Introduction
Narrative, or storytelling, is a critical tool used to share experiences and connect with others in our social world. Narrative skill is often impacted in autism spectrum disorder (ASD) and can influence participation in everyday activities such as initiating and maintaining reciprocal conversations and building relationships (Capps et al.,
2000; Colle et al.,
2008; Losh & Capps,
2003,
2006; Reilly et al.,
1998; Tager-Flusberg,
1995). Key differences in narrative skill reported in ASD include reduced mention of internal states (Diehl et al.,
2006; King et al.,
2014; Losh & Capps,
2003; Siller et al.,
2014), omission of key story elements (e.g., setting, central conflict, resolution) (Barnes & Baron-Cohen,
2012; Lombardo et al.,
2007; Losh & Capps,
2003), inclusion of tangential story details that detract from overarching plot and themes of the story (Lam & Yeung,
2012; Tager-Flusberg & Anderson,
1991), and limited use of causal language to connect and interpret the meaning of narrated experiences (Diehl et al.,
2006; Losh & Capps,
2003,
2006; Tager-Flusberg & Sullivan,
1995). Differences in the use of these narrative devices are significant, as each play important roles in supporting contingent, thematically coherent, and meaningful social communication (e.g., Bruner,
1987; Ochs & Capps,
2009). Narrative skills also play an important role in the formation and recounting of memories and construction of mental schema (Baixauli et al.,
2016). As such, differences in narrative in ASD can limit access and interaction with the social world (Losh & Capps,
2003,
2006), with important implications for impacts on daily life.
Prior work in which participants freely narrated a wordless picture book (Diehl et al.,
2006; Losh & Capps,
2003,
2006; Tager-Flusberg & Sullivan,
1995) found that although autistic individuals were as likely as their typically developing peers to establish and maintain the story’s central search theme, they included fewer story components (e.g., description of setting, resolution) and causal attributions of the characters’ internal states and behaviors (e.g., “the boy was sad
because he realized that his frog was missing”). Utilizing computational methods to examine narrative competence in different contexts, Lee et al. (
2020) and Losh and Gordon (
2014) also found that relative to controls, individuals with ASD produced poorer quality narratives during a less structured task, but similar quality narratives during a more structured task. These findings suggest that in the absence of structure, autistic individuals have greater difficulty producing coherent narratives. Studying narratives allows for the discovery of specific language patterns and can enrich understanding of how individuals with ASD encode salient information through attentional processes and use that information to inform storytelling.
Subtle differences in narrative ability (along with broader pragmatic, or social language differences) have also been documented among parents and siblings of autistic individuals (Ben-Yizhak et al.,
2011; Di Michele et al.,
2007; Landa et al.,
1991,
1992; Lee et al.,
2020; Losh et al.,
2008a; Miller et al.,
2015; Patel et al.,
2020,
2022,
2023; Piven et al.,
1997a,
b), suggesting a genetic influence on narrative abilities associated with ASD. Strong evidence suggests that differences in pragmatic language constitute a principal component of the broad autism phenotype (BAP), a core set of subclinical personality and language features in clinically unaffected relatives thought to reflect ASD-related genetic variation (Bernier et al.,
2012; Bolton et al.,
1998; Klusek et al.,
2014a,
2021; Losh et al.,
2008b,
2012; Losh & Piven,
2007; Nayar et al.,
2021; Piven et al.,
1997a,
b). Regarding narrative skills in particular, reduced narrative complexity and coherence has been reported among subgroups of parents of autistic individuals (Landa et al.,
1991; Lee et al.,
2020).
Although narrative competence has not extensively been examined in siblings of autistic individuals, studies of parent-reported and standardized tests of pragmatic language abilities more broadly have reported variable findings (cf. Ben-Yizhak et al.,
2011; Bishop et al.,
2006; Gangi et al.,
2021; Greenslade et al.,
2019; Miller et al.,
2015; Pilowsky et al.,
2003). Recent evidence from a meta-analytic study identified a small effect size indicating poorer pragmatic language abilities in siblings of autistic individuals compared to controls (Roemer,
2021). Two studies using examiner ratings of pragmatic language in school-age children revealed a step-wise pattern, with autistic individuals demonstrating the most difficulty, and clinically unaffected ASD siblings showing pragmatic skills intermediate to the ASD and control groups (Gangi et al.,
2021; Greenslade et al.,
2019). Importantly, a significant portion of the literature on pragmatic abilities of siblings has been conducted on infants and toddlers, focusing on early developmental periods before the emergence of complex pragmatic skills and often relying on parent-report measures (Iverson et al.,
2018; LeBarton & Iverson,
2016; Miller et al.,
2015; Toth et al.,
2007; West et al.,
2020), motivating the present study’s focus on school-age, adolescent, and adult individuals where pragmatics abilities are well-developed in typical development (Bamberg & Reilly,
1996; Berman & Slobin,
1994; Ervin-Tripp et al.,
1990). As such, the present study will be one of the first to extend work to children and adult siblings of individuals with ASD.
