Build your own gom jabbar

Okay, not really a gom jabbar, but I'm re-reading Dune for the millionth time so what the hey.

The gom jabbar is a test to distinguish humans from animals. Humans, say the Bene Gesserit witches, will endure pain rather than give into animal instinct. Whether this is even a remotely sensible definition of humanity is debatable, but what about consciousness ? Devising a test to see whether someone is actually experiencing thought - not just thinking but actually being aware of their own thoughts - is a lot harder.

EDIT : See this article for an intriguing way not to detect whether someone is currently conscious, but whether they will become conscious at some point in the future. The "sniff test" is remarkably accurate. I find this particularly odd since I've never (or at most very rarely) been able to smell anything in a dream, which I would think means a less direct connection between smell and awareness. But perhaps not. Maybe this could work in the other direction and dogs could be trained to sniff out the smell of dreams...


But first, every so often it's worth pausing to think about why we should even care about the nature of consciousness. It is, after all, somewhat esoteric and we seem to get by in everyday life just fine without having any clear answers. At least, no-one needs to engage in philosophical debate to decide if they want to wear shoes or not. Either put them on or accept bruised and battered feet as you walk across a floor covered in Lego - understanding the nature of the soul won't help you.

Yet there are many reasons to care. Whatever it is, consciousness undeniably exists (regardless of the illusionist perspective, which is arguably the stupidest idea in history and certainly not worth further discussion). It is therefore part of the Universe, yet no modern scientific theory alludes to the emergence of consciousness in any way. This, potentially, is a whacking great hole in our entire world view, as though we'd come up with a wonderful theory of geology but completely missed the existence of sand. Of course, while it might be a fundamental component in itself - something which has some measure of independent existence - it's also possible it is "merely" a process. But even then, it's a process we have no idea how to explain. Whether process or substance, it demands investigation.

If sheer curiosity is not enough, morality ought to be more compelling. Are we really any different from a rock ? Most of us would tend to say yes, and I'd agree - I don't think rocks are thinking about anything; it doesn't matter if we smash them to bits just for the hell of it. On the other hand, dogs and cats and college professors clearly are, to varying degrees - and it does matter if we smash them to bits. So where's the dividing line, and how do we tell ?

We can at least be confident in declaring consciousness to be a spectrum (or perhaps something more complicated) : a dreamless sleep is different from a regular dream, which is different from a lucid dream, which is different again from being fully awake, which itself is different from being drugged and so on. But how could we actually know if a rock was thinking ? On occasion, people emerge from comas after years of inactivity, so behaviour is not much help. And computers muddy the waters still further. While it's at best highly controversial whether plants can make choices, computers and other mechanistic systems can undoubtedly do this. But they don't, so far as we know, want anything - they just do what we tell them to. So making choices does not necessarily indicate any kind of desire or awareness.

But even if plants were conscious, we'd still have to eat them - and no-one ever suggested that we should force all predatory animals to become vegan. If consciousness is a guide to morality, then animals make this an extremely difficult problem. Which consciousness has more rights than another, and why ? Should we shoot the lion to save the zebra ? If not, we're choosing to let the zebra suffer and die. Why is this acceptable when cannibalism obviously isn't ? Animals don't have any compunction about eating each other, so why should we ?

And there are larger sociological questions as to how consciousness relates to free will. If we do make choices, rather than being stuck on a mechanical course which we can observe but never change, then this affects how we interact with each other - when to praise and when to shame. Our actions make a difference. If, on the other hand, such choices are mere illusions, then at best all we can do is understand what's happening - or not, since we can't "will" ourselves to learn anything, we either will or won't and there's nothing we can do about it.


Understanding the nature of consciousness, then, would be super interesting. The present article looks at ways to try and detect it.

Latin for ‘little brain’, the highly compact cerebellum occupies only 10 per cent of the brain’s volume, yet contains somewhere between 50 and 80 per cent of the brain’s neurons... in this sense that the hospitalised Chinese woman was missing the majority of her brain. Incredibly, she had been born without a cerebellum, yet had made it through nearly two and a half decades of life without knowing it was missing. Compare that with strokes and lesions of the cerebral cortex, whose neuron-count is a fraction of the cerebellum’s. These patients can lose the ability to recognise colours or faces and to comprehend language – or they might develop what’s known as a ‘disorder of consciousness’, a condition resulting in loss of responsiveness or any conscious awareness at all.

Without trying harder, we’ll never know if injured patients are truly unconscious – or unresponsive but covertly conscious with a true inner life. Without this knowledge, how can doctors know whether a patient is likely to recover or whether it’s ethical to withdraw care? 

