Presentations

Abstract

Coordination is at the heart of human conversation. In order to interact with one another through talk, we must coordinate at many levels, first and foremost at the level of our mental states, intentions and conversational contributions. In this talk, I will present findings on the pragmatics of multi-modal communication from both production and comprehension studies. In terms of production, I will talk about (1) how co-speech gestures are used in the coordination of meaning allowing interactants to arrive at a shared understanding of the things they talk about, as well as on (2) how gesture and gaze are employed in the coordination of speaking turns in conversation, with special reference to the psycholinguistic and cognitive challenges that turn-taking poses. In terms of comprehension, I will focus on the interplay of ostensive (social gaze) and semantic (gesture) signals in the context of intention perception and language processing. My talk will bring different sets of findings together to argue for richer research paradigms that capture more of the complexities and sociality of face-to-face conversational interaction. Advancing the field of multi-modal communication research in this direction will allow us to more fully understand the psycholinguistic processes that underlie human language use and language comprehension.

Abstract

Human language has long been considered a unimodal
activity, with the body being considered a mere vehicle
for expressing acoustic linguistic meaning. But theories of
language evolution point towards a close link between
vocal and visual communication early on in history,
pinpointing gesture as the origin of human language.
Some consider this link between gesture and
communicative vocalisations as having been temporary,
with conventionalized linguistic code eventually replacing
early bodily signaling. Others argue for this link being
permanent, positing that even fully-fledged human
language is a multi-modal phenomenon, with visual
signals forming integral components of utterances in faceto-
face conversation. My research provides evidence for
the latter. Based on this research, I will provide insights
into some of the factors and principles governing multimodal
language use in adult interaction. My talk consists
of three parts: First, I will present empirical findings
showing that movements we produce with our body are
indeed integral to spoken language and closely linked to
communicative intentions underlying speaking. Second, I
will show that bodily signals, first and foremost manual
gestures, play an active role in the coordination of
meaning during face-to-face interaction, including
fundamental processes like the grounding of referential
utterances. Third, I will present recent findings on the role
of bodily communicative acts in the psycholinguistically
challenging context of turn-taking during conversation.
Together, the data I present form the basis of a framework
aiming to capture multi-modal language use and
processing situated in face-to-face interaction, the
environment in which language first emerged, is acquired
and used most.

Abstract

Conversation is the core niche of human multi-modal language use and it is characterized by a system of taking turns. This organization poses a particular psycholinguistic challenge for its participants: considering the gap between two speaking turns averages around just 200 ms (Stivers et al., 2009) but the production of single word utterances takes a minimum of 600 ms alone (Indefrey & Levelt, 2004), language production and comprehension must largely run in parallel; while listening to an on-going turn, a next speaker has to predict the upcoming content and end of that turn to start preparing their own and launch it on time (Levinson, 2013). Recently, research has begun to investigate the cognitive processes underpinning turn-taking (see Holler et al., 2015 for an overview), but this research has focused on the spoken modality. The present study investigates the role co-speech gestures may play in this process. We analysed a corpus of 7 casual face-to-face conversations between English speakers for all question-response sequences (N=281), the gestures that accompanied the identified set of questions, and the timing of these gestures with respect to the speaking turns they accompanied. Moreover, we measured the length of all inter-turn gaps in our set. Our main research question was whether the length of the gap between turns varied systematically as a consequence of questions being accompanied by gesture. Our results revealed that this is indeed the case: Questions with a gestural component were responded to significantly faster than questions without a gestural component. This finding holds when we consider head and hand gestures separately, when we control for points of possible completion in the verbal utterance prior to turn end, and when we control for complexity associated with question type. Furthermore, our findings revealed that within the group of questions accompanied by gestures, those questions whose gestures retracted prior to turn end were responded to faster than questions whose gestures retracted following turn end. This study provides evidence that gestures accompanying spoken questions in conversation facilitate the coordination of turns. While experimental studies have demonstrated beneficial effects of gestures on language processing, this is the first evidence that gestures may benefit processing even in the rich, cognitively challenging context of conversational interaction. That is, gestures appear to play an important psycholinguistic function during immersed, in situ language processing. Experimental work is currently exploring at which level (semantic, pragmatic, perceptual) the facilitative effects we found are operating. The findings not only suggest psycholinguistic processing benefits but also expand on previous turn-taking models that restrict the function of gesture to turn-yielding/-keeping cues (Duncan, 1972) as well as on turn-taking models focusing primarily on the verbal modality (Sacks et al., 1974).

