An Externalistist Process-Oriented Framework for Artificial Consciousness

In this paper, we present a view of conscious perception that supposes a processual unity between the activity in the agent and the perceived event in the external world. It is a kind of radical externalism (both vehicle and content) that suggests that the boundary of the agent’s conscious mind are much larger than those of its body. We suggest a process-based approach as an explanation of ordinary perception and other variants of phenomenal experience such as illusions, memory, dreams, and mental imagery. This approach provides new insights into the problem of conscious representation in the brain and phenomenal consciousness. It is a form of anti-cranialism different from but related to other kinds of externalism. Eventually, we will sketch the relation between this model and the capability of developing new goals in an agent. Unity between the environment and the agent During the last ten years, interest in the scientific understanding of the nature of consciousness has been rekindled (Hameroff, Kaszniak et al., 1996; Jennings, 2000; Miller, 2005). To date, a satisfactory and accepted framework has not been achieved either because experimental data is scarce or because a misleading theoretical standpoint is assumed. The effort for a scientific understanding of consciousness has been flanked by a related approach named artificial consciousness (sometimes machine or synthetic consciousness) aiming at reproducing the relevant features of consciousness using non biological components (Buttazzo, 2000; Holland, 2003; Manzotti, 2003; Adami, 2006; Chella and Manzotti, 2007Adami, 2006; Bongard, Zykov et al., 2006). This new field has strong relationships with artificial intelligence and cognitive robotics. Most researchers focus on a weak form of artificial consciousness. They try to replicate forms of accessconsciousness (similar to Baars’ global workspace). On the contrary, we try to address the problem of phenomenal consciousness. Implicit in most theories of conscious perception is the supposition that, although an external event and its representation in the brain are causally connected, they are nevertheless separate. As against this, we outline a process oriented framework applicable to perception which is a foundation for the proposal that there is a unity between the “external world” and the “perceived world”. The proposal is that the classic separation between subject and object must be reconceived so that the two, while maintaining their identities as different perspectives on a process, actually occur as a unity during perception. This leads us to sketch out a new view of consciousness, which can be summarised by saying that consciousness consists in the occurrence of a unity between the brain and the part of the world that is being attended. Here, we use the word ‘unity’ in the same sense in which we say that a magnetic field is a unity that can be described in terms of the different categories of a south and a north pole. We distinguish between ordinary visual perception, the actual presence of the object of perception in the external world, and other cases of conscious experience, when the object is no longer there or has never been such as memory, mental imagery, and dreams. According to a traditional point of view, the object is separated from the subject. There is much merit in this, since the two are conceptually separable. Yet that presumed separation is less obvious than commonly supposed – an underlying processual unity might exist. In many instances, for example the touch of the skin or the taste of food, this continuity is manifest. For other senses such as vision or hearing, a fairly convincing case can be made for the occurrence of an underlying unity. Furthermore, the separation between subject and object leads to the long debated issues of mental representations and ‘qualia’ where the former usually have a functional role and the latter ought to be responsible for qualitative experience (access consciousness vs. phenomenal consciousness). However, as soon as the separation between functional and phenomenal properties is assumed, a problem arises. Why should a functional structure have a phenomenal side? As far as we know, in the brain there is nothing like the content of our phenomenal experiences. “If consciousness is a brain process ... , how could my conscious experience of my grandmother have these features — such as the colour of her eyes — that no brain process could have?” (Place, 1956). When a subject tastes the flavour of a piece of chocolate, in his/her brain there is nothing with the property of that flavour. On the contrary there are neural patterns with completely different properties. Why should the latter be experienced as the former? Nobody knows. Furthermore, nobody knows how phenomenal experience, supposedly emergent from neural patterns functionally linked with external objects, is related with the physical properties of the piece of chocolate. The multiplication of entities is the result of the above mentioned assumption about the separation between perceiver and perceived or between subject and object. If the perceiver is physically separate from the external world, what is perceived must be something else – that is, a representation of the external object. This view, attributed to René Descartes, posits a separation between the “external world” and the “mental world” (for an historical overview see Manzotti, 2006). What is a representation, or better a re-presentation? Rather naively but worryingly, it is something that re-presents something else. Up to now, the nature of the relation is a tantalizing mystery. Different solutions have been proposed: correlation, causation, lawlike causation, emergence, identity, supervenience. None has proved to be completely satisfactory. Once the separation between the subject and the object is accepted, both the representational and the phenomenal aspect of neural processes present awkward problems (Fodor, 1981; Chalmers, 1996; Lehar, 2003; Kim, 2005). With respect to the conscious experience of the world, the brain carries the same burden as the XVII century soul. The brain is supposed to be able to interpret the incoming