Editorial Board

A common feature of all languages is that nouns and verbs are classified as different parts of speech (Corina et al., 2005). During language acquisition, the verb is learned later than the noun, and it is generally believed that verbs are more greatly affected than nouns in language disorders that are more prevalent in the elderly such as aphasia and dementia. Most researchers agree that long-term processing of verbs is more difficult than that of nouns. Moreover, a dissociation between verb and noun treatment was reported in people with aphasia (PWA), suggesting that the processing of verbs is different from the processing of nouns (Mätzig et al., 2009).

Whether PWA show more deficits in nouns or verbs remains controversial. Because verbs and nouns are different parts of the vocabulary system, the semantic representation process for verbs is more difficult than that for nouns (Bae, 2019; Mätzig et al., 2009; Park, 2018). Verbs and nouns involve different grammatical categories (Caramazza & Hills, 1991). Unlike nouns, verbs require various morphemes and are subject to the syntactic influence of the argument structure. In addition, verbs and nouns have different image abilities (Bird et al., 2003). Thus, it is not meaningful to specify which of them is more difficult by assuming that the processing of nouns and verbs are of the same magnitude, and there is a need to acknowledge and approve the cognitive processing of the grammatical categories and the independence of the neurological networks involved (Kwag et al., 2014).

It is unclear if PWA performs similarly on noun and verb tasks. Most language testing tools currently used in clinical practices have been designed using mainly nouns. Particularly in Korea, testing tools that focus on verbs are limited. In the sentence comprehension assessment or the process of inducing sentence production, verb processing is necessary; however, in such cases, it is difficult to purely examine verb processing because of different context variables involved. If the verb processing skill of PWA is different from their noun processing skill, and the verb processing skill depends on the type and severity of aphasia, accurate diagnosis and analysis of verb skill is required. The performance on noun and verb tasks should be evaluated, and the direction of the targeted treatment should then be determined based on the overall language evaluation results. Because language evaluation is largely divided into assessments for comprehension and expression skills, both verb understanding and verifying skills must be evaluated. The naming test, which evaluates the ability to produce simply language, is the most basic test for language evaluation, and can be used both as screening and comprehensive tests. Therefore, this study focused on the verb production skill using the naming test.

Most verb and noun production tasks are designed using black and white static images. Recognizing motion in a static picture is more difficult than recognizing objects given that it require greater inference than does object recognition. Because of the nature of this task, a greater effort is needed for verb production (Honincthun & Pillon, 2005; Tae et al., 2017). The limitations of using static picture material for verb production have already been reported in several studies. Briefly, the impaired verb production in PWA can be attributed to the unnaturalness and complexity of the picture task rather than the pathologies language. Due to the methodological issue, it is possible to underestimate the skills involved in producing a verb, which may contribute to a decrease in the accuracy of the language evaluation and in the efficiency of speech therapy. Because of the specificity of verb processing, we can find literature that describes a more natural stimuli presentation method that helps in the visual recognition of presented stimuli and the process of conceptualization of motion more easily. In other words, the more dynamic the stimulus presentation is, the closer it is to the real-life action word, and various studies suggest that this can provide stronger neurological stimulation to induce verbal output (den Ouden et al., 2009). The output of verbs appears to be better for dynamic stimuli than for static stimuli. In addition, understanding which types of verbs (unaccusative verb, unergative verb, non-instrumental verb, and instrumental verb) are more likely to improve the performance of production by dynamic stimulation is important, and may contribute to elucidating the mechanism of the verb calculation process.

Augmented reality is a computer graphics technique that is used to synthesize virtual objects or information in a real environment to make them appear to be objects in the original environment. Recently, augmented reality has been used in various fields, including broadcast media, medicine, and education and has demonstrated effectiveness (Antkowiak et al., 2016). Additionally, in research on aphasia, unlike for still images in which only one face is displayed, augmented reality can rotate markers towards different angles, when the software is programmed to display objects from various angles by moving a predetermined marker on the picture card. This evaluation method is expected to be useful for enhancing the verb’s output because it can contribute to the creation of a new memory retrieval synapse pathway (An et al., 2017; Kim & Kwon, 2018).