Abstract

In communication, speech is often accompanied by co-speech gestures, which embody a link between language and action. Language impairments in Parkinson’s disease (PD) are particularly pronounced for action-related words in comparison to nouns. People with PD produce fewer gestures from a first-person perspective when they describe others’ actions (Humphries et al., 2016), which may reflect a difficulty in simulation. We extended this to investigate the gestural depiction of other types of action information such as “manner” (how an action is performed) and “path” (the trajectory of a moving figure in space). We also explored whether the level of motion required to perform an action influences the way that people with PD use gestures to depict those actions. 37 people with PD and 35 age-matched controls viewed a cartoon which included low motion actions (e.g. hiding, knocking) and high motion actions (e.g. running, climbing), and described it to an addressee. We analysed the co-speech gestures they spontaneously produced while doing so. Overall gesture rate was similar in both groups, but people with PD produced action-gestures at a significantly lower rate than controls in both motion conditions. Also, people with PD produced significantly fewer manner and first-person action gestures than controls in the high motion condition (but not the low motion condition). Our findings suggest that motor impairments in PD contribute to the way in which actions, especially high motion actions, are depicted gesturally. Thus, people with Parkinson’s may have particular difficulty cognitively representing high motion actions

Abstract

Human language has long been considered a unimodal activity, with the body being considered a mere vehicle
for expressing acoustic linguistic meaning. But theories of
language evolution point towards a close link between
vocal and visual communication early on in history,
pinpointing gesture as the origin of human language.
Some consider this link between gesture and
communicative vocalisations as having been temporary,
with conventionalized linguistic code eventually replacing
early bodily signaling. Others argue for this link being
permanent, positing that even fully-fledged human
language is a multi-modal phenomenon, with visual
signals forming integral components of utterances in faceto-
face conversation. My research provides evidence for
the latter. Based on this research, I will provide insights
into some of the factors and principles governing multimodal
language use in adult interaction. My talk consists
of three parts: First, I will present empirical findings
showing that movements we produce with our body are
indeed integral to spoken language and closely linked to
communicative intentions underlying speaking. Second, I
will show that bodily signals, first and foremost manual
gestures, play an active role in the coordination of
meaning during face-to-face interaction, including
fundamental processes like the grounding of referential
utterances. Third, I will present recent findings on the role
of bodily communicative acts in the psycholinguistically
challenging context of turn-taking during conversation.
Together, the data I present form the basis of a framework
aiming to capture multi-modal language use and
processing situated in face-to-face interaction, the
environment in which language first emerged, is acquired
and used most.

Abstract

The primordial site of conversation is face-to-face social interaction where participants make use of visual modalities, as well as talk, in the coordination of collaborative action. This most basic observation leads to a fundamental question: what is the place of multimodal resources such as these in the organisation of turn-taking for conversation? To answer this question, we collected a corpus of both dyadic and triadic face-to-face interactions between adults, with the aim to build on existing observations of the use of visual bodily modalities in conversation (e.g., Duncan, 1972; Goodwin, 1981; Kendon, 1967; Lerner 2003; Mondada 2007; Oloff, 2013; Rossano, 2012; Sacks & Schegloff, 2002; Schegloff, 1998).

The corpus retains the spontaneity and naturalness of everyday talk as much as possible while combining it with state-of-the-art technology to allow for exact, detailed analyses of verbal and visual conversational behaviours. Each participant (1) was filmed by three high definition video cameras (providing a frontal plus two lateral views) allowing for fine-grained, frame-by-frame analyses of bodily conduct, as well as the precise measurement of how individual bodily behaviours are timed with respect to each other, and with respect to speech; (2) wore a head-mounted microphone providing high quality recordings of the audio signal suitable for determining on- and off-sets of speaking turns, as well as inter-turn gaps, with high precision, (3) wore head-mounted eye-tracking glasses to monitor eye movements and fixations overlaid onto a video recording of the visual scene the participant was viewing at any given moment (including the other [two] participant[s] and the surroundings in which the conversation took place). The HD video recordings of body behaviour, the eye-tracking video recordings, and the audio recordings from all 2/3 participants engaged in each conversation were then integrated within a single software application (ELAN) for synchronised playback and analysis.

