Do you know what sensations you’re having?

Last week, Matt Lieberman posted the video below on Twitter. (I believe it was originally posted on TikTok by the dancer featured in it.) The video illustrates change blindness. Large visual changes occur during the course of the video, which the viewer typically doesn’t notice. You may like to watch the video a few times and see if you notice the changes.

If you still haven’t noticed the changes, I’ll tell you. [Spoiler follows]

. . .

The colours of the dancers’ tops change markedly during the video. You can see the difference easily by jumping to different points in the video and noting the colours of the tops at each point.

You may be surprised that you missed such a large change, but it is not really surprising. Our visual systems are designed to keep track of things through changes in their appearance. Imagine you’re in a forest with a tiger stalking you. As the tiger moves in and out of the shade, the light reflected from its coat changes continually, but you need to ignore these changes and focus on what’s constant: the individual animal moving through the trees. And that is exactly what your brain does. In the case of the video, your brain accurately tracked the individual dancers, not confusing one with another, and it ignored changes in colour that were irrelevant to this task. Looked at in this way, change blindness is not a bug in our visual system but a feature, and we should expect it to occur all the time.

But this feature of vision presents a problem for a certain view of consciousness, which I’ll call the three-stage view. The view goes like this. Conscious perception proceeds in three stages. First, physical stimuli impact on our sense organs and produce neural activity in sensory processing regions of our brains. Second, this neural activity produces a visual sensation — a private mental quality which makes it like something to perceive the stimuli. Third, the sensation in turn produces reactions appropriate to its nature (unpleasant sensations cause us to shun the things generating them, pleasant sensations cause us to seek them out, etc). We react as we do because of what our experiences are like.

Now, when the colours changed without your noticing it, what happened at each of the three stages? There were certainly changes at the first stage. The light rays hitting your retina changed, and, presumably, at least some of the activity in your visual cortex did, too. There were no changes at the third stage, however — or at least no major ones. Maybe there were subtle changes in your behavioural dispositions that could be detected under experimental conditions. (I don’t know if this has been investigated; it would be an interesting project.) But your reactions did not change in a way that was noticeable either to you or to a casual observer.

What about the second stage? Did your visual sensations change? Was there a change in what the experience was like for you?

If there wasn’t, then the three-stage view is undermined. For it says that our reactions are produced by our sensations; we react as if there is something green in front of us because we are having a sensation of green. But if we don’t have such a sensation until we react, then the sensation can’t be playing this role. Indeed, it not clear why we would need sensations at all, since the reactions occur without them.

So a defender of the three-stage view must say that our sensations change before we react. They can then continue to claim that when we do react we are reacting to a change in our sensations, albeit after a delay.

But this has a strange consequence. It means that we can be mistaken about our own current sensations. At the mid-point of the video, you thought you were having the same colour sensations as at the start, but you were in fact having different ones. And does that even make sense? Your sensations are supposed to define how things seem to you, and while you may be wrong about what colour something is, you can’t be wrong what colour it seems to be.

That’s not all. If you can fail to notice your sensations changing, then maybe you could fail to notice them fading out altogether. Maybe your sensations faded out an hour ago, and you haven’t noticed yet. You’ve continued to react as if they hadn’t faded out, of course, but during the video you continued to react as if your colour sensations hadn’t changed. Maybe you’ve never had colour sensations at all. Maybe you’re just reacting as if you have them. How do you know? All you can be sure of is what you think about your sensations. Maybe sensations are a sort of illusion.

A confession

I have a confession to make. I often fail to reply to people who email or message me with invitations, requests, and questions. I have an excuse, of sorts. I have many demands on my time and haven’t been in the best of health. But I feel guilty about it.

I am particularly bad at replying to messages that pose philosophical questions. Replying to such a message takes time and thought — especially if the question is a good one — and I often put it off, though fully intending to reply at some point. And then, of course, more messages come in, and my to-reply list grows longer and longer. The senders must think I am just ignoring them.

Why don’t I at least send a short acknowledgement, saying that I have received the message and will reply if and when I have time? I have thought of doing this, but the danger is that it would make me even less likely to write a full reply. Having sent the acknowledgement, I might feel that I’d dealt with the matter and could forget it. By contrast, If I don’t reply at all I feel guilty, and the guilt does sometimes push me to reply properly.

