Objective subjectivity: Giulio Tononi’s Integrated Information Theory of Consciousness

this paper was written for Joy Laine’s philosophy of mind class at Macalester College during the fall of 2014. it describes one of the most exciting new theories about consciousness, which comes straight out of my home town of Madison, WI!

Philosophy has offered many interesting opinions and insights about consciousness, but does anybody really know what it is? Humankind’s empirical understanding of the universe and how we arrived here has increased in the last several centuries. Modern science has made some advances in helping us understand fundamental physical laws and neuroscience research is perhaps the next frontier in tackling the mystery of individual selfhood. In our day and age there seems to be a general consensus that private mental phenomena and their associated brain activity are well connected, but it remains an embarrassing mystery how exactly they contribute and relate to one another. Despite plenty of factual information and data about neural correlates of consciousness it remains that without a theoretical knowledge system or ontology our subjective selfhood will continue to be the most intractable phenomenon that anyone has attempted to describe. What objective knowledge system might account for the mystery of our daily consciousness? In some sense the question becomes: how can subjective information be characterized objectively?

            Giulio Tononi is a psychiatrist and researcher at the University of Wisconsin-Madison who has proposed a bold and unique hypothesis about the nature of inner subjectivity. This “integrated information” theory of consciousness draws on Tononi’s sleep research, some thought experiments, and a robust mathematical framework to assert that inner subjectivity consists of quantifiable experiences that are generated by a set of informational relationships in a complex of elements (Tononi, 2008). The scope of this project is impressive, drawing on phenomenology, neuroscience and physics to try to make fundamental claims about consciousness. Tononi has released two accounts of IIT that are worth mentioning. The first is a very technical and scientifically rigorous paper called Consciousness as Integrated Information: A Provisional Manifesto. This work was published in 2008 and is a patchwork of philosophy, science, and mathematics.

We see in the introduction of his paper some of the problems associated with consciousness research, if there is such a thing:

“How much consciousness is there during sleepwalking or psychomotor seizures? Are newborn babies conscious, and to what extent? Are animals conscious? If so, are some animals more conscious than others? Can they feel pain? Does a bat feel space the same way we do? Can bees experience colors, or merely react to them? Can a conscious artifact be constructed with non-neural ingredients? I believe it is fair to say that no consciousness expert, if there is such a job description, can be confident about the correct answer to such questions. This is a remarkable state of affairs. Just consider comparable questions in physics: Do stars have mass? Do atoms? How many different kinds of atoms and elementary particles are there, and of what are they made? Is energy conserved? And how can it be measured? Or consider biology: What are species, and how do they evolve? How are traits inherited? How do organisms develop? How is energy produced from nutrients? How does echolocation work in bats? How do bees distinguish among colors? And so on. Obviously, we expect satisfactory answers by any competent physicist and biologist.” (Tononi, p. 217)

With all of these mysteries as a starting point Dr. Tononi uses thought experiments to formulate his argument about what consciousness is and how it arises from the natural world. Consider a photodiode. Both a photodiode and a human being are capable of indicating whether or not a nearby screen is lit. What’s the importance of this observation?

“The first problem of consciousness reduces to this: when you distinguish between the screen being on or off, you have the subjective experience of seeing light or dark. The photodiode can also distinguish between the screen being on or off, but presumably it does not have a subjective experience of light and dark. What is the key difference between you and the photodiode?” (Tononi, p. 217)

To Dr. Tononi, the difference is quantity and quality of information. Using a classical definition of information as reduction of uncertainty (and a “logarithmic entropy function”) he suggests that there is at most one bit of information represented in the photodiode at the moment it makes its decision (because there are only two possible states). A simple binary decision informs the photodiode, whereas we know that a rich subjective experience would and does inform the human decision. In other words, we as human beings are able to distinguish between many other possible states besides “light” or “dark” whereas the photodiode can’t. The question is why this is important. Tononi seems to think that it’s obvious that there is more experience contained within the subjective experiences of our day-to-day lives and that the way this information becomes subjectively charged is the means by which it is integrated. Having started by defining consciousness Tononi seems to have subsequently given himself a means to describe how it arises. That is the main argument of Tononi’s manifesto: that integration of information arranged in certain complexes (such as in the human brain) produce consciousness. The paper is very technical. The second notable work by Dr. Tononi about IIT is a book released for general audiences called Phi: A Voyage From The Brain to the Soul. 

