Tag Archives: Integrated Information

Is Consciousness Required for Discrimination?

In their book A Universe of Consciousness, Edelman and Tononi use the example of a photodiode discriminating light to illustrate the problem of consciousness:

Consider a simple physical device, such as a photodiode, that can differentiate between light and dark and provide an audible output. Let us then consider a conscious human being performing the same task and then giving a verbal report. The problem of consciousness can now be posed in elementary terms: Why should the simple differentiation between light and dark performed by the human being be associated with and, indeed, require conscious experience, while that performed by the photodiode presumably does not? (p. 17)

Does discrimination of a stimulus from a background “require conscious experience”? I don’t see why it would. This seems like something the unconscious mind could do all on its own and indeed is doing all the time. But it comes down to how we are defining “consciousness”. If we are talking about consciousness as subjective experience, the question is: does discrimination require there be something-it-is-like for the brain to perform that discrimination? Perhaps. But I also don’t know how to answer that question empirically given the subjective nature of experience and the sheer difficulty of building an objective consciousness-meter.

On the other hand, assume by “consciousness” we mean something like System II style cognition i.e. slow, deliberate, conscious, introspective thinking. On this view of consciousness, consciousness is but the tip of the iceberg when it comes to cognitive processing so it would be absurd to say that the 99% unconscious mind is incapable of doing discrimination. This is the lesson of Oswald Külpe and the Würzburg school of imageless thought. They asked trained introspectors from the Wundtian tradition to make a discrimination between two weights with their hands, to see if one weight is heavier than the other. Then the subjects were asked to introspect and see if they were aware of the process of discrimination. To their surprise, there were no conscious images associated with the weight-discrimination. They simply held the weights in their hand, consciously made an intention to discriminate, the discrimination happened unconsciously, and then they were aware of the results of the unconscious judgment. Hence, Külpe and the Würzburg school discovered a whole class of “imageless thought” i.e. thought that happens beneath the level of conscious awareness.

Of course, the Würzburg school wasn’t talking about consciousness in terms of subjective qualia. They were talking about consciousness in terms of what’s introspectable. If you can’t introspect a thought process in your mind then it’s unconscious. On this view and in conjunction with evolutionary models of introspection it seems clear that a great deal of discriminations are happening beneath the surface of conscious awareness. This is how I prefer to talk about consciousness: in terms of System II-style introspection where consciousness is but the tip of a great cognitive iceberg. On Edelman and Tononi’s view, consciousness occurs anytime there is information integration. On my view information integration can occur unconsciously and indeed most if not all non-human animal life is unconscious. Human style slow deliberate introspective conscious reflection is rare in the animal kingdom even if during the normal human waking life it is constantly running, overlapping and integrating with the iceberg of unconsciousness so as to give an illusion of cognitive unity. It seems as if consciousness is everywhere all the time and that there is very little unconscious activity. But as Julian Jaynes once said, we cannot be conscious of what we are not conscious of, and so consciousness seems pervasive in our mental life when in fact it is not.

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Book review: Giulio Tononi's Phi: A Voyage from the Brain to the Soul

Phi is easily the most unusual book on consciousness I have read in awhile. It’s hard to describe, but Tononi makes his case for “integrated information” using poetry, art, metaphor, and fiction. Each chapter is a fictional vignette or dialogue between characters inspired by famous scientists like Galileo, Darwin, or Francis Crick. At the end of every chapter is a “note” written in normal academic language explaining the context of the stories. On just about every page there are huge full-color glossy pictures of famous art. The book is simply beautiful as a physical object in an attempt, I suspect, to convince qualiaphiles that Tononi is “one of them”.

The theory of integrated information itself, however, is less appealing.  Here is how integrated information is defined:

Integrated information measures how much can be distinguished by the whole above and beyond its parts, and Phi is its symbol. A complex is where  Phi reaches its maximum, and therein lives one consciousness- a single entity of experience.

And with that Tononi hopes the “hard” problem of consciousness is solved. However, the intellectual weight of Phi  rests on a thought experiment involving a photodiode. A photodiode discriminates between light and no light. But does the photodiode see the light? Does it experience the light? Most people would think no. But the photodiode does integrate information (1 bit to be precise) and therefore, according to the theory of integrated information, has some experience, however dim. The theory of integrated information is therefore a modern form of panpsychism based on the informational axiom of “it from bit”. For obvious reasons Tononi downplays the panpsychist implications of his theory, but he does admit it. Consider this quote:

“Compared to [a camera], even a photodiode is richer, it owns a wisp of consciousness, the dimmest of experiences, one bit, because each of its states is one of two, not one of trillions” (p. 162)

The reason the camera is not rich is because it can be broken down into a million individual photodiodes. According to Tononi, the reason why the camera has a low level of  Phi compared to a brain is that the brain integrates information between all its specialized processors and the camera does not. But nevertheless, each photodiode has a “wisp of consciousness”.