So here’s a message to anyone who has written to me and not received a reply:

First, I am sorry; please accept my apologies.

Second, please don’t think that I felt your message wasn’t worth a reply. The chances are it was just the opposite: I felt that it deserved a long and careful reply, which I just didn’t have time to write.

Third, please feel free to re-send your message. I won’t be annoyed and will reply eventually!

Zac’s disappearing nonconsciousness

Clive Wearing is a former musicologist and musician who has chronic amnesia, both anterograde and retrograde. He can’t form new memories or retrieve old ones. Although he is fully conscious, Clive lives trapped in a perpetual present, with no awareness of his own past (according to Wikipedia his episodic memory has a capacity of only 30 seconds). He continually feels that he has just emerged from a long period of unconsciousness, and in his diary he repeatedly affirms that he is now at last awake, scoring out earlier entries which affirmed the same and which now mean nothing to him:

8:31 AM: Now I am really, completely awake.
9:06 AM: Now I am perfectly, overwhelmingly awake.
9:34 AM: Now I am superlatively, actually awake.

Clive’s condition is a personal tragedy for him and his loved ones, but it is a also a fascinating psychological case study, and I want to take it as the basis for a philosophical thought experiment. I hope this does not suggest any disrespect to Clive or his family. I certainly intend none.

Clive suffers from what we might call disappearing consciousness. At every waking moment he is fully conscious, but those conscious moments rapidly pass into oblivion, and Clive’s conscious life has a brief temporal extension. We can imagine his memory span reducing further — to twenty seconds, ten, one, less — until his conscious life is the merest flicker in an otherwise dark existence.

I want to imagine someone who is the inverse of Clive — someone who suffers from disappearing nonconsciousness. Consider Zac. Zac has suffered an illness which has left him a zombie in the philosopher’s sense. His brain functions exactly as it did before, taking in the same range of sensory information and using it to produce responses just like those of a fully conscious person. He can give detailed reports on the world around him and his own bodily condition, noticing everything a fully conscious person would. However, his brain no longer produces any subjective experience — his mental states no longer have any phenomenal feel to them, no ‘what-it-is-likeness’. The inner light of phenomenal consciousness has gone out, and Zac experiences the world unconsciously. Given the standard way of thinking of consciousness, this should be at least conceivable.

There is a twist, however. Zac is not a complete zombie. Unlike other philosophical zombies, he is aware that he is not phenomenally conscious. So when he describes the visual scene before him, he adds that he isn’t really seeing it. He knows what the world is like, but his experience is not like anything. If zombies are conceivable, then a partial zombie like Zac should be, too. (I have borrowed the notion of a partial zombie from Allin Cottrell, who uses it to question the conceivability of zombies. See his excellent paper ‘Sniffing the Camembert’.)

Zac’s lack of phenomenal consciousness troubles him, and he repeatedly notes it in his diary. (He can write perfectly well, of course, and is aware of what he is writing, though the experience of writing is not like anything for him.)

8:31 AM: Now I am really, completely unconscious.

So Zac is unlike Clive in not being conscious. He is unlike Clive in another way, too. Whereas Clive’s brain fails to record memories of being conscious, Zac’s brain keeps fabricating them. When it forms episodic memories of scenes and events, it tags them as having been experienced in the normal way, just as they were before Zac’s illness. So although Zac experiences the world unconsciously, he remembers it has having been experienced consciously.

The upshot is that Zac suffers from the opposite delusion to Clive. Whereas Clive continually feels that he is waking up into consciousness and denies his past consciousness, so Zac continually feels that he losing consciousness and denies his past nonconsciousness:

8:31 AM: Now I am really, completely unconscious.
9:06 AM: Now I am totally, overwhelmingly unconscious.

9:34 AM: Now I am fully, actually unconscious.

And as the latency period between experience and memory shrinks, Zac’s sense of nonconsciousness shrinks too, until it is a mere flicker of darkness in an otherwise illuminated life.

