Effect of Verb Network Strengthening Treatment (VNeST) on Lexical Retrieval in Aphasia

Stroke is the leading cause of disability in the United States today, and aphasia, a language disorder that affects production and comprehension of language, remains one of the most devastating aspects of stroke recovery. The most prominent symptom of aphasia is difficulty retrieving words, especially in sentence production and connected speech (e.g., telling a story, having a conversation). The current project examines the effect Verb Network Strengthening Treatment (VNeST), a language therapy, on the ability of persons with moderate aphasia to retrieve words in sentences and connected speech. The primary goals of VNeST are to 1) increase the specificity of nouns and verbs in sentences, 2) maximize improvement to untrained words across a variety of language tasks, and 3) engage and challenge participants with salient and relevant treatment materials and activities. Persons with aphasia who are enrolled in the study will receive VNeST for 10 weeks for 4 hours per week. Treatment tasks involve the retrieval of nouns related to a target verb. For example, for the verb measure, participants would come up with people who measure and what they measure (e.g., carpenter/lumber, chef/sugar). They would then answer questions related to why, where, and when these things might occur (e.g., for carpenter/measure, they might say "to get the right length of board," (why) "at a construction site," (where) and "when building a house" (where)). Cues and assistance are provided to the participants when they are unable to complete any given task. As the participants improve, cues are reduced.

Prior to treatment, testing will be conducted on participants to establish their abilities to retrieve words in the following contexts: 1) naming pictures of objects and actions, 2) sentences, and 3) connected speech.

Participants and a family member or friend (i.e., proxy) will also complete a questionnaire about how the participant is able to communicate in everyday tasks (e.g., indicating yes or no, providing medical information).

During the treatment phase, sentence production abilities on items related to treatment will be examined in order to determine how word retrieval abilities are changing with treatment. After the completion of treatment, all measures examined prior to treatment (including the questionnaire) will be re-examined in order to determine whether improvement was observed. Additionally, participants will complete testing one more time 3 months after the completion of treatment to determine if post-treatment improvements were maintained.

Finally, an analysis of improvement over time across the treatment phase will be examined in order to determine the rate of improvement (or lack of it) over time. All statistical analyses will use group data (i.e., group design), but additional examination of improvements for each participant (i.e., single subject design) will also be conducted. Thus, the overall experimental design is a mix of group and single subject analyses. The findings from this study will help to inform aphasia treatment practices and potentially allow for a larger study with more participants in a clinical trial.