ABSTRACT
There are some exceptions, which we shall see below, but virtually all theories in psychology and cognitive science make use of the notion of representation. Arguably, folk psychology also trafcs in representations, or is at least strongly suggestive of their existence. There are many different types of things discussed in the psychological and philosophical literature that are candidates for representation-hood. First, there are the propositional attitudes – beliefs, judgments, desires, hopes etc. (see Chapters 9 and 17 of this volume). If the propositional attitudes are representations, they are person-level representations – the judgment that the sun is bright pertains to John, not a sub-personal part of John. By contrast, the representations of edges in V1 of the cerebral cortex that neuroscientists talk about and David Marr’s symbolic representations of “zero-crossings” in early vision (Marr 1982) are at the “sub-personal” level – they apply to parts or states of a person (e.g. neural parts or computational states of the visual system). Another important distinction is often made among perceptual, cognitive, and action-oriented representations (e.g. motor commands). Another contrast lies between “stored representations” (e.g. memories) and “active representations” (e.g. a current perceptual state). Related to this is the distinction between “dispositional representations” and “occurrent representations.” Beliefs that are not currently being entertained are dispositional, e.g. your belief that the United States is in North America – no doubt you had this belief two minutes ago, but you were not consciously accessing it until you read this sentence. Occurrent representations, by contrast, are active, conscious thoughts or perceptions. Which leads us to another important distinction: between conscious and non-conscious mental representations, once a bizarre-sounding distinction that has become familiar since Freud (see Chapter 4 of this volume). I mention these distinctions at the outset to give you some idea of the range of phenomena we will be considering, and to set the stage for our central “problem of
representation”: what is a mental representation, exactly, and how do we go about deciding whether there are any? We know there are public representations of various kinds: words, maps, and pictures, among others. Are there any representations that are properly thought of as psychological? Minimally, a representation is something that possesses semantic properties: a truth value, a satisfaction value (i.e. satised or not), truth conditions, satisfaction conditions, reference, or content. So here is one way we might proceed, which we can call “the simple strategy”: rst, gure out what endows something with semantic properties, and then see if any of the objects that have semantic properties are mental or psychological. The simple strategy might ultimately work, but there are at least two prima facie problems with it. First, there is substantial disagreement over what endows an object with semantic properties, and even whether such properties are scientically accessible at all. Debates about whether thermostats or dogs harbour real representations are often just disputes about whether these things possess states with semantic properties. (The subject of what, if any, natural properties ground semantic properties is the topic of the next chapter.) The second problem with the simple strategy is that there is a danger of talking past one another: not everyone accepts that if something has semantic properties, it must be a species of representation. Many notions of representation require something more. Let us now look at the various notions of representation in common use.
