also need to translate…”

As Prisha took her mother’s arm and helped her down the corridor to my office, I noticed a distinct limp and obvious weakness on one side.

“Mother had a stroke and lost her vision,” Prisha explained, when we were in the office. She’d settled her mother in a chair beside my desk and pulled another beside it for herself. The two talked for a moment while her mother fussed in her seat. “She says she is very nervous about consulting a man, doctor, but I have just reassured her that I trust you.” She smiled at her mother. “She can see nothing at all now, and with the continuing bit of paralysis, I think she feels particularly vulnerable.”

They chatted to each other in Hindi for a moment, when suddenly her mother’s face changed and I could see her tightening her grip on Prisha’s arm.

“Is there something bothering your mother?” I asked, wondering if perhaps she’d changed her mind about being examined by a man.

Prisha immediately smiled, but I could sense her tension. “She says someone is staring at her…”

I blushed and looked down at the surface of my desk. “I’m sorry, I didn’t mean…”

Prisha shook her head. “No, it’s not you, she says.”

“But…” I was confused. “Didn’t you say she couldn’t see anything?”

Prisha smiled, embarrassed. “Nothing at all. The neurologist says she’s completely blind… But she says she can sometimes feel things,” she continued and then shrugged.

Lakshmi seemed to be staring at the office door –if ‘staring’ is the right word, so I glanced over at it. The door wasn’t completely closed, and through what little space remained I could see a pair of large blue curious eyes examining us like a visitor in the zoo. And then, realizing they were noticed, they disappeared, and the pounding of little feet echoed down the corridor.

Lakshmi’s face relaxed and she said something to her daughter.

“It’s okay now, doctor,” she said, looking at her mother with a bemused expression. “She says the eyes are gone…”

There are more things in heaven and earth, Horatio… Blindsight? I don’t know, but whatever it was, I think I was privy to something special that day so long ago.