- seCtIon tWo: tHe BRAIn
Koch, 2004), who argue that consciousness is built up only when stable coalitions
form; from Engel and Singer (above); and from Metzinger, who argues that ‘Con-
sciousness is what binds things together into a comprehensive, simultaneous
whole’, and that only if the senses are unified can you experience a world (2009,
p. 26).
Zeki’s suggestion is not a form of panpsychism (the view that everything is con-
scious), because he does not claim that all neural processing is conscious. This
means that, unlike Dennett, he must still distinguish between conscious and
unconscious processes. He speculates that neural activity remains implicit as long
as it requires further processing; when processing is complete, it becomes explicit
or conscious. Discussing blindsight (Chapter 8) and other kinds of brain damage,
he describes people who report being conscious of aspects of early motion pro-
cessing that would be implicit in other people, leading him to propose that ‘cells
whose activity is only implicit can, in the right circumstances, become explicit. Put
more boldly, cells can have double duties, rendering the incoming signals explicit
or not, depending on the activity at the next node’ (2001, p. 66).
In Zeki’s (2007) scheme, micro-consciousnesses are bound into macro-con-
sciousnesses which correspond to Block’s phenomenal consciousness. Unified
consciousness corresponds to Block’s access consciousness and comes about
only through language and the awareness of a perceiving self. This is very much
a ‘consciousness at the top’ model as discussed in Chapter 5, but one with the
idiosyncrasy of including other consciousnesses ‘lower down’. These multiple
consciousnesses constitute a hierarchy ‘with what Kant called the “synthetic, tran-
scendental” unified consciousness (that of myself as the perceiving person) sitting
at the apex’ (Zeki, 2003, p. 214). Elsewhere, however, Zeki remarks that ‘the term
microconsciousness may itself be a misnomer, because it implicitly supposes that
there is a higher unified and singular conscious entity, beyond all the microcon-
sciousnesses’ (Zeki and Bartels, 1999, p. 238).
One way of interpreting Zeki’s micro-consciousnesses is that whether bound
or not, they are all conscious, implying a head full of disconnected phenome-
nal experiences along with a unified world perceived by a constructed self. This
would avoid the problem of explaining the difference between conscious and
unconscious processes. But this cannot be what he means, for he says that ‘once
a macro-consciousness is formed from two or more micro-consciousnesses, the
constituent micro-consciousnesses cease to exist’ (2007, p. 584), and we become
aware of the composite instead – though by paying attention to the constituents
rather than the composite we can reverse this effect. The tricky point for his the-
ory is the point in space or time at which information that was previously ‘implicit’
is ‘rendered explicit’ or ‘acquires a conscious correlate’. This transition remains,
as in every other theory that comes up against it, unexplained and essentially
mysterious.
MULTISENSORY INTEGRATION
The theories considered so far have concentrated on vision, perhaps because
vision is the predominant sense in humans, and also because the visual system is
much better understood than other parts of the brain. But binding has to occur
between the senses as well as within them. This is no trivial matter, not least
IS THIS EXPERIENCE
UNIFIED?