Co-thought gesturing supports more complex problem solving in subjects with lower visual working-memory capacity

Embodying Similarity and Difference: The Effect of Listing and Contrasting Gestures During U.S. Political Speech

Public speakers like politicians carefully craft their words to maximize the clarity, impact, and persuasiveness of their messages. However, these messages can be shaped by more than words. Gestures play an important role in how spoken arguments are perceived, conceptualized, and remembered by audiences. Studies of political speech have explored the ways spoken arguments are used to persuade audiences and cue applause. Studies of politicians' gestures have explored the ways politicians illustrate different concepts with their hands, but have not focused on gesture's potential as a tool of persuasion. Our paper combines these traditions to ask first, how politicians gesture when using spoken rhetorical devices aimed at persuading audiences, and second, whether these gestures influence the ways their arguments are perceived. Study 1 examined two rhetorical devices-contrasts and lists-used by three politicians during U.S. presidential debates and asked whether the gestures produced during contrasts and lists differ. Gestures produced during contrasts were more likely to involve changes in hand location, and gestures produced during lists were more likely to involve changes in trajectory. Study 2 used footage from the same debates in an experiment to ask whether gesture influenced the way people perceived the politicians' arguments. When participants had access to gestural information, they perceived contrasted items as more different from one another and listed items as more similar to one another than they did when they only had access to speech. This was true even when participants had access to only gesture (in muted videos). We conclude that gesture is effective at communicating concepts of similarity and difference and that politicians (and likely other speakers) take advantage of gesture's persuasive potential.

Hands of confidence: When gestures increase confidence in spatial problem-solving

This study examined whether the metacognitive system monitors the potential positive effects of gestures on spatial thinking. Participants (N = 59, 31F, Mage = 21.67) performed a mental rotation task, consisting of 24 problems varying in difficulty, and they evaluated their confidence in their answers to problems in either gesture or control conditions. The results revealed that performance and confidence were higher in the gesture condition, in which the participants were asked to use their gestures during problem-solving, compared with the control condition, extending the literature by evidencing gestures' role in metacognition. Yet, the effect was only evident for females, who already performed worse than males, and when the problems were difficult. Encouraging gestures adversely affected performance and confidence in males. Such results suggest that gestures selectively influence cognition and metacognition and highlight the importance of task-related (i.e., difficulty) and individual-related variables (i.e., sex) in elucidating the links between gestures, confidence, and spatial thinking.

Gesture Use and Processing: A Review on Individual Differences in Cognitive Resources

Speakers use spontaneous hand gestures as they speak and think. These gestures serve many functions for speakers who produce them as well as for listeners who observe them. To date, studies in the gesture literature mostly focused on group-comparisons or the external sources of variation to examine when people use, process, and benefit from using and observing gestures. However, there are also internal sources of variation in gesture use and processing. People differ in how frequently they use gestures, how salient their gestures are, for what purposes they produce gestures, and how much they benefit from using and seeing gestures during comprehension and learning depending on their cognitive dispositions. This review addresses how individual differences in different cognitive skills relate to how people employ gestures in production and comprehension across different ages (from infancy through adulthood to healthy aging) from a functionalist perspective. We conclude that speakers and listeners can use gestures as a compensation tool during communication and thinking that interacts with individuals' cognitive dispositions.

Does Gesture Lighten the Load? The Case of Verbal Analogies

Gesturing has been shown to relay benefits to speakers and listeners alike. Speakers, for instance, may be able to reduce their working memory load through gesture. Studies with children and adults have demonstrated that gesturing while describing how to solve a problem can help to save cognitive resources related to that explanation, allowing them to be allocated to a secondary task. The majority of research in this area focuses on procedural mathematical problem solving; however, the present study examines how gesture interacts with working memory load during a verbal reasoning task: verbal analogies. Unlike previous findings which report improved performance on secondary tasks while gesturing during a primary task, our results show that participants showed better performance in a secondary memory task when being prohibited from gesturing during their explanation of verbal analogies compared to being allowed to gesture. These results suggest that the relationship between gesture and working memory may be more nuanced, with the type of task and gestures produced influencing how gestures interact with working memory load.

The role of gesture as simulated action in reinterpretation of mental imagery

In two experiments, we examined the role of gesture in reinterpreting a mental image. In Experiment 1, we found that participants gestured more about a figure they had learned through manual exploration than about a figure they had learned through vision. This supports claims that gestures emerge from the activation of perception-relevant actions during mental imagery. In Experiment 2, we investigated whether such gestures have a causal role in affecting the quality of mental imagery. Participants were randomly assigned to gesture, not gesture, or engage in a manual interference task as they attempted to reinterpret a figure they had learned through manual exploration. We found that manual interference significantly impaired participants' success on the task. Taken together, these results suggest that gestures reflect mental imaginings of interactions with a mental image and that these imaginings are critically important for mental manipulation and reinterpretation of that image. However, our results suggest that enacting the imagined movements in gesture is not critically important on this particular task.

Does gesture strengthen sensorimotor knowledge of objects? The case of the size-weight illusion

Co-speech gestures have been proposed to strengthen sensorimotor knowledge related to objects’ weight and manipulability. This pre-registered study (https://www.osf.io/9uh6q/) was designed to explore how gestures affect memory for sensorimotor information through the application of the visual-haptic size-weight illusion (i.e., objects weigh the same, but are experienced as different in weight). With this paradigm, a discrepancy can be induced between participants’ conscious illusory perception of objects’ weight and their implicit sensorimotor knowledge (i.e., veridical motor coordination). Depending on whether gestures reflect and strengthen either of these types of knowledge, gestures may respectively decrease or increase the magnitude of the size-weight illusion. Participants (N = 159) practiced a problem-solving task with small and large objects that were designed to induce a size-weight illusion, and then explained the task with or without co-speech gesture or completed a control task. Afterwards, participants judged the heaviness of objects from memory and then while holding them. Confirmatory analyses revealed an inverted size-weight illusion based on heaviness judgments from memory and we found gesturing did not affect judgments. However, exploratory analyses showed reliable correlations between participants’ heaviness judgments from memory and (a) the number of gestures produced that simulated actions, and (b) the kinematics of the lifting phases of those gestures. These findings suggest that gestures emerge as sensorimotor imaginings that are governed by the agent’s conscious renderings about the actions they describe, rather than implicit motor routines.