Publications

Abstract

Increasing evidence suggests that interlocutors use visual communicative signals to form predictions about unfolding utterances, but there is little data on the predictive potential of facial signals in conversation. In an online experiment with virtual agents, we examine whether facial signals produced by an addressee may allow speakers to anticipate the response to a question before it is given. Participants (n = 80) viewed videos of short conversation fragments between two virtual humans. Each fragment ended with the Questioner asking a question, followed by a pause during which the Responder looked either straight at the Questioner (baseline), or averted their gaze, or accompanied the straight gaze with one of the following facial signals: brow raise, brow frown, nose wrinkle, smile, squint, mouth corner pulled back (dimpler). Participants then indicated on a 6-point scale whether they expected a “yes” or “no” response. Analyses revealed that all signals received different ratings relative to the baseline: brow raises, dimplers, and smiles were associated with more positive responses, gaze aversions, brow frowns, nose wrinkles, and squints with more negative responses. Qur findings show that interlocutors may form strong associations between facial signals and upcoming responses to questions, highlighting their predictive potential in face-to-face conversation.

Abstract

Repair is a core building block of human communication, allowing us to address problems of understanding in conversation. Past research has uncovered the basic mechanisms by which interactants signal and solve such problems. However, the focus has been on verbal interaction, neglecting the fact that human communication is inherently multimodal. Here, we focus on a visual signal particularly prevalent in signalling problems of understanding: eyebrow furrows and raises. We present, first, a corpus study showing that differences in eyebrow actions (furrows versus raises) were systematically associated with differences in the format of verbal repair initiations. Second, we present a follow-up study using an avatar that allowed us to test the causal consequences of addressee eyebrow movements, zooming into the effect of eyebrow furrows as signals of trouble in understanding in particular. The results revealed that addressees’ eyebrow furrows have a striking effect on speakers’ speech, leading speakers to produce answers to questions several seconds longer than when not perceiving addressee eyebrow furrows while speaking. Together, the findings demonstrate that eyebrow movements play a communicative role in initiating repair during conversation rather than being merely epiphenomenal and that their occurrence can critically influence linguistic behaviour. Thus, eyebrow movements should be considered core coordination devices in human conversational interaction.

Abstract

In face-to-face conversation, people use speech and gesture to convey meaning. Seeing gestures alongside speech facilitates comprehenders’ language processing, but crucially, the mechanisms underlying this facilitation remain unclear. We investigated whether comprehenders use the semantic information in gestures, typically preceding related speech, to predict upcoming meaning. Dutch adults listened to questions asked by a virtual avatar. Questions were accompanied by an iconic gesture (e.g., typing) or meaningless control movement (e.g., arm scratch) followed by a short pause and target word (e.g., “type”). A Cloze experiment showed that gestures improved explicit predictions of upcoming target words. Moreover, an EEG experiment showed that gestures reduced alpha and beta power during the pause, indicating anticipation, and reduced N400 amplitudes, demonstrating facilitated semantic processing. Thus, comprehenders use iconic gestures to predict upcoming meaning. Theories of linguistic prediction should incorporate communicative bodily signals as predictive cues to capture how language is processed in face-to-face interaction.

Abstract

Despite the importance of greetings for opening social interactions, their multimodal coordination processes remain poorly understood. We used a naturalistic, lab-based setup where pairs of unacquainted participants approached and greeted each other while unaware their greeting behavior was studied. We measured the prevalence and time course of multimodal behaviors potentially culminating in a handshake, including motor behaviors (e.g., walking, standing up, hand movements like raise, grasp, and retraction), gaze patterns (using eye tracking glasses), and speech (close and distant verbal salutations). We further manipulated the visibility of partners’ eyes to test its effect on gaze. Our findings reveal that gaze to a partner's face increases over the course of a greeting, but is partly averted during approach and is influenced by the visibility of partners’ eyes. Gaze helps coordinate handshakes, by signaling intent and guiding the grasp. The timing of adjacency pairs in verbal salutations is comparable to the precision of floor transitions in the main body of conversations, and varies according to greeting phase, with distant salutation pair parts featuring more gaps and close salutation pair parts featuring more overlap. Gender composition and a range of multimodal behaviors affect whether pairs chose to shake hands or not. These findings fill several gaps in our understanding of greetings and provide avenues for future research, including advancements in social robotics and human−robot interaction.