The analyses focus on the use and interplay of visual bodily resources, including eye gaze, co-speech gestures, and body posture, during conversational coordination, as well as on how these signals interweave with participants’ turns at talk. The results provide insight into the process of turn projection as evidenced by participants’ gaze behaviour with a focus on the role different bodily cues play in this context, and into how concurrent visual and verbal resources are involved in turn construction and turn allocation. This project will add to our understanding of core issues in the field of CA, such as by elucidating the role of multi-modality and number of participants engaged in talk-in-interaction (Schegloff, 2009).

References

Duncan, S. (1972). Some signals and rules for taking speaking turns in conversations. Journal of Personality and Social Psychology, 23, 283-92.

Goodwin, C. (1981). Conversational organization: Interaction between speakers and hearers. New York: Academic Press.

Kendon, A. (1967). Some functions of gaze-direction in social interaction. Acta Psychologia, 26, 22-63.

Lerner, G. H. (2003). Selecting next speaker: The context-sensitive operation of a context-free organization. Language in Society, 32(02), 177–201.

Mondada, L. (2007). Multimodal resources for turn-taking: Pointing and the emergence of possible next speakers. Discourse Studies, 9, 195-226.

Oloff, F. (2013). Embodied withdrawal after overlap resolution. Journal of Pragmatics, 46, 139-156.

Rossano, F. (2012). Gaze behavior in face-to-face interaction. PhD Thesis, Radboud University Nijmegen, Nijmegen.

Sacks, H., & Schegloff, E. (2002). Home position. Gesture, 2, 133-146.

Schegloff, E. (1998). Body torque. Social Research, 65, 535-596.

Schegloff, E. (2009). One perspective on Conversation Analysis: Comparative perspectives. In J. Sidnell (ed.), Conversation Analysis: Comparative perspectives, pp. 357-406. Cambridge: Cambridge University Press.

Abstract

Coordination is at the heart of human conversation. In order to interact with one another through talk, we must coordinate at many levels, first and foremost at the level of our mental states, intentions and conversational contributions. In this talk, I will present findings on the pragmatics of multi-model communication from both production and comprehension studies. In terms of production, I will throw light on (1) how co-speech gestures are used in the coordination of meaning to allow interactants to arrive ate a shared understanding of the thins we talk about, as well as on (2) how gesture and gaze are employed in the coordination of speaking turns in spontaneous conversation, with special reference to the psycholinguistic and cognitive challenges that turn-taking poses. In terms of comprehension, I will focus on communicative intentions and the interplay of ostensive and semantic multi-model signals in triadic communication contexts. My talk will bring these different findings together to make the argument for richer reearch paradigms that capture more of the complexities and sociality of face-to-face conversational interactoin. Advancing the field of multi-model communication in this way will allow us to more fully understand the psycholinguistic processes that underlie human language use and language comprehension.