Pragmatic language in the BAP could be an etiologically significant phenotype providing clues to the complex and multifactorial causes of ASD (Losh et al.,
2008b; Nayar et al.,
2021) and may offer a promising avenue to disentangle gene-brain-behavior relationships. Evidence of visual attention differences associated with narrative skill in ASD and their parents further underscores the potential biological significance of narrative studies in ASD. Specifically, given the automatic and rapid nature of eye movements, analysis of visual attention represents an intermediate link between brain and behavior that can reveal cognitive differences reflecting neurobiology (Adolphs,
2010; Dalton et al.,
2005; Kanwisher et al.,
1997; Sabatinelli et al.,
2011; Yucel et al.,
2015). For example, visual attention influences how an individual interprets the environment, is associated with an array of neuropsychological abilities including cognition, sensory regulation, and language processing, and is strongly rooted in core neurological functions (Altmann & Kamide,
2007; Eckstein et al.,
2017; Lewis & Brooks-Gunn,
1981; Stechler & Latz,
1966).
Differences in social attention and visual attentional patterns have been repeatedly documented in ASD (Chita-Tegmark,
2016; Frazier et al.,
2017; Król & Król,
2020; Landry & Bryson,
2004; Manyakov et al.,
2018; Micai et al.,
2017; Nayar et al.,
2018,
2022; Papagiannopoulou et al.,
2014; Sacrey et al.,
2013; Sasson et al.,
2008), with similar, but more subtle differences noted in subgroups of parents and siblings of individuals with ASD (Adolphs et al.,
2008; Bhat et al.,
2010; Canu et al.,
2021; Chawarska et al.,
2016; Dalton et al.,
2007; Elsabbagh et al.,
2013; Groen et al.,
2012; Hogan-Brown et al.,
2014; Kleberg et al.,
2019; Merin et al.,
2007; Nayar et al.,
2018,
2022; Wagner et al.,
2018). Studies utilizing concurrent eye tracking and narrative elicitation have reported evidence that such visual attention differences may importantly contribute to differences in narrative (Lee et al.,
2020; Nayar et al.,
2018). Specifically, Lee et al. (
2020) found that autistic individuals and their parents attended more to the setting of a complex image than controls, and that visual attention to the setting or bodies of characters was associated with poorer narrative quality. Although not specifically examining narration, evidence also exists showing that joint attention during infancy predicts school-age pragmatic communication in ASD siblings (Greenslade et al.,
2019). Taken together, evidence supports the hypothesis that differences in attention might in part drive some of the social communication patterns observed in ASD, and perhaps among clinically unaffected relatives as well.
Current Study
The present study aimed to characterize narrative skills in ASD and first-degree relatives to determine whether similar profiles may be evident among clinically unaffected relatives. A detailed hand-coding scheme (utilizing a granular, scene-by-scene coding system that taps into elements including narrative quality, emotional inference, and detail orientation) was applied to narratives from autistic individuals, their siblings, and parents and respective control groups during free narration of a wordless picture book. In addition, this study investigated social attention differences and potential relationships to narrative skills using traditional eye-tracking measures (fixations and fixation duration towards social or non-social stimuli), as well as analysis of dynamic patterns of visual attention that are often reflected in the real world (e.g., Nayar et al.,
2022), and may help to illuminate visual attention patterns related to social-communicative features of ASD and the BAP.
Differences in narrative were predicted to be greatest in the ASD group, and evidenced through narrative elements reflecting overall structure, as well as more fine-grained narrative features serving to connect story elements, such as causal explanations and explanations of protagonists’ thoughts and emotions. More subtle differences in these narrative elements were predicted in the sibling and parent groups. Eye-tracking analyses examining links between visual attention and narrative elements were exploratory.
Discussion
This study aimed to deeply characterize how narrative skills are influenced in ASD and first-degree relatives of autistic individuals to understand the social-communicative profile impacted by ASD-related genetic variation. We also aimed to delineate narrative and potentially related attentional skills that may inform targeted social-communication interventions for autistic individuals. Prior work had shown robust differences in narrative use in ASD, and more subtle differences among parents of autistic individuals. In this study, we aimed to extend this work by examining narrative in siblings of autistic individuals as well, by applying a detailed hand coding system to assess fine-grained narrative features and potential associations with visual attention during storytelling. Findings revealed some important parallel patterns in the ASD and sibling groups and more subtle differences in the ASD parent group, with different patterns of causal explanations emerging among all groups, discussed further, below.
