Foundations Of Cognitive Science

Symbol Grounding Problem

The symbol grounding problem (Harnad, 1990) is a version of the problem of representation (Cummins, 1989): how is it possible for the symbols in a physical symbol system to designate, that is, to be meaningful?  Harnad calls this the symbol grounding problem because his proposed solution is very embodied in nature, where elementary representations (an embodied version of Cummins’ covariation?) serve to ground the meanings of more abstract symbols that categorize them: “Symbolic representations must be grounded bottom-up in nonsymbolic representations of two kinds: (1) iconic representations, which are analogs of the proximal sensory projections of distal objects and events, and (2) categorical representations, which are learned and innate feature detectors that pick out the invariant features of object and event categories from their sensory projections” (Harnad, 1990. p 35).


  1. Cummins, R. (1989). Meaning And Mental Representation. Cambridge, MA: MIT Press.
  2. Harnad, S. (1990) The symbol grounding problem. Physica D, 42, 335-346.

(Added October 2010)