Chapter
Five
The theatre
in vision) or body map (as in somatosensation), and the construction of an
illusion of ‘unity’ in consciousness and self-awareness. Pennartz goes on to
identify neural candidates for carrying out these functions, including mech-
anisms for coordinating, binding, and stabilising, and for varying the phase
and rate of cell firing.
For Pennartz, the brain has to be understood as operating in a high-dimensional
space, with each sensory modality or submodality constituting an additional
dimension. But he does not quite manage to explain why the ‘representational
power’ of the brain, vast as it may be, should in itself have or yield a subjective
quality. He has to resort in the end to a distinction between ‘brain systems for
conscious versus unconscious representations’ (2015, p. 113, original italics) and
between the ‘neural relationships [that] give rise to’ one or other kind of represen-
tation (p. 288) – which means that even if the theatre no longer has a stage and a
spotlight, it still exists in a Cartesian materialist sense.
As Pennartz points out (2009, p. 733), his view of the importance of multidimen-
sional integration bears some resemblance to the cross-brain broadcasting of
information in GWT. In this sense, it also resembles what is currently probably the
most popular of all theories of consciousness, integrated information theory (IIT).
IIT was originally proposed by Giulio Tononi in 2004, building on his work with
Gerald Edelman (Tononi and Edelman, 1998), and has since been updated several
times (Tononi, 2015). The basic principle is that the more ‘integrated information’
there is in a physical system, the more conscious that system is, and the amount of
integrated information is measured by a mathematical variable, Φ (phi).
As with Baars’s theory, consciousness is a continuous variable: you can have differ-
ent amounts of it. In this case, the system becomes conscious (and has free will)
if it has a large value of Φ, and a system is more conscious the higher its Φ value.
The fact of having a large value of Φ can also help explain the specific qualities of
a given conscious experience compared to all the other possible ones: because
‘generating a large amount of integrated information entails having a highly
structured set of mechanisms that allow us to make many nested discriminations
(choices) as a single entity’ (Tononi, 2008, p. 224), we experience the red light not
simply as the opposite of no light, or of green, but as different from any other
possible experience we might have.
For IIT, ‘consciousness is integrated information’, and ‘its quality is given by the
informational relationships generated by a complex of elements’ (Tononi, 2008,
p. 217). This means that IIT need not posit a Cartesian theatre, because any part
of the nervous system can in theory contain integrated information. What hap-
pens to any informational relationships that exist outside the integrated system?
Tononi gives the examples of sensory afferents or cortico-cortical loops imple-
menting informationally insulated subroutines. These ‘do not make it into the
quale, and therefore do not contribute either to the quantity or to the quality
of consciousness’ (p. 229). This begs the now-familiar question of why it is that
integrated information should ‘make it into the quale’ (i.e. become conscious
experience) and other kinds not – or what a quale actually is, and how you get
inside one. So, we do have a theatre of sorts, even though it is the opposite of a
spatially localised one. We will come back to other implications and criticisms of
IIT in Chapter 6.