Laughter Differs in Children with Autism: An Acoustic Analysis of Laughs Produced by Children With and Without the Disorder

Liberating the mental health and wellbeing benefits of laughing alone: a new taxonomic model and scoping review for future research

Laughter has been predominantly viewed as a social behavior, and laughing alone is often regarded doubtfully, even pathologized. While solitary laughter can be symptomatic of mental health issues, one motivation of this review was to explore whether it can also offer mental health benefits. Research demonstrates that over 10% of laughter occurs in solitude and there is increasing awareness that it is not only enjoyed but can serve important roles in supporting health and wellbeing. To establish a useful foundation for further exploration of its potential in enhancing health and wellbeing, this review scopes the subject across disciplines. An unprecedented search revealed 120 records (n = 83 academic articles n = 37 literary and book references) that mention solitary laughter in meaningful ways. The Solitary Laughter Model (SLM) developed for this research supported an initial classification according to the conditions in which the laughter took place be it complete solitary, public solitary, assisted solitary, or social solitary laughter. Our research reveals that laughing alone tends to be perceived as particularly problematic when done in public. Nevertheless, we also uncovered favorable mental health perspectives on solitary laughter and recent exciting clinical applications in assisted solitary laughter. The implications of these findings are discussed. The SLM is proposed as a pragmatic model to encourage precision in this nascent field of investigation and health practice. This review concludes that solitary laughter is an important human behavior deserving more scientific investigation to further unlock its mental health and wellbeing benefits.

Autistic adults perceive and experience laughter differently to non-autistic adults

Human interaction is immersed in laughter; though genuine and posed laughter are acoustically distinct, they are both crucial socio-emotional signals. In this novel study, autistic and non-autistic adults explicitly rated the affective properties of genuine and posed laughter. Additionally, we explored whether their self-reported everyday experiences with laughter differ. Both groups could differentiate between these two types of laughter. However, autistic adults rated posed laughter as more authentic and emotionally arousing than non-autistic adults, perceiving it to be similar to genuine laughter. Autistic adults reported laughing less, deriving less enjoyment from laughter, and experiencing difficulty in understanding the social meaning of other people's laughter compared to non-autistic people. Despite these differences, autistic adults reported using laughter socially as often as non-autistic adults, leveraging it to mediate social contexts. Our findings suggest that autistic adults show subtle differences in their perception of laughter, which may be associated with their struggles in comprehending the social meaning of laughter, as well as their diminished frequency and enjoyment of laughter in everyday scenarios. By combining experimental evidence with first-person experiences, this study suggests that autistic adults likely employ different strategies to understand laughter in everyday contexts, potentially leaving them socially vulnerable in communication.

Mapping the differential impact of spontaneous and conversational laughter on brain and mind: an fMRI study in autism

Spontaneous and conversational laughter are important socio-emotional communicative signals. Neuroimaging findings suggest that non-autistic people engage in mentalizing to understand the meaning behind conversational laughter. Autistic people may thus face specific challenges in processing conversational laughter, due to their mentalizing difficulties. Using fMRI, we explored neural differences during implicit processing of these two types of laughter. Autistic and non-autistic adults passively listened to funny words, followed by spontaneous laughter, conversational laughter, or noise-vocoded vocalizations. Behaviourally, words plus spontaneous laughter were rated as funnier than words plus conversational laughter, and the groups did not differ. However, neuroimaging results showed that non-autistic adults exhibited greater medial prefrontal cortex activation while listening to words plus conversational laughter, than words plus genuine laughter, while autistic adults showed no difference in medial prefrontal cortex activity between these two laughter types. Our findings suggest a crucial role for the medial prefrontal cortex in understanding socio-emotionally ambiguous laughter via mentalizing. Our study also highlights the possibility that autistic people may face challenges in understanding the essence of the laughter we frequently encounter in everyday life, especially in processing conversational laughter that carries complex meaning and social ambiguity, potentially leading to social vulnerability. Therefore, we advocate for clearer communication with autistic people.

