<p> This study investigated two classifications of semantic features, feature importance and feature relevance, to verify if they differentially influence lexical semantic knowledge in individuals with aphasia. Feature <i>importance </i> is defined as "how important a feature is in defining a concept" (Hampton,1979), while feature relevance represents the "core meaning of a concept" (Sartori, Lombardi &amp; Mattiuzi, 2005). </p><p> A sorting task was used with 20 volunteer participants with aphasia to investigate the semantic processing involved in the association of semantic features with nouns. A corpus of 18 nouns was displayed in front of each participant in groups of three along with a card containing the word "UNRELATED." The participants were given a deck of 18 cards containing features corresponding to the nouns and to the unrelated category, and were verbally instructed to sort the deck of cards into each of the four designated piles. The semantic features on the cards were rated as high, mid and low importance (HI, MI, LI) and <i>high, mid</i> and <i>low</i> relevance (HR, MR, LR). </p><p> Analysis was completed using a two-way between-subjects ANOVA to determine was whether the mean scores at the three different levels (e.g., low, mid and high) of importance and relevance differed, and to analyze if there was an interaction between the two classifications. The participants were able to assign <i>high importance</i> features with nouns more accurately than they did <i>mid</i> and <i>low importance</i> features. Feature <i>relevance</i> did not differentially influence noun-feature association. These results indicated that the ability of individuals with aphasia to accurately associate features with nouns is influenced by levels of feature importance. </p><p> In conclusion, this study found that individuals with aphasia are more cognitively sensitive to <i>high</i> level versus <i>low</i> level feature importance and the effect does not extend to a<i> mid</i> level of importance. The study also demonstrated that the levels of feature <i> relevance</i> did not differentially influence the ability of individuals with aphasia to associate semantic features with their appropriate nouns. Potential clinical implications and study limitations were discussed.</p>

<p> The acquisition of literacy skills influences both the perception and production of spoken language. The connection between spoken and written language processing develops differently in individuals with varying degrees of reading skill. Some specific phonological and orthographic factors which play a role in this developmental course include neighborhood density, orthographic transparency, and phonotactic probability. In the current study, nonword stimuli which contain manipulations of the above factors were created. Participants repeated or read aloud the nonwords. Three groups of readers participated: adults with typical reading skills, children developing reading skills typically, and adults demonstrating low levels of reading proficiency. Analyses of implicit linguistic processing, including measures of segmental accuracy, segmental variability, and articulatory stability, were conducted. Results indicated that these three groups followed a consistent pattern on all three measures, in that the typical adults demonstrated the strongest performance, the children demonstrated the weakest performance, and the adults with low levels of reading skill demonstrated intermediate performance. All three groups improved in both phonological and motor learning with practice, but only the adults with low reading skills demonstrated learning as a direct consequence of orthographic transparency. Finally, reading skill was correlated with articulatory stability in both groups of adults. These data make an important contribution to the understanding of the typology of reading disorders, as well as the influence of orthographic factors on typical language and reading development.</p>

<p> This study was a within subject, pretest posttest design intended to determine if a three session parent-training program (PTP) would be effective in facilitating morphosyntax in children with or suspected of having specific language impairment (SLI) over the course of 5 weeks. This was measured with the SPELT-P2. In addition, the researcher aimed to determine if parents learned from and were satisfied with the PTP, which was measured by a questionnaire given before and after the PTP was implemented. There were six parent-child dyads in this study. Three children participants demonstrated an increase in standard scores on the SPELT-P2 and three children participants demonstrated a decrease in standard scores. Parent participants demonstrated an overall increase in scores on knowledge, perceptions, and strategies learned during the PTP. Results and clinical implications are discussed.</p>

This thesis investigated sentence comprehension impairments in patients with dementia of the Alzheimer's-type (DAT). The first three experiments investigated the nature of the impairments using different tasks. Across tasks, patients' performance by syntactic complexity, but was poorer for sentences that had more propositions. Results are discussed in terms of a post-interpretive processing impairment in these patients. Two additional experiments investigated possible determinants of sentence comprehension impairments in DAT. One employed a dual-task paradigm to examine the effect of increasing the processing load associated with sentence comprehension. The other examined processing resource limitations in the patients tested in the first and second experiments by employing a battery of tasks designed to measure all aspects of working memory. In both experiments, evidence for processing resource limitations was seen in impaired performance on a concurrent task in dual-task conditions. Results of the fifth experiment also provided evidence that DAT patients' sentence comprehension impairments are correlated with processing resource limitations.

