- seCtIon tWo: tHe BRAIn
Another criticism is that research has ignored the distinction between phenom-
enal consciousness and access conscious. Block’s distinction (2007) means that
there are two NCCs, not just one: the NCC for phenomenal consciousness and the
NCC for access consciousness. The philosopher Benjamin Kozuch (2015) floats the
idea that absences in self-report do not necessarily mean that the content repre-
sented by the brain area in question is absent from experience. Instead, it might
mean that that content is cognitively inaccessible even if someone is conscious of
it. Kozuch insists on the possibility that ‘one could have a conscious mental state
and yet not know it’ (2015, p. 146) – that is, have P- without A-consciousness. In
his view, people say they are looking for the ‘correlates’ of consciousness when
what they really want to find its ‘basis’, i.e. that which is minimally sufficient for
consciousness, excluding any non-essential correlates.
This way of thinking means accepting two key principles: the P/A-consciousness
distinction and the notion that different brain areas ‘represent’ distinct ‘contents’.
Alva Noë and Evan Thompson criticise the second of these principles, outlining
problems with what they call the ‘matching-content doctrine’: the belief that ‘the
first task of the neuroscience of consciousness is to uncover the neural represen-
tational systems whose contents systematically match the contents of conscious-
ness’ (2004, pp. 3–4). They challenge the majority of neuroscientists for believing
that there must be, first, a minimal neural substrate sufficient for making experi-
ences happen, and second, a one-to-one mapping between that and the content
of the conscious experience. Chalmers (2000) calls this the content NCC, which he
says is the ‘central case’ of an NCC, and Crick and Koch work with this kind of idea
when they say that ‘Whenever some information is represented in the NCC it is
represented in consciousness’ (1998, p. 98).
Noë and Thompson (2004) list a number of reasons why the matching-content
doctrine doesn’t make sense: they argue that perceptual content is structurally
coherent, intrinsically experiential, active, and attentional, and exists at a per-
sonal, not a sub-personal, level, none of which can be said of neural activity. One
of the defining qualities of perceptual experience, for example, is that it is always
from a point of view: ‘Animals and persons experience the world as laid out before
them, but the neurons do not’ (p. 16). In other words, neuroscientists are falling
for the mereological fallacy. Similarly, as we saw in Chapter 3, occluded parts of
an object, like portions of a cat hidden behind railings, seem to be perceptually
present even though you can’t actually see them. They conclude that neurosci-
ence needs to get away from the ideas of correlation and constitution that define
work on the NCCs.
COMPETING FOR CONSCIOUSNESS
With or without the help of philosophy, the search for the NCCs has been contin-
ued in many forms. The experiments described earlier in the chapter were car-
ried out with monkeys because you cannot ethically insert electrodes into living
human brains, but developments in neuroimaging have made it possible to do
equivalent studies in humans. Lumer, Friston, and Rees (1998) used fMRI to detect
changes during binocular rivalry. Participants wore stereoscopic glasses and were
presented with a red drifting grating to one eye, and a green face to the other.‘all qualia are
experienced by the
brain, and none are
reachable objectively
from outside that
embodied brain’
(Feinberg and Mallatt, 2016,
p. 225)
‘there can be no match
between the content of
neural representational
systems and the content
of experience’
(Noë and Thompson, 2004,
p. 88)