Physical Symbol Systems & Computational Theory of Mind PDF

Physical Symbol Systems The Computational Theory of Mind Mental processes (thinking, imagining, understanding) can be best understood as computations. To compute is, roughly, to: Represent a problem Follow rules for manipulating that representation Form a representation of the solut...

Physical Symbol Systems The Computational Theory of Mind Mental processes (thinking, imagining, understanding) can be best understood as computations. To compute is, roughly, to: Represent a problem Follow rules for manipulating that representation Form a representation of the solution by following those rules Turing machine – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP Start in state A, with Machine head reading cell indicated by arrow: 1 1 1 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP It rights 1, moves Right, and stays in state A 1 1 1 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP It rights 1, moves Right, and stays in state A 1 1 1 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP 1 1 1 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP 1 1 1 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP 1 1 0 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP 1 0 0 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP 0 0 0 Machine Table – Add 1 0 1 -- A 0, R, A 1, R, A --, L, B B 1, L, STOP O, L, B 1, L, STOP 1 0 0 0 Physical Symbol System Hypothesis Physical Symbol System A physical symbol system has the necessary and sufficient means for general intelligent action. Symbols – physical patterns that can be combined to form more complex symbol structures Processes/rules – used for transforming symbols and symbol structures; can themselves be represented by symbols and symbol structures 1. Symbols Physical Objects 2. Combining symbols into symbol structures Rules govern how symbols can be combined – these rules are recursive 3. Transforming symbol structures Necessary and Sufficient for intelligence. Necessary: intelligent systems must be physical symbol systems. Sufficient: Physical symbol systems are enough for intelligence. Essentially intelligence is problem solving. Problem solving Search space: defined by all possible permissible transformations of an initial state This Photo by Unknown Author is licensed under CC BY- Problem solving Finding a solution state in the search space Brute Force? GPS program – means-end analysis This Photo by Unknown Author is licensed under CC BY-SA Means-end analysis  4. Processes for transforming symbols can themselves be represented as symbols Symbol structures can encode directions for transforming other symbol structures. This Photo by Unknown Author is licensed under CC BY- The Computational Theory of Mind Mental processes (thinking, imagining, understanding) can be best understood as computations. To compute is, roughly, to: Represent a problem Follow rules for manipulating that representation Form a representation of the solution by following those rules