Abstract

The primordial site of conversation is face-to-face social interaction where participants make use of visual modalities, as well as talk, in the coordination of collaborative action (Clark, 1996). This observation leads to a fundamental question: what is the place of multimodal resources such as these in the organisation of turn-taking for conversation’o To answer this question, we collected a corpus of both dyadic and triadic face-to-face interactions between adult native English speakers, with the aim to build on existing observations of the use of visual bodily modalities in conversation (e.g., Duncan, 1972; Goodwin, 1981; Kendon, 1967; Lerner 2003; Mondada 2007; Oloff, 2013; Rossano, 2012; Sacks & Schegloff, 2002; Schegloff, 1998). The corpus retains much of the spontaneity and naturalness of everyday talk while combining it with state-of-the-art technology to allow for exact, detailed analyses of verbal and visual conversational behaviours. Each participant (1) was filmed by three high definition video cameras (providing a frontal plus two lateral views) allowing for fine-grained, frame-by-frame analyses of bodily conduct, as well as the precise measurement of how individual bodily behaviours are timed with respect to each other, and with respect to speech; (2) wore a head-mounted microphone providing high quality recordings of the audio signal suitable for determining on- and off-sets of speaking turns, as well as inter-turn gaps, with high precision, (3) wore head-mounted eye-tracking glasses to monitor eye movements and fixations overlaid onto a video recording of the visual scene the participant was viewing at any given moment (including the other [two] participant[s] and the surroundings in which the conversation took place). The HD video recordings of body behaviour, the eye-tracking video recordings, and the audio recordings from all 2/3 participants engaged in each conversation were then integrated within a single software application (ELAN) for synchronised playback and analysis. All data have been transcribed, coded for co-speech gestures and gaze fixations on a frame-by-frame basis. The large amount of data obtained from this corpus is currently being analysed both qualitatively and quantitatively. The project aims to shed light on the cognitive puzzle that turn-taking presents us with (Levinson, 2013); interlocutors are confronted with the challenge of comprehending an on-going turn while, at the same time, planning a response and estimating when the current speaker’s talk will end in order to time their contribution as precisely as possible (the average gap between turns is a mere 200ms). The results from this project provide insight into the process of turn projection as evidenced by participants’ gaze behaviour with a focus on the role different bodily cues play in this context. Our findings so far show that co-speech gestures may play an important role in this process by guiding the projection of upcoming turn boundaries and next actions. In all, this project elucidates the role of multi-modality in the organisation of turns at talk and in the cognitive processes that underlie this organisation

Abstract

The primordial site of conversation is face-to-face social interaction where participants make use of visual modalities, as well as talk, in the coordination of collaborative action. This most basic observation leads to a fundamental question: what is the place of multimodal resources such as these in the organisation of turn-taking for conversation? To answer this question, we collected a corpus of both dyadic and triadic face-to-face interactions between adults, with the aim to build on existing observations of the use of visual bodily modalities in conversation (e.g., Duncan, 1972; Goodwin, 1981; Kendon, 1967; Lerner 2003; Mondada 2007; Oloff, 2013; Rossano, 2012; Sacks & Schegloff, 2002; Schegloff, 1998). The corpus retains the spontaneity and naturalness of everyday talk as much as possible while combining it with state-of-the-art technology to allow for exact, detailed analyses of verbal and visual conversational behaviours. Each participant (1) was filmed by three high definition video cameras (providing a frontal plus two lateral views) allowing for fine-grained, frame-by-frame analyses of bodily conduct, as well as the precise measurement of how individual bodily behaviours are timed with respect to each other, and with respect to speech; (2) wore a head-mounted microphone providing high quality recordings of the audio signal suitable for determining on- and off-sets of speaking turns, as well as inter-turn gaps, with high precision, (3) wore head-mounted eye-tracking glasses to monitor eye movements and fixations overlaid onto a video recording of the visual scene the participant was viewing at any given moment (including the other [two] participant[s] and the surroundings in which the conversation took place). The HD video recordings of body behaviour, the eye-tracking video recordings, and the audio recordings from all 2/3 participants engaged in each conversation were then integrated within a single software application (ELAN) for synchronised playback and analysis. The analyses focus on the use and interplay of visual bodily resources, including eye gaze, co-speech gestures, and body posture, during conversational coordination, as well as on how these signals interweave with participants’ turns at talk. The results provide insight into the process of turn projection as evidenced by participants’ gaze behaviour with a focus on the role different bodily cues play in this context, and into how concurrent visual and verbal resources are involved in turn construction and turn allocation. This project will add to our understanding of core issues in the field of CA, such as by elucidating the role of multi-modality and number of participants engaged in talk-in-interaction (Schegloff, 2009). References Duncan, S. (1972). Some signals and rules for taking speaking turns in conversations. Journal of Personality and Social Psychology, 23, 283-92. Goodwin, C. (1981). Conversational organization: Interaction between speakers and hearers. New York: Academic Press. Kendon, A. (1967). Some functions of gaze-direction in social interaction. Acta Psychologia, 26, 22-63. Lerner, G. H. (2003). Selecting next speaker: The context-sensitive operation of a context-free organization. Language in Society, 32(02), 177–201. Mondada, L. (2007). Multimodal resources for turn-taking: Pointing and the emergence of possible next speakers. Discourse Studies, 9, 195-226. Oloff, F. (2013). Embodied withdrawal after overlap resolution. Journal of Pragmatics, 46, 139-156. Rossano, F. (2012). Gaze behavior in face-to-face interaction. PhD Thesis, Radboud University Nijmegen, Nijmegen. Sacks, H., & Schegloff, E. (2002). Home position. Gesture, 2, 133-146. Schegloff, E. (1998). Body torque. Social Research, 65, 535-596. Schegloff, E. (2009). One perspective on Conversation Analysis: Comparative perspectives. In J. Sidnell (ed.), Conversation Analysis: Comparative perspectives, pp. 357-406. Cambridge: Cambridge University Press.