What is the moral of this? The obvious one is that even if our experiences do have a subjective phenomenal feel to them, this feel may play little or no role in generating our sense of being conscious — of its being like something to be us. So maybe consciousness doesn’t have much to do with phenomenal feel after all.

Designed for destruction?

Suppose that our universe is intrinsically special in a way that it would not have been if the physical constants had taken other possible values. (As I argued in this previous post, it’s important that it be intrinsically special, not just special in the eyes of the creatures who inhabit it.) Then this would seem to raise the credence we should give to the hypothesis that the constants were not randomly set but shaped by a purposive agency of some kind, which sought to produce a universe with this special feature. For the sake of argument, let’s grant that it does.

So is our universe intrinsically special? What might be the special-making feature be? An obvious candidate is life. Life looks pretty special, perhaps even intrinsically valuable. Now, I’m not convinced that life is intrinsically valuable in the relevant sense. (We often treat it as intrinsically valuable, of course, and it’s right that we do, but that’s another matter.) But let’s concede it. And life certainly could not have existed if the physical constants had not been within a vary small range. So we have an argument that a life-seeking agency shaped our universe to enable to it to support life. Cool!

But wait a minute! Our universe’s physical laws and constants may allow life to emerge, but they also condemn life to complete annihilation. The second law of thermodynamics secures that. The relentless growth of entropy, which actually drives the local development of complexity, will eventually dismantle all complexity, leaving the universe a cold, dead realm of undifferentiated low-energy soup. This doesn’t look like something a life-seeking agency would build in. If we were designing a giant spaceship to carry humanity to a new star system, we wouldn’t build in a self-destruct mechanism set to trigger automatically halfway through the voyage.

In fact, a more plausible hypothesis is that the special making feature is the destruction of life, and that the agency that shaped the constants was seeking this goal — an inference not dissimilar to that drawn by Gloucester in King Lear:

As flies to wanton boys are we to th’ gods,
They kill us for their sport.

A defender of the life-agency hypothesis might reply that the agency could only do so much. It could tweak the physical constants but couldn’t change the second law. But what reason do we have to think that? We know nothing of this agency and the constraints under which it operated. (Unless of course, we think that revealed religion provides such information.) The agency has been introduced simply in order to explain why the universe supports life on the assumption that life is what makes this universe intrinsically special. If the universe is not really so special in the life department, then we can’t save the life-agency hypothesis by saying that the life agency did its best. It’s begging the question. We need to identity the special-making feature independently of the process posited to explain it.

Notes on emergence

Last April, Bryce Huebner and I had a Twitter exchange about emergence in biology. I felt that we were talking past each other and tried to work out how it had happened. I suspected that it was due to the way the concept of emergence had been used in different traditions, and I sketched the following tentative history. (I should stress that this is speculative; I’m not a historian.)

1. Late 19th – early 20th century: Some British philosophers (Broad, Lloyd Morgan, Alexander) started using ’emergentism’ to describe a metaphysical view on which the world is radically layered, with new fundamental properties and powers spontaneously appearing at each level, building up to the mental.

2. Mid 20th century: That kind of emergentism was empirically falsified, and philosophers rejected it. However, dualist philosophers continued to claim that some mental properties and powers are fundamental, emerge spontaneously, and exert a ‘top-down’ influence on the physical world, causing particles to behave in ways that physics alone could not predict.

3.Late 20th century: Scientists adopted the term ’emergence’, ignoring its metaphysical baggage and using it in a different sense to characterize global features of complex systems, especially self-sustaining ones. Confusingly, these scientists often spoke of these global features as exhibiting a ‘top-down’ causal influence — meaning that the components of complex systems are causally sensitive to global conditions, not that global features appear spontaneously and exert a fundamental causal influence on the physical world, additional to that of the components.

5. Late 20th – early 21st century: To capture the difference between the philosophical and scientific uses, philosophers drew a distinction between strong and weak emergence. However, they tended to define weak emergence in terms of deducibility and denial of ‘top-down’ influences, which made scientists think that that ‘weak’ emergentists denied the kind of global influences they needed to talk about.

