Rules 1

Symbolic Cognitive Science: the Basics

• Intelligence (or cognition) involves manipulating symbols and symbol structures using rules (which are really just symbol structures).
  • Some symbols: PERSON, PERSON83, MARSHA, RED, GO, GO27, COLOR, PHYSICAL_TRANSFER, GOER, DESTINATION
  • Some symbol structures:
    (PERSON MARSHA)
    (GO MARSHA KROGERS)
    (GO GO27 (GOER MARSHA) (DESTINATION KROGERS))
    (TELL MARSHA IGOR (GO MARSHA KROGERS))
  • Rules: knowledge about what to do or what to infer under certain circumstances
    Rules require variables (like ?X and ?GIVER below) so that they can apply to many different situations; more on variables later.
    Examples:

    if (ABOVE ?X ?Y)
    then (BELOW ?Y ?X)

    if (MOVING)
    and (AHEAD ?X)
    and (SOLID ?X)
    then (TURN 90)

    if (GAVE ?GIVER ?GIVEN ?RECIPIENT)
    then (HAVE ?RECIPIENT ?GIVEN)
    and (NOT (HAVE ?GIVER ?GIVEN))

    if (GOAL (PAST_TENSE ?V))
    and (ENDING ?V /D/)
    then (SAY [?V + /ID/])

• Manipulating symbols and symbol structures means pulling them apart and creating new ones by combining them in ways prescribed by rules

Why Symbolic Cognitive Science?

• We seem to reason using symbols.
• Symbolic computational models have achieved many impressive results (though they are very far from modeling human cognition).
• From computer science there are many results telling us what we can do with symbolic models.
• There aren't any viable competitors. Yet.

Take me back to the Rhythm and Cognition Home Page.

Last updated: 9 November 1995
URL: http://www.indiana.edu/~gasser/rules1.html
Comments: gasser@salsa.indiana.edu
Copyright 1995, The Trustees of Indiana University