These three items are intended to tap mental state term comprehension with specific regard for the cognitive terms “think”, “know”, and “believe”. Counter intuitively, children’s early use of cognitive terms precedes their understanding of those terms (Astington & Baird, 2005; Johnson & Maratsos, 1977; Johnson & Wellman, 1980). Regarding the development of mental state term (use and subsequent) comprehension, a trend has been observed such that children first acquire terms of perception, emotion, and desire (e.g., see, look, happy, sad, like, love, want) which are followed by cognition terms (e.g., know, think, believe, realize) which appear later in development (Astington & Baird, 2005; Booth & Hall, 1995; Frank & Hall, 1991). This is likely because verbs like “think”, “know”, and “believe” (a.k.a. ‘metacognitive terms’) are cognitively complex in that they can be used to mark information about another’s mental state vis-à-vis one’s own mental state. As Astington and Olson (1990) explain:
“If he thinks what I take to be true, I say “he knows”, but if I take it not to be true I say “He thinks”, although the proposition and his attitude towards it may be identical, from his point of view. Thus, some of the elaboration of these terms may be due to marking another’s mental state or speech act and simultaneously marking one’s own stance toward it” (p. 79).
One major way that “think” and “believe” differ from “know” involves how they encode certainty: “know” is a factive (it presupposes fact) whereas “think” and “believe” are nonfactives (they do not presuppose fact). The understanding of these presuppositions for “think” and “know” has been estimated to emerge at age 4 years (Abbeduto & Rosenburg, 1984; Johnson & Maratsos, 1977; Kazak, Collis, & Lewis, 1997; Moore, Bryant, & Furrow, 1989; Moore & Furrow, 1991; Moore, Furrow, Chaisson, & Patriquin, 1994) which provides good justification for the comprehension of these terms as Basic level theory of mind competencies. Regardless of their status as factives or nonfactives, however, mental state term comprehension “has a long developmental trajectory” (Schwanenflugel, Henderson, & Fabricius, 1998, p. 512) that continues into adolescence and adulthood (Astington & Olson, 1990; Booth & Hall, 1995). This occurs as metacognitive terms are added to the lexicon and the subtle distinctions between terms are elaborated and differentiated. One later understood cognate of “think” and “know” is the term “believe” (perhaps because it is a more formal and lower frequency term). Of course, the list of later developing cognates is long and includes, but is by no means limited to: assume, believe, bet, conclude, confuse, compare, decide, deduce, doubt, dream, estimate, evaluate, examine, explore, figure, forget, guess, hypothesize, infer, learn, memorize, plan, predict, pretend, question, reason, recall, recognize, reflect, remember, remind, trick, understand, and wonder.
Comprehension of cognitive terms correlates with standardized vocabulary measures for samples over age 4 years (Booth & Hall, 1995). The ability to distinguish “think” and “know” also predicts performance on a range of theory of mind tasks (Flavell, Flavell, & Green, 1983; Gopnik & Astington, 1988; Patnaik & Babu, 2001; Wimmer & Perner, 1983) even after controlling for the effects of age and verbal ability (Cheung, Chen, & Yeung, 2009). The understanding of cognitive mental state terms such as “think” and “know” are believed to be relevant to the development of metacognitive thought, reading comprehension (Booth & Hall, 1994), and academic success more broadly (Astington & Olson, 1990; Patnaik & Babu, 2001).
Mental state term comprehension of cognitive terms in ASD
Most studies on this topic conclude that, as with typically developing samples, mental state term use and understanding in ASD is correlated with general language skills and performance on a range of theory of mind tasks (e.g., Leslie & Frith, 1988; Siller, Swanson, Serlin, & Teachworth, 2014; Ziatas, Durkin, & Pratt, 1998). Kazak et al. (1997) also found that although some children with ASD can use mental state terms to attribute knowledge to themselves and others, they tend to need higher verbal skills compared to neurotypical children to do so. Given the strong links between language and theory of mind (and in light of the fact that mental state terms are themselves conceptual linguistic markers of the mind), many researchers have underscored the potential for training children in mental state term comprehension to support metacognitive and metalinguistic functioning in ASD (e.g., Patnaik & Babu, 2001; Ziatas et al., 1998). Given the age-related changes observed in maternal mental state term input in typical development (Gola, 2012; Jenkins, Turell, Kogushi, Lollis, & Ross) and the patterns of mental state term comprehension described above, a general recommendation is that training proceed from early emerging perception, emotion, and desire terms, to the more advanced and later emerging cognitive and metacognitive terms for which mastery may be particularly elusive in ASD (e.g., Tager-Flusberg, 1992). In a related vein, whereas desire terms have been found to occur most frequently in the mental state language of parents of children with ASD, cognitive terms are relatively rare (Kay-Raining Bird, Cleave, Curia, & Dunleavy, 2008). Although this suggests sensitivity to the language and intellectual levels of their children with ASD, it is possible that parents also make non-optimal conversational adjustments (Kay-Raining Bird et al., 2008; Venuti, de Falco, Esposito, Zaninelli, & Bornstein, 2012). Consequently, parent (or clinician) training to facilitate the development of cognitive mental state language (and language in general) among children with ASD could profitably target[1]:
· Rich and frequent conversations about that mind that proceed from early (e.g., desire, affect, perceptual) mental state talk to cognitive state talk (Taumpoepeau & Ruffman; 2006).
