Anomia Treatment: Intensity & Training Size in Aphasia

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/6670022
Computerised treatment of anomia in acute aphasia: Treatment intensity and
training size
Article in Neuropsychological Rehabilitation · January 2007
DOI: 10.1080/09602010543000064 · Source: PubMed
CITATIONS
READS
57
658
3 authors, including:
Marina Laganaro
Marie Di Pietro
University of Geneva
Hôpitaux Universitaires de Genève, Université de Genève
110 PUBLICATIONS 1,823 CITATIONS
35 PUBLICATIONS 551 CITATIONS
SEE PROFILE
SEE PROFILE
Some of the authors of this publication are also working on these related projects:
Rapid naming and reading skills in school‐aged children: A behavioral and ERP approach to the contribution of the lexical‐phonological processes View project
Peripheral components of reading View project
All content following this page was uploaded by Marie Di Pietro on 05 June 2014.
The user has requested enhancement of the downloaded file.
NEUROPSYCHOLOGICAL REHABILITATION
2006, 16 (6), 630– 640
Computerised treatment of anomia in acute aphasia:
Treatment intensity and training size
Marina Laganaro, Marie Di Pietro, and Armin Schnider
Service de Rééducation, University Hospital, Geneva, Switzerland
In this study we analysed the outcome of computer-assisted therapy (CAT) for
anomia on eight acute aphasic patients. Since therapy for anomia generally
leads to an item-specific effect, the aim of the present study was to investigate
whether it is possible to enhance recovery from anomia by increasing the
number of treated items. Two periods of five daily written-naming CAT sessions were compared: In one period the CAT included one set of 48 words
(single list) and in the other period a double list of 96 items was treated.
Seven out of eight patients improved in naming performance for treated
items. Overall gains were superior after practising the double list, despite
fewer item repetitions. These results suggest that the size of the effect of
therapy for anomia depends more on the number of treated items than on
the number of repetitions per item. The integration of these results within the
framework of studies on intensity is discussed.
INTRODUCTION
The efficacy of aphasia therapy has been studied by comparing language
recovery in treated and untreated aphasic patients. Although lack of conclusive proof has been suggested by some authors (Greener, Enderby, & Whurr,
1999; Lincoln et al., 1984; Meikle et al., 1979), a certain number of studies
have demonstrated efficacy of therapy for aphasia (Basso, Capitani, &
Correspondence should be sent to: Marina Laganaro, Service de Rééducation, Hopitaux
Universitaires de Genève, Av. Beau-Séjour 26, CH-1211 Genève 14, Switzerland. E-mail:
[email protected]
This research was supported by Swiss National Science Foundation grant no. 105312100741/1. The authors wish to thank Myrna Schwartz, Kathleen Baynes and an anonymous
reviewer for their helpful comments on a previous version of this paper.
# 2006 Psychology Press, an imprint of the Taylor and Francis Group, an informa business
http://www.psypress.com/neurorehab
DOI:10.1080/09602010543000064
THERAPY FOR ANOMIA: INTENSITY AND TREATMENT SIZE
631
Vignolo, 1979; Mazzoni et al., 1995; Poeck, Huber, & Willmes, 1989). These
group studies analysed the effect of an unspecified therapy for aphasia —
based on a language stimulation approach — on standard aphasia assessment
batteries. By contrast, single-case studies have focused on a specific
language skill, with therapy based on a cognitive analysis of the impairment.
In particular, there is convergent agreement that therapy for anomia can be
effective, especially when a cognitive model-oriented approach is followed
(Best & Nickels, 2000; Nickels, 2002). However, no precise prediction can
be made about the size of the effect of a specific therapy for anomia with a
specific aphasic patient. Indeed, several biographical and neurological
factors, as well as factors linked to treatment type and conditions, may
affect recovery (Basso, 1991, 1992). Among these, the treatment intensity
seems to be an important predictor of the therapy outcome. Treatment
intensity was manipulated in most studies in terms of number of sessions,
and a higher number of therapy sessions was shown to have better outcome
than regular intensity therapy (Basso & Caporali, 2001; Bhogal, Teasell, &
Speechley, 2003; Denes, Perazzolo, Piani, & Piccione, 1996). Alternatively,
therapy intensity has been analysed in terms of massed practice, showing
better outcome when therapy sessions were grouped over a short period of
time rather than distributed over a longer time period (Pulvermuller et al.,
2001). Finally, intensity of treatment can be conceived in terms of drill or
repetition, i.e., number of times the task, or particular items, are presented
for practice during therapy. Indeed, cognitive therapy studies suggest that a
single item presentation has no long-term effect on naming and that several
task and item repetitions are necessary for long lasting effects (Howard
et al., 1985a, b). Although the issue of the number of item presentations
has not been addressed directly, most studies on efficacy of anomia treatment
involved many repetitions of a few items (for example, 30 items presented 50
times in Miceli, Amitrano, Capasso, & Caramazza, 1996; 60 items practised
up to 18 hours of therapy in the studies presented by Nickels & Best, 1996; 9
repetitions for each set of 30 items in Renvall, Laine, Laakso, & Martin,
2003).