The present study is an investigation of on-line and off-line processing of verb tense in individuals with developmental language impairment. Three groups of subjects performed two experiments, (1) a lexical decision task (on-line) and, (2) a grammaticality judgement task (off-line). Grammaticality was controlled by the manipulation of tense for regular and irregular verbs. Participants were six members of a large British familial aggregation diagnosed with developmental language impairment, six of their unaffected relatives, and seven unaffected Canadian individuals. The results of the lexical decision task indicate that the reaction times of the affected group were slower than the Canadian control group. Unlike the control groups, the affected group was influenced by regular and irregular verb type distinctions. Reaction times across grammatical and ungrammatical conditions did not differ among the three groups. The groups differed significantly in the off-line task; accuracy of the affected subjects was poor, while the control subjects were highly accurate. The implications of these findings for linguistic theories of SLI such as the missing rules hypothesis (Gopnik, in press) are discussed.

The present experiment was conducted to explore the time-course of lexical ambiguity resolution in normal control (NC) subjects and the nature of right hemisphere-damaged (RHD) and left hemisphere-damaged (LHD) patients' impairments in this process. NC, RHD and LHD subjects performed a cross-modal lexical decision task, in which they heard sentence contexts that were biased toward the dominant or subordinate meanings of ambiguous words occurring before the end of the sentence. Written target words related to the dominant or subordinate meaning of the ambiguous words were introduced either at the onset of the ambiguous word (immediate condition), or 1000 ms later (delayed condition). Results revealed that both dominant and subordinate meanings were primed in the immediate condition, irrespective of context type or group. In the delayed condition, only the contextually-appropriate dominant meanings were primed in normal control subjects, whereas both patient groups showed significant priming only for the contextually-inappropriate dominant meanings. Findings for the NC subjects are interpreted in support of a modular model of lexical ambiguity resolution, and more specifically of an exhaustive access view. Patients' results are discussed with reference to a delayed suppression mechanism of inappropriate meanings, which is thought to be involved in these patients' language comprehension deficits.

The development of language in physically handicapped individuals using augmentative and alternative communication (AAC) systems has not been described. Therefore our understanding of the role of AAC language encoding limitations in the development of syntax is limited. This study examined adult AAC system users' knowledge of an English grammatical process which cannot be encoded in lexically based AAC systems. Because it is not possible to mark past tense with affixation in Blissymbolics, a meaning based graphic communication system, past and future tense are neutralized syntactically. The subjects, two congenitally physically handicapped adults with normal hearing, vision, and intelligence, accessed their Blissymbol displays using four-digit eyegaze number codes. The subjects were shown a novel mechanism to enable use of affixation through manipulation of the four-digit codes. Results indicate that the subjects had developed knowledge of this grammatical rule despite the encoding limitations of their AAC systems. Clinical implications are discussed.

To target health services aimed at the impact of maladjustment secondary to a chronic disorder, it is necessary to identify specific disorders that increase the risk of maladjustment. This thesis examines whether children with communication disorders are more likely to have emotional and behavioral problems than those who are healthy or those with other chronic disorders. It also studies whether children with communication disorders are more likely than the comparison groups to develop mental health problems or to persist in having these problems as young adults. To answer these questions, cross-sectional and cohort analyses were conducted on 2,638 children from the Ontario Child Health Survey and 11,744 children from the British National Child Development Study. / Children with communication disorders from both studies were found to have more emotional and behavioral problems than those who were healthy or those with chronic physical disorders. In neither sample, however, was there evidence to conclude that these psychological problems increase or persist in early adulthood. / The implications of these findings for public health and clinical practice are discussed.