electric signal and produce a conscious experience of the world by means of some internal coding (a view labelled as “codicism” by Mark Bickhard Bickhard and Terveen, 1995). The quest for neural correlates of consciousness (NCC) is currently based on this undemonstrated framework (Koch, 2004) as well as most consciousness inspired models in AI (Baars, 1988; Aleksander, 2000; Hesslow, 2002; Baars and Franklin, 2003; Franklin, 2003; Kuipers, 2005; Shanahan, 2005). The conjectural neural coding in the brain should perform the miracle of changing the water of neural activity into the wine of phenomenal experience (the nice metaphor is due to Humprey (1992)). Once the hypothesis of the separation between subject and object (brain and external world) is accepted, a dualistic view of perception cannot be avoided. In turn, dualistic approaches lead to the issue of re-presentation and to that of the nature of phenomenal experience. Given the shortcomings of these approaches, it is worthwhile and perhaps timely questioning such an hypothesis (Rorty 1979; Searle 1980; Fodor 1981; Millikan 1984; Dretske 1993; Dretske 1995; Tye 1996; Clark 1997; Bickhard 1999; Metzinger 2003). Is the subject really separate from what s/he perceives? Is the perception really separate from the perceived? For instance, when a red patch is perceived, starting from the external object to the activity in the brain, an uninterrupted continuous physical process takes place. Rays of light in terms of actual physical quanta are continually bombarding the retina, which in turn is being successively hyperpolarized (at the receptors) and then depolarised beyond, with the nerve impulses thus set up being transmitted continuously to the relevant processingperceptual areas of the brain. This is a continuous process which occurs as long as the red patch is visually perceived – physically spanning from the patch and the brain. From a physical point of view, there is no separation between the external object and the activity inside the brain. There is a continuous chain of causally related physical phenomena. When the view of the patch is interrupted, even if momentarily, the link is broken and we cease to see the red patch. Thus, there is nothing strange in supposing that there is some kind of unity, embodied by a process, between subject and object. Rather, it is surprising, given the actual and easily demonstrable continuity, that this option has received so little attention. Moreover, the supposition of continuity leads to an alternative view of conscious experience that is worth looking into. Internalism vs externalism Currently, the majority of scientific and philosophical literature on consciousness is biased by a seldom challenged assumption – the separation between the subject and the object. Although it is obvious that the body of the subject is separate from the body of the object, it is by no means so obvious that the mind is confined by the same boundaries of the brain. “Where does the mind stop and the rest of the world begin? [...] Someone accepts the demarcations of skin and skull, and say that what is outside the body is outside the mind” (Clark and Chalmers, 1999, and more recently Wilson, 2004). Indeed, there are many phenomena which extend beyond the boundaries of the body (behaviors, actions, perceptions, ecological processes). The mind could be one of them. With regard to the nature of the mind, two very broad standpoints must be considered: internalism and externalism. The former states that our consciousness is identical (or correlated) to the processes, events or states of affairs going on inside the boundary of our body (or brain). The latter affirms that our consciousness might depend partially or totally on the events, processes or state of affairs outside our head or even outside our body. Most current approaches to the problem of consciousness lean towards the internalist viewpoint (Crick, 1994; Edelman and Tononi, 2000; Metzinger, 2000; Rees, Kreiman et al., 2002; Crick and Koch, 2003; Koch, 2004). However, this approach raises several conundrums. If the mind is entirely located or dependent on events or states of affairs located inside the cranium, how can they represent events taking place in the external world? Consciousness appears to have properties which differ from anything taking place inside the cranium (Place, 1956). Spurred on by common sense, literature has revealed a very strong impulse to “etherealize” or “cranialize” consciousness (Honderich, 2000). The internalist perspective has consistently led to dualism and still promotes a physicalist version of dualism by endowing the brain (or a brain subset, the Neural Correlate of Consciousness) with the same role as the dualistic subject. Koch’s recent book (Koch, 2004, p.87), endorses an unbiased internalist view with respect to consciousness and the brain: “The entire brain is sufficient for consciousness – it determines conscious sensations day in and day out. Identifying all of the brain with the NCC [Neural Correlate of Consciousness], however is not useful because likely a subset of brain matter will do.” On the other hand, many authors, like ourselves, have questioned the separation between subject and object – between representation and represented. They are looking for a different framework in which subject and object are two different perspectives on the same physical phenomenon. Their views could be labeled as some kind of externalism (Hurley, 2001; Hurley, 2006). According to Mark Rowlands, there are two variants of externalism: content externalism and vehicle externalism. The former corresponds to the “idea that the semantic content of mental states that have it is often dependent on factors [...] that are external to the subject of that content” (Rowlands, 2003, p. 5). The latter is more radical and affirms that “the structures and mechanisms that allow a creature to possess or undergo various mental states and processes are often structure and mechanisms that extend beyond the skin of that creature” (Rowlands, 2003, p.6). In the following paragraphs, we will present a version of vehicle externalism (Manzotti and Tagliasco, 2001; Manzotti, 2003; Manzotti, 2005; Manzotti, 2006b; Manzotti, 2006a). The Enlarged Mind: An Externalist