(A review of Ellis' book, Questioning Consciousness, by Nigel J. T. Thomas can be accessed.)
"Consciousness is a process, brain function is its substratum, and this does not necessarily mean that consciousness is caused by the actions of its substatum (the contrary arguments of Searle 1984, Smart 1959, and other epiphenomenalists notwithstanding). In living organisms, the form of the process often determines what happens to the substratum rather than the other way around. (On this point, I am in essential agreement with Merleau-Ponty 1942-1963, and with Varela et al 1993, although my reasons for this conclusion are a little different from theirs.) I shall argue that the central difference between conscious and non-conscious cognition is the presence of emotional intensity, which gives the motivational force needed to appropriate, shape, and even reproduce elements of its own substratum."Imagination (as Rosch 1975 and Newton 1993 have suggested) is the basic building block of all consciousness. That is, all contents of consciousness involve a subjunctive and imaginative element.
They involve in one way or another imagining what would happen if something were other than the way it is. Even the perceptual consciousness of an infant, according to Piaget (1928-1965, 1969), involves imagining what could be done with the object if the infant were to reach out, grasp it, beat on it, etc. This idea that identifying an object involves imagining how it could be manipulated has been supported in more recent developmental research by Becker and Ward (1991), and by Streri, Spelke, and Rameix (1993), confirming in humans the same principle that Held and Hein (1958) found for cats: When deprived of the opportunity to manipulate and interact with the objects they were looking at, kittens ended up being functionally blind."Even perceptual consciousness, then, is in part imaginative and subjunctive. This means that attentive consciousness always involves an implicit or explicit process of 'imaginative variation' as described by Husserl in his 'Lectures on Phenomenological Psychology', which is equivalent with saying that it involves counterfactuals in the same straightforward sense discussed by David Lewis (1973) in 'Counterfactuals.' A being which registers only the presence of objects as they actually are, or reacts behaviorally only to actual stimuli, is not a conscious being. To consciously see an object requires not only that light impinge on the retina, and that a nerve impulse travel through the thalmus to stimulate the primary projection area of the occipital lobe (Posner and Peterson 1990; Aurell 1983, 1989; Luria 1973); thus causing stimulation of the 'feature detectors' in the columns of neurons in the primary projection area (Hubel and Wiesel 1959). None of this yet results in consciousness of the object, as we know from PET scans and other measures of electrical activity in localized brain areas (Posner and Rothbart 1992; Aurell 1983, 1984, 1989; Posner 1980). Seeing occurs only when we attend to (i.e., look for) the object on which we are to focus. And looking for involves asking the question about a concept or image, 'Is this concept or image instantiated by what is in my visual field right now?' But the forming of an image or a concept requires a much more complex, active and global brain process than merely to receive and react to data from the senses. One reason for the importance of this point is that, even though some learning without awareness does occur, as documented by 'blindsight' and 'priming' experiments (Bullemer and Nissen 1990; Cohen et al 1990; Weiskrantz 1986), there are many kinds of learning and information that do not occur except with the help of conscious attention (Cohen et al 1990; Posner and Rothbart 1992; Hillis and Caramazza 1990).
"This implies another main difference between conscious and nonconscious processing: In conscious processing the imaginative act precedes the perceptual one as part of the arousal and attentional mechanism (Bruner 1961; Ausubel 1963; Neely 1977; Broadbent 1977; Logan 1986). This is confirmed in more recent empirical studies by Mele (1993), Rhodes et al (1993), Lavy et al (1994), Sedikides (1992), Higgins and King (1981), and Wyer and Srull (1981). A desire or interest originating in the midbrain leads to limbic activity and general increase in arousal (Hebb 1961), at which point the prefrontal cortex translates the emotional feeling of desire or interest into the formulation of questions (Luria 1973: 188-189, 211, 219ff, 1980; Sperry 1966), which entail images (requiring parietal activation), concepts and abstractions (Ornstein and Thompson 1984: 41-60) which often also involve symbolic activity (entailing interaction of left temporal syntactic and right parietal semantic functions, as discussed by Miller 1990: 78ff; Tucker 1981; Springer and Deutsch 1989: 309ff.; and Dimond 1980). Only at the point when the whole brain knows what it is 'looking for' in this sense does the occipital activity resulting from optic stimulation become a conscious registering of a perception, an attentive seeing of the object. This means that a conscious registering of a perceptual object leads to much more extensive processing of the data than the non-conscious registering of it could possibly lead to. It means that I am much more likely to remember the data, act on it, think about its further significance, and, if it is significant, look for recurrences of the object in the future. This last point is confirmed empirically by Higgins and King (1981), Wyer and Srull (1981), and many others whom we shall discuss later."