The types of language used to reflect internal states of characters (i.e., cognitive and affective states) and to establish causal connections between elements of the story were examined as an important index of narrative coherence, complementing the more global storytelling skills such as inclusion of story episodes and establishing a story’s theme. For both the ASD and ASD sibling groups, findings revealed a decreased use of cognitive and affective state language and causal language (which also withstood corrections for multiple comparisons). Similar gaze patterns in ASD and ASD sibling groups were also found, which could inform the mechanisms underlying observed narrative differences. Both groups were also more likely to omit key story components (i.e., setting, instantiation, sub-episodes, or resolution) relative to controls, suggesting a reduced tendency to attend to salient aspects of the storybook. Findings showing diminished visual exploration of the storybook scenes in the ASD and ASD sibling groups (as reflected by less dynamic gaze transitions that were focused within congruent stimuli—i.e., social to social stimuli, nonsocial to nonsocial stimuli) offer some insight into neurocognitive mechanistic processes that may underly narrative differences. In this vein, it is possible that aspects of the story that were not mentioned in narratives may have resulted from inattention to those events visually, and thus less salient or efficient encoding. Marked differences detected in the ASD Sibling Group specifically revealed a tendency to omit description of the story’s setting (while the ASD group omitted details across any key story component suggesting more general differences in story narration than those observed among siblings). Converging eye-tracking results showed reduced attention to the setting during narration in the ASD Sibling Group. For ASD parents, findings were more nuanced, revealing a subtle difference in how parents deployed causal language throughout their narratives. Specifically, whereas ASD parents used causal language with similar frequency as controls, they tended to focus more on explaining characters’ thoughts and emotions than interpreting their behaviors, relative to controls. Differences in the use of causal language have been noted repeatedly in prior studies of ASD (Diehl et al.,
2006; Losh & Capps,
2003,
2006; Tager-Flusberg & Sullivan,
1995), highlighting this finding as potentially significant and revealing of core differences in narrative associated with ASD genetic likelihood.
The patterns of differences observed in these key aspects of narrative (most obviously in the ASD Group, followed by the ASD Sibling Group) are intriguing and could suggest that these narrative skills reflect heritable traits influenced by ASD-related genetic variability. Such traits could be useful to study to help parse out gene-behavior associations in ASD, particularly given the robust literature on the biological basis of visual attention (Constantino et al.,
2017; Eckstein et al.,
2017). Observed narrative and gaze differences could also be used to help reduce heterogeneity in biological studies, by stratifying families into phenotypically more homogeneous subgroups where meaningful signals may be more easily detected. Of course, narrative skills are also known to be influenced by social and communicative environments, including parental discourse styles (e.g., Haden et al.,
1997). Bi-directional relationships are also possible, where autistic individuals’ narrative styles may be influential in siblings’ developing narrative skills (although, no notable difference in average age was observed in the current sample). However, evidence that language-related differences are observed in ASD parents during childhood (based on retrospective academic testing data; Losh et al.,
2017), well before they would become a parent of an autistic child, in addition to the extensive literature documenting pragmatic differences in the broad autism phenotype (BAP; thought to reflect underlying genetic liability to ASD), ASD-related genetic influences on siblings’ and parents’ narratives skills are important to consider.
Narrative differences observed in the ASD and ASD sibling groups may also have clinical implications. Whereas variability in narrative style is an important contributor to the complex distinctions that make individuals and cultures unique, it is important to consider the differences observed in the ASD and ASD sibling group in the context of the importance of narrative as primary social communication tool. Narrative is among the most common forms of social communication, used to share experiences with others in meaningful ways and build relationship based in part on lived experiences that are co-constructed and shared through narrative (Bruner,
1990; Ochs & Capps,
2009). The specific narrative differences observed in the ASD Group in particular, with differences also observed in the ASD Sibling Group, all serve important functions, and their absence could contribute to challenges in social communication. For instance, inferring characters’ thoughts and feelings and discussing how events are causally related in narrative are vital to conveying the importance of narrated events and for connecting meaning to characters’ experiences (Diehl et al.,
2006). Similarly, introducing a narrative topic through setting description is important for anchoring the central plot, setting the stage for the unfolding story, and engaging listeners with background for what is to come. Omission of this important component can undermine the effectiveness of a narrative, resulting in more factual description than meaningfully connected narrative. Findings are therefore important to consider in the context of broader social communication differences that characterize ASD, and the more subtle and specific social communication challenges that may be present for siblings, even in the absence of a clinical diagnosis of ASD.
