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Background Assessment and intervention for word finding deficits in aphasia address lexical retrieval in isolation from syntactic processing. Theories in linguistics and psycholinguistics, however, are increasingly adopting a more integrated approach to lexical and syntactic processing. Prominent models of spoken word production suggest that syntactic information relating to nouns is represented within the lexical architecture. Activation of such syntactic information may influence noun production. Only a small number of studies have explored the inf1uence of syntax on noun production in English. Even fewer studies have explored the influence of syntactic cues on noun production in aphasia. Aims & Methods The study included two phases: a normative phase and a therapy study. The aim of the first phase was to investigate the effects of different syntactic primes on naming accuracy and reaction times in healthy speakers. In a series of three experiments, participants named pictures of mass and count nouns following exposure to phrasal or clausal primes. The implications for models of spoken word production were considered. The data from the normative phase informed the construction of a syntactic cueing assessment and therapy program for word-finding in aphasia. The aims of this phase were to explore the effect of syntactic cues on immediate and longer-term naming and noun production in connected speech for three individuals with aphasia. Outcomes and Results Experiments I and 2 showed facilitation of noun production for healthy speakers following exposure to determiners which frequently paired with target nouns. Experiment 3 also demonstrated speeded naming following primes containing determiners. These effects were most marked when the determiner was presented within a clause. Findings from the aphasia case studies showed facilitation of immediate naming following syntactic cues for two individuals with aphasia. The pattern observed mirrored the results from healthy speakers. Following therapy, all three participants showed gains for words treated in picture naming. Improvements in untreated words 2 were observed for one participant. Two participants showed improved noun production in connected speech. Conclusion Evidence from both healthy speakers and individuals with aphasia indicates that lexical and syntactic processes interact in noun production. Models of spoken word production need to account for the influence of syntax on single word processing. It is possible that anomia therapies which target lexical and syntactic structures together increase the likelihood of generalization of therapy effects to untreated words and to noun production in connected speech.

In the current study people with fluent aphasia, Alzheimer's Dementia, and Dementia with Lewy Bodies were assessed with the same set of tests. Three different test-batteries were developed and standardised. Norms were retrieved from a large group of age-and education matched control subjects. The conceptual-semantic test-battery uses non-verbal stimuli, such as silhouettes from objects, pantomimes, object colours, and environmental sounds. Here a nonverbal response by pointing to a matching picture is required. The lexical-semantic test-battery uses the same set of stimuli but these have to be named. The lexical test-battery bypasses semantic processing by using lexical representations determined through language conventions.

Semantic dementia (SD) is a focal degenerative disorder characterised by multimodal loss of semantic knowledge. A number of studies have reported preservation of numerical and arithmetic knowledge in SD, contrasting with patients' profound impairment of object and word knowledge, a finding interpreted as evidence for the independent cerebral representation of number knowledge.

The nature of Apraxia of Speech (AOS) is poorly understood, particularly in connected speech, and there has been controversy about diagnosis, which has been based on clinical judgements without adequate measures of reliability. There have been few studies of AOS in connected speech rather than single words, fewer about grammar, and no investigations of AOS and grammar in spontaneous speech. The thesis adopts Text units ('TU's, which are smaller than traditional sentences), for segmenting connected speech when looking at AOS, and applies multilevel random-intercept logistic regression modelling to measure many factors concurrently. Three strands of evidence about AOS in connected speech are presented.