People with Autism Spectrum Disorder Could Interact More Easily with a Robot than with a Human: Reasons and Limits

Individuals with Autism Spectrum Disorder show deficits in communication and social interaction, as well as repetitive behaviors and restricted interests. Interacting with robots could bring benefits to this population, notably by fostering communication and social interaction. Studies even suggest that people with Autism Spectrum Disorder could interact more easily with a robot partner rather than a human partner. We will be looking at the benefits of robots and the reasons put forward to explain these results. The interest regarding robots would mainly be due to three of their characteristics: they can act as motivational tools, and they are simplified agents whose behavior is more predictable than that of a human. Nevertheless, there are still many challenges to be met in specifying the optimum conditions for using robots with individuals with Autism Spectrum Disorder.

A Review of and Roadmap for Data Science and Machine Learning for the Neuropsychiatric Phenotype of Autism

Autism spectrum disorder (autism) is a neurodevelopmental delay that affects at least 1 in 44 children. Like many neurological disorder phenotypes, the diagnostic features are observable, can be tracked over time, and can be managed or even eliminated through proper therapy and treatments. However, there are major bottlenecks in the diagnostic, therapeutic, and longitudinal tracking pipelines for autism and related neurodevelopmental delays, creating an opportunity for novel data science solutions to augment and transform existing workflows and provide increased access to services for affected families. Several efforts previously conducted by a multitude of research labs have spawned great progress toward improved digital diagnostics and digital therapies for children with autism. We review the literature on digital health methods for autism behavior quantification and beneficial therapies using data science. We describe both case-control studies and classification systems for digital phenotyping. We then discuss digital diagnostics and therapeutics that integrate machine learning models of autism-related behaviors, including the factors that must be addressed for translational use. Finally, we describe ongoing challenges and potential opportunities for the field of autism data science. Given the heterogeneous nature of autism and the complexities of the relevant behaviors, this review contains insights that are relevant to neurological behavior analysis and digital psychiatry more broadly.

Listener- Versus Speaker-Oriented Disfluencies in Autistic Adults: Insights From Wearable Eye-Tracking and Skin Conductance Within a Live Face-to-Face Paradigm

PURPOSE

Our study addresses three main questions: (a) Do autistics and neurotypicals produce different patterns of disfluencies, depending on the experimenter's direct versus averted gaze? (b) Are these patterns correlated to gender, skin conductance responses, fixations on the experimenter's face, alexithymia, or social anxiety scores? Lastly, (c) can eye-tracking and electrodermal activity data be used in distinguishing listener- versus speaker-oriented disfluencies?

METHOD

Within a live face-to-face paradigm combining a wearable eye-tracker with electrodermal activity sensors, 80 adults (40 autistics, 40 neurotypicals) defined words in front of an experimenter who was either staring at their eyes (direct gaze condition) or looking elsewhere (averted gaze condition).

RESULTS

Autistics produce less listener-oriented (uh, um) and more speaker-oriented (prolongations, breath) disfluencies than neurotypicals. In both groups, men produce less um than women. Both autistics' and neurotypicals' speech are influenced by whether their interlocutor systematically looks at them in the eyes or not, but their reactions go in opposite directions. Disfluencies seem to primarily be linguistic phenomena as experienced stress, social attention, alexithymia, and social anxiety scores do not influence any of the reported results. Finally, eye-tracking and electrodermal activity data suggest that laughter could be a listener-oriented disfluency.

CONCLUSIONS

This article studies disfluencies in a fine-grained way in autistic and neurotypical adults while controlling for social attention, experienced stress, and experimental condition (direct vs. averted gaze). It adds to current literature by (a) enlightening our knowledge of speech in autism, (b) opening new perspectives on disfluency patterns as important signals in social interaction, (c) addressing theoretical issues on the dichotomy between listener- and speaker-oriented disfluencies, and (d) considering understudied phenomena as potential disfluencies (e.g., laughter, breath).