A rather unique book, Phi straddles questions of metaphysical anxiety, scientific uncertainty, and philosophy with a clear and vibrant mysticism. It is written in the form of a dreaming Galileo, who encounters scientists and thinkers of the future (some of whom come from our modern day neuroscience laboratories). Step by step these strange time travelers inform Galileo of what has been discovered about the brain and mind in their time. As the dream progresses the reader’s conception of what consciousness fundamentally is becomes guided through the stages of Tononi’s argument and thought experiments that were also present in his manifesto. The difference between the book and his original paper is that subtle narrative reference and free-flowing dialogues carry the book along in lieu of the manifesto’s unintelligible equations and mathematics. One of my personal opinions about the book was that it was enormously creative and that its execution was brilliant. Some of the thought experiments and their descriptions were rambling and unnecessary for the progression of the argument, though.

There are strengths and weaknesses to the theory and much time could be spent on both of them. For convenience I will only mention one of each in this paper. First, let’s consider a unique technological advancement Tononi’s theory has been affiliated with. In medical situations it is common practice to attach electrodes to a patient’s head and measure the electrical activity on their scalp to get some indication of their brain activity. The correct interpretation of this information can offer clues as to whether or not the individual is having any significant brain activity or not. With a higher degree of understanding experts hope to be able to ascertain an exact level of consciousness via this method – with the help of Dr. Tononi’s IIT. This includes scenarios where a family may want to know if a loved one is in a coma or simply paralyzed, or if a surgical patient’s general anesthesia has successfully rendered them unconscious. Even though this is a long-standing practice, much improvement stands to be made in the technology. Tononi and a colleague have created a device that allows them to do this and hope to continue developing it (Lang, 2013).

Of the less believable repercussions of consciousness as integrated information include the possibility that the entire universe has a degree of consciousness. A complex capable of generating sufficient phi (“consciousness”) to register a private, inner “me” feeling certainly happens in our own brains. What else generates a feeling of having a self? One of the mathematical predictions of the current model of IIT suggests that even individual hydrogen atoms have a certain level of consciousness. This seems counter-intuitive: could it really be the case that every single atom is buzzing around with a tiny level of consciousness, and that certain weird configurations of matter are more conscious than others?

Galen Strawson is another current thinker who has written on the possibility of the universe being conscious. He may come to Tononi’s defense on this topic. An essay of his titled Realistic Monism: Why Physicalism Entails Panpsychism offers a rejection of traditional Cartesian opposites that has become rather familiar in our course this semester. The argument for his form of monism – more aptly called his ?-ism (Strawson, 2006) – is long and complex. The realest thing to Strawson is immediate conscious experience, and so whatever we call it – physical or mental – is what exists in his view. He insists repeatedly that to define reality in any particular terms is to simply affix some type of language pattern onto whatever we really know to be real, those being spatio-temporally located events. As long as we are being honest with ourselves, says Strawson, we must accept that consciousness at some level emerges from the universe. So it seems plausible in Strawson’s system to admit that there may be some type of phi value in all microscopic complexes, though a closer read of Tononi’s opinions suggests he himself may not even believe this.


Lang, Joshua. “Awakening.” The Atlantic. 2 Jan. 2013. Web. Nov. 2014. <http://m.theatlantic.com/magazine/archive/2013/01/awakening/309188/&gt;

Strawson, Galen. “Realistic Monism: Why Physicalism entails Panpsychism.” Oxford: Clarendon Press, 2006. Web. http://www.academia.edu/5488726/Realistic_monism_why_physicalism_entails_panpsychism_Appendix_2006

Tononi, Giulio. “Consciousness as Integrated Information: A Provisional Manifesto.” The Biological Bulletin 215.3 (2008): 216-42. Consciousness as Integrated Information (full text). Bio. Bulletin. Web. <http://www.biolbull.org/content/215/3/216.full&gt;

Tononi, Giulio. Phi: A Voyage from the Brain to the Soul. New York: Pantheon, 2012. Print.