6. Same time: Some dualist philosophers seized on this, claiming that scientists themselves were now talking of strong (spontaneous, fundamental) emergence. If strongly emergent features are common in the natural world, then why shouldn’t aspects of the mind be strongly emergent? Science vindicates dualism!

7. April 2021: Bryce and Keith talk past each other, Bryce adopting the scientific use, Keith the philosophical one.

At the time, Bryce and I talked of writing this up as a short paper, which we may still do. Meanwhile, if anyone has any comments, I’d be grateful for them. Comments from historians of science and philosophy would be particularly welcome!

Nostos 2024

I want to suggest a project: Nostos 2024. ‘Nostos’ is the ancient Greek word for a voyage home, and the project I suggest is that the Parthenon marbles, removed from the Athenian Acropolis by agents of Lord Elgin in the early nineteenth century and currently housed in the British Museum in London, should complete their long-delayed voyage home to Athens before the end of the year 2024.

Why should the marbles go home? This hardly needs asking. Elgin took them without clear permission from the Ottoman Empire, which then ruled Greek lands, and certainly without permission from the subject Greek people. Even at the time, their removal was controversial, and the Greek state has been campaigning for their return since its foundation in 1832.

Today, their retention in London is indefensible, morally and aesthetically, if not legally. They were designed to be part of the Acropolis complex and belong with the other remaining Parthenon sculptures in the Acropolis Museum, which has been specially designed to exhibit them. Many organizations campaign for the return, working under the aegis of the International Association for the Reunification of the Parthenon Sculptures, and UNESCO has recently called on Britain to hand them back.

Why 2024? Because it’s the bicentenary of the death of Lord Byron. Byron was a passionate philehellene who sold his estate in England to fund the cause of Greek independence and travelled to Greece to help lead the fight. It was there that he died on 19 April 1824.

Byron had condemned Elgin’s removal of the marbles in his poems, ‘The Curse of Minerva’ and ‘Childe Harold’s Pilgrimage’, writing this of Elgin and his men:

Curst be the hour when their isle they roved,
And once again thy hapless bosom gored,
And snatched thy shrinking Gods to northern climes abhorrd!
–Childe Harold’s Pilgrimage, Canto II, Stanza XV

The British will want to celebrate the bicentenary of the death of one of their greatest poets, and I can think of no finer or more appropriate tribute than the righting of this wrong done by his countrymen to a country he loved. If we could ask him what memorial he would like, I have no doubt he would choose this one.

Statue of Lord Byron in Athens, Greece.

Statue by Alexandre Falguière showing Greece as a female figure crowning Lord Byron.

It would be a generous, noble gesture, befitting Byron, and would reaffirm the long-standing bonds of friendship between Britain and Greece.

I know it’s presumptuous of me to ‘suggest’ this, as if no one else had thought of it. There are many people working hard for the return of the marbles, and doubtless others have made the connection with Byron’s bicentenary. But I wanted to add my voice and propose Nostos 2024 as a watchword.

Φέτος

Φέτος πήρα την ελληνική υπηκοότητα. (Δεν λέω ιθαγένεια αφού αυτή η λέξη σημαίνει κάτι πιο σύνθετο.) Μπορώ όμως να πω ότι πλέον είμαι Έλληνας και το λέω με μεγάλη περηφάνια. Είναι μεγάλη τιμή να ανήκεις σε αυτό το έθνος, με ιστορία υψηλού πολιτισμού και βαθύ αγώνα. Μα είναι ακόμη μεγαλύτερη τιμή να πάρεις υπηκοότητα τη χρονιά που γιορτάζουμε την επέτειο των διακοσίων χρόνων από την Ελληνική Επανάσταση. Ευχαριστώ όλη την οικογένεια μου και όλους τους φίλους μου που με καλωσόρισαν στη χώρα τους και λέω σε όλους τους Έλληνες πόσο περήφανος είμαι που είμαι συμπολίτης τους.
Σας ευχαριστώ και εύχομαι τα καλύτερα σε όλους.
–Κηθ

Mezedes

Where to find the best mutton soup, mascarpone torte and anise-flavoured spirit in Crete.

Children, education, and open doors: Some Ancient Greek proverbs.

