Jump to first page Computationalism: The Very Idea David Davenport Bilkent University, Ankara – Turkey. disclaimer (non-standard!)

Jump to first page Introduction n Wealth of detail n lacks solid foundations n Understand the “big-picture” n organising principle - vocabulary COMPUTATIONALISMCOMPUTATIONALISM 101

Jump to first page Outline n Introduction n What is Computation? n What is Cognition? n Is Computationalism correct? n Issues u Meaning u Symbols & Rules u Representation u Timing n Concluding Remarks

Jump to first page Models… n Physical Replicas u Answer questions u Make predictions u Implementation independent u Observer-relative u Cost, time, difficulty of production

Jump to first page Models… n Abstract {computational} n Answer questions, make predictions! n Map questions to answers n All equivalent a=f(q) a=r(s(s(t(q)))) a=u(v(q)) g=t(q) for 2 times h=s(g) g=h a=r(h)

Jump to first page Implementation n Map states & seq. u Find existing system u Construct one anew u Use digital computer n Rely on causation n Program/algorithm/computation is u abstract spec. of causal system.

Jump to first page What is Computation? n Models… u Answer questions, make predictions! u Physical/abstract {computational} n Computational Model u Is a function! {questions to answers} u Equivalent views… n Implementation u Find existing system u Construct one anew {use computer} u Rely on causation n Program/algorithm/computation u abstract spec. of causal system.

Jump to first page What is Computation? n Answer questions, make predictions! n A function! Abstract, but physical implementation. n Program/algorithm/computation u abstract spec. of causal system.

Jump to first page Computation… Target system Implementation Abstraction

Jump to first page Putnam’s Argument… n Explain & refute

Jump to first page What is Computation? n About Prediction n Program/algorithm/computation u abstract spec. of causal system. n Concept is not vacuous! n But, it is in the eye of the beholder u Interpretation u State & system!

Jump to first page What is Cognition? n Agents – parts of world n Cognitive Agents use knowledge n Prediction is the key! n Models predict n Choose most appropriate action based on present situation, past experience, knowledge of effects of own actions.

Jump to first page Computationalism n Can cognition be described or simulated by computations? n Different levels! n Assuming physical basis n & occurs elsewhere

Jump to first page Computationalism n Is cognition literally computation? n Computation is part of cognition (the agent’s world model) n The rest, I/O, goals, matching & decision making mechanism? n Semantics? n Subjective aspects…?

Jump to first page Computationalism n Can the notion of computation help explain cognition? n Computation is clearly u Of practical & historic importance! u Related to cognition u Not vacuous! n Does lack semantics, timing & is not embedded, but…

Jump to first page Meaning n Representations acquire it u From other symbols? F Chinese Room Argument F Foreign language dictionary u From causal links to environment? F Symbol Grounding, but… n State has meaning for the agent F If it has predictive value! F May be wrong, unreal, undemonstrated, etc.

Jump to first page Symbols & Rules n Model viewed as formal system n Symbols & rules may be u Innate or Learnt u Primitive symbols F Disjunctions/Conjunctions u Internal or External n Rules – logical mechanism!

Jump to first page Representation n Symbolic, Connectionist, Dynamicist? n Functional accounts of Cognition & computation n Organisation/Implementation issue.

Jump to first page Timing n Too quick n Too slow n Unstable! Maybe time is sequence!

Jump to first page Concluding Remarks n Computationalism is right! u Computation, is about prediction u Cognition, demands prediction n Computation - states representational u only to observer n Cognition - states representational u to observer u & for agent itself (i.e. has predictive value.)

Jump to first page Physical Systems Cognitive Actually Computing Systems Potentially Computational Systems Classes of Systems

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