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.
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.
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.