· Talk that is semantically contingent and/or follows the child’s attentional focus (Haebig, McDuffie, & Weismer, 2013; McDuffy & Yoder, 2010; Prelock, Calhoun, Morris, & Platt, 2011)
· Use of a playful, activity-based interactional style with younger children that incorporates nonverbal turns, affection, and short, simple utterances and avoidance of frequent and repetitive questioning (Geils & Knoetze, 2008)
· Use of explanatory talk about the causes and consequences of mental states (Kay-Raining Bird et al., 2008)
· Use of contrastive talk about emotions (Slaughter, Peterson, & Mackintosh, 2007)
· The use of ‘thought bubbles’ during semi-structured conversation to make inner mental states explicit (Wellman et al., 2002)
Mental state term comprehension of cognitive terms in ADHD
Very few studies have examined the understanding of cognitive mental state terms in ADHD and those that have focus primarily on the ability to make reference to mental state terms (a.k.a. internal state language) in narratives and the research is mixed. Rumpf, Kamp-Becker, Becker, and Kauschike (2012) found no difference between children with ADHD and typically-developing 8-12 year-olds. By contrast, Miranda, Baixauli, and Colomer (2013) found that adults with ADHD made fewer references to internal mental states than neurotypical controls in a narrative writing task. These data suggest the potential for weakness in the ability of individuals with ADHD to make use of mental states to facilitate cohesion in narrative construction. Of course, because these studies were limited to mental state use in narrative construction, more research is necessary to elucidate cognitive mental state comprehension in ADHD more generally.
Mental state term comprehension of cognitive terms in DoHH
Most studies on this topic conclude that, as with typically developing samples, mental state term use and understanding in oral and late-signing children who are DoHH is correlated with general language skills and performance on a range of theory of mind tasks (especially the understanding of false beliefs, e.g., de Villiers & deVilliers, 2000; Moeller & Schick, 2006; Pyers & Senghas, 2009; Schick, de Villiers, de Villiers, & Hoffmeister, 2007). In terms of their production and comprehension of mental state terms, children who are DoHH appear to follow the typical developmental sequence: from terms of perception, emotion, and desire (e.g., see, happy, sad, like, want) which are followed by cognition terms (e.g., know, think, believe, realize) (e.g., Peterson and Slaughter, 2006). As is true for children with ASD, children who are DoHH tend to use desire terms more than their hearing counterparts. This overreliance may be due to the fact that 1) desires are developmentally earlier and/or easier to learn nonverbally and 2), from a functional standpoint, communicating about desires is prioritized because it can have immediate consequences (desires are met or not met) that may be imperiled in light of the frequent communication breakdowns experienced between DoHH children and their hearing parents (Rieffe & Terwogt, 2000).
Crucially, research indicates that the amount and quality of mental state talk in the home not only predicts theory of mind development in children who are DoHH (e.g., Peterson & Slaughter, 2006) but that it also explains unique variance above and beyond general language ability (Moeller & Schick, 2006). In fact, limited exposure to talk about mental states by hearing parents has been hypothesized as a source of deaf children’s deficits in mental state term comprehension and theory of mind development more generally (Peterson & Siegal, 1995, 2000). The limited exposure of oral deaf and late-signing children to such talk likely results from the nature of the communication interactions in which these children participate (e.g., a lack of topic diversity or thematic complexity), avoidance of interaction related to communication failure, and/or lack of ability to overhear the conversations of others (Gola, 2012; Moeller & Schick, 2006).