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23549550.

Distinctive prosodic features of people with autism spectrum disorder: a systematic review and meta-analysis study

In this systematic review, we analyzed and evaluated the findings of studies on prosodic features of vocal productions of people with autism spectrum disorder (ASD) in order to recognize the statistically significant, most confirmed and reliable prosodic differences distinguishing people with ASD from typically developing individuals. Using suitable keywords, three major databases including Web of Science, PubMed and Scopus, were searched. The results for prosodic features such as mean pitch, pitch range and variability, speech rate, intensity and voice duration were extracted from eligible studies. The pooled standard mean difference between ASD and control groups was extracted or calculated. Using I2 statistic and Cochrane Q-test, between-study heterogeneity was evaluated. Furthermore, publication bias was assessed using funnel plot and its significance was evaluated using Egger's and Begg's tests. Thirty-nine eligible studies were retrieved (including 910 and 850 participants for ASD and control groups, respectively). This systematic review and meta-analysis showed that ASD group members had a significantly larger mean pitch (SMD =  - 0.4, 95% CI [- 0.70, - 0.10]), larger pitch range (SMD =  - 0.78, 95% CI [- 1.34, - 0.21]), longer voice duration (SMD =  - 0.43, 95% CI [- 0.72, - 0.15]), and larger pitch variability (SMD = - 0.46, 95% CI [- 0.84, - 0.08]), compared with typically developing control group. However, no significant differences in pitch standard deviation, voice intensity and speech rate were found between groups. Chronological age of participants and voice elicitation tasks were two sources of between-study heterogeneity. Furthermore, no publication bias was observed during analyses (p > 0.05). Mean pitch, pitch range, pitch variability and voice duration were recognized as the prosodic features reliably distinguishing people with ASD from TD individuals.

Pre-SMA activation and the perception of contagiousness and authenticity in laughter sounds

Functional near-infrared spectroscopy and behavioural methods were used to examine the neural basis of the behavioural contagion and authenticity of laughter. We demonstrate that the processing of laughter sounds recruits networks previously shown to be related to empathy and auditory-motor mirror networks. Additionally, we found that the differences in the levels of activation in response to volitional and spontaneous laughter could predict an individual's perception of how contagious they found the laughter to be.

The relationship between autistic characteristics, social engagement and executive function in a typical sample

Purpose

This study aims to represent a first attempt to examine in a non-clinical population the interplay between social engagement, executive function (EF) and theory of mind (ToM) within a social motivation theory framework.

Design/methodology/approach

A total of 170 participants (135 female; mean age = 19.01 and standard deviation = 1.27) completed measures of ToM (Faux Pas task), autistic traits (Autism Spectrum Quotient), social engagement (reward dependence subscale of the Temperament and Character Inventory), sociability and EF (both subscales of the Adult Temperament Questionnaire).

Findings

Path analyses found that EF, sociability and social engagement were negatively associated with autistic traits both directly and indirectly. Results indicate that EF may impact sociability and social engagement and their interaction may relate to the degree of autistic traits shown in a typical sample. However, ToM (as measured by the Faux Pas test) was not related to any of the other variables.

Originality/value

Sociability, social engagement and effortful control deficits may be linked to higher levels of autistic traits. These factors appear to form a hierarchy of factors underpinning autism spectrum disorder, with EF contributing to all aspects, followed by sociability and social engagement at a higher level. Future research examining in clinical populations the utility of a more integrated model of social motivation that incorporates EF appears warranted.

