Typicality of inanimate category exemplars in aphasia treatment: further evidence for semantic complexity

Abstract

Purpose: The typicality treatment approach on improving naming was investigated within 2 inanimate categories (furniture and clothing) using a single-subject experimental design across participants and behaviors in 5 patients with aphasia.

Method: Participants received a semantic feature treatment to improve naming of either typical or atypical items within semantic categories, whereas generalization was tested to untrained items of the category. The order of typicality and category trained was counterbalanced across participants.

Results: Results indicated that 2 out of 4 patients trained on naming of atypical examples demonstrated generalization to naming untrained typical examples. One patient showed trends toward generalization but did not achieve criterion. Furthermore, all 4 patients trained on typical examples demonstrated no generalized naming to untrained atypical examples within the category. Also, analysis of errors indicated an evolution of errors as a result of treatment, from those with no apparent relationship to the target to primarily semantic and phonemic paraphasias.

Conclusion: These results extend our previous findings (S. Kiran & C. K. Thompson, 2003a) to patients with nonfluent aphasia and to inanimate categories such as furniture and clothing. Additionally, the results provide support for the claim that training atypical examples is a more efficient method of facilitating generalization to untrained items within a category than training typical examples (S. Kiran, 2007).

Figure 1

(a) Naming accuracy for atypical (trained) and typical (untrained) items for the category clothing, and (b) naming accuracy for typical (trained) and atypical (untrained) when treatment was provided for typical examples for the category furniture for Participant 1. Treatment was subsequently shifted to atypical examples while maintenance of the previously trained typical examples was observed.

Figure 2

(a) Naming accuracy for typical (trained) and atypical items (untrained) for the category furniture during baseline and treatment phases for Participant 2.

Figure 3

(a) Naming accuracy for atypical (trained) and typical (untrained) items for the category furniture, and (b) naming accuracy for typical (trained) and atypical (untrained) items for the category clothing across baseline, treatment and follow-up phases for Participant 3.

Figure 4

(a) Naming accuracy for typical (trained) and atypical (untrained) items for the category clothing, and (b) naming accuracy for atypical (trained) and typical (untrained) items for the category furniture across baseline and treatment phases for Participant 4. The hashed line indicates a change in probe protocol.

Figure 5

(a) Naming accuracy for atypical (trained) and typical (untrained) items for the category furniture across baseline, treatment and follow up phases for Participant 5. The hashed line indicates a change in probe protocol.