Cognition and FDG 79an autonomous way (as can be seen, for instance, in the study of certain
aphasias, as in Saffran 1982, Saffran et al. 1980, or Schwartz 1987); but,
at the same time, there is also some evidence that interaction does take
place (cf. Olson 1973, Shatz 1977).
Another consideration is that we have a certain knowledge of the struc-
ture of external reality, which is based on bodily and sensory experience, as
cognitive linguistics has argued (cf. Radden 1992, Lakoff 1990). This
means that we have an internal representation of that structure in terms of
entities that interact in time and in space, with certain properties and cer-
tain relations, and we also have an idea of the causal structure of events in
the world. This long-term knowledge of an experiential nature can be
mapped onto knowledge about word classes and grammar categories
(nouns, verbs, categories of number, person, tense, aspect, mood, modality,
etc.) and this mapping can be assumed to take place in the cognitive com-
ponent, which is like a black box to the Functional Discourse Grammar
model, since the three levels in this model can receive its input but can nei-
ther see nor influence its contents.
- The computer metaphor
The most interesting feature of the Functional Discourse Grammar model,
however, may not lie in its structure, but rather in its functioning. I there-
fore want here to put forward a conceptualization, congruent with the
encoding-decoding process that takes place in actual communicative inter-
action, of what this functioning might look like. In order to do this, I will
use a model from computer science.
Cognitive psychology has always been characterized, since its start in
the late fifties, by its repeated use of the computer metaphor in all the mod-
els it has presented. Broadbent (1968), for instance, used flow diagrams to
show the workings of our faculty of attention. Flow diagrams have also
been used to show the different kinds of memories (long-term memory,
short-term memory, and, later on, working memory) as storage places out
of which or into which a flow of information comes and goes (Atkinson
and Shiffrin 1968, Baddeley and Hitch 1974). Now that we have entered
the 21st century, psychologists do not feel so enthusiastic about using flow
diagrams, so that the situation has been reversed, with computer scientists
now looking to the brain itself for a model in the form of connectionism.
However, there is still room for the computer metaphor in the explana-
tion of the mind’s workings, and obviously there is room too for that