Naming and Inhibition in Aphasia

Lexical retrieval models illustrate both activation and inhibition between concepts, words, and phonemes. When semantic activation spreads from one concept to its related concepts, inhibition is recruited so that competition between related concepts can be overcome and a target production achieved. Persons with aphasia often exhibit difficulty with producing the desired response, which could be the result of inadequate inhibitory processes to overcome response competition. Inhibitory processing is typically measured using a negative priming task. Twenty participants with aphasia, twenty-five young participants, and twenty age-matched aphasia group controls were recruited for this study. Participants with aphasia completed a picture-naming task, two written lexical decision tasks, subtests of an aphasia assessment, and the negative priming lexical decision task. Control groups completed only the negative priming task. This task consisted of 4 blocks of 72 trials each in which target words were related associates (RA), related distractors (RD), or unrelated (UN), or pseudowords. Results indicate that no groups showed predicted decreased reaction times to the RA condition. Instead of showing the fastest reaction times, the average RTs in the RA condition were between those in the RD and the UN conditions. Error rates were higher in the aphasia group, with significantly more errors for related conditions. In the young control group, significant negative priming was achieved. However, in the aphasia and aphasia-control groups, there was no significant negative priming. Multiple regression analysis determined that time post onset, age, education, type of fluency, and classification of anomia were not significant predictors of these results in the aphasia group. It is argued that these results are not strategically induced secondary to expectancy or a semantic expectancy or a semantic-matching process. Using a prospective or a retrospective strategy would be useless since only a small portion of the prime-probe pairs are directly related. The results of the aphasia group and the aphasia-control group are similar to those found in the aging negative priming literature, but it is unclear if this should be interpreted as degraded inhibitory processes. Future studies to further explore negative priming in aphasia are discussed

Cognition and discourse production in right hemisphere disorder

This study sought preliminary relationships between discourse deficits and cognitive abilities in persons with right hemisphere disorder (RHD). Seven participants with RHD were matched with a non-neurologically impaired control group. One narrative and two procedural samples were elicited: the story of Cinderella and two procedural discourse samples based on familiar tasks. Macrostructural and microstructural measures of the discourse samples were correlated to cognitive domain scores achieved on a cognitive assessment, the Cognitive Linguistic Quick Test (CLQT [Helm-Estabrooks, N. (2001). Cognitive Linguistic Quick Test. San Antonio, TX: The Psychological Corporation]). Two-tailed t-tests indicated that there were no statistically significant differences in cognitive scores between the RHD and control groups, nor were there differences in discourse measures between the two groups on either procedural task. The narrative production task yielded significant group differences on four measurements—CIU, CIU/minute, total main concept points, and number of absent main concepts. Within the RHD group, there were correlations between the attention, clock drawing, and visuospatial domains of the cognitive measure and narrative measures. The results of this study indicated that although there were no significant differences between the two groups on the cognitive measure, the RHD group produced insufficient narratives. Narrative discourse appears to be a sensitive context in which to pursue the exploration of cognitive–discourse relationships in RHD

Towards a consumer-informed research agenda for aphasia: preliminary work

PURPOSE: Person-centeredness in clinical practice incorporates the values of clients into a shared decision-making approach. The values of person-centeredness can be extended into the realm of research when the views of consumers towards relevant and important research topics are sought. Work in other health domains has shown the importance of gathering consumer views on health care research, which ultimately extends into health care policy and practice. The purpose of this paper is to report methods used successfully to gather the views of individuals living with aphasia on research topics they view as important. METHODS: The project is founded on principles of community-based participatory research. Using a modified nominal group technique, members of an aphasia support group generated a list of research topics. RESULTS: The Aphasia Support Group identified twenty-two potential research questions. Although a majority (59%) of the research questions generated by persons with aphasia could be addressed with accumulated scientific evidence, the remainder of the generated questions has not been addressed in the research literature. CONCLUSIONS: This project demonstrates that consumers with aphasia can participate as stakeholders in the discussion of research needs in aphasia. Additional work is needed to fully develop a consumer-informed research agenda for aphasia. IMPLICATIONS FOR REHABILITATION: The perspectives of individuals with post-stroke aphasia on research needs can be successfully collected using nominal group techniques. Consumer input to research agendas and priorities can help to address potential research biases. Clinicians and researchers can use these techniques and other communication supports to foster collaborative, patient-centered care in their practice and work