Review of The Sciences of Aphasia |
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Date: Fri, 18 Jul 2003 14:26:16 -0500
From: Liang Chen
Subject: The Sciences of Aphasia: From Therapy to Theory
Papathanasiou, Ilias and Ria De Bleser, ed. (2003) The Sciences
of Aphasia: From Therapy to Theory, Elsevier Science Ltd.
Liang Chen, University of Louisiana at Lafayette.
SYNOPSIS
This book grew out of the first European Research Conference
on Aphasia (Euroconference 2000: The Sciences of Aphasia: From
Therapy to Theory). It consists of 18 chapters in addition
to a preface by John C. Marshall. Each chapter is an
independent article by different authors, and provides
state-of-the-art review on controversial research and
clinical issues in aphasia and aphasia therapy. The editors
arranged these articles according to 4 major sections. It
will be an invaluable resource for clinicians, students and
researchers involved in aphasia and aphasic therapy
including doctors, psychologists, linguists and speech and
language therapists.
Chapter 1, 'Prospects in the Study of Aphasia: The Nature of
the Symptom and Its Relevance for Future Research' by Jason
Brown, stands on its own. It attempts to formulate a
scientific theory of the symptom by focusing on the growth
process of morphogenesis in the fetal brain that 'mediates
the translation from the genetic code to brain structure'
(p. 5). Two mechanisms, namely, parcellation and
heterochrony are involved in morphogenesis. Parcellation
essentially involves initial proliferation cells and their
connections with later loss of cells and cell connectivity
due to competitive interactions to achieve synaptic
specificity. Heterochrony is the rate or timing of
parcellation. It refers to the idea that 'in brain
development or evolution, different organ systems can
develop at different rates, and that this difference in the
timing of development can lead to shifts in evolutionary
outcomes, including adaptations, errors, and severe
aberrations' (p. 8). The author advances the concept of the
error 'as a link between specification and timing, or the
pattern of process and its rate' (p. 11), and argues that
'The recapitulation is for the process, not the actualized
elements it deposits' (p. 11). Symptoms are predicted to
undergo a coherent rather than piecemeal transition.
Section 1: THE NEUROSCIENCES OF APHASIA
Chapter 2. The Neurology of Recovery From Stroke, by Nick
Ward and Martin Brown. The authors recommend the admission
of the patient to a stroke unit to enhance early recovery
during the acute stage. After the acute stage,
rehabilitation input from specialist therapists (e.g.,
physiotherapy) is recommended. In assessing any form of
rehabilitative strategy, including treatment of aphasia, it
is important to look beyond improvements in activities of
daily living. This idea echoes the functional, pragmatic,
communicative, quality-of-life orientation in aphasia
assessment, therapy, and outcome research.
Chapter 3. Evidence from Basic Neuroscience and Human
Studies of Pharmacologic Therapy, by Delaina Walker-Batson.
The author first reviews theories of neuroplasticity thought
to underlie behavioral recovery. The author then reviews a
number of animal studies of recovery which suggest 'that the
type of input may effect neural reorganization and that the
timing of retraining or rehabilitation may be very
important' (p. 37). They also suggest that 'treatment
approaches can be either adaptive or maladaptive' (p. 37).
The author then reports some data from humans on
pharmacologic therapy in the treatment of hemiplegia and
aphasia. The data suggest that 'low-dose amphetamine
accelerates the rate and in some patients the extent of
aphasia recovery when entered in the subacute but not the
chronic recovery period independent of initial language
severity, age or lesion size' (p. 41).
Chapter 4. Neuroanatomical Substrates of Recovery of
Function in Aphasia: Techniques and Evidence from
Neurophysiology, by Ilias Papathanasiou. The author first
discusses various theories of functional neuroanatomical
recovery mechanisms and their limitations. Then current
neurophysiological techniques used to study brain structure
and brain function are described. For example, the
neuroimaging methods used to study brain structure include
CT (transmission tomography), MRI (magnetic resonance
imaging), PET (positron emission tomography) and SPECT
(single photon emission tomography). Techniques available to
study brain function include (a) using PET or fMRI to image
brain during a 'task' by looking at the blood flow, (b)
using EEG (electoencephalography) and MEG
(magnetoencephalography) to record electrical or magnetic
activity of the brain during performance of a task, and (c)
using TMS (transcranial magnetic stimulation) to stimulate
brain neurons and examine the effects on behavior. Finally,
the author reviews a number of animal studies, brain imaging
studies, and TMS studies which 'provide empirical evidence
for functional neuroanatomical mechanisms involved in the
recovery of function' (p. 55). The author recommends the use
of available neurophysiological techniques in future therapy
studies in order to provide better service delivery.