Abstract

During conversation, speakers coordinate and synergize their behaviors at multiple levels, and in different ways. The extent to which individuals converge or diverge in their behaviors during interaction may relate to interpersonal differences relevant to social interaction, such as empathy as measured by the empathy quotient (EQ). An association between interpersonal difference in empathy and interpersonal entrainment could help to throw light on how interlocutor characteristics influence interpersonal entrainment. We investigated this possibility in a corpus of unconstrained conversation between dyads. We used dynamic time warping to quantify entrainment between interlocutors of head motion, hand motion, and maximum speech f0 during question–response sequences. We additionally calculated interlocutor differences in EQ scores. We found that, for both head and hand motion, greater difference in EQ was associated with higher entrainment. Thus, we consider that people who are dissimilar in EQ may need to “ground” their interaction with low-level movement entrainment. There was no significant relationship between f0 entrainment and EQ score differences.

Abstract

When engaged in spoken conversation, speakers convey meaning using both speech and visual signals, such as facial expressions and manual gestures. An important question is how information is distributed in utterances during face-to-face interaction when information from visual signals is also present. In a corpus of casual Dutch face-to-face conversations, we focus on spoken questions in particular because they occur frequently, thus constituting core building blocks of conversation. We quantified information density (i.e. lexical entropy and surprisal) and the number and relative duration of facial and manual signals. We tested whether lexical information density or the number of visual signals differed between the first and last halves of questions, as well as whether the number of visual signals occurring in the less-predictable portion of a question was associated with the lexical information density of the same portion of the question in a systematic manner. We found that information density, as well as number of visual signals, were higher in the first half of questions, and specifically lexical entropy was associated with fewer, but longer visual signals. The multimodal front-loading of questions and the complementary distribution of visual signals and high entropy words in Dutch casual face-to-face conversations may have implications for the parallel processes of utterance comprehension and response planning during turn-taking.

Abstract

The core use of language is in face-to-face conversation. This is characterized by rapid turn-taking. This turn-taking poses a number central puzzles for the psychology of language.

Consider, for example, that in large corpora the gap between turns is on the order of 100 to 300 ms, but the latencies involved in language production require minimally between 600ms (for a single word) or 1500 ms (for as simple sentence). This implies that participants in conversation are predicting the ends of the incoming turn and preparing in advance. But how is this done? What aspects of this prediction are done when? What happens when the prediction is wrong? What stops participants coming in too early? If the system is running on prediction, why is there consistently a mode of 100 to 300 ms in response time?

The timing puzzle raises further puzzles: it seems that comprehension must run parallel with the preparation for production, but it has been presumed that there are strict cognitive limitations on more than one central process running at a time. How is this bottleneck overcome? Far from being 'easy' as some psychologists have suggested, conversation may be one of the most demanding cognitive tasks in our everyday lives. Further questions naturally arise: how do children learn to master this demanding task, and what is the developmental trajectory in this domain?

Research shows that aspects of turn-taking such as its timing are remarkably stable across languages and cultures, but the word order of languages varies enormously. How then does prediction of the incoming turn work when the verb (often the informational nugget in a clause) is at the end? Conversely, how can production work fast enough in languages that have the verb at the beginning, thereby requiring early planning of the whole clause? What happens when one changes modality, as in sign languages -- with the loss of channel constraints is turn-taking much freer? And what about face-to-face communication amongst hearing individuals -- do gestures, gaze, and other body behaviors facilitate turn-taking? One can also ask the phylogenetic question: how did such a system evolve? There seem to be parallels (analogies) in duetting bird species, and in a variety of monkey species, but there is little evidence of anything like this among the great apes.

