Wendy Best

Phonological therapy for word-finding difficulties: A re-evaluation

Background: Treatments for word-finding difficulties in aphasia using semantic techniques have been shown to be effective (e.g., Marshall, Pound, White-Thomson, & Pring, 1990). The evidence with regard to phonological treatment is more equivocal, however, with some studies reporting only short-term improvement in word retrieval (e.g., Howard, Patterson, Franklin, Orchard-Lisle, & Morton, 1985a) and other studies reporting lasting effects (e.g., Miceli, Amitrano, Capasso, & Caramazza, 1996). There is also little in the literature on the use of orthographic cues in treatment (Howard & Harding, 1998). Additionally, whereas several studies have reported the results of using cues in facilitation of word-finding difficulties (e.g., Patterson, Purrell, & Morton, 1983), none so far has attempted to relate response to facilitation and response to treatment using similar techniques in the same individuals. Aims: This study set out to investigate whether the use of phonological and orthographic cues in the treatment of word-finding difficulties could produce lasting improvements in word retrieval. The response of the participants to phonological and orthographic cues in a facilitation study was also related to their response to treatment using similar cues. Methods & Procedures: The study used a case series design. The participants were eight people with acquired aphasia who were all at least 1 year post-onset, had a single left CVA, and had word-finding difficulties as a significant aspect of their aphasia. Detailed assessment of each participant was carried out to identify the nature of their word-finding difficulties and this was related to response to treatment. Outcomes & Results: Results are given for the eight participants, seven of whom benefited overall from treatment. Both phonological and orthographic cues were effective in improving word retrieval. For the group as a whole there was a significant correlation between the overall outcome of facilitation and response to treatment.

Therapy for naming disorders (Part I): Principles, puzzles and progress

Abstract This paper takes the form of a selective review of studies of therapy for aphasic-naming disorders. There is a bias in the literature towards studies involving the use of semantic tasks (particularly word-to-picture matching) in therapy and therefore this is reflected here. These studies provide clear evidence that aphasic naming disorders can be remediated but it remains difficult to ascertain the precise mechanism by which this improvement in naming is achieved. Several issues are discussed which pertain to this problem: the effectiveness of ‘semantic’ and ‘phonological’ tasks; the relevance of each component of the therapy task to the outcome of the therapy; the relationship between the type of deficit and the effectiveness of a task; when generalization can be expected as opposed to (treated) item-specific improvement; and the importance of patient success on the task to the success of the therapy. Finally, the paper concludes with suggestions for the possible direction of further research in...

Therapy for naming disorders (Part II): Specifics, surprises and suggestions

Abstract This paper presents a series of therapy studies aimed at remediation of the word-retrieval deficits of three aphasic patients. All three patients are argued to have semantic deficits and are given semantic therapy in the form of word-to-picture matching tasks. Two of the patients (A.E.R. and T.R.C.) show improved naming as a result of the therapy, with generalization to untreated items. The third patient (P.A.) does not improve as a result of the word-to-picture matching therapy, even though her pattern of deficits appears similar. However, she does show item-specific improvement in naming with a different therapy (lexical therapy). The reasons for the differences between the patients in their response to therapy are discussed. In particular we consider the effect of the production of the word during the therapy, and the patients ability to perform the task accurately. Additionally, we investigate the role of modality of input and generalization across modality of output, and the use of differen...

Developmental Phonological Dyslexia: Real Word Reading Can Be Completely Normal

This paper provides a detailed analysis of the reading performance of an 85year-old subject with developmental phonological dyslexia. Although her nonword reading was severely impaired, Melanie-Jane read real words with normal latencies and accuracy. Investigation of the factors aΠecting reading latencies showed that M-J had normal eΠects of frequency and imageability and no eΠects of regularity. Like many phonological dyslexics, M-J was impaired in phonological tasks not involving written stimuli. The implications of this pattern of results for theories of reading development and for recent computational models of skilled reading are considered.

Do picture‐naming tests provide a valid assessment of lexical retrieval in conversation in aphasia?

Background: Word‐finding problems commonly occur in aphasia and can significantly affect communication. Assessment of this deficit typically involves naming pictures. However, this method has been criticised as lacking ecological validity. Alternative methods include the measurement of lexical retrieval in narration or conversation, although few published studies have quantified word finding in the latter. Aims: We aimed to identify a reliable and valid assessment of lexical retrieval in conversation, and to elucidate the nature of the relationship between lexical retrieval in picture naming and in conversation. Methods and Procedures: We developed a quantitative measure of word finding in conversation in aphasia and established the reliability and stability of the method. We compared the scores of a group of people with aphasia on this measure with their scores on a picture‐naming test. Outcomes and Results: We found significant relationships between picture‐naming scores and a number of key variables analysed in the conversation measure. We propose that scores on picture naming relate to the ability to retrieve nouns in everyday conversation for the people with aphasia who took part in this study. Conclusions: The use of picture‐naming tasks is justified, providing a valid and rich means of assessment of lexical retrieval. Further research is required to replicate these results with more people with aphasia. We offer the quantitative assessment of conversation developed here for use in research and clinical spheres.