Abstract

Background: Gesture and speech are theorized to form a sin- gle integrated system of meaning during language produc- tion (McNeill, 1992), and evidence is mounting that this in- tegration applies to language comprehension as well (Kelly, Ozyurek & Maris, 2010). However, it is unknown whether gesture is uniquely integrated with speech or is processed like any other manual action. To explore this issue, we compared the extent to which speech is integrated with hand gestures versus actual actions on objects during comprehension. Method: The present study employed a priming paradigm in two experiments. In Experiment 1, subjects watched multi- modal videos that presented auditory (words) and visual (ges- tures and actions on objects) information. Half the subjects related the audio information to a written prime presented be- fore the video, and the other half related the visual informa- tion to the written prime. For half of the multimodal video stimuli, the audio and visual information was congruent, and for the other half, incongruent. The task was to press one but- ton if the written prime was the same as the visual (31 sub- jects) or audio (31 subjects) information in the target video or another button if different. RT and accuracy were recorded. Results: In Experiment 2, we reversed the priming se- quence with a different set of 18 subjects. Now the video became the prime and the written verb followed as the target, but the task was the same with one differenceXto indicate whether the written target was related or unrelated to only the audio information (speech) in preceding video prime. ERPs were recorded to the written targets. In Experiment 1, subjects in both the audio and visual tar- get tasks were less accurate when processing stimuli in which gestures and actions were incongruent versus congruent with speech, F(1, 60) = 22.90, p < .001, but this effect was less prominent for speech-action than for speech-gesture stimuli. However, subjects were more accurate when identifying ac- tions versus gestures, F(1, 60) = 8.03, p = .006. In Experiment 2, there were two early ERP effects. When primed with gesture, incongruent primes produced a larger P1, t (17) = 3.75, p = 0.002, and P2, t (17) = 3.02, p = 0.008, to the target words than the congruent condition in the grand-averaged ERPs (reflecting early perceptual and atten- tional processes). However, there were no significant differ- ences between congruent and incongruent conditions when primed with action. Discussion: The incongruency effect replicates and ex- tends previous work by Kelly et al. (2010) by showing not only a bi-directional influence of gesture and speech, but also of action and speech. In addition, the results show that while actions are easier to process than gestures (Exp. 1), gestures may be more tightly tied to the processing of accompanying speech (Exps. 1 & 2). These results suggest that even though gestures are perceptually less informative than actions, they may be treated as communicatively more informative in rela- tion to the accompanying speech. In this way, the two types of visual information might have different status in language comprehension.

