1. Dependency structure and cognition
Richard Hudson
Depling2013, Prague

2. The question What is syntactic structure like?
Does it include dependencies between words (dependency structure)?
Or does it only contain part-whole links (phrase structure)?
She looked after him
after him
She
looked
after
him

3. Relevant evidence: familiarity
University courses teach only one approach.
School grammar sometimes offers one.
Usually dependency structure
even in the USA
Reed-Kellogg sentence-diagramming
especially in Europe
and especially in the Czech Republic!

4. What Czech children do at school
blossomed out
kingcups
by stream
yellow
near
Jirka Hana & Barbora Hladká 2012

5. or even …

6. Relevant evidence: convenience
Dependency structure is popular in computational linguistics.
Maybe because of its simplicity:
few nodes
little but orthographic words
Good for lexical cooccurrence relations

7. Relevant evidence: cognition
Language competence is memory
Language processing is thinking
Memory and thinking are part of cognition
So what do we know about cognition?
A. Very generally, cognition is not simple
so maybe syntactic structures aren't in fact simple?

8. B. Knowledge is a network
Gretta
John
Colin me
Gaynor
Lucy
Peter

9. C. Links are classified relations
person
relative
is-a
woman
man
parent
child
mother
father

10. D. Nodes are richly related
Gretta
John m m s f f s s s
Colin b me
Gaynor w b h d gf
Lucy s
Peter

11. E. Is-a allows default inheritance
Is-a forms taxonomies.
e.g. 'linguist is-a person', 'Dick is-a linguist'
Properties 'inherit' down a taxonomy.
But only 'by default' – exceptions are ok.
e.g. birds (normally) fly
but penguins don't.

12. Penguins bird 'flies' robin penguin 'doesn't fly' robin* 'flies'

13. Cognitivism 'Cognitivism'
'Language is an example of ordinary cognition'
So all our general cognitive abilities are available for language
and we have no special language abilities.
Cognitivism matters for linguistic theory.

14. Some consequences of cognitivism
Word-word dependencies are real.
'Deep' and 'surface' properties combine.
Mutual dependency is ok.
Dependents create new word tokens.
Extra word tokens allow raising.
But lowering may be ok too.

15. 1. Word-word dependencies are real
Do word-word dependencies exist (in our minds)?
Why not?
Compare social relations between individuals.
What about phrases?
But maybe only their boundaries are relevant?
They're not classified, so no unary branching.

16. Punctuation marks boundaries
At the end of the road, turn right.
Not:
At the end of the, road turn right.
At the end, of the road turn right.
At the end of the road turn right,
How do we learn to punctuate if we can't recognise boundaries?

17. No unary branching If S NP + VP, then:
But if a verb's subject is a noun: NP VP N V N V
moo.
Cows
moo.
Cows

18. 2. 'Deep' and 'surface' properties combine.
Dependencies are relational concepts.
Concepts record bundles of properties that tend to coincide
e.g. 'bird': beak, flying, feathers, two legs, eggs
'mother': bearer, carer
So one dependency has many properties:
semantic, syntactic, morphosyntactic
e.g. 'subject' ….

19. 'subject' The typical subject is defined by meaning
typically 'actor' or …
word order and/or case
typically before verb and/or nominative
agreement
typically the verb agrees with it
status
obligatory or optional, according to finiteness

20. So …
Cognition suggests that 'deep' and 'surface' properties should be combined
not separated
They are in harmony by default
but exceptionally they may be out of harmony
this is allowed by default inheritance

21. 3. Mutual dependency is ok.
Mutual dependency is formally impossible in standard notation
And is formally impossible in phrase structure theory
So if it exists, we need to
resist PS theory
change the standard notation

22. Mutual dependency exists
I wonder who came?
Who is subject of came,
so who depends on came.
But who depends on wonder
and came can be omitted:
e.g. Someone came – I wonder who.
So came depends on who.

23. Standard notation A 'dominates' B so A is above B A B
so B cannot 'dominate' A B A

24. 4. Dependents create new word tokens.
General cognition:
every exemplar needs a mental node.
no node carries contradictory properties.
so some exemplars need two nodes.
E.g. when we re-classify things.
NB we can remember both classifications

25. What kind of bird?
bird
blackbird B ?
mate B*

26. NB like* is a token of a token
And in language …
word
LIKE-verb I
like ?
subject
like*
NB like* is a token of a token

27. The effect of a dependent
When we recognise a dependent for W, we change W into a new token W*.
The classification of W* may change.
W* also has a new meaning
normally a hyponym of W
but may be idiomatic
If we add dependents singly, this gives a kind of phrase structure!

28. typical French house HOUSE meaning house house meaning house French

29. Notation
house**
house*
typical
French
house
typical
French
house

30. 5. Extra word tokens allow raising.it
subject
rains it
subject
subject
predicative
it*
raining
keeps

31. Raising in the grammar A* is-a A, so A* wins. higher parent A* B
shared
lower parent A C

32. 6. But lowering may be ok too.
Raising is helpful for processing
the higher parent is nearer to the sentence root.
But sometimes lowering is helpful too
e.g. if it allows a new meaning-unit.
Eine Concorde gelandet ist hier nie.
a Concorde landed has here never.
A-Concorde-landing has never happened here.

33. German Partial VP fronting
Eine Concorde
higher parent
Eine Concorde*
gelandet
ist
hier
nie
lower parent
lowered

34. Conclusions Language is just part of cognition.
So syntactic dependencies are:
psychologically real
rich (combining 'deep' and 'surface' properties)
complex (e.g. mutual, multiple).
And dependency combines with
default inheritance
multiple tokens