Cognitive Computing 2012

Cognitive Computing 2012 The computer and the mind Wheeler: ‘From robots to Rothko:the bringing forth of worlds’ Mark Bishop

Rothko: spirituality and mysticism • How do we explain and shed light on our human understanding and experience of art? • Rothko describes his experience of painting as a ‘religious experience’ (cf. The ‘Rothko chapel’ in Houston) • And many people experience feelings akin to mysticism and reverence when viewing the huge Rothko canvases in the “Rothko room” at the Tate Modern. • And yet Rothko maintained he was a materialist and resisted the label of ‘otherworldliness’. (c) Bishop: The computer and the mind

Art and cognition • Michael Wheeler is sceptical that ‘orthodox cognitive science’ … • I.e. Symbolic data structures and heuristic search; • Distributed patterns of activation spreading across networks of processing nodes; • … can enlighten our encounters with art. • Conversely Wheeler suggests that concepts from A-life may serve to clarify these encounters … • and it is not just that GAs can be used to generate art; • or that ‘doing A-life’ has been compared to ‘doing art’; • but rather, A-life accounts of cognition can potentially help explain our experience and understanding or art. (c) Bishop: The computer and the mind

On animats • In the paper Wheeler reflects mainly upon the ‘animat’ approach to A-Life. • Wheeler uses the term ‘animat’ to mean artificial animals / artificial autonomous agents. • Such systems could be realised as: • Autonomous real (physical) robots with sensory motor mechanisms; • Autonomous simulated agents in simulated environments. • More recently the term animats has been used to describe robots controlled by engineered matrices of real, living, neurons, but that is not the sense in which Wheeler uses the term herein. (c) Bishop: The computer and the mind

Autonomy • A system must have adaptive behaviour to be a truly autonomous agent. • i.e. Behaviour which increases its chances of survival in its interactions with the environment (adaption as survival based “teleology”) … • Wheeler, “For a system to be an autonomous agent it must exhibit adaptive behavior, behavior which increases the chances that the system can survive in a noisy, dynamic, uncertain environment.” • And not merely environmental adaptation in the context of, say, a river. • The animat approach aims to understand the adaptive behaviours of simple artificial ‘creatures’ as they interact with their environment • … rather than attempt to understand the complex reasoning capacities of humans. (c) Bishop: The computer and the mind

On hermeneutics • Hermeneutics is the formal study of linguistic interpretation. • It originally was confined to the study of ancient texts & scripture but also developed as a universal discipline of study by Schleiermacher. • Following the work of Gadamer, Dilthey and Ricouer, the hermeneutical process is often regarded as involving a complex interaction between the ‘interpreting subject’ and the ‘interpreted object’. • The task is complicated because of the apparent ‘hermeneutical circularity’ of understanding particular elements in light of the text as a whole, a text which in turn can only be understood by reference to those particular elements. (c) Bishop: The computer and the mind

Understanding and hermeneutics • Wheeler on hermeneutics • The phenomenon of understanding is an ongoing series of historically embedded events; • We must consider the role played by a person’s ‘socio-cultural’ biases and history: • These define the pre-structures of her understanding; • The given in any understanding event (such as looking at art); • The very lens through which she makes sense of things. • Such a hermeneutical approach is seemingly in conflict with the ‘naturalism’ of cognitive science • all there that exists is material stuff; • the study of the mind is coextensive with the study of the natural sciences. (c) Bishop: The computer and the mind

Hermeneutics and cognitive science • In a naturalistic cognitive science the problem is how to objectify the pre-structures necessary for understanding? • To ground cognitive science we need to objectively/scientifically explain the ‘pre-structures of understanding’ yet the paradox of ‘hermeneutical circularity’ denies this is possible.. • Secondly for many hermeneuticists, the pre-structures of understanding are linguistic • Skill, craft or ‘work of art’ are intelligible only insofar as they are explainable in linguistic terms; • But Wheeler wants to apply ‘understanding’ – non metaphorically – to non-linguistic ‘animats’. • Hence it appears that Wheeler must steer clear of hermeneutics… (c) Bishop: The computer and the mind

