Treatment for lexical retrieval using abstract and concrete words in persons with aphasia: Effect of complexity

Abstract

BACKGROUND: The significance of imageability and concreteness as factors for lexical tasks in aphasic individuals is under debate. No previous treatment studies have looked specifically at training abstract words compared to concrete for improved lexical retrieval in patients with chronic aphasia. AIM: The goal of the present study was to determine the efficacy of a treatment for lexical retrieval that is based on models of lexical processing by utilizing abstractness as a mode of complexity. It was hypothesized that training abstract words in a category will result in improvement of those words and generalization to untrained target concrete words in the same category. Training concrete words in a category, however, will result in the retrieval of trained concrete words, but not generalization to target abstract words. METHODS #ENTITYSTARTX00026; PROCEDURES: A single subject experimental design across participants and behaviors was used to examine treatment and generalization. Generative naming for three categories (church, hospital, courthouse) was tested during baseline and treatment. Each treatment session was carried out in five steps: (1) category sorting, (2) feature selection, (3) yes/no feature questions, (4) word recall, and (5) free generative naming. RESULTS: Although participant 1 demonstrated neither significant learning nor generalization during abstract or concrete word training, participants 2, 3, and 4 showed significant learning during abstract word training and generalization to untrained concrete words. Participants 3 and 4 were also trained on concrete words which they improved on but did not show generalization to untrained abstract words. CONCLUSIONS: The results of the present experiment support our hypothesis that training abstract words would result in greater learning and generalization to untrained concrete words. They also tentatively support the idea that generalization is facilitated by treatment focusing on more complex constructions (Kiran & Thompson, 2003; Thompson, Shapiro, Kiran, & Sobecks, 2003).

Figure 1

Schematic illustration of hypothetical representation of abstract and concrete words within a specific location context (e.g., church). Abstract words have stronger connections to other concrete words whereas concrete words are not strongly linked to other abstract words. Therefore, training abstract words will activate related concrete words whereas training concrete words will not activate related abstract words.

Figure 2

Generative naming accuracy for (a) abstract (trained), concrete (untrained), and other abstract and concrete (untrained) items for the category church;, and (b) concrete (trained), abstract (untrained), and other abstract and concrete (untrained) items for the category hospital during baseline and treatment phases for Participant 1.

Figure 3

Generative naming accuracy for abstract (trained), concrete (untrained), and other abstract and concrete (untrained) items for the category church during baseline and treatment phases for Participant 2.

Figure 4

Generative naming accuracy for (a) abstract (trained), concrete (untrained) ), and other abstract and concrete (untrained) items for the category hospital, and (b) concrete (trained), abstract (untrained), and other abstract and concrete (untrained) items for the category courthouse during baseline and treatment phases for Participant 3.

Figure 5

Generative naming accuracy for (a) concrete (trained), abstract (untrained), and other abstract and concrete (untrained) items for the category church, and (b) abstract (trained), concrete (untrained), and other abstract and concrete (untrained) items for the category hospital during baseline and treatment phases for Participant 4.