Language and Cognition
Colombo, June 2011
Day 9
Aphasia: disorders of syntax
Agrammatism
• Deficits in syntactic aspects of production and
comprehension of sentences
• Word level is often (comparatively) spared
• Agrammatism has been identified in other
clinical populations, but has been studied
most extensively in Broca’s aphasics
Characteristics of Broca’s aphasia
• Spoken language:
– Short phrase length, limited range of syntactic structures
– Telegraphic speech – primarily content words (function word
omission)
– Speech may be very effortful – prosody is often abnormal
– Articulatory difficulties are common (apraxia / dysarthria)
– Poor repetition
– Disrupted naming ability
– A range of impairments in reading and writing
• Receptive language:
– Relatively good for single words and short sentences
– Impairments in comprehension of grammatically complex
sentences
• Often very good insight into deficits
Syntax
• Structure in language – just like structure
in (the rest of) nature
The sailor
is kissing
the girl
Syntactic movement
• The sailor is kissing the girl
• Who is the sailor kissing?
• The sailor is kissing who
• Who is the sailor tis kissing tthe girl/who?
• Movement leaves “traces” behind
Mapping
• It’s not enough to “know” (implicitly) what the
structure of a sentence is
• We also have to know how to interpret the
structure
• Thematic roles (also called theta theory,
argument structure etc):
– subject of a sentence is usually the AGENT of the
verb
– Object of a sentence is usually the PATIENT or
THEME of the verb
Mapping
• Theta-roles: assignment of interpretive roles to syntactic objects
subject
John
verb
object
kissed
Mary
Grammatical roles
Theta roles
Agent
Patient
• Non-canonical word order  reliance on grammatical structure
object
John
verb
subject
was kissed by Mary
Agent??
Patient??
In English….
• Mapping between theta roles and
grammatical roles is achieved by using word
order
• Subject first = Agent
• Object first is non-canonical, and indicates a
passive
In Sinhala….
• Literary and colloquial language varieties
• There is a passive construction in the literary
variety of Sinhala
• Mapping between theta roles and syntactic roles
is achieved using grammatical morphemes – NOT
by changing word order
In Sinhala….
• The colloquial variety only has the active
construction
• BUT there are volitive and involitive ways to
express the same sentence
In Sinhala….
• Sinhala passive requires the Agent to be in a
position at the front of the sentence
• Other constructions seem to show free word
order
All Sinhala examples are from Gunasinghe & Kess, 1985
http://sealang.net/sala/archives/pdf8/kess1985preliminaries.pdf
Agrammatism in English and Sinhala
• English: omitted morphemes
• Sinhala: substituted morphemes
• English: passive is interpreted like active
• Sinhala: nonvolitional may be interpreted like
volitional
Agrammatic comprehension
• Sentence-picture matching tasks
• Non-reversible sentences are easier to
interpret than reversible ones
• Canonical sentences – subject-verb-object
– are easier to interpret than noncanonical ones
– Passive vs active
– Object relative vs subject relative
• Less complex phrase structure makes a
sentence easier to understand
The mother is calling her child who has light hair
The woman who is fat is kissing her husband
Syntactic trees
Questions (in English)
In Sinhala…
• Sinhala is considered a “wh in situ” language
• That means it does not move wh elements from one position in
the sentence to another
• BUT whether we are speakers of English or Sinhala (or whatever)
there is evidence to show that we all apply the SAME processes of
linguistic analysis to understanding sentences
• Underneath it all, it seems that every language DOES move WH
items
• In some languages, the WH item is pronounced in its moved
position (this is called OVERT movement)
• In some languages, the WH item is pronounced at the trace
position (this is called COVERT movement)
Maybe agrammatism = central
syntactic deficit
• Caramazza and Zurif, 1976
• Agrammatic aphasics DO have comprehension
problems
• They have difficulties understanding sentences
when they must rely on syntactic knowledge to
do so
• This parallels their production deficits
• They have lost knowledge of syntactic structure
(affects all modalities in similar ways)
Another view: is agrammatism a
problem with mapping?
• Problems with the central syntactic deficit account:
– agrammatics do have some ability to interpret complex
utterances - in particular, they are quite good at
grammaticality judgement
– Some agrammatics are modality-specifically impaired –
note assumptions of central deficit hypothesis
– Some fluent aphasics show comprehension deficits
similar to those found in Broca’s aphasics
• Perhaps the deficit is not central to syntax, but
involves only the mapping between syntax and
interpretation of sentences (Saffran et al 1980)
Is agrammatism a problem with
syntactic representations? The trace
deletion hypothesis
• We have seen that things move around in sentences
• And we have seen that interpreting sentences does not
just mean knowing where the subject and the object are
– it means knowing what theta roles to assign, too
• In the normal language system, movement leaves
traces behind
• Theta roles can be assigned to traces, and then
transmitted to the moved item
• Grodzinsky (1990) asked: what if traces get deleted
from the syntactic representation?