Dualism and cognitive science • Dualism • The mind and physical body are made of two different kinds of substances which can causally interact; • No explanation how they interact; • There is an ‘explanatory gap’ between mind (& its representations) and the world (that is represented). • Hence dualism views cognition as a process of optimisation • I.e. Cognition seeks to optimise the fit between internal states of the mind (representations) and the external world. (c) Bishop: The computer and the mind

Orthodox cognitive science • Although representationalism had been around for centuries, orthodox cognitive science was formed when the computational theory of cognition linked to the representational theory of mind. • Hence the need to optimise the fit between representations and the external world; • but in cognitive science even deciding exactly what counts as a representation is a hotly debated issue (cf. Chemero)... (c) Bishop: The computer and the mind

Sense, plan and act • The ‘Sense-Plan-Act’ cycle in orthodox cognitive science: • SENSE • a perception module constructs a model (a set of representations) of the world; • PLAN • a central control system performs ‘planning’ and ‘action’; • ACT • a set of sub modules which manipulate the ‘representations’ and communicate with each other then output another set of representations to which the action-mechanisms respond. (c) Bishop: The computer and the mind

Cognitive science and Cartesian dualism • In orthodox cognitive science, because ‘representations are physical’ and computations are ‘realised by machine’ cognitive science appears very distant from dualism. • But in fact both CS and Dualism agree on: • The use of ‘optimal’ inner states/representations; • That physical states of brain causally affect behaviour; • The cogniser’s body is essentially a courier system, delivering sensory-input messages to, and collecting motor-output messages from, the “thinking thing”. • That perception - thought - action are each “temporally distinct”. (c) Bishop: The computer and the mind

Cartesian relations to computationalism • Although orthodox cognitive science is seen as having physicalist roots, it is clearly linked to Cartesian ideas. • Albeit orthodox cognitive science attempts to explain the link from physical states to behaviour, whereas dualism does not. • In the paper Wheeler will set out to explain how A-life is non-Cartesian. • Wheeler’s central thesis being that, ‘perception is active’. (c) Bishop: The computer and the mind

Perception as an ‘activity’ • Robots built following orthodox principles could not act adaptively in ‘real time’. • So in animat research ‘active perception’ came to the fore. • Perception seen as an activity performed by agent as part of its autonomous behaviour. • The perception–action (sensorimotor) cycle. • Cf. Arbib & Ballard (active vision); (c) Bishop: The computer and the mind

Brooks’ subsumption architecture • Brooks ‘subsumption architecture’ replaced orthodox cognitivist approaches (cf. ‘Intelligence without representation’, 1991) • Robot control is divided into independent layers (communication only via suppression or inhibition mechanisms; no detailed message passing as in classical cognitive science); • Each layer is coupled to the environment via a ‘channel of ecological significance’ is responsible for a sensing and motor (sensorimotor) activity: • Movement; object avoidance; mapping etc. (c) Bishop: The computer and the mind

The phonotaxis architecture of the female cricket • Webb describes cricket ‘phonotaxis’, a process whereby female crickets locate mates by tracking auditory signals. • The female cricket’s body is designed in such a way that the frequency of the make cricket’s signal pulls her towards him. • Thus the female doesn’t have to discriminate sounds in general and subsequently need a separate process to identify the males, and yet another process for deciding what to do after hearing it. (c) Bishop: The computer and the mind

Artificial life and the ‘perception–action’ cycle • The success of such special purpose mechanisms (e.g. phonotaxis) is not due to optimisation of one feature; rather it is achieved by the whole agent adapting to ‘the right’ environmental context. • The cricket’s control system is layered. • There is a close coupling between the male signal and the layer which controls the female’s sensori–motor behaviour. • As the male signal is at a set-frequency, there is no need for complex ‘recognition’ – simply a tube resonating at a particular frequency. • Movement towards the signal is ‘automatic’ via direction dependent intensity difference. (c) Bishop: The computer and the mind

