Figure 9.2 The tree of consciousness theoriespropose that phenomenal consciousness may be identiWed with syn-
chronised 35- to 75-hertz neural oscillations in the sensory areas of the
cortex. Given the points made in section 2.3 above, however, in our
discussion of McGinn, it seems unlikely that any reductive explanation
into neurobiological terms can be successful – this is trying to jump over
too many explanatory levels at once.
A number of diVerent functional theories have been proposed which
incorporate some sort of ‘phenomenal-consciousness box’. In some of
these the consciousness box is located in relation to other aspects of
cognition, but no attempt is made to explain those features of phenomenal
consciousness which seem most puzzling. For want of a better term, we
label these ‘pure boxological theories’ (the term ‘obviously non-explana-
tory boxological theories’ might be descriptively more accurate). For
example, in a model due to Schacteret al. (1988), there is a conscious
awareness system (or CAS) deWned by its relations with a number of
specialist modules, on the one hand, and the executive and verbal memory
systems on the other. The model is designed to explain a variety of
dissociation data – for example, that people with prosopagnosia can lack
any conscious recognition of faces, while recognition can nevertheless be
248 Consciousness: theWnal frontier?