All this constitutes a neglected set of problems at the heart of the psychology of language and of the language sciences. This research topic welcomes contributions from right across the board, for example from psycholinguists, developmental psychologists, students of dialogue and conversation analysis, linguists interested in the use of language, phoneticians, corpus analysts and comparative ethologists or psychologists. We welcome contributions of all sorts, for example original research papers, opinion pieces, and reviews of work in subfields that may not be fully understood in other subfields.

Abstract

A combination of impaired motor and cognitive function in Parkinson’s disease (PD) can impact on language and communication, with patients exhibiting a particular difficulty processing action verbs. Co-speech gestures embody a link between action and language and contribute significantly to communication in healthy people. Here, we investigated how co-speech gestures depicting actions are affected in PD, in particular with respect to the visual perspective—or the viewpoint – they depict. Gestures are closely related to mental imagery and motor simulations, but people with PD may be impaired in the way they simulate actions from a first-person perspective and may compensate for this by relying more on third-person visual features. We analysed the action-depicting gestures produced by mild-moderate PD patients and age-matched controls on an action description task and examined the relationship between gesture viewpoint, action naming, and performance on an action observation task (weight judgement). Healthy controls produced the majority of their action gestures from a first-person perspective, whereas PD patients produced a greater proportion of gestures produced from a third-person perspective. We propose that this reflects a compensatory reliance on third-person visual features in the simulation of actions in PD. Performance was also impaired in action naming and weight judgement, although this was unrelated to gesture viewpoint. Our findings provide a more comprehensive understanding of how action-language impairments in PD impact on action communication, on the cognitive underpinnings of this impairment, as well as elucidating the role of action simulation in gesture production

Abstract

Objective

Despite the need for effective pain communication, pain is difficult to verbalise. Co-speech gestures frequently add information about pain that is not contained in the accompanying speech. We explored whether recipients can obtain additional information from gestures about the pain that is being described.
Methods

Participants (n = 135) viewed clips of pain descriptions under one of four conditions: 1) Speech Only; 2) Speech and Gesture; 3) Speech, Gesture and Face; and 4) Speech, Gesture and Face plus Instruction (short presentation explaining the pain information that gestures can depict). Participants provided free-text descriptions of the pain that had been described. Responses were scored for the amount of information obtained from the original clips.
Findings

Participants in the Instruction condition obtained the most information, while those in the Speech Only condition obtained the least (all comparisons p<.001).
Conclusions

Gestures produced during pain descriptions provide additional information about pain that recipients are able to pick up without detriment to their uptake of spoken information.
Practice implications

Healthcare professionals may benefit from instruction in gestures to enhance uptake of information about patients’ pain experiences.

Abstract

In human face-to-face communication, language comprehension is a multi-modal, situated activity. However, little is known about how we combine information from different modalities during comprehension, and how perceived communicative intentions, often signaled through visual signals, influence this process. We explored this question by simulating a multi-party communication context in which a speaker alternated her gaze between two recipients. Participants viewed speech-only or speech + gesture object-related messages when being addressed (direct gaze) or unaddressed (gaze averted to other participant). They were then asked to choose which of two object images matched the speaker’s preceding message. Unaddressed recipients responded significantly more slowly than addressees for speech-only utterances. However, perceiving the same speech accompanied by gestures sped unaddressed recipients up to a level identical to that of addressees. That is, when unaddressed recipients’ speech processing suffers, gestures can enhance the comprehension of a speaker’s message. We discuss our findings with respect to two hypotheses attempting to account for how social eye gaze may modulate multi-modal language comprehension.

