Mahatma Ghandi
Representation and Computation
The central hypothesis of cognitive science is that thinking can best be understood in terms of representational structures in the mind and computational procedures that operate on those structures. While there is much disagreement about the nature of the representations and computations that constitute thinking, the central hypothesis is general enough to encompass the current range of thinking in cognitive science, including connectionist theories which model thinking using artificial neural networks.
Most work in cognitive science assumes that the mind has mental representations analogous to computer data structures, and computational procedures similar to computational algorithms. Cognitive theorists have proposed that the mind contains such mental representations as logical propositions, rules, concepts, images, and analogies, and that it uses mental procedures such as deduction, search, matching, rotating, and retrieval. The dominant mind-computer analogy in cognitive science has taken on a novel twist from the use of another analog, the brain.
Connectionists have proposed novel ideas about representation and computation that use neurons and their connections as inspirations for data structures, and neuron firing and spreading activation as inspirations for algorithms. Cognitive science then works with a complex 3-way analogy among the mind, the brain, and computers. Mind, brain, and computation can each be used to suggest new ideas about the others. There is no single computational model of mind, since different kinds of computers and programming approaches suggest different ways in which the mind might work. The computers that most of us work with today are serial processors, performing one instruction at a time, but the brain and some recently developed computers are parallel processors, capable of doing many operations at once.
REPRESENTATION IN SEMIOTICS
The definition of representation is complex and can be used in two ways. The first being, “To represent something is to describe or depict it, to call it up in the mind by description or portrayal or imagination. To place a likeness of it before us in our mind or in the senses.” (Oxford English Dictionary) The image of the mind here is significant, as will be shown later on. And the second, “To represent also means to symbolise, stand for, to be a specimen of, or to substitute for, as in the sentence; “In Christianity, the cross represents the suffering and crucifixion of Christ.” (Oxford English Dictionary) In semiotic terms “representation is the production of meaning through language.” (Hall 1997: 28). This is the angle we shall look at to define what representation means in a semiotic manner.
In representation we use signs that are organised into languages of different kinds, to communicate meaningfully to others. Both definitions correlate with the concept of signs. Signs carry meaning; therefore they have to be interpreted. These signs can be words, images or even sounds. They constantly surround us. Stuart Hall suggests that there are two systems of representation that we work with (Hall 1997: 29). Firstly he states that all objects, people and events in our minds are connected with a set of concepts. Without this system we would not understand much, as the meaning depends on the links we make between an image and its concept.
Ferdinand de Saussure, a Swiss languist, claimed that each sign has two parts: the signifier which is “the vehicle which expresses the sign” (Bignell 1997: 11) and the signified which is “the concept which the signifier calls forth when we perceive it” (Bignell 1997: 12). So the cross that symbolises the sufferance of Christ used in the definition, would be the signifier. These relations allow us to draw meaning from a sign.
http://www.aber.ac.uk/media/Students/scl0001.html (A semiotic analysis of the representation of ‘the family’ in children’s commercials
Scarlett Lloyd-Davis)
