Melanie Moses

Disentangling the Web: Neologistic Perseverative Errors in Jargon Aphasia

Abstract This article explores the relationship between the neologisms and perseverative errors produced by KVH, a man with severe neologistic jargon aphasia. Detailed examination of KVHs level of language processing breakdown revealed mild difficulties with phonological encoding and severe difficulties accessing the lexical form of the word. Many of KVHs neologisms contained phonemes perseverated from previous neologisms, suggesting an integral relationship between the production of neologisms and the perseveration of phonemes. Furthermore, KVHs patterns of whole word (total) and phonological (blended) perseverations reflected his proposed underlying language processing deficits, consistent with recent literature on perseveration (e.g., Cohen and Dehaene, 1998). However, the simple binary distinction of total and blended perseveration is proposed to be somewhat limited for understanding the underlying nature of KVHs complex neologistic errors. Possible explanations regarding the mechanisms underlying the production of KVHs neologistic and perseverative errors also are discussed.

''I'm Sitting Here Feeling Aphasic!'' A Study of Recurrent Perseverative Errors Elicited in Unimpaired Speakers.

In this study, the recurrent perseverative errors produced by 44 speakers without impairment were examined in picture naming and reading aloud tasks under a fast response deadline. The proportion of perseverative relative to non-perseverative errors was greater in picture naming, the more error-prone task, than in reading aloud. Additionally, although perseverative errors were less likely to be related to the target than non-perseverative errors, the overall distribution of perseverative and non-perseverative errors in each task was similar. It is concluded that the perseverative errors produced by the participants reflected both the degree and level at which language processing efficiency was reduced in each task. This is consistent with a more recent account of perseveration as a result of normally existing persistent activation overcoming weakened activation of a target at any level of language processing. These results are compared with recent studies of recurrent perseverative errors produced by people with aphasia in light of the cognitive neuropsychological assumption that speakers with and without impairment utilise a common language processing system.

Treatment of word retrieval impairments in aphasia: Evaluation of a self-administered home programme using personally chosen words

Background: While previous research has shown that a number of tasks can be successful in improving word retrieval following aphasia, the majority of studies result in improvement restricted to treated items. This has two major implications: first it is essential that personally relevant items of communicative value are treated. Second, treatment is likely to be required long term. Therapy provided as a self-administered home programme has the potential to improve the long-term accessibility of therapy and to be more cost effective. This research was part of a larger investigation into treatment for lexical retrieval difficulties in adults with aphasia. Our earlier research found that treatment using repetition in the presence of a picture conducted by a clinician was effective in improving the later retrieval of treated words. In this study we modified the treatment programme such that it could be carried out independently by the participants as a home programme using personally chosen words. Aims: The aims of our study were first, to determine if a home treatment programme for word retrieval with personally chosen words could result in significant improvements in lexical retrieval, and second, to observe if there would be carry over to improved word retrieval in conversation. Methods & Procedures: Three people with aphasia participated, and selected 60 personally relevant words for treatment. These stimuli were treated in two sets, each for eight sessions over 2 weeks. Outcomes of treatment were evaluated by comparing naming of these items on three pre-treatment baselines, with naming following the completion of the programme. Semi-structured conversations based around topics relating to the target words were sampled prior to treatment and following treatment to observe generalisation to conversation. Outcomes & Results: Two participants showed evidence of increased accuracy for naming of treated items following the home programme with no change in naming of unseen controls. The conversation outcomes were less clear, with only one participant showing any evidence of greater production of treated items in conversation. Conclusions: This study found that the home treatment programme using personally chosen words improved word retrieval for some participants. However, the outcomes were less robust than those of a clinician-directed therapy study previously conducted by the researchers. There were limitations in the sensitivity of the measures of transfer to conversation and further investigation is required into the extent to which benefits in single word retrieval carry over into word retrieval in conversation.

Chips, cheeks and carols: A review of recurrent perseveration in speech production

Background: Recurrent perseverative errors involve either the complete or partial repetition of a prior response to a new stimulus. They are commonly produced by speakers with aphasia and are difficult to remediate. During the preparation of this paper, Dr Lyndsey Nickels was funded by an Australian Research Council QE2 Fellowship. Aims: This paper reviews research on recurrent perseverative errors with a focus on different theoretical accounts. Main Contribution: Comparisons are drawn between the literature on perseveration in the non‐language‐impaired population and in aphasia. In addition, theories that relate perseverative errors to underlying levels of language processing breakdown are described and contrasted with those that propose that they are primarily caused by impaired inhibition of recent memory traces. Conclusions: Most recent studies have demonstrated systematic links between patterns of recurrent perseverative errors and underlying levels of language‐processing breakdown in individual speakers with aphasia. For the comprehensive investigation of recurrent perseverative errors the examination of both whole word (i.e., total) and phonological (i.e., blended) perseverations is important, as is the use of case series rather than group designs.

Brain mechanisms underlying phonological treatment effects in aphasia

A functional MRI-naming paradigm was employed to investigate the neural correlates of successful phonological treatment in an individual with impaired word-retrieval poststroke. Items to be treated were selected in a pretest. A subsequent pretreatment fMRI scan measured brain activity during unsuccessful naming of objects to be treated and during successful naming of a comparison set of items. A phonological naming treatment was delivered 2 to 3 times weekly over 3 weeks with posttreatment behavioural testing indicating 100% accuracy on treated items. A posttreatment fMRI scan indicated that compared to the pretreatment scan, successful naming of treated items was associated with significantly increased brain activity in a number of left and right hemisphere regions including the left inferior parietal cortex which has been associated with phonological processing in healthy individuals, suggesting a candidate neural mechanism for sound-based treatments of naming.