Kat’s lecture notes
Day 5 – Producing the Spoken word
Word finding in Aphasia
Almost all aphasic people have some degree of word finding difficulty or anomia. This results in
hesitancies, blocks, omissions and speech errors. Aphasic people often cite word finding as
their major problem and a priority for therapy. Below are some typical examples of aphasic
word finding errors. Most occurred during picture naming tasks, which enable us to compare
the error to a known target.
Target
anchor
Production
for holding the sleep steady when its
sunk in water
Classification
Circumlocution
iron
Hoover
bus
Sarabang
semantic
error/paraphasia
mixed error
dart
Dark
table
kurzle, kazle, tazle, tayzle, table
phonological error or
literal paraphasia
conduite d’approche
jacket
Helicopter
verbal paraphasia
onion
Thustle
Neologism
Failure point
Knows meaning.
Can’t access
phonology
Partial semantic
knowledge
Phon. Distortion
with a sem error
(charabanc)
Impaired
phonology
Impaired
phonology
Unrelated to
target!
Unrelated to target
What would happen if any of these stages failed?
Impaired object recognition
Recognition problems, or agnosias, are different from naming problems. There is an
example from Oliver Sack's book, 'The man who mistook his wife for a hat'. Sacks asks
Dr P to name a glove. As he cannot recognise the object he cannot do this. Instead, he
describes it: ‘a continuous surface infolded on itself. It appears to have ... five
outpouchings'. Later in the session Dr P accidentally slips the glove over his hand and
immediately exclaims "My God its a glove'. He had Visual Agnosia, or an inability to
recognise objects from sight. Despite this, he could see & describe them. He could
also recognise from touch.
Impaired access to the semantic system or damage within the system itself
This leads to a poor understanding of objects/words, eg the person may not recall the
function of an item or its relationship to other objects. We expect semantic errors in
production (eg calling an iron a hoover). If the semantic system is impaired,
comprehension will also be poor (as we assume that just one semantic system serves
both production and comprehension). Word production will be affected by semantic
variables, such as imageabilty. There is good evidence that people with aphasia have
problems with semantic access rather than a difficulty within the system itself. This
makes them different from people with dementia (Jeffries and Lambon Ralph 2006).
Loss of access to the phonological output lexicon
Here the person knows the meaning of the word, but cannot access its phonology. The
person may circumlocute, or describe the blocked word (see table above for an
example of circumlocution). A phonologically related word (or non word) may be
produced instead of the target. Access to the POL is influenced by frequency, ie high
frequency words are typically named better than low frequency words. Problems at this
level often reflect blocked access to words, rather than a loss of words in the POL.
Evidence:
o naming is often helped by cues, eg where we supply the first sound of the word
o naming is often inconsistent, ie an item may be named on one occasion but not
on the next
A problem with phonological assembly (eg Franklin et al 2002)
Target words are distorted in production, eg segments may be omitted, substituted or
exchanged. There may be conduite d'approche, where the person gradually gets closer
to the target via a series of phonological errors. Length could be a factor – with longer
words being more impaired than shorter words. Fluent, effortless articulation shows
that it is not a motor problem. People with Conduction Aphasia are thought to have a
problem at this level of processing.
A problem with the motor stages of production
This will be marked by poor organisation or execution of speech movements. There
may be hesitant, groping articulation, with dyspraxia or dysarthria. This is strictly a
speech problem, rather than a naming problem.
Some questions to ask
 Is word retrieval failing?
 What is the extent of the problem and does it impede everyday communication?
 Is word retrieval a priority for the aphasic person?
 Why is word retrieval failing, in terms of the level of breakdown?
 What helps?
 Is the person using any strategies and what strategies might be used?
A Case Example: RS (Marshall et al 1990)
RS was a 45 year old company director who acquired aphasia after a left CVA. His speech was
hesitant with word finding problems. He flagged these up as a priority for intervention.
Observations on his dialogue:
There are a number of points in the conversation where RS experiences word finding difficulties,
causing hesitancies and word substitutions. Most of the words that he uses seem to be very
high frequency (although he uses these to good effect). When he has to access a specific term
(such as ‘bank’) his problems emerge. Word finding is not obliterated. He may retrieve a word
after a delay or come up with a close alternative (such as ‘fee’ for ‘offer’). R has some good
strategies for getting round his problems (such as ‘goodbye’ for the concept of redundancies).