Covert consciousness includes not only locked-in syndrome, but also patients with damage to the cerebral cortex. In that instance, covert consciousness is harder to identify because the mental abilities these patients retain are likely impaired. For example, such a patient might be unresponsive not because she is unconscious, but because a lesion to her cerebral cortex has taken away her ability to understand spoken language. 

To detect covert consciousness in patients diagnosed with disorders of consciousness, an international team of researchers, including my current supervisor, Martin Monti, have used a clever task that exploits the mental imagery that some otherwise unresponsive patients can generate on command. The team wheeled 54 patients inside a brain scanner. [Not all at once, I hope !] There, the team imaged their brain function using functional MRI (fMRI) in order to deduce what fraction, if any, might be covertly conscious. 

Once inside the MRI machine, researchers asked unresponsive patients to imagine one of two tasks, playing tennis or walking around their house. Exactly how many patients would be responsive was anyone’s guess, Monti told me. But with the first swing of the racket, so to speak, the team found an otherwise unresponsive patient who appeared to understand the tennis task. The patient fulfilled all the criteria for a vegetative state diagnosis but was, in fact, conscious.

Hang on, how do you know they were conscious and not just responding to stimuli ? Did you test the same procedure on someone who was merely asleep ? Even that isn't going to help without a very clear definition of what you mean by "conscious" in the first place. Memory is hardly perfect when remembering dreams, so asking people when they regain normal consciousness isn't going to tell you much. So yes, you can monitor that the brain is doing something, but monitoring for an inner awareness, I suspect, is by definition impossible.

At least in the strictest sense. A more reasonable approach would be to compare the responses to people in all sorts of different states, especially those who are as awake as awake can be - at some point, it's sensible to concede that while we can't prove anyone else is conscious, we have to assume that they are. If if a supposedly unconscious person wakes up and says, "I remember you asked me that question about tennis", it's only reasonable to assume they were conscious. But still, that the brain processes the input "game of tennis" differently to "walking around a house", measured by means of a scanner, is a long way off concluding inner awareness. Plenty of everyday sensory input is processed subconsciously.

Alarmingly, one out of the five healthy volunteers who had undergone general anaesthesia for the sake of science using the drug propofol was able to do what shouldn’t be possible: generate mental imagery upon request in the scanner. The implications are clear: we aren’t necessarily blissfully unconscious when the surgeon puts us under.

But unless anaesthetic also blocks memory, that seems daft. Where are the hordes of people screaming about how they felt the incision of the scalpel ? Again, it seems more likely that they're just unconsciously processing input. There's no reason to assume they're aware of it. More reasonably :

Consciousness can also occur without language comprehension or hearing. In their absence, a patient might still experience pain, boredom or even silent dreams. Indeed, if only certain regions of the cerebral cortex were lesioned, vivid conscious experiences might persist while the patient remains unable to hear the questions asked by Monti’s team. Because of this, MRI scans might miss many people who are conscious, after all. Rather than depending on mental imagery that must be wilfully generated by brain-injured patients who can hear and understand language, an alternative marker of consciousness – a superior consciousness detector – is needed to shine a piercing light in the dark.

A large chunk of the rest of the article then gets quite dull, but it picks up again toward the end when it starts describing another possible gom jabbar :

Formally known as the perturbational complexity index, the technique is sometimes referred to as ‘zap-and-zip’ because it involves first zapping the brain with a magnetic pulse and then looking at how difficult the EEG response is to compress, or zip, as a measure of its complexity. Researchers have already used zap-and-zip to determine whether an individual is awake, deeply sleeping, under anaesthesia, or in a disorder of consciousness such as the vegetative state. Soon, the approach could tell us which unresponsive, brain-injured patients (not to mention patients anaesthetised for surgery) are covertly conscious: still feeling and experiencing, despite an inability to communicate. Indeed, this is the closest science has ever come to ‘quantifying the unquantifiable’.

Children with a rare genetic disorder called Angelman syndrome display electrical brain activity that lacks differentiation even when the kids are awake and experiencing the world around them. There’s no question that these children are conscious, as one clearly sees from watching their rich spectrum of purposeful behaviour. And yet, placing an EEG cap on the head of a child with Angelman syndrome reveals neurons that [unlike others] appear to be locked into agreement.

Which brings us back to the woman missing a big chunk of her brain. The adaptability of the brain to process and/or generate conscious thought is fascinating, but that would seem to make it inherently very difficult indeed to make a consciousness detector : never mind that animal brains may be different yet again.

To say what consciousness is, science explores where it isn't - Joel Frohlich | Aeon Essays

In 2014, a month-long bout of dizziness and vomiting brought a 24-year-old woman in China to the hospital. She was no stranger to these symptoms: she'd never been able to walk steadily and suffered from dizziness nearly her whole life.