Chapter 5. Subcortical Aphasia: Evidence from Stereotactic
Surgical Lesions, by Bruce E. Murdoch, Brooke-Mai Whelan,
Deborah G. Theodoros, and Peter Silburn. The authors
examined the pre- and post-surgical language abilities of
two subjects, one of whom underwent pallidotomy, and the
other thalmotomy. Results support the hypothesized role for
subcortical structure (i.e., globus pallidus and the
dominant thalamus) in linguistic processes. They also lend
support to the hypothesis of a cortico-striato-pallido-
thalamo-cortical loop subserving language function. However,
the authors point out immediately that more data for larger
sample of subjects need to be collected to substantiate
these results.
Section 2: COGNITIVE AND PSYCHOLINGUISTIC APPROACH TO
APHASIA THERAPY
Chapter 6. Cognitive Neuropsychological Approaches to
Aphasia Therapy: An Overview, by Ria De Bleser and Jürgen
Cholewa. They first describe the three approaches to aphasia
therapy, namely, communicative, linguistic, and cognitive
approaches. Shift of paradigm from group studies to single
case studies in aphasia therapy has brought about the shift
of paradigm from linguistic or communicative disabilities to
impaired cognitive language functions in efficacy study of
aphasia therapy. In order to be able to predict and
generalize, any cognitive approach need to meet several
requirements of therapy design. Among them are: (a) clearly
defined and evaluable dependent variable, (b) consistent
therapy method throughout the intervention, and (c) multiple
baselines design. As examples of cognitive therapy research,
the authors review several studies on deficits in segmental
written language processing. [>> see p. 102-106).]These
studies raise the question of 'why certain therapeutic
procedures but not others lead to the desired results with
certain patients, or why some patients but not others
benefit from a particular intervention procedure' (p. 106).
To answer such questions, 'several authors (e.g., Hillis and
Caramazza, 1994; Schwartz and Whyte, 1992; Wilson and
Patterson, 1990) advocate that new models on cognitive
learning mechanisms must be developed in addition to the
existing cognitive models of language' (p. 107).
In Chapter 7. Lurian Approach to Aphasia Therapy: A Review,
Zsolt Cséfalvay reviews Luria's approach to clinical
aphasiology which characterized by a 'logical link between
diagnosis of aphasia and its treatment' (p. 111). The review
is based on Luria (1963, 1973). As Caplan (1987: 132) points
out, 'Luria provided the first reasonably detailed model of
language processing related to aphasia and to the brain'.
For Luria, aphasia therapy must consider patients'
personality and must always be directed toward the whole
person instead of his/her isolated abilities. Luria and his
colleagues proposed five methodlogical principles of
clinical therapy. They are (a) identification of the primary
problem, (b) inclusion of intact systems of analyzators, (c)
transfer of the function to hierarchically higher or lower
level of realization, (d) inclusion of intact cognitive
processes, and (e) including control and feedback into
therapy.
Chapter 8. Therapy for Lexical Disorders, by Anna Basso.
Assuming that therapy for lexical disorder should take both
the form and the origin of the error into consideration, the
author sketches a dual-route model of the structure of the
lexical system which has been used as a reference point in
analyzing the patients' functional damage. Several
distinctions are made in such a model: meaning/form
distinction of a lexical item; input/output lexicon
distinction; orthographic/phonological information
distinction; and lexical/sublexical processes distinction. A
review of several studies on cognitive rehabilitation of
naming disorders shows that (a) no treatment has been
reported for rehabilitation of comprehension, (b) no really
new technique for naming disorders has been reported, and
(c) cognitive approaches are limited to treating patients in
clinical setting, but may not improve the patients' everyday
life. Therefore, the author suggests that we need consider
data about learning in normal subjects in constructing a
theory of aphasia therapy, as long as we don't know more
about how recovery from aphasia occurs.
