Lyndsey Nickels

Therapy for naming disorders: Revisiting, revising, and reviewing

Background: Impairments of word retrieval and production are a common and distressing feature of aphasia, and much clinical time is devoted to attempts at their remediation. There are now many research papers devoted to case studies examining treatments for word-retrieval impairments using a wide range of tasks with individuals who have varying levels of impairment. Aims: This paper aims to continue the selective review of this literature carried out by Nickels and Best (1996a). It summarises in table form those published papers since 1980 which present single case studies of treatment for word-retrieval impairments and which satisfy minimal methodological criteria. Main Contribution: Several main themes are derived from the literature and discussed in more detail, these include strategic approaches and facilitative or repair approaches to remediation, the contrast between semantic and phonological tasks in therapy, generalisation in therapy tasks and the relationship between impairment, therapy task, and outcome. Further discussion relates to the relationship between impairment level treatments, and measures of disability and handicap, and between therapy research and therapy practice. Conclusions: There are now many research papers devoted to impairments of word retrieval, and there can be no doubt that therapy for word-retrieval impairments can be highly successful, resulting in long-term improvements which can be of great communicative significance for the individual with aphasia. However, predicting the precise result of a specific treatment task with a specific individual with certainty is still not possible. For clinicians the recommendation is to use analyses of functional impairments to guide the choice of task, but to ensure that efficacy is tested and not assumed. Furthermore, structured multi-modal and multicomponent tasks (e.g., “semantic” or “phonological” cueing hierarchies) may hold the most promise for many individuals. For researchers, there remains a need to further dissect tasks, impairments, and their interactions across series of single cases.

Aphasic naming: What matters?

This paper investigates the factors which affect naming performance for two groups of aphasic subjects. The effects of word age-of-acquisition, operativity, frequency, familiarity, imageability, concreteness, length and the visual complexity of the stimulus picture were examined. In contrast to previous studies, we found remarkably small effects of word frequency on naming performance; these studies, we argue, have failed to control sufficiently for the effects of variables which intercorrelate with frequency. However, many patients were significantly affected by age-of-acquisition even when any effects of frequency and familiarity had been accounted for. Operativity, imageability and word length were also predictive of naming performance for some of the patients investigated, unlike visual complexity. The applicability of conclusions drawn from groups of aphasics is again thrown into doubt, as these two groups showed different patterns of predictor variables, and the variables affecting the performance of individuals could be different from those affecting the group.

The autocue? Self-generated phonemic cues in the treatment of a disorder of reading and naming

Abstract This study describes a therapy programme that aimed to improve oral reading and spoken naming in a deep dyslexic patient by teaching the patient grapheme-phoneme correspondences. This aim was achieved and the improvement could be attributed to the specific effects of the therapy. However, the pattern of results obtained was very different to that predicted. The patient proved unable to perform or to relearn one of the processes necessary for successful reading by a sublexical routine (blending of individual phonemes to form a word). It is concluded that the improvement had been achieved not by a learned mechanism for sublexical reading but instead by enabling the use of patient-generated phonemic cues. The therapy had enabled the patient to produce successfully the phoneme associated with the initial letter of the word, which then acted as a phonemic cue facilitating reading of that word. Spoken naming was also facilitated as information on the written form of the word could similarly be used to ...

A frequent occurrence? factors affecting the production of semantic errors in aphasic naming

Abstract Both normal and aphasic subjects produce picture naming errors that are semantically related to the target. This study investigates the effects of different word properties on the production of semantic errors by aphasic subjects. A correlation is found between the production of semantic errors and deficits in the comprehension of high-imageability words, with those patients who make semantic errors in comprehension also producing them in naming. This suggests an absence of deficits resulting in semantic errors only in word production. For some patients, semantic errors are more likely to occur with lower-imageability targets, despite the restricted range of imageability values for stimuli in this picture naming task. However, not all of those patients who produce semantic errors show an effect of imageability on their occurrence, suggesting a dissociation between central conceptual/semantic deficits and post-semantic deficits. The majority of patients fail to show frequency effects in the produc...

Spoken word production and its breakdown in aphasia

Part I: Models of Spoken Word Production. Introduction. Lexical Representation and Access. Phonological Encoding: Slots and Fillers. More Phonological Encoding: Motor Control and Monitoring. Part II: The Breakdown of Spoken Word Production in Aphasia. Introduction. Semantic Deficits and Semantic Errors. Deficits of Lexical Retrieval. Phonological Errors: Deficits of Phonological Encoding and Beyond.

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...

Improving word finding: Practice makes (closer to) perfect?