The experiments presented in this work are aimed at gaining a greater understanding of the semantic impairment in semantic dementia (SD) in terms of modality-specificity and category-specificity, and to consider the implications for the organisation of the semantic system. To this end, the semantic abilities of a group of twelve SD patients with varying impairment severity were examined using a variety of methods - tests from a traditional semantic battery and novel tests, which examined the verbal and nonverbal knowledge of concepts and the semantic attributes of those concepts. The methods of assessment were directly contrasted and relationships between them explored. Throughout this work, comparisons with normal performance were drawn using data collected from age-matched healthy subjects. Longitudinal analyses of the performance of a subset of the patients were also presented to investigate any decline in patient performance over time. The findings suggest a remarkable degree of consistency in semantic performance in the patient group, regardless of stimulus modality or feature type, with few exceptions. However, this consistency was not reflected in the influence of semantic domain. Some patients showed category-specificity while others did not. These differences could not be explained by reference to psycholinguistic variables or evolutionarily determined categories. Differential processing of feature types was more satisfactory as an explanation but required the implication of more fine-grained distinctions than the binary sensory/functional knowledge classification. Recent models of which consider multiple principles of organisation within the semantic system are more likely to be able to account for all the data showing both consistency and inconsistency within the present cohort of SD patients, and the myriad findings in the semantic memory literature.

Some people with aphasia may have difficulty in talking about events because of trouble in processing situations in a language-ready fashion. A number of models of language production include a level at which messages are shaped to the demands of a particular language system. However, the relation between such conceptual processing and production in aphasia has been less fully explored. This study takes an empirical approach, investigating the relationship between the verb and sentence difficulties of six people with aphasia and their conceptualisation of events. Following a range of preparatory assessments, so individuals were hypothesised to have some difficulty in conceptualising events for language. Three novel tests were then devised to explore the skills of these individuals, and in one case, the whole group, in more detail. One test examines participants' focus over pictured situations, through their naming of the people and objects involved. A second probes the adoption of perspective over a particularly problematic situation type, investigating the effect of visual and linguistic cues on verb production. The third test focuses on gesture, exploring the relationship between verbal description and the production of action gestures. One participant's drawing of simple events was also probed using a recently developed assessment (Sacchett, 2005). In each case the results point to some differences between the participants with aphasia and a group of non-brain damaged speakers, thus providing support for the psychological reality of the notion of 'thinking for speaking' (Slobin, 1996) in aphasia. In addition, the test findings bring to light some previously hidden processing strengths. However, they also highlight the difficulty both of designing valid tests in this area and of accurately interpreting their results. The discussion considers the implications of the findings for therapy in aphasia, and for our understanding of the relationship between language loss and event conceptualisation.

This thesis is in two parts: the first focuses on theories of SLI and the development of argument structure while the second focuses on intervention. Chapter 1 reviews experimental findings and theories of SLI and finds that while some areas of language are well-researched, others (including argument structure) have received relatively little attention. Chapter 2 reviews the literature regarding the development of argument structure and concludes that studies of typical development have not investigated use of alternations and omissions of obligatory arguments, whereas studies of SLI have little focus on alternations or overgeneralisations. Chapters 4 and 5 therefore consider the performance of typically developing children and children with SLI on all these areas. I find typically developing children differ from adults in their use of the causative alternation and overgeneralisation of the locative alternation. The children with SLI have difficulties with argument structure, avoiding the ditransitive form of the dative alternation and making more errors with change of state verbs and omission of arguments. A secondary focus (Chapter 6) is on the influence of phonological complexity and length (measured by a non-word repetition test) on the language abilities of children with SLI. The results show a bimodal split where half the children with SLI show normal abilities and half have significant difficulties. Chapter 7 discusses the implications of the experimental findings for theories of SLI. Part 2 reviews intervention studies for SLI (Chapter 8) and presents an intervention study focusing on argument structure (Chapter 9). 27 secondary-aged children with SLI are randomly assigned to three groups, one control and two target therapies focusing on semantics vs constructions. Both target groups show significant progress. Thus, this thesis shows that detailed investigations of the nature of the deficit in SLI can lead to successful interventions even for children with severe, persistent difficulties.