The role of context in verbal humor processing in autism

Difficulties in processing humor have been associated with individuals with autism. The current study investigated whether humor comprehension and appreciation could be augmented in children with autism by providing contextual support suggesting that humor was to be expected. A verbally presented riddle task was used in which participants were assessed for their subjective ratings and comprehension of the materials. They were also filmed to record any smiling or laughing. Both riddles and control stimuli were presented with supporting verbal context and also without it. The results showed that (a) the greater subjective appreciation of riddles than of control stimuli was dependent on the provision of context for the participants with autism and that (b) context statistically equated these ratings of riddles between participants with autism and matched typically developing controls. However, context had no effect on comprehension or affective response. The results of the current study demonstrate that children with autism are, even in the most conservative interpretation, able to use verbal context to recognize verbal humor. This lays the foundation of possible interventions based on training sensitivity to context.

Imitation and recognition of facial emotions in autism: a computer vision approach

Background

Imitation of facial expressions plays an important role in social functioning. However, little is known about the quality of facial imitation in individuals with autism and its relationship with defining difficulties in emotion recognition.

Methods

We investigated imitation and recognition of facial expressions in 37 individuals with autism spectrum conditions and 43 neurotypical controls. Using a novel computer-based face analysis, we measured instructed imitation of facial emotional expressions and related it to emotion recognition abilities.

Results

Individuals with autism imitated facial expressions if instructed to do so, but their imitation was both slower and less precise than that of neurotypical individuals. In both groups, a more precise imitation scaled positively with participants’ accuracy of emotion recognition.

Limitations

Given the study’s focus on adults with autism without intellectual impairment, it is unclear whether the results generalize to children with autism or individuals with intellectual disability. Further, the new automated facial analysis, despite being less intrusive than electromyography, might be less sensitive.

Conclusions

Group differences in emotion recognition, imitation and their interrelationships highlight potential for treatment of social interaction problems in individuals with autism.

Emotional contagion in children with autism spectrum disorder varies with stimulus familiarity and task instructions

Although deficits in cognitive empathy are well established in individuals with autism spectrum disorder (ASD), the literature on emotional empathy, or emotional contagion, in individuals with ASD is sparse and contradictory. The authors tested susceptibility to contagious yawning and laughter in children with ASD (n = 60) and typically developing (TD) children (n = 60), ages 5-17 years, under various conditions, to elucidate factors that may affect emotional contagion in these populations. Although TD children showed equal amounts of emotional contagion across conditions, children with ASD were highly influenced by the familiarity of the target stimulus, as well as task instructions that encourage eye gaze to target. More specifically, children with ASD exhibited less contagious yawning and laughter than their TD peers except when their attention was explicitly directed to the eyes or (and even more so) when their parents served as the stimulus targets. The authors explore the implications of these findings for theories about the mechanisms underlying empathic deficits in ASD as well as the clinical implications of having parents involved in treatment.

Measuring Social Motivation in Autism Spectrum Disorder: Development of the Social Motivation Interview

Social motivation in individuals with ASD is inferred from the observation of overt behaviors and neurological correlates. Motivation, however, can be distinguishable from overt behavior and neurologic reactivity. Nevertheless, few studies have examined the cognitive processes that may influence goal-directed tasks involved in social interaction. This study addressed this conceptual need by developing a novel interview. The social motivation interview (SMI) assesses for internal cognitions as they relate to social motivation by evaluating social desire, interest, and behaviors in eighteen children with ASD (M years = 12.84). Pilot testing suggested feasibility of administration, user satisfaction, and promising psychometric properties. Future examination of the SMI in large-scale field testing is warranted.