Here we address the study of intensity in terms of drill by varying the
number of exposures to items during therapy as a function of the number
of treated words. One way of increasing item drill during therapy is the
introduction of computer-assisted treatment (CAT). CAT programs, designed
to treat anomia, have shown encouraging results with chronic aphasic
speakers (Bruce & Howard, 1987; Fink, Brecher, Schwartz, & Robey,
2002; Pedersen & Olsen, 2001). An item-specific improvement in naming
was described by Bruce and Howard (1987) after five sessions with a computer program providing oral cue. Fink et al. (2002) also reported mostly
item-specific benefits of a computer-assisted phonological cueing therapy
in six chronic aphasic subjects. A written-naming task was used in the
632
LAGANARO, DI PIETRO, SCHNIDER
study by Deloche et al. (1992) and an item-specific improvement with
generalisation from the written to the oral modality was observed for most
patients. Finally, Pedersen et al. (2001) reported efficacy of home-based
CAT for anomia in three aphasic subjects. They also used a written-naming
task and observed an item-specific improvement in two subjects.
Although the issue of therapy intensity has not been explicitly addressed
in CAT studies, authors suggested that the benefits of CAT may be linked
to increased treatment in terms of item repetitions (Mortley, Enderby, &
Petheram, 2001). Since the benefits of therapy for anomia are mostly itemspecific, it would be desirable to increase the number of treated items in
order to increase the amount of recovery. But it is unknown whether improvement can be enhanced by increasing the number of items, or whether the
amount of drill necessary per item, i.e., the number of times each item is
presented as a therapy stimulus, limits the number of treatable items. In a
previous study (Laganaro, Di Pietro, & Schnider, 2003), we analysed the
outcome of computer-assisted therapy for anomia with chronic outpatients
and with acute patients. In the group of acute aphasic patients, daily
CAT sessions were added to individual aphasia therapy sessions, while
CAT sessions were alternated with an equal number of clinical treatment
sessions in the group of chronic patients. An item-specific effect of CAT
for anomia was observed in all chronic patients and in three out of the
seven acute patients.
Our results with acute patients and the observation that the effect of
therapy for anomia is mostly item-specific raised the question as to whether
doubling the number of items practised during a limited number of sessions
would increase recovery, or whether the number of items should be limited
in order to increase repetition of treated items. This question is addressed
by comparing gains in naming after CAT on one set of stimuli versus the
double amount of stimuli for an equal number of sessions.
METHOD
Subjects
Eight patients suffering from aphasia after stroke or traumatic brain injury
(TBI) participated in the study. The inclusion criteria were based on the
outcome of our previous study (Laganaro et al., 2003): Patients had mild to
severe anomia among other aphasic symptoms; correct naming of at least
5% of the items on a screening picture-naming task; no stereotyped
answers; no evident signs of apraxia of speech; mild or no comprehension
impairment; and insight into their language difficulties. The patients were
required to be motivated for therapy and for adding a therapy session to
THERAPY FOR ANOMIA: INTENSITY AND TREATMENT SIZE
633
their daily planning. Concerning computer skills, patients had to be able to
use the keyboard for writing or copying and the mouse for selecting a
button on the screen. These abilities were assessed in a training session
with the same computer program as was used in the study, but with different
word stimuli. Patients were expected to be independent with the computer
program after one or two training sessions. Only one patient, presenting
with limb apraxia and executive dysfunction, was unable to work alone
on the computer program after several training sessions and could not be
included in the study. All the participants were in-patients and were
between one and two months post-onset. They agreed to participate in
the study by accepting a consent form specifically designed for this study
according to institutional guidelines.