R’s comprehension seems good. He shows understanding of specific and abstract words (such
as ‘staff’ and ‘offer’).
Assessment Plan
Tests aimed to find out:
The extent of R’s naming problem
Whether he could be cued
Where word retrieval was breaking down:
 Semantics?
 Phonology?
Tests of semantic knowledge
Our model assumes that we have just one store of semantic knowledge which we access on
input and for output. We can therefore use input tests to explore semantic knowledge. Here
are the results of some semantic tests with RS
Pyramids and Palm Trees (all picture version)
3 errors (within normal limits)
Spoken word to picture matching
98%
Synonym judgements with concrete words
95%
Judging picture names*
100%
*R was shown a picture and offered a name that was either correct or semantically related to
the target. He had to accept or reject the name.
R shows good understanding of pictures and concrete words. It seems that his naming
problem is not primarily due to a semantic impairment. In line with this he does not make
semantic errors in naming, and cannot be tricked into making them.
Test of phonological knowledge
30 pictures were presented for naming. If R could not think of the work he was offered a cue
(eg /l/ for lion). Occasionally the therapist miscued him (ie /t/ for lion), to see if he could be
‘tricked’ into making semantic errors. R named 10 pictures correctly. Most of his errors were
failures to respond. He found correct phonological cues helpful, but did not respond to miscues.
Is language breaking down at the level of phonology?
We already have one piece of evidence here. R could be cued with the first sound of the word.
This suggested that the phonological representation may be retained in the POL, but difficult to
access.
There was some more evidence. R was asked to read a number of regular and irregular words
aloud. He performed perfectly. It seems that he could produce word phonologies as long as he
was provided with the written word form. The fact that he could read irregular words shows that
he was not simply using GPC.
Conclusions
It looks like the semantic system is relatively ok (good performance on semantic tests, at least
with concrete items). The Phonological output lexicon also seems preserved (response to cues,
reading aloud). R can also articulate (spontaneous speech, reading aloud). We therefore
concluded that the problem lay in the link between the semantic system and POL.
Picture naming
30 pictures were presented for naming. If R could not think of the work he was offered a cue
(eg /l/ for lion). Occasionally the therapist miscued him (ie /t/ for lion), to see if he could be
‘tricked’ into making semantic errors. R named 10 pictures correctly. Most of his errors were
failures to respond. He found correct phonological cues helpful, but did not respond to miscues.
Moving into Therapy
Therapy took advantage of two processing strengths:
the ability to make semantic discriminations between related words
the ability to read aloud
Therapy task: matching a picture to one of 5 written related words, eg for the target ‘television’
the pictures might show: a radio, Hi Fi, television, computer & camera. After RS selected the
target word he had to read it aloud. Thus RS accessed the phonological form of the word, in the
context of making a semantic decision about it. We hoped that this might re-build the links
between semantics and phonology, and so improve naming. 25 words were treated in this way,
in about 3 hours of therapy. RS was consistently successful on the therapy task. Feedback
was used to discuss the differences between the target and foils.
Results (on a picture naming task):
pre
treated words
8/25
untreated words
8/25
naming therapy foils -
post
20/25
10/25
11/12
follow up (one month later)
18/25
9/25
-
Therapy recovered access to the phonologies of treated words and perhaps related foils which
appeared in the treatment tasks (the lack of a baseline score requires caution here). The
improvement was well maintained. Generalised access has not occurred, as indicated by the
static performance of the controls. A follow up study showed that RS could benefit from this
type of task even when self administered as a home programme, and that effects were long
lasting. We hypothesised that therapy worked by enabling RS to re-connect semantics with
phonology.
A phonological approach to naming therapy: GF (Robson et al 1998)
GF had a left hemisphere stroke resulting in fluent but meaningless speech (jargon), eg:
I was quite erm that’s why I can’t get weyerd keep ... erm makes me very um here up here
makes him all /s/ all mingsing but these come and I can’t it might be because I had another
setoid no sort of um I mean but when you cough you different but when you right you lie to her
...’ (replying to a question about her holiday)
Assessment results:
Pyramids and Palm Trees
Spoken word to picture matching
Auditory synonym judgements (concrete)
Naming pictures
Reading aloud picture names (reg and irreg)
4 errors (near normal)
39/40
87%
1/40 (awareness of failure)
10/40
Response to cues:
When GF failed to name a picture she was offered either a semantic or a phonological cue.
