Participation was voluntary, and the parents or legal guardians of all participants provided informed written consent. We expected moderate group-differences in metaphor comprehension that would be explained by different aspects of core language.Īfter obtaining ethical approval from the Norwegian Ethics committee, we recruited participants from across the country to obtain as large a sample as possible. This allowed us to directly assess the extent to which each participant could understand each metaphor. We operationalized metaphor comprehension in a within-subjects multi-item experiment, where the literal and metaphorical meaning of words were tested. In this study, we investigated how different aspects of core language contribute to metaphor comprehension in individuals with ASD and TD. Therefore, we do not know what the extent of difficulties in metaphor comprehension in individuals with ASD compared to those with TD is, and which variables can explain metaphor comprehension difficulties in individuals with ASD. How metaphor comprehension is related to different aspects of core language skills has not been investigated systematically so far. However, since this meta-analysis examined different types of figurative language (e.g., metaphors, idioms, and irony), and understanding each of these may depend on different aspects of core language, more studies on each of these figurative language types are needed. ( 2018) concluded that core language was closely related to figurative language comprehension in ASD. In a recent meta-analysis, Kalandadze et al. This might not be surprising as they only measured word comprehension, which is necessary but not sufficient for metaphor comprehension (Gernsbacher & Pripas-Kapit, 2012). In their own work, Rundblad and Annaz ( 2010) did not find any significant relationship between core language skills as indexed by receptive vocabulary and metaphor comprehension. Norbury ( 2005) found that broader semantic knowledge was a significant predictor of metaphor comprehension, but Rundblad and Annaz ( 2010) argued that this finding was an artefact of the figurative language items included in the measure used. The few studies that have investigated the association between core language skills and metaphor comprehension in ASD and TD remain inconclusive. In addition, metaphors are usually embedded in sentences and advanced command of syntax is necessary to understand them (see Kalandadze et al., 2019).

For example, in the metaphor “Mary is a busy bee”, Mary (the topic-a human being) shares semantic properties (being occupied with work) with a bee (the vehicle-an insect), and this commonality must be grasped to decipher the metaphorical meaning. To understand a metaphor, the shared semantic features or common ground between two different entities (the “topic” and “vehicle”) need to be grasped (Bühler et al., 2018 van Herwegen & Rundblad, 2018). However, the potential link between metaphor comprehension and core language skills have not been fully explored. Core language in this study refers to the structural aspects of language such as semantics and grammar. However, some of the subsequent studies proposed that difficulties in metaphor comprehension individuals with ASD often show, cannot be explained solely by impairments in ToM, rather by compromised core language skills (Norbury, 2005 for a review see Gernsbacher & Pripas-Kapit, 2012).

Traditionally, compromised Theory of Mind (ToM) ability, that is, the ability to understand the mental states of others (Baron-Cohen et al., 1985) has been suggested as the main explanation of difficulties in metaphor comprehension (e.g., Happé, 1993). However, more recent studies have not shown statistically significant differences in metaphor comprehension between individuals with ASD and individuals with TD (e.g., Gold et al., 2010 Hermann et al., 2013 Kasirer & Mashal, 2014 Mashal & Kasirer, 2011). This intriguing difference between these groups in metaphor comprehension has been investigated for more than three decades (see Kalandadze et al., 2019 for a review), and findings of older studies have contributed to the view that metaphor comprehension is universally impaired in ASD (Gernsbacher & Pripas-Kapit, 2012). While children with TD are able to understand metaphors that are linguistically and cognitively age-appropriate (Pouscoulous, 2011), metaphor comprehension has been shown to be a great challenge even for verbally fluent individuals with ASD (Adachi et al., 2004 Vulchanova et al., 2015).

Autism spectrum test circle