Do Children Understand Iconic Gestures About Events as Early as Iconic Gestures About Entities?

Children can understand iconic co-speech gestures that characterize entities by age 3 (Stanfield et al. in J Child Lang 40(2):1-10, 2014; e.g., "I'm drinking" [Formula: see text] tilting hand in C-shape to mouth as if holding a glass). In this study, we ask whether children understand co-speech gestures that characterize events as early as they do so for entities, and if so, whether their understanding is influenced by the patterns of gesture production in their native language. We examined this question by studying native English speaking 3- to 4 year-old children and adults as they completed an iconic co-speech gesture comprehension task involving motion events across two studies. Our results showed that children understood iconic co-speech gestures about events at age 4, marking comprehension of gestures about events one year later than gestures about entities. Our findings also showed that native gesture production patterns influenced children's comprehension of gestures characterizing such events, with better comprehension for gestures that follow language-specific patterns compared to the ones that do not follow such patterns-particularly for manner of motion. Overall, these results highlight early emerging abilities in gesture comprehension about motion events.

Iconic Gestures Facilitate Discourse Comprehension in Individuals With Superior Immediate Memory for Body Configurations.

To understand a speaker's gestures, people may draw on kinesthetic working memory (KWM)-a system for temporarily remembering body movements. The present study explored whether sensitivity to gesture meaning was related to differences in KWM capacity. KWM was evaluated through sequences of novel movements that participants viewed and reproduced with their own bodies. Gesture sensitivity was assessed through a priming paradigm. Participants judged whether multimodal utterances containing congruent, incongruent, or no gestures were related to subsequent picture probes depicting the referents of those utterances. Individuals with low KWM were primarily inhibited by incongruent speech-gesture primes, whereas those with high KWM showed facilitation-that is, they were able to identify picture probes more quickly when preceded by congruent speech and gestures than by speech alone. Group differences were most apparent for discourse with weakly congruent speech and gestures. Overall, speech-gesture congruency effects were positively correlated with KWM abilities, which may help listeners match spatial properties of gestures to concepts evoked by speech.

Identifying Patterns of Similarities and Differences between Gesture Production and Comprehension in Autism and Typical Development.

Production and comprehension of gesture emerge early and are key to subsequent language development in typical development. Compared to typically developing (TD) children, children with autism spectrum disorders (ASD) exhibit difficulties and/or differences in gesture production. However, we do not yet know if gesture production either shows similar patterns to gesture comprehension across different ages and learners, or alternatively, lags behind gesture comprehension, thus mimicking a pattern akin to speech comprehension and production. In this study, we focus on the gestures produced and comprehended by a group of young TD children and children with ASD-comparable in language ability-with the goal to identify whether gesture production and comprehension follow similar patterns between ages and between learners. We elicited production of gesture in a semi-structured parent-child play and comprehension of gesture in a structured experimenter-child play across two studies. We tested whether young TD children (ages 2-4) follow a similar trajectory in their production and comprehension of gesture (Study 1) across ages, and if so, whether this alignment remains similar for verbal children with ASD (M age = 5 years), comparable to TD children in language ability (Study 2). Our results provided evidence for similarities between gesture production and comprehension across ages and across learners, suggesting that comprehension and production of gesture form a largely integrated system of communication.

Production and comprehension of co-speech gestures in Parkinson's disease.

This study examined how impairments in sensorimotor abilities of individuals with Parkinson's Disease (PD) can be related to the use and understanding of co-speech hand gestures involving literal and figurative actions. We tested individuals with PD (n = 18, 12 males, Mage = 56.5, SDage = 8.16, PD duration since onset: M = 5.36 years, SD = 3.51, Hoehn and Yahr Scale:MH&Y = 2.09, SDH&Y = 0.50) and age- and education-matched neurotypical controls (n = 18, 14 males, Mage = 56.61, SDage = 8.88) with two experimental tasks. In the gesture production task, participants retold the narratives presented to them in a written format. In the gesture comprehension task, participants were asked to match a gesture with a novel verb in literal and figurative sentence contexts. Results showed that patients with PD gestured significantly less than the neurotypical controls. No group differences were found for the type of gesture use. Individuals with PD performed worse than controls on matching gestures with novel verbs, particularly for figurative meanings. Individuals' severity in the disease negatively correlated with their performance for these figurative novel verb-gesture matches. The performances in the two tasks did not correlate. These findings suggest that problems in sensorimotor abilities resulting from PD can influence overall gesture production and gesture comprehension, providing further evidence on the relations between PD and the impaired use of multimodal language.

Cooperative Communication with Humans Evolved to Emerge Early in Domestic Dogs.

Although we know that dogs evolved from wolves, it remains unclear how domestication affected dog cognition. One hypothesis suggests dog domestication altered social maturation by a process of selecting for an attraction to humans.1-3 Under this account, dogs became more flexible in using inherited skills to cooperatively communicate with a new social partner that was previously feared and expressed these unusual social skills early in development.4-6 Here, we comparedog (n = 44) and wolf (n = 37) puppies, 5-18 weeks old, on a battery of temperament and cognition tasks. We find that dog puppies are more attracted to humans, read human gestures more skillfully, and make more eye contact with humans than wolf puppies. The two species are similarly attracted to familiar objects and perform similarly on non-social measures of memory and inhibitory control. These results are consistent with the idea that domestication enhanced the cooperative-communicative abilities of dogs as selection for attraction to humans altered social maturation.

