The effects of observing different gestures during storytelling on the recall of path and event information in 5-year-olds and adults

Through Thick and Thin: Gesture and Speech Remain as an Integrated System in Atypical Development

Gesture and speech are tightly linked and form a single system in typical development. In this review, we ask whether and how the role of gesture and relations between speech and gesture vary in atypical development by focusing on two groups of children: those with peri- or prenatal unilateral brain injury (children with BI) and preterm born (PT) children. We describe the gestures of children with BI and PT children and the relations between gesture and speech, as well as highlight various cognitive and motor antecedents of the speech-gesture link observed in these populations. We then examine possible factors contributing to the variability in gesture production of these atypically developing children. Last, we discuss the potential role of seeing others' gestures, particularly those of parents, in mediating the predictive relationships between early gestures and upcoming changes in speech. We end the review by charting new areas for future research that will help us better understand the robust roles of gestures for typical and atypically-developing child populations.

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.

Interpretations of meaningful and ambiguous hand gestures in autistic and non-autistic adults: A norming study

Gestures are ubiquitous in human communication, and a growing but inconsistent body of research suggests that people with autism spectrum disorder (ASD) may process co-speech gestures differently from neurotypical individuals. To facilitate research on this topic, we created a database of 162 gesture videos that have been normed for comprehensibility by both autistic and non-autistic raters. These videos portray an actor performing silent gestures that range from highly meaningful (e.g., iconic gestures) to ambiguous or meaningless. Each video was rated for meaningfulness and given a one-word descriptor by 40 autistic and 40 non-autistic adults, and analyses were conducted to assess the level of within- and across-group agreement. Across gestures, the meaningfulness ratings provided by raters with and without ASD correlated at r > 0.90, indicating a very high level of agreement. Overall, autistic raters produced a more diverse set of verbal labels for each gesture than did non-autistic raters. However, measures of within-gesture semantic similarity among the responses provided by each group did not differ, suggesting that increased variability within the ASD group may have occurred at the lexical rather than semantic level. This study is the first to compare gesture naming between autistic and non-autistic individuals, and the resulting dataset is the first gesture stimulus set for which both groups were equally represented in the norming process. This database also has broad applicability to other areas of research related to gesture processing and comprehension. The video database and accompanying norming data are available on the Open Science Framework.

The role of hand gestures in emotion communication: Do type and size of gestures matter?

We communicate emotions in a multimodal way, yet non-verbal emotion communication is a relatively understudied area of research. In three experiments, we investigated the role of gesture characteristics (e.g., type, size in space) on individuals' processing of emotional content. In Experiment 1, participants were asked to rate the emotional intensity of emotional narratives from the videoclips either with iconic or beat gestures. Participants in the iconic gesture condition rated the emotional intensity higher than participants in the beat gesture condition. In Experiment 2, the size of gestures and its interaction with gesture type were investigated in a within-subjects design. Participants again rated the emotional intensity of emotional narratives from the videoclips. Although individuals overall rated narrow gestures more emotionally intense than wider gestures, no effects of gesture type, or gesture size and type interaction were found. Experiment 3 was conducted to check whether findings of Experiment 2 were due to viewing gestures in all videoclips. We compared the gesture and no gesture (i.e., speech only) conditions and showed that there was not a difference between them on emotional ratings. However, we could not replicate the findings related to gesture size of Experiment 2. Overall, these findings indicate the importance of examining gesture's role in emotional contexts and that different gesture characteristics such as size of gestures can be considered in nonverbal communication.

Comparing mnemonic effects of iconic gestures and pictures on word memory

Previous studies using intermodal semantic priming have found that gestures improve language memory. In the present study, we ask whether the inherent characteristics of representative gestures (iconic gestures) facilitate word memory, or it is simply the semantic content shared with the words. Two analogous experiments were carried out presenting iconic gestures, pictures, or null primes to target words (nouns and action verbs). In Experiment 1, participants performed a free word recall task. In Experiment 2, the task was one of recognition. The results showed that participants recalled (Experiment 1) an equivalent number of words preceded by gestures or pictures compared with words alone, with no prime. However, a significantly higher number of words were recognised (Experiment 2) when they were primed by iconic gestures compared with the other two conditions, an advantage also found in reaction times (RTs) and both effects being larger in verbs than in nouns. These findings are discussed regarding the differences between recall and recognition processes as well as the particular characteristics of representative gestures.

A Hands-On Approach to Learning: Gesture Production During Encoding and its Effect on Narrative Recall

Research has shown that gesture production supports learning across a number of tasks. It is unclear, however, whether gesture production during encoding can support narrative recall, who gesture production benefits most, and whether certain types of gestures are more beneficial than others. This study, therefore, investigated the effect of gesture production during the encoding of a narrative on subsequent narrative recall, and whether individuals' levels of verbal and nonverbal memory moderated this effect. Additionally, this study investigated whether producing certain types of gestures during encoding was more beneficial than others. Participants (N = 90, M_age = 20.43) read aloud a narrative while under instruction to produce gestures, under no specific instruction to produce gestures, or were required to keep their hands behind their back to prevent them from gesturing. Participants completed measures assessing verbal and nonverbal memory. While gesture production during encoding benefitted narrative recall (as measured through specific questions), verbal memory moderated the effect, such that gesture production was more beneficial for individuals with higher than lower verbal memory. Furthermore, producing representational gestures during encoding benefitted recall of points in the narrative at which those gestures were produced, while beat gestures had no effect. Findings have implications for understanding the mechanisms underlying the links between gesture and learning, as well as practical implications in instructional settings.

The Role of Iconic Gestures in Speech Comprehension: An Overview of Various Methodologies

Iconic gesture-speech integration is a relatively recent field of investigation with numerous researchers studying its various aspects. The results obtained are just as diverse. The definition of iconic gestures is often overlooked in the interpretations of results. Furthermore, while most behavioral studies have demonstrated an advantage of bimodal presentation, brain activity studies show a diversity of results regarding the brain regions involved in the processing of this integration. Clinical studies also yield mixed results, some suggesting parallel processing channels, others a unique and integrated channel. This review aims to draw attention to the methodological variations in research on iconic gesture-speech integration and how they impact conclusions regarding the underlying phenomena. It will also attempt to draw together the findings from other relevant research and suggest potential areas for further investigation in order to better understand processes at play during speech integration process.

The Value of Non-Referential Gestures: A Systematic Review of Their Cognitive and Linguistic Effects in Children's Language Development

Speakers produce both referential gestures, which depict properties of a referent, and non-referential gestures, which lack semantic content. While a large number of studies have demonstrated the cognitive and linguistic benefits of referential gestures as well as their precursor and predictive role in both typically developing (TD) and non-TD children, less is known about non-referential gestures in cognitive and complex linguistic domains, such as narrative development. This paper is a systematic review and narrative synthesis of the research concerned with assessing the effects of non-referential gestures in such domains. A search of the literature turned up 11 studies, collectively involving 898 2- to 8-year-old TD children. Although they yielded contradictory evidence, pointing to the need for further investigations, the results of the six studies-in which experimental tasks and materials were pragmatically based-revealed that non-referential gestures not only enhance information recall and narrative comprehension but also act as predictors and causal mechanisms for narrative performance. This suggests that their bootstrapping role in language development is due to the fact that they have important discourse-pragmatic functions that help frame discourse. These findings should be of particular interest to teachers and future studies could extend their impact to non-TD children.

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.