Co-verbal gestures among speakers with aphasia: Influence of aphasia severity, linguistic and semantic skills, and hemiplegia on gesture employment in oral discourse

Anthony Pak-Hin Kong, Sam-Po Law, Watson Ka-Chun Wat, Christy Lai
2015 Journal of Communication Disorders  
The use of co-verbal gestures is common in human communication and has been reported to assist word retrieval and to facilitate verbal interactions. This study systematically investigated the impact of aphasia severity, integrity of semantic processing, and hemiplegia on the use of coverbal gestures, with reference to gesture forms and functions, by 131 normal speakers, 48 individuals with aphasia and their controls. All participants were native Cantonese speakers. It was found that the
more » ... of aphasia and verbal-semantic impairment was associated with significantly more co-verbal gestures. However, there was no relationship between right-sided hemiplegia and gesture employment. Moreover, significantly more gestures were employed by the speakers with aphasia, but about 10% of them did not gesture. Among those who used gestures, content-carrying gestures, including iconic, metaphoric, deictic gestures, and emblems, served the function of enhancing language content and providing information additional to the language content. As for the non-content carrying gestures, beats were used primarily for reinforcing speech prosody or guiding speech flow, while non-identifiable gestures were associated with assisting lexical retrieval or with no specific functions. The above findings would enhance our understanding of the use of various forms of co-verbal gestures in aphasic discourse production and their functions. Speech-language pathologists may also refer to the current annotation system and the results to guide clinical evaluation and remediation of gestures in aphasia. (2005) who reported that the complexity of gestures employed in a task of orally describing an object's motion paralleled speakers' use of single or multiple clauses. Speakers who produced a single clause to describe the manner and path of a motion tended to use a single gesture, while those who produced multiple clauses had a tendency to employ separate gestures in the task. Moreover, gestures play a primary role in enhancing communication through providing extra information to the listener (see review by de Ruiter, 2006). According to the conclusion by de Ruiter, gestures served as a communicative device that could provide information to compensate for verbal breakdown in language output. Independent annotation of gesture forms and functions Although a relationship between gesture use and language production is apparent, coding gestures with respect to form and function and quantifying how they may be related to language processes is far from straightforward. Variations among different gesture coding systems have complicated the annotation and interpretation of gesture use as well as their function during production of spontaneous speech (Scharp, Tompkins, & Iverson, 2007) . Kong, Law, Kwan, Lai, and Lam (2015) have recently proposed a gesture classification framework to independently annotate co-verbal gestures in terms of their forms and functions. This was motivated by the fact that mixed coding of gesture forms and functions within one quantification system, a characteristic of many existing frameworks (see review by Kong et al., 2015) , can be conceptually problematic and may create confusion when it comes to interpreting gesture employment. This is especially the case when a particular gesture form carries more than one function under different communication conditions. In the Kong et al. framework, there are six forms of gestures, including (1) iconic gestures that model the shape of an object or the motion of an action, (2) metaphoric gestures that show pictorial content to communicate an abstract idea, (3) deictic gestures such as familiar pointing gestures that indicate objects in conversational space, (4) emblems with standard properties, language-like features, and culturally-specific conventionalized meanings, (5) beats including rhythmic beating of a finger, hand or arm that are used in the format of a simple hand or arm flick or a moving motion of finger(s), hand(s), or arm(s) in an up-anddown or a back-and-forth fashion, and (6) non-identifiable gestures such as uncodable finger, hand, and/or arm movement due to its ambiguous connection or lack of a direct meaning to the language content. While the first four forms are content-carrying, the other two are non-content-carrying. In the dimension of functions, Kong et al. (2015) classified gestures by their primary function in relation to the language content, including (1) providing additional information to message conveyed, i.e., the content of the gesture gave additional information related to the speech, (2) enhancing the language content -gestures that signal the same meaning as the language content and potentially facilitate a listener to decode language content, (3) providing alternative means of communication -gestures that carry meaning or information not included in the language content, (4) guiding and controlling the speech flow -gestures that reinforce the speech rhythm with the rate of gesture movement synchronized with the speech pace, (5) reinforcing the intonation or prosody of speech -gestures that involve a speaker's intensifying or accentuating a target element in the speech, (6) assisting lexical Kong et al.
doi:10.1016/j.jcomdis.2015.06.007 pmid:26186256 pmcid:PMC4530578 fatcat:3u26fh4mprf2vgmxdrn25trjxm