This thesis is concerned with understanding the psychosocial effects of aphasia for partners, and with the outcomes and processes of group programmes of support and conversation training. It comprises three studies, each of which builds upon the other in method and depth. Study One utilised the quantitative, idiographic Personal Questionnaire Rapid Scaling Technique (Mulhall, 1978) to examine the psychosocial issues of 12 partners of people with aphasia (PWA) before and throughout the programmes. Individual statistical analysis suggested that the scores of four partners showed significant positive change as a result of the support programme, and two changed as a result of the conversation training programme. Results were achieved by considerable data reduction, so changes in individual issues could not be determined. Study Two therefore shifted from the quantitative, researcher's perspective to a method able to capture more fully insider perspectives. The Framework Method (Ritchie and Spencer, 1994) was used to analyse semi-structured interview data from the programme participants. This highlighted, within broad themes, varied and interacting factors that influenced participation and psychosocial change: programme content and organisation, individual circumstances, group and personal processes. The predominant focus of Study Two's findings was the process of intervention, leaving the essential question of how partners really experience psychosocial life with PWA unanswered. By taking a further qualitative shift, Study Three answers that question for one woman. An interpretative phenomenological analysis (Smith, 1996) of her in-depth interview suggests her experience was a complicated process of accommodation linked to life pre-stroke and post-stroke. This process featured complex phases labelled as 'rescue mission and hope', 'endurance, loss and hopelessness' and, finally, 'regeneration'. These phases were linked to her changing perception of her relationship with her husband, her role and her self-image. The thesis concludes with a discussion of methodology, theoretical findings and avenues for further research.

This thesis applies Conversation Analysis (CA) to the phenomenon of agrammatism, a particular type of aphasia (a language difficulty acquired most commonly after stroke) which is characterised by grammatical impairment. Although mainstream research has done much to characterise the nature of the underlying disorder, most studies have analysed elicited, task-based data by applying the theoretical concepts of a standard grammar the well-formed sentence, clause and phrase. As a result, little is known about the grammar that people with agrammatism use in real, everyday talk-in-interaction with habitual conversational partners. This study investigates the utility of CA as a tool for the exploration of conversational grammar in agrammatic aphasia. The data comprise video-recordings of the conversation of two adults with agrammatic aphasia, recorded in the home talking to a family member or friend. Conversation is contrasted with single word-, sentence- and narrative-level language samples elicited via commonly used clinical assessments. The data-driven procedures of CA reveal recurring turn construction formats in the talk of the individuals with aphasia. Cognitive neuropsychological, linguistic and psycholinguistic methodologies are drawn on to analyse the elicited language samples, in order to produce the type of clinical profile of agrammatism on which speech and language therapy is based. A comparison of the two samples finds that turn construction for conversation differs from sentence construction for testing. The thesis concludes that the conversation of both aphasic speakers exhibits structure and systematicity, a 'grammatical' organisation, but that the constructions documented do not resemble the sentences, clauses and phrases of a standard grammar. Rather, their form is shaped by the interactional demands of taking a turn at talk. The study questions the widely-held assumption that elicited language tests provide a view of grammatical impairment that is synonymous with the reality of the condition for the person who lives, and most crucially talks with it.

Language anxiety is a type of situational anxiety closely linked to communication apprehension. This thesis examines the phenomenon of language anxiety in 14-16 year old learners in the UK and proposes a contextually-based model to account for the variables involved. The research consists of two main parts: a survey of 607 learners using a modified version of the FLCAS (Foreign Language Communications Anxiety Scale) and a case study of 53 learners of different ability levels from the same school. Results from the survey showed that language anxiety existed in significant numbers and that it was linked with gender and perceived difficulty of the language. Investigations during the period of the case study further demonstrated a negative correlation between achievement (as measured by self-report) and anxiety levels. While anxiety about the act of communicating was felt to have a generally negative effect on learning, in contrast to a number of other studies, test anxiety was found to have a generally facilitating effect providing the test was pitched at an appropriate level of difficulty. The findings of the case study uncovered a range of sources of language anxiety. These included negative experiences in the past, usually involving a teacher. A number of classroom practices such as error correction and certain types of group work were also found to be further causes of anxiety, as were feelings of conspicuousness and the reaction of peers. The implications of the research for the classroom teacher are discussed and ways in which anxiety can be minimised are outlined. Areas for further investigation are suggested in order to further both theory and practice.