Doctor of Philosophy (PhD) / Ensuring that speech pathology students are sufficiently competent to practise their profession is of critical importance to the speech pathology profession, students, their future employers, and clients/patients. This thesis describes the development and validation of a competency based assessment of speech pathology students’ performance in the workplace and their readiness to enter the profession. Development involved an extensive literature review regarding the nature of competency and its relationship to professional practice, the purpose and nature of assessment, and the validation of performance assessments. An online and hard copy assessment tool (paper) was designed through integrating multiple sources of information regarding speech pathology and assessment of workplace performance. Sources included research, theory, expert opinion, current practice, and focus group consultations with clinical educators and speech pathology students. The resulting assessment tool and resource material included four generic components of competency (clinical reasoning, professional communication, lifelong learning, and professional role) and seven occupational competencies previously developed by the speech pathology profession. The tool comprised an assessment format, either in a booklet or online, for clinical educators to rate students’ performances on the competencies at mid and end placement using a visual analogue scale. Behavioural descriptors and an assessment resource booklet informed and supported clinical educators’ judgement. The validity of the assessment tool was evaluated through a national field trial and using Messick’s six interrelated validity criteria which address content, substantive, structural, generalisability, external, and consequential aspects of validity (Messick, 1996). The validity of the assessment tool and its use with speech pathology students was evaluated through Rasch analysis, parametric statistical evaluation of relationships existing between information yielded by the Rasch analysis and other factors, and student and clinical educator feedback. The assessment tool was found to have strong validity characteristics across all validity components. Item Fit statistics generated through Rasch analysis ranged from .81 to 1.17 strongly upholding that the assessment items sampled a unidimensional construct of workplace competency for speech pathology students and confirming that generic and occupational competencies are both necessary for competent practice of speech pathology. High Item and Person Reliabilities (analogous to Cronbach’s alpha) were found (.98 and .97 respectively) and a wide range of person measures (-14.2 to 13.1) were generated. This indicated that a large spread of ability and a clear hierarchy of development on the construct was identified and that the assessment tool was highly reliable. This was further confirmed by high Intra Class Correlation coefficients for a small group of paired clinical educators rating the same student in the same workplace (.87) or in different workplaces concurrently (.82). Rasch analysis of the visual analogue scale used to rate student performance on 11 items of competence identified that clinical educators were able to reliably discriminate 7 categories or levels of student performance. This, in combination with careful calibration procedures, has resulted in an assessment tool that Australian Speech Pathology pre-professional preparation programs can use with confidence to place their students’ level of workplace competence into 7 zones of competency, with the seventh representing sufficient competence to enter the profession. The assessment tool also showed strong potential for identifying marginal students and for future use in promoting quality teaching and learning of professional competence. Limitations to the research and the tool validity were discussed, and recommendations made regarding future research. First, the clinical educator, who has dual and possibly conflicting roles as facilitator and assessor of student learning, made the assessment. Second, situating the assessment in the real workplace limits the students’ opportunities to demonstrate competence to those that naturally arise in the workplace. Paradoxically, both these factors also contributed to the validity of the assessment tool. It was recommended that the assessment tool be revised on the basis of the information gathered from the field trial, that further data be collected to ensure a broader proportional representation of speech pathology programs, to investigate possible threats to validity as well as those areas for which the tool showed promise. This research developed the first prototype of a validated assessment of entry level speech pathology competence that is grounded in a unified theoretical conception of entry level competence to the profession of speech pathology and the developmental progression required to reach this competence. This research will assist the profession of speech pathology by ensuring that speech pathologists enter the workplace well equipped to provide quality care to their future clients, the ultimate goal of any professional preparation program. Messick, S. (1996). Validity of performance assessments. In G. W. Phillips (Ed.), Technical Issues in Large-Scale Performance Assessment (pp. 1-18). Washington: National Centre for Education Statistics.

Thesis (Ph. D.)--University of Wisconsin - Madison, 2006. / (UnM)AAI3222972. Adviser: Diane M. Bless. Source: Dissertation Abstracts International, Volume: 67-06, Section: B, page: 3098.