In our study, PWA were able to use various pantomime techniques. As a group, they used these techniques differently from PWBD and relied more heavily on the use of shape techniques. This was not influenced by a hemiparesis, but seemed dependent on semantic processing. Clinical implications are discussed.

Pantomime, gesture in absence of speech, has no conventional meaning. Nevertheless, individuals seem to be able to produce pantomimes and derive meaning from pantomimes. A number of studies has addressed the use of co-speech gesture, but little is known on pantomime. Therefore, the question of how people construct and understand pantomimes arises in gesture research. To determine how people use pantomimes, we asked participants to depict a set of objects using pantomimes only. We annotated what representation techniques people produced. Furthermore, using judgment tasks, we assessed the pantomimes' comprehensibility. Analyses showed that similar techniques were used to depict objects across individuals. Objects with a default depiction method were better comprehended than objects for which there was no such default. More specifically, tools and objects depicted using a handling technique were better understood. The open-answer experiment showed low interpretation accuracy. Conversely, the forced-choice experiment showed ceiling effects. These results suggest that across individuals, similar strategies are deployed to produce pantomime, with the handling technique as the apparent preference. This might indicate that the production of pantomimes is based on mental representations which are intrinsically similar. Furthermore, pantomime conveys semantically rich, but ambiguous, information, and its interpretation is much dependent on context. This pantomime database is available online: https://dataverse.nl/dataset.xhtml?persistentId=hdl:10411/QZHO6M. This can be used as a baseline with which we can compare clinical groups.

Background: Studies have shown that the gestures produced by people with aphasia (PWA) can convey information useful for their communication. However, the exact significance of the contribution to message communication via gesture remains unclear. Furthermore, it remains unclear how different gesture types and representation techniques impact message conveyance. Aims: The present study aimed to investigate the contribution of gesture to PWA's communication. We specifically focussed on the degree to which different gesture types and representation techniques convey information absent in the speech of PWA. Methods & Procedure: We studied the gestures produced by 46 PWA and nine non-brain-damaged participants (NBDP) during semi-structured conversation. For each of the different types of gestures and representation techniques we identified whether these conveyed essential information, that is information that was absent in speech. Rather than looking at information that was either similar to information in speech or additional to information in speech, we focused on the essential gestures only. Outcomes & Results: For PWA, a fifth of their gestures were Essential. Despite individual differences between PWA, the majority produced more Essential gestures than NBDP, who produced limited amounts of Essential gestures. Essential information was mostly conveyed by specific gesture types: Pointing, Emblems and Iconic gesture. Within the group of iconic gestures, not only Handling and Enact but also Object and Shape gestures, were often Essential. Conclusions: Our findings suggest that a great proportion of gestures produced by most PWA convey information essential for understanding their communication. In their communication advice, speech language therapists could draw attention to specific gesture types to make sure that interlocutors pay more attention to these gestures when communicating with PWA.

It was concluded that all 3 gesture types under investigation contributed to the expression of semantic meaning communicated by PWA. Gestures are an important communicative means for PWA and should be regarded as such by their interlocutors. Gestures have been shown to enhance listeners' interpretation of PWA's overall communication.

Although QH did not make full use of each gesture modes' potential, both did contribute to QH's comprehensibility. Crucially, the benefits of each mode differed across tasks. This implies that both gesture modes should be taken into account separately in models of speech and gesture production and in clinical practice for different communicative settings.