Evolutionary robotics • In evolutionary robotics the robot’s control systems are encoded as genotypes and over many generations, the better performing control structures evolve and are used. (c) Bishop: The computer and the mind

Room centering robot (c) Bishop: The computer and the mind

On the interpretation of behaviour • The room centering robot controller ‘evolves’ its own neural connections instead of having them predefined by the engineer; • Hence it is difficult to analyse the robot’s behaviour using a traditional computational / representational model. • But even if it is possible to give an information processing account of some behaviour do we have to conceptualise cognition in this way? • We can describe rivers using mathematical models of flow, but nobody seriously suggest that rivers compute such models. • But what is the alternative to the classical information processing model? (c) Bishop: The computer and the mind

Dynamical systems theory • A dynamic system is any system for which we can provide: • A finite number of state variables which capture the state of the system at a given time; • A set of state space evolution equations defining the system’s phase space - showing how the values of the state variables change over time. • Parameters • Affect the dynamic behaviour of a system without ever changing themselves over time. • I.e. Changing parameter values can change system behaviour but the system cannot change its own parameters values. Trajectory (c) Bishop: The computer and the mind

Coupled dynamical systems • Coupling occurs when two separable dynamical systems are bound together and can affect each others parameter values. • Changes in one system’s state variables produce changes in the other system’s parameter values which in turn to produce changes in the state variables (and hence phase portrait) of the first system. • A set of coupled dynamic systems can be described with only one set of equations. • In coupling between say, an agent and environment the agent and environment can be seen as one coupled dynamical system. • A ‘Cartesian approach’cannot account for on-going agent-environment interactions in this way. (c) Bishop: The computer and the mind

Dynamic systems and room centering robots • Husbands et al demonstrates how methods form dynamic system theory can be used to explain and predict the behaviours of a room centering robot. • The dynamic systems theory model correctly predicts the behaviours of the robot, even when the environment changes: • E.g. If the wall height is increased, although the controller was not specifically evolved for this situation the robot still converges to the attractor at the centre of the room. (c) Bishop: The computer and the mind

The radical dynamic systems theory of cognition (DSC) claim • It is up to the observer to decide where to draw the boundaries between the coupled dynamical system between the ‘internal’ states of the agent and the ‘external’ states of the environment. • On some occasions it will be useful to consider a coupled {agent + environment} system (perhaps to improve the controller); • On other occasions it may be more useful to consider the {agent + environment} as one (complex) dynamic system. • Hence Wheeler asserts any conceptualisation based on a simple Cartesian perspective of divided subject and object is bound to fail because it takes one possible abstraction as an ontological fact about all possible agents and their ‘lived worlds’. (c) Bishop: The computer and the mind

Heideggerian perspective • Heidegger coined the term “Dasein” (being there) to describe the way humans are. • Our everyday activity can be described in terms of ‘equipment’ and our understanding of this equipment is governed by what we use it for. • e.g. A hammer is used for hammering; • This provides an activity based account of everyday understanding. • Thus the meaning of a piece of equipment (like the hammer) is its ‘possibilities for interaction’ to Dasein. (c) Bishop: The computer and the mind

Dasein and the ‘background’ • Hence the Dasein’s meaning of equipment comes from the background involvements of culture and society not just the thing-in-itself. • i.e. in our culture we use a coke bottle to hold a fizzy carbonated drink but in other countries it might be a hammer; a status symbol; a vehicle for carry water or measuring sand • C.f. “The Gods must be crazy” • The ‘totality of all such possible involvements’ defines “the meaning of the entity as a whole” [which relates to Dasein]. • Dasein and radical holism • A world is the totality of an involvement whole, (i.e. it is inseparable from all the skills and practises that make up that whole); a hermeneutic circle. (c) Bishop: The computer and the mind