Investigating Humor in Social Interaction in People With Intellectual Disabilities: A Systematic Review of the Literature

Background: Humor, both producing and appreciating, underpins positive social interactions. It acts as a facilitator of communication. There are clear links to wellbeing that go along with this form of social engagement. However, humor appears to be a seldom studied, cross-disciplinary area of investigation when applied to people with an intellectual disability. This review collates the current state of knowledge regarding the role of humor behavior in the social interactions of people with intellectual disabilities and their carers. Method: A systematic review utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was completed, which aimed to explore the current state of knowledge and quality of empirical evidence relating to humor in people with intellectual disabilities. Following this, articles were grouped thematically and summarized. A comprehensive search of four electronic databases (1954-2017) and additional search strategies yielded 32 articles which met the final inclusion criteria. Results: Humor played a significant positive and negative role in the social interactions of people with intellectual disabilities. Research had investigated humor in the classroom and humor expression in different groups including those with autism, Down syndrome, Angelman syndrome, Williams syndrome, and Rett syndrome. Few investigations directly studied humor appreciation and comprehension. Humor comprehension was reportedly supported by gestures. Some groups with intellectual disabilities found non-literal humor (e.g., sarcasm, irony) more difficult to understand, which may affect social relationships. Various types of humor were found to be appreciated. The role of humor in relationship development, social facilitation, creativity, and stigma had all received some limited attention. Humor also played a role for carer groups in coping with and enjoying the caring role. Research varied in quality with few experimental studies and mainly quasi-experimental and well-conducted, qualitative studies. Conclusions: This review revealed the importance of humor behavior in many aspects of the social lives of people with intellectual disabilities. Limited disparate research exists pertaining to humor in this group, suggesting the need for further robust research in this area, including more high quality primary research in the areas of humor production, appreciation, comprehension, and stigma.

I Think We're Alone Now: Solitary Social Behaviors in Adolescents with Autism Spectrum Disorder

Research into emotional responsiveness in Autism Spectrum Disorder (ASD) has yielded mixed findings. Some studies report uniform, flat and emotionless expressions in ASD; others describe highly variable expressions that are as or even more intense than those of typically developing (TD) individuals. Variability in findings is likely due to differences in study design: some studies have examined posed (i.e., not spontaneous expressions) and others have examined spontaneous expressions in social contexts, during which individuals with ASD-by nature of the disorder-are likely to behave differently than their TD peers. To determine whether (and how) spontaneous facial expressions and other emotional responses are different from TD individuals, we video-recorded the spontaneous responses of children and adolescents with and without ASD (between the ages of 10 and 17 years) as they watched emotionally evocative videos in a non-social context. Researchers coded facial expressions for intensity, and noted the presence of laughter and other responsive vocalizations. Adolescents with ASD displayed more intense, frequent and varied spontaneous facial expressions than their TD peers. They also produced significantly more emotional vocalizations, including laughter. Individuals with ASD may display their emotions more frequently and more intensely than TD individuals when they are unencumbered by social pressure. Differences in the interpretation of the social setting and/or understanding of emotional display rules may also contribute to differences in emotional behaviors between groups.

Emotion Dysregulation and Anxiety in Adults with ASD: Does Social Motivation Play a Role?

Young adults with ASD and no intellectual impairment are more likely to exhibit clinical levels of anxiety than typically developing peers (DSM-5, American Psychiatric Association, 2013). This study tests a mechanistic model in which anxiety culminates via emotion dysregulation and social motivation. Adults with ASD (49 males, 20 females) completed self-report measures on emotion regulation, caregivers completed measures on ASD severity and both on social anxiety. Results indicated that emotion dysregulation (p < .001; p < .05) and social motivation (p < .05, p < .001) significantly predicted social anxiety as reported by caregivers and young adults respectively. However, social motivation did not appear to play a moderating role in the relationship between emotion regulation and anxiety, even when controlling for social awareness. Significant predictor variables of social anxiety varied based on reporter (i.e. caregiver versus young adult), with difficulty engaging in goal-directed behaviors during negative emotions serving as the only shared predictor.