Phonological and orthographic facilitation of word-retrieval in aphasia: Immediate and delayed effects

In the literature on repetition priming of word-production in normal participants, long-lasting effects can be found from a single prime. This contrasts with the findings with adults with anomia (as part of their aphasia) where phonological cues, such as first sound or rhyme, have been shown to have very short-lasting effects on word retrieval (Patterson, Purell, & Morton, 1983). In addition, the research into treatment of anomia suggests that semantic techniques produce longer-lasting effects than phonological techniques (Howard et al., 1985b). One difference between phonological and semantic techniques is in the element of choice available. Typically phonological cues are simply provided. This contrasts with semantic techniques where a choice is available, for example selecting from a set of pictures to match a word. This study, using a case series design, set out to replicate the finding, that phonological techniques have only short-lasting effects on word retrieval in aphasia and to investigate the influence of providing a choice of cues. Items that participants with aphasia were unable to name after 5 seconds were allocated to one of three conditions: extra time (control condition), single cue, and choice of two cues. Naming was assessed immediately and at a delay (over 10 minutes later). Four different cue types were used: whole word, spoken CV, written CV, and rime. The results were surprising. The cues influenced immediate naming, as predicted. However, this effect was still significant a delayed naming. Additionally, the benefits from a choice of cues were generally similar to those from a single cue. Different patterns of cue effectiveness were found for different participants. Further investigations shed some light on the mechanisms of cueing, orthographic cueing in particular.

When Racquets Are Baskets But Baskets Are Biscuits, Where Do the Words Come From ? A Single Case Study of Formal Paraphasic Errors in Aphasia

This paper provides evidence for the existence of real-word errors phonologically related to targets (formal paraphasias) in the naming attempts of a person with aphasia, MF. In particular, this is the first demonstration that such errors are genuine lexical errors and not jargon homophones (phonological errors that happen to be words by chance; Butterworth, 1979). This finding was replicated on a second naming attempt. MFs naming accuracy was influenced by length and by imageability/concreteness. There was no effect of frequency or age of acquisition. In addition to formal errors, he made semantic errors and nonword errors that were phonologically related to the target. The apparently mixed (semantic and formal) errors are argued not to be truly mixed on the grounds that they do not share phonology with the targets at greater than chance rates. A detailed analysis of MF s errors is followed by discussion of the findings in relation to a variety of models of speech production including those with one (M...

Combining lexical and interactional approaches to therapy for word finding deficits in aphasia

Background: There are two distinct theoretical positions underlying approaches to aphasia therapy. The first addresses the language impairment directly through tasks designed to improve performance in that language function. This form of therapy was employed in a related study involving the participants reported here (Hickin et al., 2002a). The second seeks to bypass the language impairment by, for example promoting alternative forms of communication, and stressing the importance of successful rather than normal communication. There are few studies that combine the structured principled methods of the first with the ecologically valid basis of the second approach. Aims: Our aim was to investigate the effectiveness of combining a lexical therapy, targeting a discrete set of items and using cues to prompt name retrieval, with communicative use of those items, in tasks ranging from naming to definition through to structured conversation. We investigated the effects of the therapy in terms of gains in picture naming, and performance in a task simulating communication situations (production of nouns in everyday communication). Methods & Procedures: The study is a case series design involving six people with aphasia. All were adult English speakers aged 39 and upwards who were aphasic following a single left hemisphere stroke. Picture naming and production of nouns in everyday communication was assessed prior to and after therapy. Outcomes & Results: The combined therapy described here was effective for five of the six participants in terms of gains in picture naming, and an increase in communicatively effective responses in the noun production task. One person, for whom the lexical therapy described in Hickin et al. (2002a) was not effective, did however respond to the therapy reported here. For one of the six participants, the therapy was not effective. Conclusions: Therapy that targets a specific set of words, and encourages their use in tasks approaching everyday communication, can be effective in improving word finding in picture naming and in a functional speech task. As therapy effects are restricted to items undergoing therapy on the whole it is essential that words are selected for therapy on the basis of their functional use to the participant. This therapy was effective for most of the six participants and we are unable at this stage to identify exclusion criteria for undergoing this therapy.

From theory to therapy in aphasia: Where are we now and where to next?

Language therapy for acquired aphasia has come under much scrutiny in recent years, with debate focusing on whether or not it is effective and how best efficacy can be measured. In this paper, we argue that although the efficacy of many different therapies has been clearly documented, there remain unanswered questions. In particular, it is still difficult to predict which therapeutic task or approach will be successful at remediating which particular disorders. We argue that this is particularly true in the rehabilitation of anomia, whilst in other areas (e.g., reading) the relationship between deficit, task, and outcome is easier to interpret. We discuss in detail the reasons for these differences arguing that specificity of theoretical models, complexity of therapeutic tasks, and a lack of (reporting of) comprehensive assessment of linguistic deficits all contribute to the problem. We conclude that research needs to perform a microanalysis of the interactions between tasks and deficits.

Optimising the design of intervention studies: critiques and ways forward

Background: There is a growing body of research that evaluates interventions for neuropsychological impairments using single-case experimental designs and diversity of designs and analyses employed. Aims: This paper has two goals: first, to increase awareness and understanding of the limitations of therapy study designs and statistical techniques and, second, to suggest some designs and statistical techniques likely to produce intervention studies that can inform both theories of therapy and service provision. Main Contribution & Conclusions: We recommend a single-case experimental design that incorporates the following features. First, there should be random allocation of stimuli to treated and control conditions with matching for baseline performance, using relatively large stimulus sets to increase confidence in the data. Second, prior to intervention, baseline testing should occur on at least two occasions. Simulations show that termination of the baseline phase should not be contingent on “stability.” For intervention, a predetermined number of sessions are required (rather than performance-determined duration). Finally, treatment effects must be significantly better than expected by chance to be confident that the results reflect change greater than random variation. Appropriate statistical analysis is important: by-item statistical analysis methods are strongly recommended and a methodology is presented using WEighted STatistics (WEST).