The Montréal-Toulouse aphasia examination (Nespoulous et al., 1992) was
used for assessing aphasia. Subjects’ demographic data and aphasia subtype
are given in Table 1. All but two subjects were French native speakers; P2
and P3 were not native speakers, but French was their main language
for over 20 years and the language they recovered best after their stroke.
Therapy design
A spoken picture-naming task of 144 items was used for assessment at
baseline and after each therapy period. The naming material was made up
of three sets of 48 words each and the corresponding line drawings selected
from Alario et al. (2004) and Bonin, Chalard, Méot, and Fayol (2002).
The items in the three lists were matched for name agreement, lexical
frequency, words’ age of acquisition, length and syllabic structure. For
therapy, two sets of items were grouped in order to form a double list of 96
items. These lists (the single list and the double list) were treated following
a crossover design. After baseline testing, the double and the single list
TABLE 1
Subjects’ demographic data
Subjects
Age
Months
post-onset
P1
30
P2
P3
P4
P5
P6
P7
P8
48
56
38
48
39
76
62
Gender
Aphasia type
Aetiology
Lesion
1
M
TBI
Left frontoparietal
1
1
1
1
2
1
2
M
F
F
F
F
M
M
Transcortical
sensory
Conduction
Mixed
Broca
Anomic
Anomic
Wernicke
Anomic
CVA
TBI
CVA
TBI
CVA
CVA
CVA
Left temporoparietal
Left frontotemporoparietal
Left capsulo-lenticular
Left temporal
Left temporoparietal
Left temporal
Extended left perisylvian
634
LAGANARO, DI PIETRO, SCHNIDER
were treated separately by CAT for one week each (5 sessions for each list)
with a post-test assessment in between (Post-test 1) and at the end of the
therapy period (Post-test 2). A third assessment (Post-test 3) was carried
out 2 weeks after the end of the therapy period. Four patients worked on
the single list in the first CAT period and on the double list in the second
CAT period (group A) and four patients started with the double list and
finished with the single list (group B). During the study period, all patients
received one daily CAT session and one daily session of clinical therapy
for aphasia.
A written naming CAT program was used with all patients. The patients
had to write the word corresponding to a coloured picture, which appeared
on the screen with empty boxes corresponding to the number of letters of
the target word. Two help buttons were available: One provided the pronounced word, and the second provided help on each letter of the word.
The graphemes were provided incrementally, that is, the subject could
press the button for help with the next letter only once he had written
down the previous one (or copied it from an earlier cue). Only correct
letters were displayed on screen. This CAT program was chosen because it
involves several cognitive components (orthography, phonology, and semantics), since it has been suggested that a multicomponent treatment may
work in different ways for different anomia types (Best, Howard, Bruce, &
Gatehouse, 1997; Deloche et al., 1992; Nickels, 2002). Moreover, this
same computer program led to significant benefit in three out of four patients
presenting with mixed anomia in our previous study (Laganaro et al., 2003).
During CAT sessions, patients worked alone, but could call a therapist
for technical help. Each CAT session lasted from 30 to 60 minutes, depending
on the patient’s speed, motivation or fatigue. For each therapy session the
computer program recorded the time spent on it, the number of trials, and
any help the subjects had used. Thus, the number of sessions was controlled
during each CAT period, but the time spent on it and the number of item
repetitions varied across patients.
RESULTS
Naming accuracy at baseline and post-tests was transcribed and scored
online by trained speech and language therapists. Only first attempt correct
responses within a delay of 5 seconds were scored as correct.
Naming scores at baseline varied across patients from 8% to 58% correct,
with similar proportional scores on the double and the single list for each
patient (see Table 2). Pearson’s Chi square calculated on each patient’s
naming accuracy on the single and the double list showed no significant
difference between the two lists (all x2 , 1).