Chpater 9. Verbal Retrieval Problems at the Word and
Sentence Level: Localization of the Functional Impairments
and Clinical Implications, by Roelien Bastiaanse. Following
Levelt's (1989) model for speech production, this paper
argues that the impairments in verb retrieval in Broca's and
anomic aphasia arise at different levels (lemma vs. lexeme
level respectively). For Broca's aphasia, verb retrieval
deficits arise at thematic (argument-structure),
morphological, and syntactic levels, but usually not at the
lexical-semantic level. In contrast, lexical-semantic
factors do affect verb retrieval ability of anomic aphasics.
The author also reports two recent studies to address the
question of whether lemma selection itself or the processing
of lemma information (i.e., grammatical encoding) is
impaired in Broca's aphasics. It is found that grammatically
more complex constructions (e.g., those with verb movement)
are more difficult for patients with Broca's aphasia,
suggesting the locus of impairment in Broca's aphasia is in
the grammatical encoder. The clinical implication of this
approach to verb retrieval deficits is the necessity to
identify the level of breakdown and then focus on the
training of verb production as an essential part of language
therapy, because 'verbs are not only central in the sentence
construction process, but also contain much semantic
information' (p. 146).
In Chapter 10, Luise Springer describes 'Reduced Syntax
Therapy (REST): A Compensatory Approach to Agrammatism'.
Assuming the adaptation theory (i.e., aphasic symptoms can
reflect either the underlying deficit or the attempt to
compensate this deficit), the REST approach focuses on
reduced sentence structures, 'deliberately encouraging
rather than preventing the production of a telegraphic
style' (p. 152). There are five levels in the REST-approach
to treatment of agrammatism, namely, (1) 2-word utterances:
VP with direct objects, (2) 2+1-word utterances: VP with
prepositional phrase, (3) 3-word utterances: VP plus
subject, (4) 3-4-word utterances: VP plus S-Adverb, and (5)
3-4 word utterances: VP plus indirect object. Each level is
exemplified for both German and English. From Level 1 to
Level 5, there is the systematic expansion of sentence
fragments and syntactic frames, and the verb is always the
focus. Springer also reports the findings of a study using
REST approach to treat a group of 11 right-handed patients
with chronic agrammatism. After a total of 30 full hour
treatments each, eight patients showed significantly more
constituents per utterance, more non-finite verbs in their
spontaneous language. Moreover, follow-up data in four
patients show that REST approach, in contrast to earlier
approaches focusing on the relearning of grammatically
correct sentences, has led to stable transfer into
spontaneous speech. As a conclusion to the paper, Springer
suggests the potential of integrating REST into computer-
mediated-communication, and thus providing patients with
impairments of sentence production possibilities for remote
communication.
Section 3: FUNCTIONAL, PRAGMATIC AND PSYCHOLOGICAL
APPROACHES TO APHASIA THERAPY
Chapter 11. Functional and Pragmatic Directions in Aphasia
Therapy, by Leonard L. LaPointe. Since 1970s, aphasiology
has undergone a shift of focus from formal aspects of
language (e.g., phonology, morphology, syntax and semantics)
to functional, pragmatic, and communicative aspects of
language use. Models of aphasia incorporate more and more
social elements and interaction needs of communicators
(e.g., the life participation approaches in US, UK, and
Australia). These models pay special attention to the
subjective quality of life of aphasic people (Simmons-Mackie
& Damico, 2001). People start to accept the notion that
'aphasia in most cases is a chronic condition' (p. 164), and
group treatment become popular again. LaPointe asserts that
the functional, pragmatic, and life participation approaches
are effective in facilitating successful life with aphasia,
and he suggests that clinical aphasiology need 'adapt to the
changing landscape of aphasia intervention' (p. 170), and
aphasia researchers and practioners need to 'find out a lot
more within the realm of aphasia sociology to better guide
our services' (p. 168).
Chapter 12. Conversation Analysis and Aphasia Therapy, by
Ruth Lesser. The functional and social/societal aspects of
language use have been increasingly important in aphasia
assessment and therapy since 1970s. Conversation analysis
(CA) provides not only a useful means for assessing
functional communication, but also 'a structure for directly
targeting the ultimate aim of therapy in improving quality
of life' (p. 183). This paper illustrates CA through
examining repairs in conversation and correction as the
interactional business. It also deals with the implications
of CA in intervention and how CA can be applied in therapy.