Tononi also uses a thought experiment involving a “qualiascope”, a hypothetical device that measures integrated information and can therefore be used to detect consciousness in the world around us. In the vignettes, Tononi writes that when you use the qualiascope:

“‘You’ll look in vain at rocks and rivers, clouds and mountains,’ said the old woman. ‘The highest peak is small when you compare it to the tiny moth'” (p. 222).

This is how he downplays his panpsychism. Notice how he doesn’t say that rocks and clouds  altogether lack consciousness. It’s just that their “highest peak” of  Phi is low compared to a moth. The important part however is that the  Phi of rocks and clouds is low but not nonexistent.

Why is this important? Because Tononi wants to have his cake and eat it too. To see why just look at some of his chapter subtitles:

Chapter 3 “In which is shown that the corticothalamic system generates consciousness”
Chapter 4 “In which is shown that the cerebellum, while having more neurons than the cerebrum, does not generate consciousness.”

 This is because Tononi admires the Neural Correlates of Consciousness methodology founded by none other than Francis Crick, who has a strong intellectual presence throughout the book. According to most NCC approaches, consciousness seems to depend on “corticothamalic” loops and not just specialized processors alone (like the cerebellum).This finding comes from research correlating behavioral reports of consciousness with activity of the brain. When most people report being conscious, higher-order system loops are activated. And in monkey experiments the “report” is a judgement about whether they see a stimulus, which can be made by pressing a lever. What they find in the NCC approach is that consciousness seems to depend on more than just specialized processors operating alone. It requires a kind of globalized network of communicating modules to “generate” consciousness.

It should now be plain as day why Tononi is inconsistent in trying to have his cake and eat it too. If a lowly inorganic photodiode has a “wisp of consciousness”, then clearly, by any standard, a single neuron also has a wisp of consciousness, as well as the entire cerebellum. Tononi acknowledges this:

“Perhaps a whiff of consciousness still breathes inside your sleeping brain but is so feeble that with discretion it makes itself unnoticed. Perhaps inside your brain asleep the repertoire is so reduced that it’s no richer than in a waking ant, or not by much. Your sleeping  Phi would be much less than when your brain is fast awake, but still not nil” (p. 275).

“Early on, an embryo’s consciousness – the value of its  Phi – may be less than a fly’s. The shapes of its qualia will be less formed than its unformed body, and less human than that: featureless, undistinguished, undifferentiated lumps that do not bear the shape of sight and sound and smell” (p. 281)

” Phi may be low for individual neurons” (p. 344)

But if a single neuron has a wisp of consciousness, then clearly consciousness is not “generated” by the corticothalamic system. It is instead a fundamental property of matter itself. It from bit. What Tononi means to say with his chapter subtitles is that “The corticothalamic system generates the right amount of  Phi to make consciousness interesting and precious to humans”. The difference between the photodiode and the corticothalamic system is a difference of degree. The corticothalamic system has a high enough level  Phi such that it makes an interesting difference to human experience such that we can report or notice it, distinguishing coma patients (very low  Phi) from awake alert adults (very high  Phi).

But now there is an interesting tension in Tononi’s theory. If there is a low but nonnegligible amount  of  Phi in a human embryo, Tononi’s theory must now figure out how to make a cut-off point between the lowest amount of  Phi we actually care about so we can figure out when to stop giving people abortions. Until Tononi answers that question, his “solution” to the hard problem of consciousness is fairly disappointing. He came up with this notion of integrated information to explain qualia, but now we are faced with the difficult question of “How much  Phi is necessary for us to care about?” Clearly no one really cares about the “wisp of consciousness” in a photodiode. So having solved the “hard” problem of qualia, Tononi just creates an equally difficult problem: how to figure out the amount of  Phi worth caring about from a moral perspective. And he plainly admits he hasn’t solved these problems.

But for me this is a huge problem. You can’t have your cake and eat it to if you are a panpsychist. You can’t say that photodiodes are conscious but then say the only interesting consciousness is that of corticothalamic systems. This seems rather ad hoc to me; a solution meant to fit into prexisting research trends. If you are a panpsychist you should embrace the radical conclusion. According to  Phi theory, Consciousness is everywhere. It is not “generated” in the brain. It only reaches a high level of  Phi in the brain. And if that’s the case, then the entire methodology of NCC is mistaken. NCC is not a true NCC but rather the “Neural Correlates of the Amount of Consciousness Humans Actually Care About”.

Overall conclusion: Phi is an interesting book and worth borrowing from the library. But I wouldn’t say it adequately solves the hard problem of consciousness. Not even close. What it does is arbitrarily stipulate criteria for pointing out consciousness in nonhuman entities. But Tononi never makes a real argument beyond appeals to intuition for why we should accept a definition of consciousness such that the ascriptions come out with photodiodes having a “wisp” of consciousness. I think most people will want to define stipulation criteria such that the ascriptions come out with only biological creatures having consciousness. Panpsychism is just too radical for most. So while I applaud Tononi for exploring this ancient idea from a modern perspective, I ultimately think that when people truly understand that Tononi is a panpsychist they will be less attracted to it despite its close relationship to Francis Crick and the wildly popular NCC approach.

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