Quantitative Laughter Detection, Measurement, and Classification-A Critical Survey

The study of human nonverbal social behaviors has taken a more quantitative and computational approach in recent years due to the development of smart interfaces and virtual agents or robots able to interact socially. One of the most interesting nonverbal social behaviors, producing a characteristic vocal signal, is laughing. Laughter is produced in several different situations: in response to external physical, cognitive, or emotional stimuli; to negotiate social interactions; and also, pathologically, as a consequence of neural damage. For this reason, laughter has attracted researchers from many disciplines. A consequence of this multidisciplinarity is the absence of a holistic vision of this complex behavior: the methods of analysis and classification of laughter, as well as the terminology used, are heterogeneous; the findings sometimes contradictory and poorly documented. This survey aims at collecting and presenting objective measurement methods and results from a variety of different studies in different fields, to contribute to build a unified model and taxonomy of laughter. This could be successfully used for advances in several fields, from artificial intelligence and human-robot interaction to medicine and psychiatry.

The Interplay between Emotion and Cognition in Autism Spectrum Disorder: Implications for Developmental Theory

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that is clinically defined by abnormalities in reciprocal social and communicative behaviors and an inflexible adherence to routinised patterns of thought and behavior. Laboratory studies repeatedly demonstrate that autistic individuals experience difficulties in recognizing and understanding the emotional expressions of others and naturalistic observations show that they use such expressions infrequently and inappropriately to regulate social exchanges. Dominant theories attribute this facet of the ASD phenotype to abnormalities in a social brain network that mediates social-motivational and social-cognitive processes such as face processing, mental state understanding, and empathy. Such theories imply that only emotion related processes relevant to social cognition are compromised in ASD but accumulating evidence suggests that the disorder may be characterized by more widespread anomalies in the domain of emotions. In this review I summarize the relevant literature and argue that the social-emotional characteristics of ASD may be better understood in terms of a disruption in the domain-general interplay between emotion and cognition. More specifically I will suggest that ASD is the developmental consequence of early emerging anomalies in how emotional responses to the environment modulate a wide range of cognitive processes including those that are relevant to navigating the social world.

The social motivation theory of autism

The idea that social motivation deficits play a central role in Autism Spectrum Disorders (ASD) has recently gained increased interest. This constitutes a shift in autism research, which has traditionally focused more intensely on cognitive impairments, such as theory-of-mind deficits or executive dysfunction, and has granted comparatively less attention to motivational factors. This review delineates the concept of social motivation and capitalizes on recent findings in several research areas to provide an integrated account of social motivation at the behavioral, biological and evolutionary levels. We conclude that ASD can be construed as an extreme case of diminished social motivation and, as such, provides a powerful model to understand humans' intrinsic drive to seek acceptance and avoid rejection.

Diminished social motivation negatively impacts reputation management: autism spectrum disorders as a case in point

Human beings are endowed with a unique motivation to be included in social interactions. This natural social motivation, in turn, is thought to encourage behaviours such as flattery or self-deprecation aimed to ease interaction and to enhance the reputation of the individual who produces them. If this is the case, diminished social interest should affect reputation management. Here, we use Autism Spectrum Disorders (ASDs)--primarily characterised by pervasive social disinterest--as a model to investigate the effect of social motivation on reputation management. Children first rated a set of pictures and were then given the opportunity to inflate their initial ratings in front of an experimenter who declared that she had drawn the picture. Contrary to the controls, children with ASD did not enhance their ratings in the drawer's presence. Moreover, participants' flattery behaviour correlated with self-reports of social enjoyment. Our findings point to a link between diminished social interest and reputation management.

Listeners prefer the laughs of children with autism to those of typically developing children

The purpose of this study was to investigate the impact of laugh sounds produced by 8- to 10-year-old children with and without autism on naïve listeners, and to evaluate if listeners could distinguish between the laughs of the two groups. Results showed that listeners rated the laughs of children with autism more positively than the laughs of typically developing children, and that they were slightly above chance levels at judging which group produced the laugh. A subset of participants who reported listening for “uncontrolled” or “longer” laughs were significantly better at discriminating between the laughs of the two groups. Our results suggest that the laughs of children with autism have the potential to promote the formation of relationships.