• Maybe this is what happens in agrammatism
• The trace deletion hypothesis
If traces are deleted…
• No problem understanding a sentence where
nothing has moved (i.e., canonical word order)
• Problems come when trying to understand
sentences where movement has occurred (i.e.,
non-canonical word order)
• Without traces to help them understand where
the moved elements have come from,
agrammatic aphasics cannot figure out the roles
of the subject and the object in a sentence
• So they guess  chance performance
In Sinhala…
• If traces are deleted, word order will be free
• This might change things for production:
• WH items might be produced in moved
positions? – may not matter given free word
order
• But it is predicted to cause problems for
comprehension, because the reconstruction of
underlying structure is important for sentence
interpretation in every language
Trace Deletion Hypothesis
• Assigning a theta role to ‘the girl’
should be no problem – no trace
involved in that
• P ‘by’ assigns a theta role of
Agent – so ‘the girl = Agent
• But, if traces are deleted, then ‘the
boy’ has no theta role
• So follow your instincts –
USUALLY, the first noun in a
sentence is the Agent
• So ‘the boy’ is probably an Agent
• Now, the agrammatic thinks:
‘the boy’ = Agent AND
‘the girl’ = Agent
• What to do? GUESS at the right
interpretation of this sentence
A simpler view…
• Ouhalla (1993) and
others
• The syntactic tree of
a typical sentence is
large and complex
• People who have an
agrammatic deficit
may be unable to
access higher parts
of the tree
Recommendations:
• So, we should not be using the higher parts
of the tree, so far as possible, when working
with agrammatic patients
• Can educate communicative partners this
way too – show how a wh question involves
a great deal of syntactic complexity; a yesno question is relatively simpler; passives,
relative clauses and locatives may overload
the system very easily
• simplest of all is an active, nonreversible
statement
Planning intervention
What person can do
cannot do
does do
closing the gap
What person needs to do
wants to do
Planning intervention
What person cannot do
can do
closing the gap
What person needs to do
wants to do
does do
Desired ability
Person needs/wants to make
statements & requests
Cannot produce a variety of
syntactic constructions
Communicates through use of
substantive words and occasional,
simple syntactic constructions
Has relatively spared auditory
comprehension
needs/wants to ask
questions and socially
converse
Treating sentence level deficits: a
mapping approach
•
Recall: the Mapping Hypothesis
–
•
•
•
There is not a problem in syntax per se; the problem is in
assigning thematic roles to grammatical objects
MAPPING THERAPY
Present a typed sentence
Make the thematic roles explicit
1. Where are thematic roles assigned from?
•
What’s the main word in this sentence? What is this sentence
about? What action is happening here?
2. What’s the Agent?
•
Which one is doing the V-ing?
3. What’s the Patient?
•
•
•
Which one is getting V-ed? What is s/he V-ing?
Pre and post testing
Generalization issues
Schwartz, MF, Saffran, EM, Fink,
RB, Myers, JL, Martin, N. (1994)
Mapping therapy: A treatment
program for agrammatism.
Aphasiology, 8: 19-54.
Treating sentence level deficits: TDH
• Linguistic specific treatment (LST)
Thompson et al, 1993 onwards
• Train subjects to recognize parts of the
sentence, and then show them how to
move things to form questions
• Generalized to new sentences, and also
from ‘who’ questions to ‘what’ questions
• Also helpful for training on cleft sentences;
may extend to passives
Thompson, C. K., Shapiro, L. P., Ballard, K. J., Jacobs,
B. J., Schneider, S. L., & Tait, M. E. (1997).
Training and generalized production of wh- and NPmovement structures in agrammatic aphasia.
Journal of Speech, Language, and Hearing Research,
40, 228–244.
The man
is
sending
flowers
what
Agent
Aux
verb
is
The man
Agent
sending
verb
1. Move Aux to front (= I to C movement)
what
what
is
The man
Agent
sending
verb
2. Move wh word to front (= wh movement to spec, CP)
Production of grammatical morphemes
• Production deficit in nonfluent aphasics
• Cannito & Vogel, 1980: Training regular plurals
on nouns – no carryover to irregular plurals
• Thompson et al 1982: Matrix training of
prepositional forms, allows for testing of
generalization
• Kearns & Salmon 1984: Training on copula is
found to generalize to auxiliary is (but not to
is+locative)
NP1
The river
PP1
Under the
hill
PP2
Behind the
house
PP3
Beside the
mountain
NP2
The tree
NP3
The bridge
The river is
under the
hill
The tree is
behind the
house
The bridge
is beside
the
mountain
Training sentence production
• Syntax Production Program for Aphasia
(Helm-Estabrooks 1981) / Direct
Production Training (Wambaugh &
Thompson 1989)
• Story completion format
• Again, limited generalization to untrained
sentence types
• Little effect on spontaneous language
production
Functional communication
• E.g. Promoting Aphasics Communicative
Effectiveness (PACE)
–
–
–
–
Clinician and client participate equally
There is an exchange of new information
Speaker can choose modality
Feedback focuses on adequacy of message
• Training conversational partners
• Spouses, volunteers
–
–
–
–
Get the message in
Provide a means for getting messages out
Maintain the flow of conversation
You have to want to communicate
The importance of assessment
• Assessment can be hypothesis driven
• We need to compare the observed deficits with a model
of normal processing
• Then we can formulate a hypothesis about what has
gone wrong for some individual – and what they can still
do
• Example: if someone has a problem with wh question
production
– Could be an issue with syntactic movement
– So test other constructions involving movement – such as
passives, object relatives
– If they are bad at these also, then movement may indeed be the
problem
– If they are good at these, in contrast with questions, then maybe
their problem is one with representing higher levels in the
syntactic tree
– Then you test other constructions involving higher levels in the
tree – such as embedded clauses
The importance of assessment
• If we have a model, we can test / assess
at each level of the model and form more
precise hypotheses about the nature of the
Pt’s impairment  more focused
intervention
• Relating aphasic language impairments to
models of normal language function at
least “forces one to think hard and with
precision about the patient” (Byng et al
1990)