TheCognition-Action Dichotomy 17 various aspects of so-called ‘Human-centreddesign’, as we shall see. It has made it extremelydifficultto find a place in our views of human meaningand rationality for structuresofimagination.AsJohnson(1987,xxix)expressedit:“Imaginationseems to exist in a no-man’s-land between the clearly demarcated territories of reason and sensation.” Traditionally, HCI researchers have the assumption that the brain functions to construct and utilize representations of the world around us, via ‘a model of the world’ (Craik 1943; Reed 1996). The human organism must collect, collate, and interpret stimuli until it has an internal model of the world constructed by the brain (or mind), in order to let it send commands that will cause its body to behave in suitable ways. Several scholars and disciplines have argued against the limitations of this cognitivist view of HCI, as found in discussions in terms of augmented and mixed realities, tangible interaction, and situated action (e.g. Dourish 2001; Suchman2007).Wereturntothese later. Lakoff refers to the view that the mind is a computer with biological hardware: the mind runs using programs essentially like those used in computers today and it may take input from the body and provide output to the body, but there is nonetheless a purely mental sphere of symbolic manipulation that can be characterized in terms of algorithms of the sort used in computer programs. (Lakoff 1987, p. 338) Suchmechanicalsystemsallhaveonethingincommon:Theymusthaveanexternal agencyin order to let them act. Based on this assumption, it may be true that a tool is something that extends the action of workers. Therefore a tool, for example a computer,candothisonlybecauseworkersandothersourcesofpowerbringitinto action. Designers of interactive systems adopting this cognitivist view have tended to assume that every emergence of action/behaviour needs a stimulus either from outsidethesystemorfrominside.Theseareso-calledreactivemechanismsbasedon externalstimuli and instructivemechanismsbasedoninternalstimuliorcommands, accordingto some theories of ecological psychology(Reed 1996). Whereasmachinesneedastimulustobringthemintoaction,animalsarealways active in whole or in part. We experientially know also that humans are always activeanddifferentfrommachines.Andeventhoughmachines,toolsandcomputers are not active in the way that animals are, interactive systems have been designed on the basis of modelling animal and human behaviour on mechanical principles. For example, Card et al. (1983) introduced the idea of a model human processor (MHP) in their GOMS (goals, operators, methods and selection rules) approach to understanding interaction. The MHP describes human behaviour in terms of memories, processors, their parameters and interconnections. It is supposed to be used for approximate prediction, such as the assumed information processing capacities of a person, gross behaviour, and user behaviour in HCI, by applying a simplified view of psychological theories and empirical data. The MHP can be said to be an integration of a set of memories and processors. The MHP is composed of three subsystems that have their own memories and processors: the perceptual system, the cognitive system and the motor system. The perceptual system consists of two different image stores: an auditory image store