Therefore, it may be most appropriate to compare the dynamic augmented reality with the static image stimulus. In this study, we investigated the effectiveness of the expression of verbal vocabulary using self-generated augmented reality contents to dynamically elicit core motions only. Therefore, the purpose of this study is two-folds: (1) to compare the response scores in people with and without aphasia when static and dynamic augmented reality stimuli were presented, and (2) to examine the effects of augmented reality on verb production.

The purposes of this study were (1) to compare the response scores of people with and without aphasia when static and dynamic augmented reality stimuli were presented, and (2) to examine the effects of augmented reality on verbal production. It was found that the participants performed better on the naming test when the augmented reality stimuli were presented compared to when the static picture stimuli were provided. In addition, participants’ responses across the two conditions were significantly different. It is known that the concept of a verb is formed primarily through the process of storing a visual image in the visual cortex. The output of the verb also occurs through a conceptualization process that reactivates the stored image (Bendy et al., 2012).

The findings that people with aphasia showed more difficulty in production in unaccusative verbs than unergative verbs were consistent with previous studies (Kegl, 1995; Lee & Thompson, 2004). In a previous study that examined the verb production of eight patients with agrammatism through the verb naming task, it was reported that patients with agrammatism had more difficulty in producing unaccusative verbs showed than unergative verbs (Lee & Thompson, 2004). The findings of this study imply that the skills to produce verbs through dynamic stimuli may be more preserved than to do so through static stimuli. Previous investigations have shown disadvantages of picture stimuli. For example, the ability to name motion words was significantly impaired picture stimuli were provided, but the performance was improved when the stimuli were presented in direct gestures (Druks & Shallice, 2000). With visual stimuli, the verbal production of people with aphasia decreased significantly (Honincthun & Pillon, 2005). In this study, using the augmented reality content effectively led the reaction to the subject with aphasia instead of the therapist providing the gesture.

During the examination of the participants’ response to the pictured and animated verbs, it was found that unaccusative, non-instrumental, and instrumental verbs were associated with significantly higher correct scores. This finding supports previous studies of typically developing children that report improved performance for transitive and automatic verbs during video stimulus situation compared to picture stimulus situation (An et al., 2017; Davidoff & Masterson, 1995).

The findings of this study suggest that augmented reality may help PWA improve verb production by re-activating the images necessary for the verb production skill and reasoning process essential for the recognition of the actions, compared with the unnaturalness and the complexity of recognition.

This study is preliminary to evaluate the effects of augmented reality content on verb production in PWA. Therefore, future studies addressing following limitations are warranted: First, research should employ people with various types of language disorder and a large number of participants. Second, when applying augmented reality to treatment, its long-term effect should be taken into account, not just a shot-term interest. Third, comparative studies on various presentation methods (picture, photo, video, animation, augmented reality) are necessary considering the nature of the presentation of a task expressing the action of the verb. It is efficient to suggest appropriate tasks (static and dynamic stimuli) according to the severity of aphasia. Finally, how to present contents through augmented reality needs to be considered. In this study, the camera identified the marker of the picture card and sent an output to the monitor. This may yield inaccurate results, in case the person watches the picture card and the monitor at the same time.

Augmented reality can be an effective tool to address the needs of PWA in the clinic. Research demonstrates that augmented reality can be used to improve verb expressions through the use of a simple marker triggering a 3D virtual model. Deeper and focused video instructions of verbs can be overlaid onto a storybook to develop an understanding of verbs. With the technology to integrate augmented reality into one’s own reality, offering one live information during one’s activities, projecting images at a high resolution, and even allowing one to manipulate 3D objects with ease, it is only a matter of time before smart glasses become a part of an individual’s daily life.