# Computational Theory of Mind The Computational Theory of Mind (CTM) holds that the mind is an information-processing system and that cognition is computation over mental representations. Developed during the [[Cognitive Revolution]] of the 1950s-60s, CTM emerged from the work of [[Alan Turing]], [[Hilary Putnam]], [[Jerry Fodor]], and [[Noam Chomsky]], overthrowing [[Behaviorism]]'s rejection of mental states. The core idea: minds are to brains what software is to hardware—mental processes are algorithms operating on symbolic data structures, and these processes can be studied independently of their physical implementation. CTM combines with the [[Language of Thought]] hypothesis to give a complete picture: thoughts are sentences in Mentalese, and thinking is computational manipulation of these sentences. [[Steven Pinker]], [[Zenon Pylyshyn]], and other cognitive scientists have used this framework to explain perception, language, reasoning, and memory. Critics like [[John Searle]] (Chinese Room argument), [[Hubert Dreyfus]], and connectionists argue that computation alone cannot produce understanding, that symbol manipulation misses embodied cognition, and that neural networks offer better models. The debate between classical computational approaches and neural/connectionist models remains central to cognitive science and AI. ## Computational Mind Architecture ``` ┌─────────────────────────────────────────────────────────────┐ │ COMPUTATIONAL THEORY OF MIND │ ├─────────────────────────────────────────────────────────────┤ │ │ │ ┌─────────────────┐ │ │ │ INPUT │ │ │ │ (perception) │ │ │ └────────┬────────┘ │ │ │ │ │ ▼ │ │ ┌─────────────────────────────────────────────────────┐ │ │ │ MENTAL REPRESENTATIONS │ │ │ │ ┌─────────────────────────────────────────────┐ │ │ │ │ │ Symbols in Language of Thought (Mentalese) │ │ │ │ │ │ │ │ │ │ │ │ BELIEVES(JOHN, RAINING) │ │ │ │ │ │ DESIRES(JOHN, UMBRELLA) │ │ │ │ │ │ ─────────────────────── │ │ │ │ │ │ ∴ INTENDS(JOHN, GET_UMBRELLA) │ │ │ │ │ └─────────────────────────────────────────────┘ │ │ │ │ │ │ │ │ COMPUTATIONAL PROCESSES │ │ │ │ ┌─────────────────────────────────────────────┐ │ │ │ │ │ Algorithms operating on symbols: │ │ │ │ │ │ • Inference rules │ │ │ │ │ │ • Pattern matching │ │ │ │ │ │ • Memory retrieval │ │ │ │ │ └─────────────────────────────────────────────┘ │ │ │ └─────────────────────────────────────────────────────┘ │ │ │ │ │ ▼ │ │ ┌─────────────────┐ │ │ │ OUTPUT │ │ │ │ (behavior) │ │ │ └─────────────────┘ │ │ │ │ MULTIPLE REALIZABILITY: Same computation can run on │ │ different hardware (brains, silicon, alien substrate) │ │ │ └─────────────────────────────────────────────────────────────┘ ``` ## Core Claims | Claim | Description | |-------|-------------| | **Representationalism** | Mind has mental representations | | **Computation** | Cognition is rule-governed symbol manipulation | | **Multiple realizability** | Mind not tied to specific physical substrate | | **Formalism** | Mental processes defined by syntax, not semantics | | **Functionalism** | Mental states defined by causal roles | ## Historical Development | Year | Development | Figure | |------|-------------|--------| | 1936 | Turing machine formalism | [[Alan Turing]] | | 1943 | Neural network model | McCulloch & Pitts | | 1956 | Dartmouth AI conference | McCarthy, Minsky | | 1959 | Machine functionalism | [[Hilary Putnam]] | | 1967 | Psychological functionalism | Putnam | | 1975 | Language of Thought | [[Jerry Fodor]] | | 1980 | Chinese Room argument | [[John Searle]] | ## Key Figures | Thinker | Contribution | |---------|--------------| | [[Alan Turing]] | Computation concept, Turing test | | [[Hilary Putnam]] | Functionalism, multiple realizability | | [[Jerry Fodor]] | [[Language of Thought]], [[Modularity of Mind]] | | [[Noam Chomsky]] | Computational linguistics | | [[Steven Pinker]] | Evolutionary computational psychology | | [[David Marr]] | Computational vision (3 levels) | ## Arguments For CTM | Argument | Description | |----------|-------------| | **Explanatory success** | Cognitive science progress | | **Productivity** | Explains infinite thought capacity | | **Systematicity** | Explains thought patterns | | **Rationality** | Explains valid inference | | **AI success** | Computers can do cognitive tasks | ## Arguments Against CTM | Criticism | Proponent | Objection | |-----------|-----------|-----------| | **Chinese Room** | [[John Searle]] | Syntax insufficient for semantics | | **Embodied cognition** | [[Hubert Dreyfus]] | Mind requires body, not just computation | | **Connectionism** | Rumelhart, McClelland | Neural networks, not symbols | | **Phenomenal consciousness** | Chalmers, Nagel | Qualia unexplained by computation | | **Frame problem** | McCarthy, Fodor | Inference is intractable | ## Marr's Three Levels | Level | Question | Example (Vision) | |-------|----------|------------------| | **Computational** | What is computed and why? | 3D structure from 2D images | | **Algorithmic** | How is it computed? | Edge detection algorithms | | **Implementational** | How is it physically realized? | Neural circuits | ## CTM vs Alternatives | Aspect | CTM | Connectionism | Embodied | |--------|-----|---------------|----------| | **Representations** | Symbolic | Distributed | Sensorimotor | | **Processing** | Serial, rule-based | Parallel, weighted | Situated, dynamic | | **Learning** | Hypothesis testing | Weight adjustment | Skill acquisition | | **Mind-body** | Software/hardware | Emergent | Inseparable | ## Implications | Domain | Implication | |--------|-------------| | **AI** | Strong AI possible (minds are programs) | | **Psychology** | Information processing models | | **Neuroscience** | Brain implements computations | | **Philosophy** | Functionalist metaphysics of mind | ## References - Fodor, Jerry. *The Language of Thought* (1975) - Putnam, Hilary. "Minds and Machines" (1960) - Marr, David. *Vision* (1982) - Pinker, Steven. *How the Mind Works* (1997) - https://plato.stanford.edu/entries/computational-mind/ ## Related - [[Jerry Fodor]] - [[Language of Thought]] - [[Modularity of Mind]] - [[Steven Pinker]] - [[Cognitive Revolution]] - [[Behaviorism]] - [[Philosophy of Mind]] - [[Functionalism]] - [[John Searle]] - [[Chinese Room Argument]] - [[Cognitive Architecture]]