Clinical Trial: Word-Retrieval Treatment for Aphasia: Semantic Feature Analysis

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Word-Retrieval for Aphasia: Facilitation of Generalization

Brief Summary: The purpose of this investigation is to further develop and test a treatment for word-finding problems in aphasia. The treatment is designed to strengthen meaning associations within categories of words (e.g., animals, tools, fruits). The treatment is also designed to be used as a search strategy in instances of word-finding difficulty. The study was devised to evaluate the extent to which treatment increases the ability to recall trained, as well as untrained, words.

Detailed Summary:

The purpose of the proposed research is to examine the effects of a semantically-oriented treatment on word retrieval in persons with aphasia. The planned investigations are designed to further the development of semantic feature training so that it may serve as not only a mechanism for improving disrupted lexical semantic processing, but also as a compensatory strategy during word retrieval failures. The proposed research will also address the issue of exemplar typicality (Kiran & Thompson, 2003) by examining the effects of training typical versus atypical exemplars of various categories with individuals with different types of aphasia. A series of 24 single subject experimental designs will be conducted in the context of a group design to address the following experimental questions:

• Will training atypical examples of living and artifact noun categories using semantic feature training result in a significantly different outcome* than training typical examples of living and artifact noun categories?
• Will training of one category of nouns using semantic feature training result in improved retrieval of untrained categories of nouns?
• Will effects of semantic feature training vary across aphasia types?
• Will semantic feature training result in increased production of content during discourse?

• Will generalization to untrained typical examples vary across generalization lists that are repeatedly exposed and those that are limited in exposure? (i.e., Does repeated exposure appear to contribute to generalization?)

  • Outcome measure will reflect acquisition, response generalization w
    Sponsor: VA Office of Research and Development
    

    Current Primary Outcome: Word Retrieval Accuracy [ Time Frame: End of treatment and at 6 weeks post treatment ]

    Accuracy of naming of pictured treated and untreated items was assessed in probes conducted separate from treatment. Probes were conducted repeatedly throughout the study, from baseline (prior to treatment) to follow-up (6 weeks following treatment). All naming responses were scored using a 0-10 scale reflecting promptness and presence of errors; scores of 8-10 received an "accuate" score and scores of 0-7 received an "inaccurate" score. A percentage accuracy score was calculated for each experimental set of items for every probe session. Baseline probe scores were compared to end of treatment and follow-up probe scores to obtain individual effect sizes for each experimental list of items for each participant (i.e., several effect sizes were calculated for each participant). All effect sizes were utlized to obtain an average effect size for each participant; these averages were then utlized to obtain a group average.
    
    
    

    Original Primary Outcome: The primary outcome measure is a metric that incorporates acquisition, response generalization within category, and response generalization across category effects. Probes of naming performance will be completed at 6 weeks post-treatment and performance.
    
    

    Current Secondary Outcome:
    
    

    Original Secondary Outcome:

    • Naming of trained and untrained typical exemplars of trained categories.
    • Naming of trained and untrained atypical exemplars of
    • trained categories.
    • Naming of exemplars of untrained categories.
    • Production of information units in story retells.
    • All of the above to be measured repeatedly throughout the
    • course of the investigation as well as at 2 & 6 weeks post-tx.
    
    
    Information By: VA Office of Research and Development
    

    Dates:
    Date Received: July 27, 2005
    Date Started: July 2005
    Date Completion:
    Last Updated: December 22, 2014
    Last Verified: December 2014