‘My father always hoped that Gerry and I would marry.’

3,000-year-old Olive tree on the island of crete still produces olives today.

Greek center shelters orphaned bear cubs.

Greece allows gay couples to foster children.

Ashes from Santorini’s Minoan eruption found in Smyrna excavation.

Illusionism cover image

Front cover of Illusionism book

The cover image for my 2017 book Illusionism as a Theory of Consciousness is a painting of a rather flamboyant stage magician performing a variety of tricks simultaneously. I found the image on Wikimedia and thought it was an appropriate visual metaphor for the theory discussed in the book. But who was this magician? Wikimedia says only this about the image:

Zan Zig performing with rabbit and roses, including hat trick and levitation. Advertising poster for the magician (who seems to have left no other trace behind).

Could it be Julius Zancig? It seemed unlikely to me, given the description of Julius’s act, which he performed with his wife Anges. I put a message on my website asking if anyone could find out more.

In 2020, Jeff Miner (a former student of Kent Bach at SFSU, now working in tech) contacted me to say that he’d done some research on the image, which he has kindly given me permission to share. Jeff wrote:

I asked around and crowd-sourced a bit.

It looks as though he was a magician (possibly from the Cincinnati area) who named himself in such a way as to be confused with Zancig.

There’s a second lithograph of him at the LoC.

This response I got seems the most complete:

It was fairly common for second and third rank magicians to use names that resembled those of first-rank magicians (e.g. Hoodini, Howdini, Houdyni, etc.). The Zancigs, (Agnes and Julius) toured with a two-person telepathy (second sight) act. They didn’t do bunnies, doves and goldfish. It’s possible there was a fellow who called himself “Zan Zig” in hopes that people would think they were seeing the Zancigs.

Since the US Copyright Office is part of the Library of Congress, and since this lithograph was copyrighted, I expect the LOC got the name from the copyright registration. Librarians are pretty good about researching items in their collections, and the LOC librarians are some of the best in the world.

As to who “Zan Zig” might have been, at least on the Google-Indexed Web all hits on “Zan Zig” are to this picture (or the second lithograph also at the LOC showing a fellow who looks like the same guy doing four different illusions.) The fellow top left in that second lithograph is the standard stage version of Mephistopheles from Faust.

Doing a search in The New York Clipper and the New York Dramatic Mirror for the year 1899 might reveal more, or maybe not if this fellow was a local Cincinnati magician.

In a second email, Jeff forwarded further information from one of his correspondents:

There was a magician of this period named “Zanzic,” He was referred to in Leaves From Conjuror’s Scrapbooks, with this paragraph:

Another magician by the name of Robinson has been traveling in the Western States for the past few years, but is going under the professional name of Zanzic. Being a clever performer, it would seem he ought to have originated a more healthful-sounding name, which is “sick’led o’er with a pale cast of thought.”

There is quite a bit more about him in Jim Steinmeyer’s book The Glorious Deception, pages 135-138. The first paragraph there reads:

Zanzic was a tall, slender, dark-haired magician. His real name was Robertson or Brenner, and he also worked under the name Henry Andre. Zanzic had been born in New Orleans, the son of a Creole fortune-teller. He was six years younger than Will [Robinson], an old friend from the days when they were both starting out in magic and used to meet at Martinka’s shop. His associates thought of Zanzic as unstable: accident-prone and filled with half-baked schemes. He certainly had the skill to be a good magician. But for Zanzic, the adrenaline of a performance was like a strange, addictive sort of poison that made him giddy and stupid.

In short, the illustration is of a hyperactive magician who was hoping to deceive people about his very identity. I think that makes it even more appropriate for a book about the addictive self-illusions our brains create.

The title of this blog

The title of this blog, Tricks of Mind, reflects the role that notions of illusion and artifice play in my view of the human mind. We humans have learned a variety of subtle but powerful tricks — strategies of self-control, self-manipulation, and extended problem-solving — which vastly extend the power of our biological brains and give us the sense of having a unified, phenomenally conscious mind, self, or soul. The conscious mind is a virtual system, constituted by these activities. It is, in a sense, a trick of the biological mind.