Abstract

Background: Gesture and speech are theorized to form a single integrated system of meaning during language production (McNeill, 1992), and evidence is mounting that this integration applies to language comprehension as well (Kelly, Ozyurek & Maris, 2010). However, it is unknown whether gesture is uniquely integrated with speech or is processed like any other manual action. To explore this issue, we compared the extent to which speech is integrated with hand gestures versus actual actions on objects during comprehension. Method: The present study employed a priming paradigm in two experiments. In Experiment 1, subjects watched multimodal videos that presented auditory (words) and visual (gestures and actions on objects) information. Half the subjects related the audio information to a written prime presented before the video, and the other half related the visual information to the written prime. For half of the multimodal video stimuli, the audio and visual information was congruent, and for the other half, incongruent. The task was to press one button if the written prime was the same as the visual (31 subjects) or audio (31 subjects) information in the target video or another button if different. RT and accuracy were recorded. Results: In Experiment 2, we reversed the priming sequence with a different set of 18 subjects. Now the video became the prime and the written verb followed as the target, but the task was the same with one differenceXto indicate whether the written target was related or unrelated to only the audio information (speech) in preceding video prime. ERPs were recorded to the written targets. In Experiment 1, subjects in both the audio and visual target tasks were less accurate when processing stimuli in which gestures and actions were incongruent versus congruent with speech, F(1, 60) = 22.90, p<.001, but this effect was less prominent for speech-action than for speech-gesture stimuli. However, subjects were more accurate when identifying actions versus gestures, F(1, 60) = 8.03, p = .006. In Experiment 2, there were two early ERP effects. When primed with gesture, incongruent primes produced a larger P1, t (17) = 3.75, p = 0.002, and P2, t (17) = 3.02, p = 0.008, to the target words than the congruent condition in the grand-averaged ERPs (reflecting early perceptual and attentional processes). However, there were no significant differences between congruent and incongruent conditions when primed with action. Discussion: The incongruency effect replicates and extends previous work by Kelly et al. (2010) by showing not only a bi-directional influence of gesture and speech, but also of action and speech. In addition, the results show that while actions are easier to process than gestures (Exp. 1), gestures may be more tightly tied to the processing of accompanying speech (Exps. 1 & 2). These results suggest that even though gestures are perceptually less informative than actions, they may be treated as communicatively more informative in relation to the accompanying speech. In this way, the two types of visual information might have different status in language comprehension

Abstract

Pain is a frequent feature of medical consultations and must be communicated effectively if health care providers are to understand the experience and provide treatment. However, pain is difficult to verbalise and spoken pain descriptions are subject to misinterpretation (Schott, 2004). It is well known that when we speak we also produce co-speech hand ges- tures, and during pain communication these gestures have been found to depict aspects of pain that are not contained in the accompanying speech, such as location, sensation and cause of pain (Rowbotham et al., 2012, 2013a, 2013b). Al- though recipients are known to be able to comprehend the information contained in gestures produced during descrip- tions of concrete entities and events (see Hostetter, 2011 for a review), it is not yet known whether this is the case for sub- jective experiences such as pain. We investigated whether un- trained observers are able to glean any additional information from the gestures that accompany spoken pain descriptions, and whether this can be enhanced through a short instruction session on co-speech gestures. Participants (n = 30 per condi- tion) viewed 20 short video clips (mean length = 7.5 seconds) of pain descriptions under one of three presentation condi- tions: 1) Speech Only, 2) Speech and Gesture, or 3) Speech and Gesture plus Instruction (a short presentation, prior to the video clips, explaining what co-speech gestures are and the types of pain information they can depict). Following each clip, participants provided a free-text description of the pain and a “traceable additions” analysis (Kelly et al., 2002) was used to assess whether participants’ descriptions contained any information that was uniquely contained in gestures in the original clips. Participants who had received instruction in co-speech gestures (Speech and Gesture plus Instruction con- dition) obtained the most information from gestures, while those who did not have access to gestures (Speech Only con- dition) obtained the least. There were no differences in the amount of information obtained from speech across the con- ditions, suggesting that neither having access to gestures nor being instructed to attend to these has any detrimental effect on pain understanding. These results suggest that attending to the speaker’s gestures during pain communication can en- hance the recipients understanding of this subjective experi- ence. These findings have important implications for com- munication in medical settings, suggesting that health care professionals may benefit from training in co-speech gestures in order to improve their understanding of patients’ pain ex- periences