Abstract

One reason for the apparent gulf between animal and human communication systems is that the focus has been on the presence or the absence of language as a complex expressive system built on speech. But language normally occurs embedded within an interactional exchange of multi-modal signals. If this larger perspective takes central focus, then it becomes apparent that human communication has a layered structure, where the layers may be plausibly assigned different phylogenetic and evolutionary origins—especially in the light of recent thoughts on the emergence of voluntary breathing and spoken language. This perspective helps us to appreciate the different roles that the different modalities play in human communication, as well as how they function as one integrated system despite their different roles and origins. It also offers possibilities for reconciling the ‘gesture-first hypothesis’ with that of gesture and speech having evolved together, hand in hand—or hand in mouth, rather—as one system.

Abstract

Effective pain communication is essential if adequate treatment and support are to be provided. Pain communication is often multimodal, with sufferers utilising speech, nonverbal behaviours (such as facial expressions), and co-speech gestures (bodily movements, primarily of the hands and arms that accompany speech and can convey semantic information) to communicate their experience. Research suggests that the production of nonverbal pain behaviours is positively associated with pain intensity, but it is not known whether this is also the case for speech and co-speech gestures. The present study explored whether increased pain intensity is associated with greater speech and gesture production during face-to-face communication about acute, experimental pain. Participants (N = 26) were exposed to experimentally elicited pressure pain to the fingernail bed at high and low intensities and took part in video-recorded semi-structured interviews. Despite rating more intense pain as more difficult to communicate (t(25) = 2.21, p = .037), participants produced significantly longer verbal pain descriptions and more co-speech gestures in the high intensity pain condition (Words: t(25) = 3.57, p = .001; Gestures: t(25) = 3.66, p = .001). This suggests that spoken and gestural communication about pain is enhanced when pain is more intense. Thus, in addition to conveying detailed semantic information about pain, speech and co-speech gestures may provide a cue to pain intensity, with implications for the treatment and support received by pain sufferers. Future work should consider whether these findings are applicable within the context of clinical interactions about pain.

Abstract

Pain is a private and subjective experience about which effective communication is vital, particularly in medical settings. Speakers often represent information about pain sensation in both speech and co-speech hand gestures simultaneously, but it is not known whether gestures merely replicate spoken information or complement it in some way. We examined the representational contribution
of gestures in a range of consecutive analyses. Firstly, we found that 78% of speech units containing pain sensation were accompanied by gestures, with 53% of these gestures representing pain sensation. Secondly, in 43% of these instances, gestures represented pain sensation information that was not contained in speech, contributing additional, complementary information to the pain sensation message.
Finally, when applying a specificity analysis, we found that in contrast with research in different domains of talk, gestures did not make the pain sensation information in speech more specific. Rather, they complemented the verbal pain message by representing different
aspects of pain sensation, contributing to a fuller representation of pain sensation than speech alone. These findings highlight the importance of gestures in communicating about pain sensation and suggest that this modality provides additional information to supplement and clarify the often ambiguous verbal pain message

Abstract

Gesture is an important precursor of children’s early language development, for example, in the transition to multiword speech and as a predictor of later language abilities. However, it is unclear whether gestural input can influence children’s comprehension of complex grammatical constructions. In Study 1, 3- (M = 3 years 5 months) and 4-year-old (M = 4 years 6 months) children witnessed 2-participant actions described using the infrequent object-cleft-construction (OCC; It was the dog that the cat chased). Half saw an experimenter accompanying her descriptions with gestures representing the 2 participants and indicating the direction of action; the remaining children did not witness gesture. Children who witnessed gestures showed better comprehension of the OCC than those who did not witness gestures, both in and beyond the immediate physical context, but this benefit was restricted to the oldest 4-year-olds. In Study 2, a further group of older 4-year-old children (M = 4 years 7 months) witnessed the same 2-participant actions described by an experimenter and accompanied by gestures, but the gesture represented only the 2 participants and not the direction of the action. Again, a benefit of gesture was observed on subsequent comprehension of the OCC. We interpret these findings as demonstrating that representational cospeech gestures can help children comprehend complex linguistic structures by highlighting the roles played by the participants in the event.