The materialist "theory" of consciousness
(An improved and updated version of this material has appeared in my book Why Materialism Is Baloney. The version below is kept for legacy purposes.)
In a recent talk he gave at the 2011 Singularity Summit (see video above), neuroscientist Christof Koch, the world's leading consciousness researcher from a scientific perspective, has named Giulio Tononi's "theory" of consciousness as the best current attempt at a causal explanation for how consciousness emerges from the otherwise unconscious matter of the brain. This is significant, for it identifies the best line of argument available today in the current paradigm. Therefore, defeating this argument defeats the best that materialism currently has to offer as far as consciousness. In this article, I hope to raise significant doubts about whether Tononi's "theory" is a causal explanation for consciousness at all.
As one can see in his article, Tononi looks at the amount of information integrated by a given brain process (which he calls a "complex"). This amount is ultimately represented by a variable "phi," derived from the topology of the elements in the complex. When "phi" crosses a certain threshold, the complex is considered conscious, a correlation refined through empirical calibration. If this sounds somewhat arbitrary, it's because – at least in my opinion – it is, as I hope to explain below. In the video above, Koch provides a summary of Tononi's ideas, so here I will not elaborate further on it.
Now here is my critique: Tononi's "theory" explains consciousness no more than a speedometer explains how a car moves. In other words, it doesn't causally explain consciousness at all; it is merely a heuristic indicator for the presence of consciousness; an ad hoc rule-of-thumb, if you will. When the needle of your speedometer moves up, you know that your car is moving. But that needle movement gives you no insight into the fact that there is a combustion engine freeing up energy stored in the molecular bonds of hydrocarbons, thereby making such energy available for turning a crankshaft connected to the axis of the car's wheels, which in turn grip the irregularities of the road and, through Newton's third law of motion, cause the car to move. The latter would be a causal explanation, but Tononi's "theory" entails nothing analogous to it.
Let us look at another example of a true causal explanation to drive home what I am trying to say: the Krebs cycle of cellular respiration. This cycle is a full causal explanation for how energy is made available to an organism's cells. We know the inputs of the process: molecules of sugars and fats; we know the chemical reactions (oxidization) that progressively free up the energy stored in the molecular bonds of these sugar and fat molecules; we know in what form this energy becomes available to the cells (namely, ATP); we know where all of this takes place (in the mitochondria); and we know how the cells put the ATP to use. In other words, we have a closed and complete causal chain that permits us to infer the properties of the observed phenomenon (i.e. the ability of cells to perform work) from the properties of the inputs of the process (i.e. sugar and fat molecules, and cell structures like the mitochondria).
Tononi's "theory" does not offer us any such causal chain. It does not permit us to infer, not even in principle, the properties of the observed phenomenon (i.e. consciousness) from the properties of the inputs of the process (i.e. interconnected neurons). It only offers a heuristic correlation without a theoretical framework that allows us to understand where consciousness comes from, or why a certain level of information integration leads to such an extraordinary property as being conscious. Nearly all relevant questions remain unanswered by "phi," just like all relevant questions about how the car moves remain unanswered by the speedometer.
Tononi's "theory" does have practical applications. If it can, for instance, help us, on an heuristic basis, tell whether a patient in a vegetative state is actually conscious or not, it has great value to society. But this kind of pragmatic application should not be confused with an ontological explanation for the nature of consciousness. That a certain story is useful does not entail that it is true. It's useful to pretend that gravity is a force acting at a distance between two bodies; we've put a man on the moon by pretending just that. But that does not mean that such magical action-at-a-distance really exists, as Einstein showed (gravity, after all, is merely the effect of a curvature of space-time).
Materialism has consistently failed to give us a proper causal account for how consciousness emerges from matter. Koch's and Tononi's story, if anything, makes this painfully clear. Is it not time to look more broadly?
Important observation: This article should not be construed as an attempt to dismiss the value or importance of the work of either Christof Koch or Giulio Tononi. I deeply respect and applaud their courage in attempting to tackle the problem of consciousness from a strict, scientific perspective. Their courage has lacked in science for decades. However critical I may be of their progress or claims, whatever progress there is is to their credit. Besides the immense, potential practical applications of their work in medicine and psychiatry – which hold regardless of ontological interpretations – their efforts may be fundamental even in exhausting the current scientific paradigm; a necessary step before science can progress to a broader view of nature.