“The Gods must be crazy” • Xi and his tribe of San/Bushmen relatives are living well off the land in the Kalahari Desert; they are happy because the gods have provided plenty of everything, and no one in the tribe has unfulfilled wants. • One day, a glass Coke bottle is thrown out of an aeroplane and falls to earth unbroken. • Initially, this strange artifact seems to be another boon from the gods • Xi's people find many uses for it. • But unlike anything that they have had before, there is only one bottle to go around. • This exposes the tribe to a hitherto unknown phenomenon, property, and they soon find themselves experiencing things they never had before: jealousy, envy, anger, hatred, even violence. • Since it has caused the tribe unhappiness on two occasions, Xi decides that the bottle is an evil thing and must be thrown off of the edge of the world. (c) Bishop: The computer and the mind

On subject and object • A fundamental feature of our everyday activity is one in which divisions between subject and object have no meaning - what Heidegger calls the ready-to-hand - consider the expert hammerer as she hammers in a nail; the expert car driver driving a car etc. • In this mode common sense operates without ‘thoughts-that’ or ‘thoughts-about’; indeed they only become aware of division [between subject/object] when something goes wrong: • Heidegger, the ‘un-ready-to-hand’ mode. • Dasein’s problem solving ability now comes to the fore and a division between subject and object is appropriate: • Heidegger, this mode of engagement is called the ‘present-to-hand’. (c) Bishop: The computer and the mind

On Dasein • Dasein does not start out socialised and later become socialised; Dasein is socialised! • Hence [radically] animals and infants cannot be Dasein. • These ‘ways of acting’ are the background cultures and practises of a society and constitute the norms that allow the involvement as a whole to exist • It is only within socialisation into our culture that equipment (e.g. hammer) become meaningful / significant. • Thus it is ‘culture and society’ that defines the pre-structures of understanding and the start of the hermeneutical situation. (c) Bishop: The computer and the mind

A Heideggarian cognitive science: Dasein and dynamic systems • Recall, when an observer attempts to understand an environmentally situated agent, we require a framework which does not pre-suppose the subject-object division. • Heidegger’s concept of ‘being in the world’ partners the ‘hyphen’ in the ‘agent-environment’ dynamic system. • The separation into two (or more) systems is thus imposed by the external theorist, when this is most appropriate, (e.g. in the design of a system controller). • Thus both Heidegger and the DSC stand in opposition to Cartesian framework (c) Bishop: The computer and the mind

Bringing forth worlds • It looks as though from Heidegger’s perspective that non-human autonomous agents can’t have a world of meaning (cf. children and animals) • Conflict with the animat (& animal) approach; • Wheleler suggest that, “… if being embodied in a culture is the only source of significance than we might as well throw-in-the-towel”. • But Wheeler highlights that animals [animats] inhabit different ecological worlds to social humans. • The significances which characterise these worlds can be identified by appeal to the ecological norms of ‘optimally-fit’ behaviours • Wheeler, “the evolutionary pre-structures of understanding for the animal”. • How an agent embedded in its environment exploits its ‘optimal fitness-es’ is the cumulative effect of the sets of its on-going sensorimotor couplings (cf. the cricket) with that environment bringing forth its world. (c) Bishop: The computer and the mind

Wheeler on art and language • To explain the event of viewing a piece of art, a dynamical systems theory could be applied. • And we should apply the one system model where the history and culture of the observer is coupled with the work of art. • Neither system, on its own, suffices to explain the nature of the event. • The Hermeneutical approach can thus offer us some understanding and Wheeler’s A-Life approach suggests how there can be much more to the personal [mystic] lived experience of Rothko than can be communicated merely linguistically… (c) Bishop: The computer and the mind

Cognitive Computing 2012