Findings of limited differences in the parent groups are perhaps not surprising, given the subclinical presentation of the BAP-related pragmatic differences documented previously among parents, and that the highly structured nature of this narrative task (e.g., unfolding with serially ordered events and page-by-page presentation offering scaffolding for participants to develop their stories) may have obscured more subtle differences in narrative skill. Prior differences reported in parent groups have indeed been quite subtle, and it may be that the picture book task in this study was not sufficiently challenging to elicit more obvious differences that had been reported in prior work using more complicated narrative tasks (e.g., Landa et al.,
1991; Lee et al.,
2020). Different patterns in parents’ use of types of causal language stand in contrast to the otherwise intact narrative skill observed across other narrative variables. When considered together with similar differences detected in ASD and in siblings, and with prior reports of differences in causal language during narration and conversation in ASD (Diehl et al.,
2006; Losh & Capps,
2003,
2006; Tager-Flusberg & Sullivan,
1995), causal attributions may be considered a critical narrative skill impacted by ASD-related genetic variation. Although the ASD parent group produced overall causal language at rates similar to controls, they tended to focus more on causal explanations of affect and cognition, and less on causal explanations of behavior, relative to controls.
It may be that parents of autistic individuals find the integration of the character within the larger story to be more salient, thereby leading them to discuss them more in their narratives. This possibility is supported by gaze patterns which showed associations between greater descriptions of affect/cognition and greater social attention. In another narrative task including a portion of the participants reported here, and examining more coarse-grained gaze variables, Nayar et al. (
2022) identified differential patterns of fixations, where the ASD group showed elevated perseverative attention towards non-social information while parents showed reduced perseveration towards social information. As with causal language differences, such patterns could represent a pathoplasticity, where biologically meaningful ASD-related traits manifest variably across the spectrum of the condition from clinical to sub-clinical levels, and may permeate across cognitive functions from gaze to language.
Limitations and Future Directions
The present study assessed narrative abilities in individuals with ASD and their siblings and parents within a highly structured task, which may have limited power to detect more subtle differences present in relatives. Future studies should further assess narrative skills in less structured tasks with different social and cognitive demands (e.g., semi-structured conversations) (Goodkind et al.,
2018; Klusek et al.,
2014b) to fully understand genetically meaningful phenotypes associated with narrative deficits in ASD. Further, whereas the current study expanded on previous literature and developed a detailed hand-coding system with more in-depth coding of features such as detail orientation and classification of sub-episodes to deeply characterize participants’ narratives (Losh & Capps,
2003), results did not reveal difference in those more detailed codes, with primary differences instead found with variables coded with the less detailed coding systems used in prior work. This finding is important in guiding future work, suggesting that the highly time intensive coding conducted here may not be necessary to capture clinically and potentially biologically meaningful differences in narrative in ASD and first-degree relatives. Analyses involving categorical variables (and specifically findings pertaining omission of the setting) did not include relevant covariates and future analyses may consider an alternative coding system to ensure inclusion of covariates.
Relatedly, although patterns of differences in narrative and gaze were related conceptually (and were often of marginal significance and thus not reported), few significant narrative-gaze associations emerged across groups. It is possible that the eye-tracking metrics applied across the entirety of the picture book task masked potentially meaningful and important patterns of gaze that could unfold over the course of time (e.g., see Nayar et al.,
2018,
2022). Future efforts may benefit from application of a temporal longitudinal analyses to gaze patterns that are synchronized to speech to robustly capture relationships more reflective of the dynamic nature of visual attention. Additionally, given findings of different pragmatic and narrative skills among males versus females with ASD (Boorse et al.,
2019; Bylemans et al.,
2023; Conlon et al.,
2019; Kauschke et al.,
2016), as well as sex-linked differences in pragmatic functions in the BAP (Nayar et al.,
2021), it will be important for future studies to include well-powered groups of females to detect possible sex differences in narration and gaze in ASD and among relatives. Although several racial identities were included in this study, most participants self-identified their race as “White”. As such, future work assessing narrative ability in autism should involve a more diverse sample of participants, encompassing different racial/ethnic backgrounds as well as other dimensions of diversity, such as sex/gender, culture, and language. Finally, due to the research questions addressed, the current study included a sample of participants who were verbally fluent with a VIQ of at least 80, and studying participants with more limited verbal abilities is an important next step to understand the generalizability of findings to individuals with a wider range of cognitive and verbal abilities.
In sum, by characterizing narrative skills in ASD and among first-degree relatives using an extensive hand-coding system and collecting gaze during narration, this study captured important features of narrative skills impacted across the spectrum of ASD genetic influence. Important parallel patterns were detected in ASD and in siblings, with more subtle patterns of narrative differences observed in parents, which together, may help to refine the profile of social communication skills impacted by ASD-related genetic variation.
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