- seCtIon tWo: tHe BRAIn
is’ (in Blackmore, 2005, p. 54). Similarly with sound and heat. Even though it seems
difficult for us now, he – like David Papineau, whom we heard from in Chapter 2 –
thinks that in time we’ll come to accept that to have a sensation of red
is to have all of your three kinds of opponent processing cells showing a
certain pattern of relative stimulation. [. . .] The pattern of activation for
red will be, say, 50%, 90%, 50%, across the three kinds of cells.
(2005, p. 55)
There is no need for any theatre imagery here, and the problem of subjectivity is
dealt with by claiming identity between neural processes and subjective expe-
riences. There remains a problem with our driving example, though, because
presumably the driver attending to the road and the distracted driver who still
stopped at the red light would both have had the right proportions of opponent
processing cells firing in their visual systems. The difference in their experiences
would have to be accounted for in some other way, perhaps by differences in
recall when they got to their journey’s end. More generally, this account does not
explain how we can overcome our intuitions, or advance the science, enough to
see how experience is brain activity.
Many other theories of consciousness avoid the controversial imagery of
stage and theatre, at least on the surface. These include the most explicitly
reductionist theories, like Crick’s ‘astonishing hypothesis’: ‘that “you”, your joys
and your sorrows, your memories and your ambitions, your sense of personal
identity and free will, are in fact no more than the behaviour of a vast assembly
of nerve cells and their associated molecules’ (Crick, 1994, p. 3). The theory
involves no explicit theatre imagery, yet Crick compares thalamic control of
attention with a spotlight, giving a hint of the theatrical. He claims that brain
activities ‘reach consciousness’, and speaks of ‘the seat of visual awareness’
(p. 171), of ‘the location of awareness in the brain’ (p. 174), and of locating the
‘awareness neurons’ (pp. 213, 224). So arguably, Crick’s theory is still a form of
Cartesian materialism.
As far as the red traffic light is concerned, Crick’s early theory required the right
oscillations to bind the features of the red light. His later theory with Christof Koch
involves the activation of thalamocortical loops. In both cases (see Chapter 6),
the theory requires specific brain processes that correlate with the light being
consciously perceived or not.
Other theories avoid the theatre by focusing on massive cross-brain inte-
gration. For the Dutch neuroscientist Cyriel Pennartz, for example, con-
sciousness is the solution to ‘the brain’s representational problem’: how to
integrate multiple pieces of sensory information ‘into a coherent whole that
can be immediately recognized, rapidly understood, and acted upon’ (2015,
p. 10). Pennartz splits up the requirements for consciousness into ‘hard’
(non-optional) and ‘soft’ (optional though common). The ‘hard’ prerequisite
of consciousness is an ability to interpret multiple sensory inputs as having
particular qualities, meaning, or content – in our example, interpreting all
the visual qualities of the red light in tandem with surrounding stimuli, and
attributing the meaning ‘stop’ to them. The ‘soft’ requirements include pro-
jection of interpreted sensory inputs into an external, perspectival space (as‘You’re nothing but a
pack of neurons’
(Crick, 1994, p. 3)