Issues of quantification in the use of CA are also briefly
discussed.
Chapter 13. Supported Self-Help Groups for Aphasia People:
Development and Research, by Chris Code, Chris Eales, Gill
Pearl, Margaret Conan, Kate Cowin and Julie Hickin. The
authors first relate the development of supported self-help
groups for people with aphasia to the disability movement
and an interest in 'more socially relevant and authentic
rehabilitation' (p. 189). Aphasia clinicians may help the
members with both practical issues (e.g., finding a meeting
place) and professional advising. They then report the
results of a study which aimed to determine the profile of
the membership of the supported self-help groups for aphasic
people in Britain. They find that most self-help group
members are chronic, relatively less severe and young
aphasics. Most groups center around densely populated urban
areas, Although self-help in aphasia is still evolving, the
authors suggest that it ' can make an effective contribution
to the psychosocial reintegration of aphasic people,
encouraging autonomy and empowerment' (p. 199).
Chapter 14, 'The Science or Sciences of Aphasia?', by Sally
Byng, Susie Parr, and Deborah Cairns, highlights the
important role of qualitative methods in aphasia research
(see e.g., Damico et al., 1999a, b) and in other scientific
displines. If we consider aphasia as social as well as a
physiological or biological event (Goodwin, 1995), we cannot
study it in isolation from the social context. In this
regard, 'Qualitative methods are particularly suited to
capturing the subjective, social and changing aspects of
illness and healthcares and the complexities of sickness in
context' (p. 204). The authors argue that qualitative
methodologies contribute to (a) a better and more complete
understanding of aphasia; (b) an examination of the
assumptions underlying the sciences of aphasia; and (c)
opening up new areas for intervention and legitimating
current areas that are practiced by clinicians but not
explored or evaluated by researchers, e.g., the relationship
between identity, language and communication for aphasics.
Section 4: METHODOLOGY AND EFFICACY IN APHASIA THERAPY
RESEARCH
In Chapter 15, Klaus Willmes talks about 'Some Psychometric
Issues in Aphasia Therapy Research'. Topics include scales
in neuropsychological assessment and rehabilitation,
psychometric single case analysis (e.g., individual profile
analysis and intra-individual profile comparisons), and
randomization tests for single-subject therapy research. The
paper is mainly concerned with various considerations in the
development of assessment methods. In order to conform to
the theme of the book, it also suggests some specific
applications in aphasia research. Due to its high
technicality, however, its applicability might be limited.
In Chapter 16, David Howard compares the characteristics of
'Single Cases, Group Studies, and Case Series in Aphasia
Therapy'. The author first examines two examples of group
studies (Pring et al., 1993; Howard et al., 1985), which
reported misleading results due to their reliance on
analysis of variance and to their false assumption of
homogeneous treatment effects. The author thus suggests the
use of statistical tests for homogeneity of treatment
effects in group studies. Then, in spite of being 'simple,
cheap, and when properly designed, very informative',
single case studies are 'clearly open to the accusation that
these are selected results from selected participants' (p.
254). Moreover, selected reports of improvement in specific
patient may be misleading because 'it might be a chance
improve (a type I statistical error), or it might be a
patient who would have improved under any circumstances' (p.
254). In fact, such 'selection bias' is evident in the
published single case studies. Finally, the author concludes
that case series designs involving a series of participants
given the same treatment in the same way can have the
advantages of both single case studies and group studies,
while avoiding their drawbacks. In particular, 'supported by
proper use of homogeneity tests, it is possible to address
the null hypothesis that treatment gains are equal for all
the participants' (p. 257).
David Howard assumes that therapy program and the criteria for
its effectiveness should be personalized/individualized for
the individual patient, due to the qualitative heterogeneity
of impairments and therefore treatments. Treatment studies
in a sense should 'establish what treatments are effective
and for whom' (p. 246). This requires any such study to
specify the treatment, the nature of the impairment, and
which of the participants benefited; and to differentiate
the sources of improvement if there is any (e.g., is the
improvement due to spontaneous recovery, or placebo effect,
or to specific treatment?).
Chapter 17, 'Efficacy of Aphasia therapy, Escher, and
Sisyphus', by Robert T. Wertz, is a review on the efficacy
of aphasia therapy. Wertz first suggests three possible
"rules" in designing and evaluating aphasia outcomes
research, namely, precise definitions of the terminology,
the five-phase outcomes research model (Robey & Schultz,
1998), and levels or quality of evidence scales (e.g., The
American Academy of Neurology, 1994; Birch & Davis, 1997).