THERAPY FOR ANOMIA: INTENSITY AND TREATMENT SIZE
635
TABLE 2
Correct naming (percent) at baseline, mean item repetitions during each CAT period
(columns 4 and 6) and number of recovered items after each period (columns 5 and 7) on
the single list and on the double list for the eight patients
% correct at
baseline
5 CAT sessions on 48
(single list)
5 CAT sessions on 96
(double list)
Item repetitions
per treatment
period
Recovered
treated
words
(post–pre)
n%
Single list
(48) %
Double list
(96) %
Item repetitions
per treatment
period
Recovered
treated words
(post–pre)
n (%)
Group A
P1
P2
P3
P4
7
44
15
8
7
47
13
7
6
9
5
5
7 (15)
11 (23)
25 (52)
3 (6)
4.5
3
2.5
2.5
14 (15)
29 (30)
65 (68)
11 (11)
Group B
P5
P6
P7
P8
58
10
40
17
65
7
49
13
5
5
15
21
12 (25)
18 (37)
22 (46)
20 (42)
5
2.5
4.3
7.2
37 (39)
27 (28)
18 (19)
47 (49)
Subject
Table 2 also shows the amount of gains in naming the treated items for
each patient after each CAT period and the number of item repetitions
during each therapy period (i.e., the number of times each item was practised
as a therapy stimulus during the CAT sessions). Gains are the increase in
the number of correct naming responses in two consecutive testing periods.
All but one patient (P4) improved significantly in picture naming after
CAT (McNemar’s Chi square calculated on the correct naming score on
the 144 items at post-test 3 versus baseline: for P4, x2 ¼ 3,7, p ¼ .06; for
all other participants, x2 . 14.3, all ps , .01). It can be noticed that some
patients practised each set of 48 items only once at each CAT session
(thus, only half of the 96 items were treated during each session when
practising the double list), while other patients repeated each set up to five
times (see P8). Despite these differences, the number of item repetitions
was always much higher for CAT on a single list than for CAT on the
double list.
Figure 1 shows percent correct naming on each list (48 items and 96 items)
at baseline and at each post-therapy assessment period. A repeated measure
ANOVA was carried out on correct naming scores before and after each
therapy period with lists (single, double) and assessment period as within
subject factors. A significant improvement in naming is observed after each
636
LAGANARO, DI PIETRO, SCHNIDER
Figure 1. Correct naming (mean percent) on the single list and the double list for group A (single list
treated first) and group B (double list treated first) at baseline and at each post-test
CAT period, F(1, 7) ¼ 6.9, p , .05 after CAT on the single list, and
F(1, 7) ¼ 40.2, p , .001 after CAT on the double list with a significant
interaction with lists, respectively, F(1, 7) ¼ 7, p , .05 and F(1, 7) ¼ 35.7,
p , .001, showing that improvement is limited to the single list after CAT
on the single list and to the double list after CAT on the double list. Thus,
improvement in naming is linked to CAT and is item-specific.
THERAPY FOR ANOMIA: INTENSITY AND TREATMENT SIZE
637
Results at post-test 3 compared to post-test 2 were unchanged, F(1, 7) , 1,
with no further improvement during the 2 weeks without therapy despite the
ongoing clinical therapy. Proportional naming scores were similar on the
single and the double list at the end of the study (see Figure l), which
means that the absolute gain was double on the double list. A paired t-test
calculated on total gains on the single and the double lists per subject
shows significantly higher improvement on the double list, t(7) ¼ 23.28,
p , .05. Thus, total gains were superior on the 96-items list than on the
48-items list despite less exposure to items (fewer item repetitions). This is
further confirmed by an absence of correlation between the number of item
repetitions for each patient during each treatment period and the related
number of recovered items, r ¼ 2.131, N ¼ 16, p ¼ .63.
DISCUSSION
We described the effect of computer assisted therapy (CAT) for anomia
on eight acute aphasic patients who underwent daily CAT sessions with a
written-naming program, first on a single list (48 items) and then on a
double list (96 items) and vice-versa. A significant improvement in naming
after both CAT periods was observed, which was restricted to the treated
items in both periods. These results are consistent with previous studies
showing item-specific effect of therapy for anomia (Hillis & Caramazza,
1994; Laganaro et al., 2003; Miceli et al., 1996) and cannot be explained
by generalisation, which would have led to improvement in both the
treated and the untreated list. For the same reasons, spontaneous recovery
and/or clinical aphasia therapy do not account for the observed improvement
in naming pictures, which patients were unable to name at baseline.