Background: One application of a task, such as word-picture matching or repetition, has been demonstrated to affect subsequent picture naming (‘facilitation’ or ‘priming’) in both aphasic and non-aphasic subjects. As aphasia assessment frequently involves repeated use of the same stimuli in different tasks, it is suggested that some aphasic individuals may have improved performance in picture naming as a result of assessment. Aims: The aim of this paper is to demonstrate that there can be improvements in picture naming as a result of repeated presentation of stimuli and promote discussion regarding the mechanisms that may have caused such effects and their corresponding implications for treatment. Methods & Procedures: This paper describes a single case study of JAW, a man with aphasia. JAWs picture naming had been observed to improve over time while other tasks remained stable. An investigation was performed to identify the source of this improvement. Three treatment tasks were used, attempting to name the picture, reading aloud and delayed copying of the picture names. Outcomes and Results: All three tasks significantly improved subsequent picture naming of the treated items despite the fact that no feedback or error correction was provided. It is argued that the source of this improvement is from priming of retrieval of the phonological form. In the ‘attempted naming’ condition, this priming occurred every time a picture name was successfully produced. As JAW was not perfectly consistent, on each attempt at naming some additional items were primed. Thus, over time an increasing proportion of stimulus items were primed and were hence more likely to be successfully produced. Conclusions: This study demonstrated that for at least one aphasic man, JAW, practice makes (closer to) perfect, even without correction. Not only was there significant improvement from tasks that provided the word form (reading aloud and delayed copying) as has been shown in the past, but also there was the novel finding that simply attempting to name a picture can improve subsequent word retrieval. It is argued that this novel finding could be applicable to other aphasic individuals and has functional significance.

Replicating therapy for mapping deficits in agrammatism: Remapping the deficit?

Abstract This study was designed to replicate and extend an earlier study in which a therapy programme was carried out with two agrammatic aphasic patients with sentence processing impairments suggested to be at the level of mapping thematic roles and grammatical relations (Byng 1988). In the current study one of the therapy procedures implemented in the previous study was repeated with three different people with long-term ‘agrammatism’. The outcome of the therapy resulted in some gains in sentence production and verb retrieval, but these gains varied across the three patients. Whilst some change had taken place for each person, the pattern of results showed that the quality and extent of the change was different in each case. The potential source for these differences is explored and the implications of the study for the necessary development of theories about therapy are discussed.

Impairment‐ and activity/participation‐directed interventions in progressive language impairment: Clinical and theoretical issues

Background: There is a broad constellation of clinical syndromes in which the most prominent initial and ongoing symptom is deterioration in spoken or receptive language processing, reading, writing, or semantic knowledge. Despite the core language impairments, people with these disorders are likely to be under‐referred for speech pathology services (Taylor, Kingma, Croot, & Nickels, 2009 this issue), and there is limited published research on speech pathology interventions in these disorders. Aims: This paper reviews the published impairment‐ and activity/participation‐directed interventions in semantic dementia and progressive aphasia to determine the current evidence base for clinical decisions about client suitability and selection of treatment goals, methods, and measures. We also identify questions that need to be addressed in future therapy research. Methods & Procedures: We reviewed 15 reports of impairment‐directed behavioural, pharmacological, and repeated transcranial magnetic stimulation treatments that implemented some level of experimental control. We reviewed a further 10 reports of interventions generally carried out without experimental control, targeting impairments, activity/participation limitations, education, carer training, or a mixture of these approaches. Outcomes & Results: In the impairment‐directed studies almost all participants showed improvement on treated items immediately post‐treatment. Improvement was specific to treated items in most word retrieval studies, but there is a possibility that greater generalisation to other items or other language tasks/contexts may have occurred in treatments not targeting naming, and/or for clients with articulatory impairments. Without ongoing practice of therapy activities, treatment gains declined for all participants over a period varying from 2 months to between 6 months and 1 year. There was only one experimentally controlled activity/participation‐directed intervention reported for people with progressive language impairments, although other reports of activity/participation‐directed interventions described increased communicativeness and communication effectiveness for participants following intervention. Consistent with the aims of activity/participation‐interventions, these interventions appear to have a greater impact on everyday communication outside the clinic than impairment‐directed interventions, but these impacts need to be investigated and documented. Conclusions: These studies highlight the need for rigorous research design to identify treatment, generalisation, and maintenance effects (Rapp & Glucroft, 2009 this issue), and to identify outcomes that go beyond improvement in the clinic on targeted words, language structures, and behaviours. It is important to tailor interventions closely to individual client needs, involve the spouse/carer in intervention, and ensure that clients have appropriate expectations about therapy. The patterns of therapy gain, limited generalisation, and decline following cessation of therapy activities in impairment‐directed studies raise questions about the learning mechanism(s) involved. They also have implications for client suitability, and for choice of therapy items, and therapy delivery and duration. Thanks to Elizabeth Armstrong and Regina Jokel for helpful comments on an earlier draft of the paper. Lyndsey Nickels was funded by a National Health and Medical Research Council Senior Research Fellowship during the preparation of this paper.