Stevan Harnad - Computation is symbol manipulation

Question 1

CTTP (Church-Turing Thesis Physical)

Answer 1

It extends the Church-Turing Thesis, which asserts that any effectively calculable function can be computed by a Turing machine.

A system where actions are determined by the current state, possible transitions, and symbols read.

Whatever physical systems can do, computers can do.

Question 2

Computation

Answer 2

Manipulating symbol tokens based solely on their shapes.

Question 3

Computationalism

Answer 3

Proposes cognition as a form of computation.

Question 4

Semantic Interpretability

Answer 4

The symbols and operations within a computational system have meaningful and contextually appropriate interpretations that correspond to real-world entities and concepts.

Important, because it requires understanding of semantics and not just syntax for a machine to replicate cognition.

Question 5

Trivial vs. Nontrivial Computation

Answer 5

Nontrivial systems possess inherent structure and resist arbitrary changes, unlike trivial systems.

Question 6

Implementation Independence

Answer 6

Allows replacing symbols without altering computation, abstracting it from physical details.

Question 7

Turing Indistinguishability

Answer 7

States that if someone or something behaves indistinguishably from others, it’s rational to attribute similar capabilities.

Question 8

Symbol Grounding Problem

Answer 8

Involves connecting symbols directly to what they represent without external interpretation

Question 9

Cognition: Virtual vs. Real

Answer 9

Weak CTTP suggests physical systems are equivalent to Turing Machines, but simulations don’t equate to genuine understanding.

Question 10

Differential Equations and Implementation Dependence

Answer 10

Strong CTTP overlooks implementation independence, crucial for distinguishing computation from other natural phenomena.