The main question addressed in this study was whether doubling the
number of stimuli enhances treatment gains from anomia. Results showed
similar proportional improvement on both lists, with numerically higher
gains on the double list than on the single list. Improvement in naming was
not directly linked to the number of times an item was practised, since the
number of recovered words was higher when the double list was treated
despite less item practice, and no correlation between drill and improvement
was found. This result appears to contradict studies suggesting an effect of
treatment intensity on recovery. However, in these studies intensity was
manipulated in terms of number of sessions rather than in terms of drill,
i.e., daily sessions compared to 2 – 3 weekly sessions (Denes et al., 1996)
and 2 –3 hours per day compared to 1 hour (Basso & Caporali, 2001), or in
terms of distribution of sessions over time (3 hours per day as compared to
the same number of sessions over a longer period in Pulvermuller et al.,
2001). In the present study the number of exposures to items during CAT
638
LAGANARO, DI PIETRO, SCHNIDER
varied depending on the number of treated words. Our results suggest that
2– 3 item repetitions in daily therapy may be sufficient for some aphasic
speakers to enable improvement in naming on a one-week period (at least
in the acute stage). Indeed, the number of item repetitions in relation to the
training-set size is very low by comparison with other CAT studies on
anomia, which provided a high number of therapy sessions and of exposure
to target items (20 items repeated up to 12 times in Fink et al., 2002; from
20 to 66 hours therapy for a maximum of 60 items in Pedersen et al., 2001;
and up to 25 session in Deloche et al., 1992). However, we do not argue
that therapy intensity does not play a role in recovery from anomia. First of
all, the conditions of our study are in the form of an intensive therapy with
a daily CAT session added to a daily clinical therapy session. Moreover,
some patients spontaneously practised, twice or more, the CAT program
during each session, in order to increase exposure to items (up to 20 times
for P8). Taken together, our results suggest that, within the framework of
intensive therapy for anomia, improvement is enhanced when the training
size is increased, even in patients practising items at a high repetition rate.
These individual variations of practice with a CAT program may probably
reflect self-evaluation of needs in therapy and item repetitions. Although
doubling the number of treated items increased improvement also in patients
who spontaneously practised each list more than requested, neither list of
items ever was completely recovered after therapy. This suggests that some
items can be recovered under a certain amount of intensity, while others probably need more drill in order to be recovered. Thus, the numerically higher
gains on the double list than on the single list despite a minor drill per item
may reflect that doubling the number of treated items increased the number
of items presenting characteristics that correlate with easier recovery.
Further studies should be oriented to the analysis of the conditions predicting
amount and speed of recovery as a function of training-set size and intensity,
in order to guide item selection and duration in therapy for anomia.
REFERENCES
Alario, X., Ferrand, L., Laganaro, M., New, B., Frauenfelder, U. H., & Segui, J. (2004).
Predictors of picture naming speed. Behavior Research Methods, Instruments, and
Computers, 36, 140 – 155.
Basso, A. (1991). Therapy of aphasia. In F. Boller & J. Grafman (Eds.), Handbook of clinical
neuropsychology. Amsterdan: Elsevier.
Basso, A. (1992). Prognostic factors in aphasia. Aphasiology, 6, 337– 348.
Basso, A., Capitani, E., & Vignolo, L. A. (1979). Influence of rehabilitation on language skills
in aphasia patients: A controlled study. Archives of Neurology, 36, 190– 196.
Basso, A., & Caporali, A. (2001). Aphasia therapy or the importance of being earnest. Aphasiology, 15(4), 307– 332.
THERAPY FOR ANOMIA: INTENSITY AND TREATMENT SIZE
639
Best, W., Howard, D., Bruce, C., & Gatehouse, C. (1997). A treatment for anomia: Combining
semantics, phonology and orthography. In S. Chiat, J. Marshall, & J. Law (Eds.),
Language disorders in children and adults, psycholinguistic approaches to therapy.
London: Whurr.
Best, W., & Nickels, L. (2000). From theory to therapy in aphasia: Where are we now and where
to next? Neuropsychological Rehabilitation, 10, 231 – 247.
Bhogal, S.K., Teasell, R., & Speechley, M. (2003). Intensity of aphasia therapy, impact on
recovery. Stroke, 34(4), 987 –992.
Bonin, P., Chalard, M., Méot, A., & Fayol, M. (2002). The determinants of spoken and written
picture naming latencies. British Journal of Psychology, 93, 89– 114.
Bruce, C., & Howard, D. (1987). Computer-generated phonemic cues: An effective aid for
naming in aphasia. British Journal of Disorders of Communication, 22, 191– 201.
Deloche, G., Ferrand, I., Metz-Lutz, M. N., Dordain, M., Kremin, H., Hannequin, D.,
Perrier, D., Pichard, B., Quint, S., Larroque, C., Cardebat, D., Naud, E., Bargego, C.,
Pradat, P., & Tessier, C. (1992). Confrontation naming rehabilitation in aphasics: A computerised written technique. Neuropsychological Rehabilitation, 2, 117– 124.
