Publications

Abstract

Gestures express redundant or complementary information to speech they accompany by depicting visual and spatial features of referents. In doing so, they recruit both spatial and verbal cognitive resources that underpin the processing of visual semantic information and its integration with speech. The relation between spatial and verbal skills and gesture comprehension, where gestures may serve different roles in relation to speech is yet to be explored. This study examined the role of spatial and verbal skills in processing gestures that expressed redundant or complementary information to speech during the comprehension of spatial relations between objects. Turkish-speaking adults (N=74) watched videos describing the spatial location of objects that involved perspective-taking (left-right) or not (on-under) with speech and gesture. Gestures either conveyed redundant information to speech (e.g., saying and gesturing “left”) or complemented the accompanying demonstrative in speech (e.g., saying “here,” gesturing “left”). We also measured participants’ spatial (the Corsi block span and the mental rotation tasks) and verbal skills (the digit span task). Our results revealed nuanced interactions between these skills and spatial language comprehension, depending on the modality in which the information was expressed. One insight emerged prominently. Spatial skills, particularly spatial working memory capacity, were related to enhanced comprehension of visual semantic information conveyed through gestures especially when this information was not present in the accompanying speech. This study highlights the critical role of spatial working memory in gesture processing and underscores the importance of examining the interplay among cognitive and contextual factors to understand the complex dynamics of multimodal language.

Abstract

In spoken languages, children acquire locative terms in a cross-linguistically stable order. Terms similar in meaning to in and on emerge earlier than those similar to front and behind, followed by left and right. This order has been attributed to the complexity of the relations expressed by different locative terms. An additional possibility is that children may be delayed in expressing certain spatial meanings partly due to difficulties in discovering the mappings between locative terms in speech and spatial relation they express. We investigate cognitive and mapping difficulties in the domain of spatial language by comparing how children map spatial meanings onto speech versus visually motivated forms in co-speech gesture across different spatial relations. Twenty-four 8-year-old and 23 adult native Turkish-speakers described four-picture displays where the target picture depicted in-on, front-behind, or left-right relations between objects. As the complexity of spatial relations increased, children were more likely to rely on gestures as opposed to speech to informatively express the spatial relation. Adults overwhelmingly relied on speech to informatively express the spatial relation, and this did not change across the complexity of spatial relations. Nevertheless, even when spatial expressions in both speech and co-speech gesture were considered, children lagged behind adults when expressing the most complex left-right relations. These findings suggest that cognitive development and mapping difficulties introduced by the modality of expressions interact in shaping the development of spatial language.

Abstract

During face-to-face communication, one does not only hear speech but also see a speaker's communicative hand movements. It has been shown that such hand gestures play an important role in communication where the two modalities influence each other's interpretation. A gesture typically temporally overlaps with coexpressive speech, but the gesture is often initiated before (but not after) the coexpressive speech. The present ERP study investigated what degree of asynchrony in the speech and gesture onsets are optimal for semantic integration of the concurrent gesture and speech. Videos of a person gesturing were combined with speech segments that were either semantically congruent or incongruent with the gesture. Although gesture and speech always overlapped in time, gesture and speech were presented with three different degrees of asynchrony. In the SOA 0 condition, the gesture onset and the speech onset were simultaneous. In the SOA 160 and 360 conditions, speech was delayed by 160 and 360 msec, respectively. ERPs time locked to speech onset showed a significant difference between semantically congruent versus incongruent gesture–speech combinations on the N400 for the SOA 0 and 160 conditions. No significant difference was found for the SOA 360 condition. These results imply that speech and gesture are integrated most efficiently when the differences in onsets do not exceed a certain time span because of the fact that iconic gestures need speech to be disambiguated in a way relevant to the speech context.

Abstract

Even though most studies of language have focused on speech channel and/or viewed language as an
amodal abstract system, there is growing evidence on the role our bodily actions/ perceptions play in language and communication.
In this context, Özyürek discusses what our meaningful visible bodily actions reveal about our language capacity. Conducting cross-linguistic, behavioral, and neurobiological research,
she shows that co-speech gestures reflect the imagistic, iconic aspects of events talked about and at the same time interact with language production and
comprehension processes. Sign languages can also be characterized having an abstract system of linguistic categories as well as using iconicity in several
aspects of the language structure and in its processing.
Studying language multimodally reveals how grounded language is in our visible bodily actions and opens
up new lines of research to study language in its situated,
natural face-to-face context.