Abstract

Common ground (CG), i.e. the knowledge, beliefs and assumptions that interlocutors mutually share in interaction, is fundamental t o successful communication (Clark, 1996). An increasing number of studies have shown that speakers use co - speech gestures at the same rate (or even higher) when they share CG as opposed to when they do not (e.g. Campisi & Ozyurek, 2013; Holler & Wilkin, 20 09; Holler, Tutton & Wilkin, 2011). There are two alternative explanations for this finding. On the one hand, it has been argued that mentally representing our addressee’s knowledge can require considerable cognitive effort (Pickering & Garrod, 2004). Henc e, gesture rate may be high in CG contexts because the cognitive effort involved in mentally representing CG is considerable. In contrast, this high gesture rate may be due to the fact that gestures play an important communicative role, even when conveying information that is already mutually shared (Holler & Wilkin, 2009). The present study tested these two hypotheses by combining the manipulation of CG with a manipulation of communicative context. We used a 2(CG) x 3(communication context) between - partici pants design (18 participants per condition, N=108). All participants watched a short film and narrated it to their addressee. Addressees had either seen parts of the film together with the speaker (CG) or not (no - CG). In addition, we manipulated communica tive context by asking speakers to narrate their story either face - to - face, via an occluding screen, or into a tape - recorder, a manipulation that has been shown to affect gesture rate in no - CG contexts (Bavelas et al., 2008). Our results revealed a signifi cant main effect of communicative context, with gesture rate being highest in the face - to - face condition, followed by the screen condition, and lowest in the tape - recorder condition. Importantly, we did not find a main effect of common ground on gesture ra te, and no interaction between our two factors. This finding supports the hypothesis that gestures representing CG information are communicatively intended as opposed to being triggered by an increased cognitive load.

Abstract

Common ground (CG), i.e., the knowledge, beliefs and assumptions interlocutors mutually share in interaction, is fundamental to successful communication (Clark, 1996). Next to studies finding gestural ellipsis in the context of CG, an increasing number of studies has shown that speakers use co-speech gestures at the same rate (or even a higher one) when they do compared to when they do not share CG with their interlocutor (e.g. Campisi & Ozyurek, 2013; Holler & Wilkin, 2009; Holler, Tutton & Wilkin, 2011). Common ground (CG), i.e. the knowledge, beliefs and assumptions that interlocutors mutually share in interaction, is fundamental to successful communication (Clark, 1996). In contrast to studies that have found gestural ellipsis when a speaker shares CG with an interlocutor, an increasing number of studies have shown that speakers use co-speech gestures at the same rate (or even higher) when they share CG as opposed to when they do not (e.g. Campisi & Ozyurek, 2013; Holler & Wilkin, 2009; Holler, Tutton & Wilkin, 2011). There are two alternative explanations for this finding. On the one hand, it has been argued that mentally representing our addressee’s knowledge can require considerable cognitive effort (Pickering & Garrod, 2004). In combination with evidence that gesturing helps to reduce cognitive load in cognitively effortful tasks (e.g., Goldin-Meadow, 1999), one hypothesis is that gesture rate is high in CG contexts because cognitive effort involved in mentally representing CG is high. This contrasts markedly with the hypothesis that gesture rate remains high when CG exists because the gestures play an important communicative role even when they are conveying information that is mutually shared (Holler & Wilkin, 2009). There are two alternative explanations for this finding. On the one hand, it has been argued that mentally representing our addressee’s knowledge can require considerable cognitive effort (Pickering & Garrod, 2004). In combination with evidence that gesturing helps to reduce cognitive load in cognitively effortful tasks (e.g. Goldin-Meadow, 1999), one hypothesis is that gesture rate is high in CG contexts because the cognitive effort involved in mentally representing CG is high. This contrasts markedly with the hypothesis that gesture rate remains high when CG exists because gestures play an important communicative role, even when conveying information that is already mutually shared (Holler & Wilkin, 2009). The present study tested these two hypotheses by combining the manipulation of CG with a manipulation of communicative context. We used a 2(CG) x 3(communication context) between-participants design (18 participants per condition, N=108). All participants watched a short film and narrated it to their addressee. Addressees had either seen parts of the film together with the speaker (CG) or not (no- CG). In addition, we manipulated communication context by asking speakers to narrate their story either face-to-face, via an occluding screen, or into a tape-recorder, a manipulation that has been shown to affect gesture rate in no-CG contexts (Bavelas et al., 2008). If gestures produced in CG contexts are triggered by the cognitive effort of having to mentally represent CG, then social manipulations of this kind should not influence gesture rate in. If gestures conveying information already in CG are communicatively intended, however, then we would expect gesture rate to be different in the three conditions. Our results revealed a significant main effect of social context, with gesture rate being highest in the face-toface condition, followed by the screen condition, and lowest in the tape-recorder condition. Importantly, we did not find a main effect of common ground on gesture rate, and no interaction between our two factors.The present study tested these two hypotheses by combining the manipulation of CG with a manipulation of communicative context. We used a 2(CG) x 3 (communication context) between-participants design (18 participants per condition, N=108). All participants watched a short film and narrated it to their addressee. Addressees had either seen parts of the film together with the speaker (CG) or not (no-CG). In addition, we manipulated communicative context by asking speakers to narrate their story either faceto- face, via an occluding screen, or into a tape-recorder, a manipulation that has been shown to affect gesture rate in no- CG contexts (Bavelas et al., 2008). If gestures produced in CG contexts are triggered by the cognitive effort of having to mentally represent CG, then social manipulations of this kind should not influence gesture rate. However, if gestures conveying information already in CG are communicatively intended, then we would expect gesture rate to be different in the three conditions. Our results provide several insights. Firstly, they add to the growing body of evidence for maintained/high gesture rate in some common ground contexts. Secondly, they replicate effects of visual access and dialogue on gesture rate found in earlier studies manipulating social interaction. Thirdly, and most importantly, this social interaction effect affected gesture rates in both the common ground and no-common ground conditions equally. This finding is compatible with the account that gestures representing CG information are communicatively intended but not with a cognitive effort-based explanation. Our results revealed a significant main effect of communicative context, with gesture rate being highest in the face-to-face condition, followed by the screen condition, and lowest in the tape-recorder condition. Importantly, we did not find a main effect of common ground on gesture rate, and no interaction between our two factors

