Slaying the chimera: a complementarity approach to the extended mind thesis

Much of the literature directed at the Extended Mind Thesis (EMT) has revolved around parity issues, focussing on the problem of how to individuate the functional roles and on the relevance of these roles for the production of human intelligent behaviour. Proponents of EMT have famously claimed that we shouldn’t take the location of a process as a reliable indicator of the mechanisms that support our cognitive behaviour. This functionalist understanding of cognition has however been challenged by opponents of EMT [such as Rupert (2009); Adams & Aizawa (2009)], who have claimed that differences between internal, biological processes and putatively extended ones not only exist but are actually crucial to undermine the idea that inner and outer are functionally equivalent. This debate about how to individuate the functional roles has led to a treacherous stand-off, in which proponents of EMT have been trapped under the persistent accusation of causal/constitution conflation. My strategy for responding to this charge is to look precisely at those functional differences highlighted by critics of EMT. I reckon that extended cognitive systems are endowed with quite different properties from systems that are “brain bound” and argue that it is precisely these differences that allow human minds to transcend their biological limitations. I thus defend a complementarity version of the extended mind, according to which externally located resources and internal biological elements make a different but complementary contribution to bringing about intelligent behaviour [Sutton (2010)]. My defence of complementarity is based on both the phylogeny and the ontogeny of cognitive systems. I initially explore the interrelation between brain and cognitive development from a neuroconstructivist perspective [Quartz & Sejnowski (1997); Mareshal et al. (2007)] and then argue that our brains do not have fixed functional architectures but are sculpted and given form by the activities we repeatedly engage in. As a result of repeated engagements in socio-cultural tasks, relevant brain pathways undergo substantial rewiring. Development thus scaffolds our brains, which become geared into working in symbiotic partnership with external resources. [Kiverstein & Farina (2011)]. On these grounds, I call into question any tendency to interpret the human biological nature as fixed and endogenously pre-determined and side with proponents of DST [Oyama (2000); Griffiths & Gray (2001)] and ontogenetic niche construction [Stotz (2010)] in arguing that we should think of natural selection as operating on whole developmental systems composed of living organisms in culturally enriched niches. [Wheeler & Clark(2008)]. Complementarity defences of EMT argue that many of the kinds of cognition humans excel at can only be accomplished by brains working together with a body that directly manipulates and acts on the world [Rowlands (2010); Menary (2007)]. I take Sensory Substitution Devices (SSDs henceforth) as my empirical case study. SSDs exploit the remarkable plasticity of our brains and with training supply a novel perceptual modality that compensates for loss or impaired sensory channel. I argue that the coupling with these devices triggers a new mode of phenomenal access to the world, something I propose to label as a kind of “artificial synaesthesia [Ward & Meijer (2010)].This new mode of access to the world transforms our cognitive skills and gives rise to augmented processes of deep bio-technological symbiosis. SSDs therefore become mind enhancing tools [Clark (2003)] and a perfect case study for Complementarity. Having shown the relevance of SSDs for EMT, I then take up the possibility that these devices don’t just relocate the boundaries of cognition but may also stretch the bounds of perceptual awareness. I explore the possibility that perceivers using SSDs count as extended cognitive systems and therefore argue that the experiences they enjoy should be counted as extended conscious experiences.[Kiverstein & Farina, (forthcoming)]. SSDs are quite often said to involve some form of incorporation.[Clark (2008)]. Rupert has challenged this idea and its relevance for EMT on the grounds of his embedded approach. Particularly, he has explained tool-use in terms of the causal interaction between the subject and its detached tool. In the final chapter of my dissertation I critically look at his objections and argue that all his arguments fail to apply to SSDs. In SSD perception in fact the tool becomes geared to work in symbiotic partnership with the active subject and then get factored into its’ body schema so that both of them come to form a single system of cognitive analysis

The role of simulation in developing and designing applications for 2-class motor imagery brain-computer interfaces

A Brain-Computer Interface (BCI) can be used by people with severe physical disabilities such as Locked-in Syndrome (LiS) as a channel of input to a computer. The time-consuming nature of setting up and using a BCI, together with individual variation in performance and limited access to end users makes it difficult to employ techniques such as rapid prototyping and user centred design (UCD) in the design and development of applications. This thesis proposes a design process which incorporates the use of simulation tools and techniques to improve the speed and quality of designing BCI applications for the target user group. Two different forms of simulation can be distinguished: offline simulation aims to make predictions about a user’s performance in a given application interface given measures of their baseline control characteristics, while online simulation abstracts properties of inter- action with a BCI system which can be shown to, or used by, a stakeholder in real time. Simulators that abstract properties of BCI control at different levels are useful for different purposes. Demonstrating the use of offline simulation, Chapter 3 investigates the use of finite state machines (FSMs) to predict the time to complete tasks given a particular menu hierarchy, and compares offline predictions of task performance with real data in a spelling task. Chapter 5 aims to explore the possibility of abstracting a user’s control characteristics from a typical calibration task to predict performance in a novel control paradigm. Online simulation encompasses a range of techniques from low-fidelity prototypes built using paper and cardboard, to computer simulation models that aim to emulate the feel of control of using a BCI without actually needing to put on the BCI cap. Chapter 4 details the develop- ment and evaluation of a high fidelity BCI simulator that models the control characteristics of a BCI based on the motor-imagery (MI) paradigm. The simulation tools and techniques can be used at different stages of the application design process to reduce the level of involvement of end users while at the same time striving to employ UCD principles. It is argued that prioritising the level of involvement of end users at different stages in the design process is an important strategy for design: end user input is paramount particularly at the initial user requirements stage where the goals that are important for the end user of the application can be ascertained. The interface and specific interaction techniques can then be iteratively developed through both real and simulated BCI with people who have no or less severe physical disabilities than the target end user group, and evaluations can be carried out with end users at the final stages of the process. Chapter 6 provides a case study of using the simulation tools and techniques in the development of a music player application. Although the tools discussed in the thesis specifically concern a 2-class Motor Imagery BCI which uses the electroencephalogram (EEG) to extract brain signals, the simulation principles can be expected to apply to a range of BCI systems