Semantic Relationships Between Representational Gestures and Their Lexical Affiliates Are Evaluated Similarly for Speech and Text.

This research examined whether the semantic relationships between representational gestures and their lexical affiliates are evaluated similarly when lexical affiliates are conveyed via speech and text. In two studies, adult native English speakers rated the similarity of the meanings of representational gesture-word pairs presented via speech and text. Gesture-word pairs in each modality consisted of gestures and words matching in meaning (semantically-congruent pairs) as well as gestures and words mismatching in meaning (semantically-incongruent pairs). The results revealed that ratings differed by semantic congruency but not language modality. These findings provide the first evidence that semantic relationships between representational gestures and their lexical affiliates are evaluated similarly regardless of language modality. Moreover, this research provides an open normed database of semantically-congruent and semantically-incongruent gesture-word pairs in both text and speech that will be useful for future research investigating gesture-language integration.

The relationship between handedness and valence: A gesture study.

People with different hand preferences assign positive and negative emotions to different sides of their bodies and produce co-speech gestures with their dominant hand when the content is positive. In this study, we investigated this side preference by handedness in both gesture comprehension and production. Participants watched faceless gesture videos with negative and positive content on eye tracker and were asked to retell the stories after each video. Results indicated no difference in looking preferences regarding being right- or left-handed. Yet, an effect of emotional valence was observed. Participants spent more time looking to the right (actor's left) when the information was positive and to the left (actor's right) when the information was negative. Participants' retelling of stories revealed a handedness effect only for different types of gestures (representational vs beat). Individuals used their dominant hands for beat gestures. For representational gestures, while the right-handers used their right hands more, the left-handers gestured using both hands equally. Overall, the lack of significant difference between handedness and emotional content in both comprehension and production levels suggests that body-specific mental representations may not extend to the conversational level.

Do Verbal Children with Autism Comprehend Gesture as Readily as Typically Developing Children?

Gesture comprehension remains understudied, particularly in children with autism spectrum disorder (ASD) who have difficulties in gesture production. Using a novel gesture comprehension task, Study 1 examined how 2- to 4-year-old typically-developing (TD) children comprehend types of gestures and gesture-speech combinations, and showed better comprehension of deictic gestures and reinforcing gesture-speech combinations than iconic/conventional gestures and supplementary gesture-speech combinations at each age. Study 2 compared verbal children with ASD to TD children, comparable in receptive language ability, and showed similar patterns of comprehension in each group. Our results suggest that children comprehend deictic gestures and reinforcing gesture-speech combinations better than iconic/conventional gestures and supplementary combinations-a pattern that remains robust across different ages within TD children and children with ASD.

18-month-olds comprehend indirect communicative acts.

From soon after their first birthdays young children are able to make inferences from a communicator's referential act (e.g., pointing to a container) to her overall social goal for communication (e.g., to inform that a searched-for toy is inside; see Behne, Carpenter, & Tomasello, 2005; Behne, Liszkowski, Carpenter, & Tomasello, 2012). But in such cases the inferential distance between referential act and communicative intention is still fairly close, as both container and searched-for toy lie in the direction of the pointing gesture. In the current study we tested 18- and 26-month-old children in a situation in which referential act and communicative goal were more distant: In the midst of a game, the child needed a certain toy. The experimenter then held up a key (that they knew in common ground could be used to open a container) to the child ostensively. In two control conditions the experimenter either inadvertently moved the key and so drew the child's attention to it non-ostensively or else held up the key for her own inspection intentionally but non-communicatively. Children of both ages took only the ostensive showing of the key, not the accidental moving or the non-ostensive but intentional inspection of the key, as an indirect request to take the key and open the container to retrieve the toy inside. From soon after they start acquiring language young children thus are able to infer a communicator's social goal for communication not only from directly-referential acts, but from more indirect communicative acts as well.

Co-speech iconic gestures and visuo-spatial working memory.

Three experiments tested the role of verbal versus visuo-spatial working memory in the comprehension of co-speech iconic gestures. In Experiment 1, participants viewed congruent discourse primes in which the speaker's gestures matched the information conveyed by his speech, and incongruent ones in which the semantic content of the speaker's gestures diverged from that in his speech. Discourse primes were followed by picture probes that participants judged as being either related or unrelated to the preceding clip. Performance on this picture probe classification task was faster and more accurate after congruent than incongruent discourse primes. The effect of discourse congruency on response times was linearly related to measures of visuo-spatial, but not verbal, working memory capacity, as participants with greater visuo-spatial WM capacity benefited more from congruent gestures. In Experiments 2 and 3, participants performed the same picture probe classification task under conditions of high and low loads on concurrent visuo-spatial (Experiment 2) and verbal (Experiment 3) memory tasks. Effects of discourse congruency and verbal WM load were additive, while effects of discourse congruency and visuo-spatial WM load were interactive. Results suggest that congruent co-speech gestures facilitate multi-modal language comprehension, and indicate an important role for visuo-spatial WM in these speech-gesture integration processes.