The Role of Executive Function and Theory of Mind in Pragmatic Computations

Abstract

In sentences such as “Some dogs are mammals,” the literal semantic meaning (“Some and possibly all dogs are mammals”) conflicts with the pragmatic meaning (“Not all dogs are mammals,” known as a scalar implicature). Prior work has shown that adults vary widely in the extent to which they adopt the semantic or pragmatic meaning of such utterances, yet the underlying reason for this variation is unknown. Drawing on theoretical models of scalar implicature derivation, we explore the hypothesis that the cognitive abilities of executive function (EF) and theory of mind (ToM) contribute to this observed variation. In Experiment 1, we show that individuals with better ToM are more likely to compute a scalar implicature and adopt the pragmatic meaning of an utterance; however, EF makes no unique contribution to scalar implicature comprehension after accounting for ToM. In Experiment 2, we replicate this finding and assess whether it generalizes to the comprehension of other pragmatic phenomena such as indirect requests (e.g., “It's hot in here” uttered to ask for something to be done) and metaphor (e.g., “to harvest courage”). This is the first evidence that differences in ToM are associated with pragmatic competence in neurotypical adults across distinct pragmatic phenomena.

What second-language speakers can tell us about pragmatic processing

“…ToM is thought to be involved in comprehending different types of pragmatic inferences, among which is the computation of scalar implicatures [29]. To engage in ToM requires the interlocutor not only to interpret the linguistic behavior from their own self-perspective, but also from the perspective of others and therefore to keep track of the interlocutor's epistemic state necessary for scalar implicature derivation [1,11,30,31].…”

“…Recent experimental investigations on the role of ToM in determining pragmatic behavior show that participants' variable performance in comprehending scalar inferences is largely correlated with participant's social skills or mindreading abilities (e.g., [17,25,37]). Those with inferior ToM abilities tend to be more literal in interpreting under-informative sentences than those with strong ToM abilities, in both irony [37] and scalar implicatures [29,38]. For instance, Fairchild and Papafragou [29] examined the role of ToM in scalar implicature computation, particularly the unique roles of EF and ToM abilities in deriving scalar inferences.…”

“…Those with inferior ToM abilities tend to be more literal in interpreting under-informative sentences than those with strong ToM abilities, in both irony [37] and scalar implicatures [29,38]. For instance, Fairchild and Papafragou [29] examined the role of ToM in scalar implicature computation, particularly the unique roles of EF and ToM abilities in deriving scalar inferences. They used the digit span task and high cognitive load memory trials embedded in a scalar implicature task to measure EF, whereas the participants' performance on the mind in the eyes task and strange stories was used to provide a measure of ToM abilities.…”

“…Given that ToM itself can explain some the inter-individual variability in interpreting pragmatic inferences [29,37], the question of how L2 learners use their ToM abilities to calculate a pragmatic inference remains under-explored. Several developmental studies on children showed evidence of a strong bidirectional relationship between ToM abilities and linguistic competence (e.g., [39,40]), but we have limited information about how L2 adults with varying proficiency levels would depend on their ToM to compute scalar inferences.…”

On the Variability of Scalar Implicature Computation: Evidence from L2 English Adults

“…Are there certain linguistic and logical properties that are taxing the working memory and inflate the processing times independently of the inferential mechanism? There are several speculations which suggest that the cognitive effort observed in computing scalar inferences is not a product of the inferential process but rather a product of various aspects that are dependent upon cognitive resources, such as the application of the Theory of Mind in inferring the speaker's knowledge state (e.g., [22][23][24]), contrasting and evaluating alternatives (e.g., [19]), the decision to derive the implicature (e.g., [21,25,26]), some difficulty inherent in the semantic structure of upper-bound sentences compared to lower-bound sentences (e.g., [12,16,19,25]), embedded negativity (e.g., [2,27,28]), and/ or polarity effects (e.g., [27,29,30]), although there is no verdict on which subprocess contributes to memory taxation.…”