Semantic cues were useless (GF was irritated by them). Phonological cues were mildly
facilitative (15 words were cued, resulting in 5 correct responses).
Conclusions from Assessments:
Semantic processing is relatively unimpaired at least for concrete words and pictures. Despite
this, naming is virtually impossible. Although reading is also poor it is significantly better than
naming. There is equal success on regular and irregular words, suggesting that GF is not just
using GPC. It seems likely, therefore, that she reads aloud using VIL to POL. The reading
results suggest that some phonological representations are retained. So the naming problem
seems due to impaired access to the POL from semantics.
Therapy Decisions:
Therapy aimed to restore access to lexical phonologies. Therapy could recruit GF’s good
monitoring skills to encourage reflection upon the phonological properties of words. Tasks also
encouraged GF to make use of any partial phonological knowledge she might have about
words, rather than simply providing her with cues. Thus we were aiming to develop a
conscious, phonological self cueing strategy. Therapy comprised 40 sessions (each 20
minutes) conducted in GF’s own home. Therapy lasted 6 months.
Therapy stimuli: a core group of 24 words featured in every session (these were the treated
items tested before and after therapy). Plus 50 words were used in therapy, on a random basis.
These words were used to expand the therapy set and to make sure that GF was not simply
drilled on a small group of items. Tasks:
1.
Syllable judgement
GF heard a spoken word and had to judge whether it contained 1 or 2 syllables. At first the
syllable structure was emphasised through exaggerated intonation. Then normal speech was
used. Finally GF made the judgement purely from a picture of the item or from the real object
(ie now she had to access the phonology herself). If she failed to make the judgement the
therapist spoke the word for GF to judge.
2.
Initial phoneme judgement
GF heard a word and had to judge its first phoneme, first from a choice of 2, then from a choice
of 6 (phonemes were presented as written letters on a card). Finally GF had to make the
judgement from a picture of the item, or from the real object. If GF made an error the therapist
pointed to and produced the correct first phoneme.
3.
Judgement tasks with naming
This level encouraged GF to use the accessed phonological information about a word as a self
cue. As above, she was required first to judge the syllable structure and then the first phoneme
of a word. Having accessed the phoneme she was encouraged to produce it as a cue for
naming. If she could not, the therapist supplied the phoneme, which GF had to repeat and than
attempt to name the item.
This stage was the least successful. Often GF simply named the item after making her
judgement, making the self cueing strategy redundant. If she did not name it, she found it very
difficult to ‘translate’ her phonological knowledge into a cue, eg she could often not articulate the
phoneme.
Results of therapy (picture naming assessment)
pre
Treated words
6/24
Phonologically related controls
5/24
Phonologically unrelated controls
2/24
Total
13/72
post
18/24
14/24
12/24
44/72
follow up
16/24
12/24
10/24
38/72
pre 2
1/40
28/40
post
17/40
31/40
Other PALPA tests
naming pictures
matching written words to pictures
(pre 1 = 6 months before the study)
pre 1
0/40
There was a dramatic improvement in naming which seemed to generalise both to related
words (starting with the same first phoneme as the treated set) and unrelated words. The
generalisation to controls might suggest that the results simply reflect spontaneous recovery.
However, this seems unlikely since GF’s naming prior to therapy was stable, and unrelated
tasks, like written word to picture matching, were unchanged.
As the self cueing component of therapy was least successful. We argued that GF had
recovered ‘automatic’ and generalised access to the POL.
A final point. After assessment we speculated that GF had impaired access to entries in the
POL, rather than the loss of those entries. The fact that therapy gains generalised to untreated
items supports this hypothesis (ie if entries had to be ‘reinstated’ there could have been no such
generalisation).
Conclusions:
Hickin et al 2007: Gains in narrative and conversation depend on the person recovering some
generalised access to word forms. Given that this generalisation is not always achieved, it is
important to integrate naming therapy with a more global approach to the person’s difficulties.
For example, the therapist might also work on compensatory strategies, such as gesture,
drawing or a communication book. Therapy can also aim to change the behaviours of those in
the aphasic person’s environment, so that communication can proceed despite the aphasia.