Characteristics of drawing deficits in people with aphasia: Differences between symbolic and realistic drawn objects

Pictures drawn by people with aphasia (PWA) are often more challenging to understand than those drawn by healthy people. There are two types of objects: those that tend to be drawn symbolically (symbolically drawn objects-SOs) and those that are likely to be drawn realistically (realistically drawn objects-ROs).

To compare the identification rate and number of misunderstanding types between SOs and ROs drawn by PWA and healthy controls (HCs). To reveal trends in the misunderstandings of drawings by PWA, and to identify the language or cognitive abilities related to the identification rate of pictures drawn by PWA.

We designed a drawing task involving SOs and ROs. A total of 18 PWA and 30 HCs completed the task, and respondents identified the drawings. The identification rate and number of misunderstandings were analysed with two-way analysis of variance (ANOVA) including group (PWA and HCs) and object type (SOs and ROs). The misunderstandings were divided into four categories varying in semantic and morphological similarity; these ratios were examined with a chi-square test. The relationships of language and cognitive abilities with the identification rate were investigated with multiple regression analyses.

There was a significant effect of the interaction between group and object type on the identification rate (F(1.1387) = 3.90, Mean Squared Error (MSE) = 4139.67, p = 0.04): the identification rates for ROs were lower in the PWA than in the HCs. For the number of misunderstanding types, an interaction was observed between group and object type (F(1.56) = 8.26, MSE = 26.93, p < 0.01): the number of misunderstanding types for ROs in the PWA was greater than that in the HCs. The misunderstanding patterns differed between ROs and SOs (χ²(3) = 694.30, p < 0.001, V = 0.37). ROs were semantically related, whereas SOs were morphologically related. The identification rates of ROs and SOs were correlated only with Kanji writing scores (ROs: β = 3.66, p = 0.01; SOs: β = 6.57, p < 0.01).

In drawings by the PWA, SOs had a higher identification rate, while ROs had a lower identification rate and a greater variety of misunderstandings. SOs may increase drawing motivation. Interventions to improve the identifiability of SOs and ROs should reflect each character. Identification rates were correlated only with Kanji writing scores. The PWA, whose native language was Japanese and had preserved Kanji writing abilities, and their communication abilities may be increased through drawing.

What is already known on the subject PWA often have impaired drawing abilities and draw pictures that third parties misinterpret. Some objects tend to be drawn symbolically, and some are drawn realistically. However, it is not clear whether there is a difference between these types of drawings depicted by PWA in identifiability and the tendency to be misunderstood by ordinary people. In addition, the relationships between language or cognitive abilities and the identification rate of drawn pictures are not clear. What this paper adds to the existing knowledge The identification rate differed between SOs and ROs. In drawings by PWA, SOs had a higher identification rate, while ROs had a lower identification rate and the greatest variety of misunderstandings. Approximately half of the misunderstandings were related to the target object. SOs tended to be confused with morphologically related objects, while ROs tended to be confused with semantically related objects. Identification rates were correlated only with Kanji writing scores. What are the potential or actual clinical implications of this work? To motivate PWA's drawing, it is suitable to begin with SOs. Examining drawing ability from the perspective of SOs and ROs increases the chance of identifying drawing ability. PWA whose native language is Japanese and have preserved Kanji writing abilities may be able to increase their communication abilities through drawing.