Abstract

Traditionally, language comprehension has been studied as a solitary and unimodal activity. Here, we investigate language comprehension as a joint activity, i.e., in a dynamic social context involving multiple participants in different roles with different perspectives, while taking into account the multimodal nature of facetoface communication. We simulated a triadic communication context involving a speaker alternating her gaze between two different recipients, conveying information not only via speech but gesture as well. Participants thus viewed videorecorded speechonly or speech+gesture utterances referencing objects (e.g., “he likes the laptop”/+TYPING ON LAPTOPgesture) when being addressed (direct gaze) or unaddressed (averted gaze). The videoclips were followed by two object images (laptoptowel). Participants’ task was to choose the object that matched the speaker’s message (i.e., laptop). Unaddressed recipients responded significantly slower than addressees for speechonly utterances. However, perceiving the same speech accompanied by gestures sped them up to levels identical to that of addressees. Thus, when speech processing suffers due to being unaddressed, gestures become more prominent and boost comprehension of a speaker’s spoken message. Our findings illuminate how participants process multimodal language and how this process is influenced by eye gaze, an important social cue facilitating coordination in the joint activity of conversation.

Abstract

Human face-to-face communication is a multi-modal activity. Recent research has shown that, during comprehension, recipients integrate information from speech with that contained in co-speech gestures (e.g., Kelly et al., 2010). The current studies take this research one step further by investigating the influence of another modality, namely eye gaze, on speech and gesture comprehension, to advance our understanding of language processing in more situated contexts. In spite of the large body of literature on processing of eye gaze, very few studies have investigated its processing in the context of communication (but see, e.g., Staudte & Crocker, 2011 for an exception). In two studies we simulated a triadic communication context in which a speaker alternated their gaze between our participant and another (alleged) participant. Participants thus viewed speech-only or speech + gesture utterances either in the role of addressee (direct gaze) or in the role of unaddressed recipient (averted gaze). In Study 1, participants (N = 32) viewed video-clips of a speaker producing speech-only (e.g. “she trained the horse”) or speech+gesture utterances conveying complementary information (e.g. “she trained the horse”+WHIPPING gesture). Participants were asked to judge whether a word displayed on screen after each video-clip matched what the speaker said or not. In half of the cases, the word matched a previously uttered word, requiring a “yes” answer. In all other cases, the word matched the meaning of the gesture the actor had performed, thus requiring a ‘no’ answer.