Denes, G., Perazzolo, C., Piani, A., & Piccione, F. (1996). Intensive versus regular speech
therapy in global aphasia: A controlled study. Aphasiology, 10(4), 385–394.
Fink, R. B., Brecher, A., Schwartz, M. F., & Robey, R. R. (2002). A computer-implemented
protocol for treatment of naming disorders: Evaluation of clinician-guided and partially
self-guided instructions. Aphasiology, 16, 1061 –1086.
Greener, J., Enderby, P., & Whurr, R. (1999). Speech and language therapy for aphasia
following stroke. The Cochrane Database of Systematic Reviews (Issue 4). Oxford, UK:
Update Software.
Hillis, A., & Caramazza, A. (1994). Theories of lexical processing and rehabilitation of lexical
deficits. In M. J. Riddoch & G. W. Humphreys (Eds.), Cognitive neuropsychology and
cognitive rehabilitation. Hove, UK: Lawrence Erlbaum Associates Ltd.
Howard, D., Patterson, K. E., Franklin, S., Orchard-Lisle, V., & Morton, J. (1985a). The
facilitation of picture naming in aphasia. Cognitive Neuropsychology, 2, 49– 80.
Howard, D., Patterson, K. E., Franklin, S., Orchard-Lisle, V., & Morton, J. (1985b). The
treatment of word retrieval in aphasia: A comparison of two therapy methods. Brain, 108,
818– 829.
Laganaro, M., Di Pietro, M., & Schnider, A. (2003). Computerised treatment of anomia in
chronic and acute aphasia: An exploratory study. Aphasiology, 17(8), 709– 721.
Lincoln, N. B., McGuirk, E., Mulley, G. P., Lendrem, W., Jones, A. C., & Mitchell, J. R. (1984).
Effectiveness of speech therapy for aphasic stroke patients: A randomized controlled trial.
Lancet, 8388, 1197 –1200.
Mazzoni, M., Vista, M., Geri, E., Avila, L., Bianchi, F., & Moretti, P. (1995). Comparison
of language recovery in rehabilitated and matched, non-rehabilitated aphasic patients.
Aphasiology, 9, 553 –563.
Meikle, M., Wechsler, E., Tupper, A., Benenson, M., Butler, J., Mulhall, D., & Stern, G. (1979).
Comparative trail of volunteer and professional treatments of dysphasia after stroke. British
Medical Journal, 14(2), 87– 89.
Miceli, G., Amitrano, A., Capasso, R., & Caramazza, A. (1996). The treatment of anomia
resulting from output lexical damage: Analysis of two cases. Brain and Language, 52,
150– 174.
Mortley, J., Enderby, P., & Petheram, B. (2001). Using a computer to improve functional
writing in a patient with severe dysgraphia. Aphasiology, 15(5), 443– 461.
Nespoulous, J. L., Lecours, A. R., Lafond, D., Lemay, A., Puel, M., Joannette, Y., Cot, F., &
Rascol, A. (1992). Protocole Montréal-Toulouse d’examen linguistique de l’aphasie
(MT86). Isbergues, France: L’Ortho-Edition.
640
LAGANARO, DI PIETRO, SCHNIDER
Nickels, L. (2002). Therapy for naming disorders: Revisiting, revising, and reviewing.
Aphasiology, 16, 935 –979.
Nickels, L., & Best, W. (1996). Therapy for naming disorders (Part II): Specifics, surprises and
suggestions. Aphasiology, 10, 109 – 136.
Pedersen, P. M. V. K., & Olsen, T. S. (2001). Improvement of oral naming by unsupervised
computerised rehabilitation. Aphasiology, 15, 151 – 169.
Poeck, K., Huber, W., & Willmes, K. (1989). Outcome of intensive language treatment in
aphasia. Journal of Speech and Hearing Disorder, 54, 471–479.
Pulvermuller, F., Neininger, B., Elbert, T., Mohr, B., Rockstroh, B., Koebbel, P., & Taub, E.
(2001). Constraint-induced therapy of chronic aphasia after stroke. Stroke, 32(7),
1621– 1626.
Renvall, K., Laine, M., Laakso, M. & Martin, N. (2003). Anomia treatment with contextual
priming: A case study. Aphasiology, 17, 305 – 328.
Manuscript received April 2004
Revised manuscript received January 2005
View publication stats