Wertz then applies these "rules" to evaluate selected
literature on the efficacy of aphasia therapy. This article
highlights the confusion that exists in the research on the
efficacy of aphasia therapy. As is also pointed out in the
next chapter, some researchers see positive aphasia
treatment outcome while others conclude aphasia treatment is
not efficacious on the basis of the same literature. To
avoid the confusion, speech-language pathologists and
investigators need first differentiate terms like 'outcome',
'efficacy', 'effectiveness' and 'efficiency'. In particular,
we cannot 'leap to effectiveness and efficiency studies
without having demonstrated a treatment's efficacy' (p.
262). It is necessary to progress from efficacy to
effectiveness to efficiency by following the Five-Phase
Outcomes Research Model. Meanwhile, outcome evaluations
should also follow the appropriate quality of evidence of
scales.
Chapter 18, 'Meta-Analysis in Aphasia Therapy' by Chad Nye
and Renata Whurr, focuses on systematic summary or meta-
analysis of research data in aphasia therapy. Such
systematic summary should 'provide at least two important
general results: (1) a basis for estimating the quantitative
effects of treatment, and (2) a guide for future research
agenda' (p. 274). The authors first briefly survey four
basic methods of summary. They are from the least systematic
to the most systematic narrative review, significance vote
counting method, cumulation of p-values method, and meta-
analysis. According to Nye and Whurr, the first three
methods suffer from subjectivity, scientific flaws, and
inefficiency. Meta-analysis, by contrast, deals with those
problems in combining findings using statistically
systematic procedures. Meta-analysis should follow the same
procedure for conducting a primary research, and must (a)
define the problem, (b) describe the method, (c) analyze the
data, and (d) interpret the data. Nye and Whurr warn us
that different conclusions might be drawn from similar
sources even with meta-analysis, due to use of different
study inclusion criteria, use of different effect size
formula, and outcome criteria selected for analysis. All of
them make it difficult if not impossible to evaluate the
speech and language effects in aphasia therapy.
CRITICAL EVALUATION
The articles are concise, comprehensible, and accessible to
a wide audience. For the interested general public though,
some more technical background might be necessary to
understand some of the articles in full. Given that the book
is intended to provide 'state of the art review chapters on
controversial research and clinical issues in aphasia and
aphasia therapy' (back cover), various ways of cross-
referencing suitable for exploratory as well as reference
reading may be added in later editions.
The broad range of the articles shows clearly that a
simplistic medical model is not adequate to accommodate the
metamorphosis in the neuropathologies. A much more complex
systems-theory/social model may better approximates the
needs of individuals in the neuropathologies, i.e., aphasics
in this case. This book helps researchers and clinicians to
recognize the important conceptual issues, and better
understand the framework manifested in the World Health
Organization's newest tripartite classification system of
impairments, activity limitations, and participation
restrictions (WHO, 2000).
I would like to end this review with a serious concern
for the typographic errors. On pp. 249-250, one whole
paragraph was repeated, and the names of two subjects are
'PR and BB' in the text but 'BR and PB' in Figure 2 on page
250. On p. 280, either 'Xc' should be changed to 'Xpre' or
the other way round. The most noticeable and most
disconcerting are the references. For example, in Chapter
18, several major references are confusing and inconsistent.
Robey (1999) should be Robey et al. (1999); Whurr (1992)
should be Whurr et al. (1992). Moreover, we find Greener
(1998, 1999) and Greener et al. (1998) in the text, but we
only find Greener et al. (2002) in the reference list. Such
confusion may also be found in other chapters like Chapter
17. While one may think the typographic errors will not
detract the value of the book as an invaluable source of
information on present and future development of aphasia and
aphasia therapy, it is hoped that future editions avoid the
noted problems.
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ABOUT THE REVIEWER:
ABOUT THE REVIEWER Liang Chen is a doctoral student of Applied Language and Speech Sciences in the Department of Communicative Disorders at University of Louisiana at Lafayette. His current research includes theoretical semiotics, language disorders, language assessment, and bilingualism and bi-literacy. Other interests include syntactic theory and Chinese linguistics. |
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