Research has also documented that the quality of maternal sign is associated with the amount and quality of maternal mental state input to children who are DoHH. For example, Morgan et al. (2014) found that hearing mothers of DoHH children used less mental state language compared with mothers of hearing children. But interestingly, even mothers who used only spoken communication produced significantly fewer mental state cognitive references than mothers of hearing children. “Apparently, it is not just the mother’s ability in sign language that is affecting mental-state talk, but something related to having a child with a hearing loss” (Stanzione & Schick, 2014). As with other clinical populations, it appears that caregivers of DoHH children are sensitive in adjusting to the perceived level of the child’s language and intellectual level but it is also true that caregivers sometimes make non-optimal adjustments. There is also growing evidence from training studies with preschoolers, school-aged children, and children with hearing loss/deafness that demonstrate a positive effect in mental state understanding when children are exposed to mental state language. Consequently, parent (or clinician) training to facilitate the development of cognitive mental state language among children who are DoHH could profitably target[2]:
· Rich and frequent conversations about the mind that proceed from developmentally early (e.g., desire, affect, perceptual) mental state talk to later cognitive state talk (Peterson & Slaughter, 2006; Taumpoepeau & Ruffman; 2006).
· Talk about the mind that proceeds from talk about self to talk about other; the latter is associated with greater perspective-taking gains (Lecce, Bianco, Devine, Hughes, & Banerjee, 2014; Taumpoepeau & Ruffman; 2006).
· The use of ‘thought bubbles’ during semi-structured conversation to make inner mental states explicit (Wellman & Peterson, 2013)
· Cognitive state talk that is increasingly elaborative in terms of the content words (e.g., ‘think’, ‘know’, ‘believe’, ‘remember’, ‘imagine’) as well as the themes and topics of conversation (Peterson & Slaughter, 2006).
· Use of mental state talk and vocabulary using a conversational approach to storybooks and story-telling that incorporates references to beliefs (Beazley & Chilton, 2016); sharing these techniques with parents to practice these conversations about the mind more frequently is also recommended (Stanzione & Schick, 2014)
For more information about mental state term comprehension see the description of the Mental State Term Comprehension Subscale.
REFERENCES
Abbeduto, L., & Rosenberg, S. (1985). Children’s knowledge of the presuppositions of know and other cognitive verbs. Journal of Child Language, 12, 621-641.
Astington, J., & Baird, J. (2005). Introduction: Why language matters for theory of mind. In J. A. Astington & J. A. Baird (Eds.), Why language matters for theory of mind (pp. 3-25). Oxford: Oxford University Press
Astington, A., & Olson, D. (1990). Metacognitive and metalinguistic language: Learning to talk about thought. Applied Psychology: An International Review, 39(1), 77-87.
Beazley, S., & Chilton, H. (2016). The voice of the practitioner: Sharing fiction books to support the understanding of theory of mind in deaf children. Deafness and Education International, 17(4).
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Booth, H., & Hall, W. (1994). Role of the cognitive internal state lexicon in reading comprehension. Journal of Educational Review, 86(3), 413-422.
Cheung, H., Chen, H., & Yueng, W. (2009). Relations between mental verb and false belief understanding in Cantonese-speaking children. Journal of Experimental Child Psychology, 104, 141-155.
de Villiers, P. A., & de Villiers, J. G. (2000). Linguistic determinism and the understanding of false beliefs.
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Flavell, H., Flavell, E., & Green, F. (1983). Development of the appearance-reality distinction. Cognitive Psychology, 15, 95-120.
Frank, R., & Hall, W. (1991). Polysemy and the acquisition of cognitive internal state lexicon. Journal of Psycholinguistic Research, 20, 283-304.
Gopnik, A., & Astington, J. (1988). Children’s understanding of representational change and its relation to the understanding to false belief and the appearance-reality distinction. Child Development, 59, 26-37.
Geils, C., & Knoetze, J. (2008). Conversations with Barney: A conversation analysis of interactions with a child with autism. South African Journal of Psychology, 38(1), 200-224.
Haebig, E., McDuffie, A., & Weismer, S. (2013). Brief report: Parent verbal responsiveness and language development in toddlers on the autism spectrum. Journal of Autism and Developmental Disorders, 43, 2218-2227.
Jenkins, J., Turrell, S., Kogushi, Y., Lollis, S., & Ross, H. (2003). A longitudinal investigation of the dynamics of mental state talk in families. Child Development, 74(3), 905-920.