Publications

Abstract

Human social intelligence relies on our ability to infer other people’s mental states such as their beliefs, desires,and intentions. While people are proficient at mental state inference from physical action, it is unknown whether people can make inferences of comparable granularity from simple linguistic events. Here, we show that people can make quantitative mental state attributions from simple referential expressions, replicating the fine-grained inferential structure characteristic of nonlinguistic theory of mind. Moreover, people quantitatively adjust these inferences after brief exposures to speaker-specific speech patterns. These judgments matched the predictions made by our computational model of theory of mind in language, but could not be explained by a simpler qualitative model that attributes mental states deductively. Our findings show how the connection between language and theory of mind runs deep, with their interaction showing in one of the most fundamental forms of human communication: reference.

Abstract

We hypothesize that contrast perception works as a visual heuristic, such that when speakers perceive a significant degree of contrast in a visual context, they tend to produce the corresponding adjective to describe a referent. The contrast perception heuristic supports efficient audience design, allowing speakers to produce referential expressions with minimum expenditure of cognitive resources, while facilitating the listener's visual search for the referent. We tested the perceptual contrast hypothesis in three language-production experiments. Experiment 1 revealed that speakers overspecify color adjectives in polychrome displays, whereas in monochrome displays they overspecified other properties that were contrastive. Further support for the contrast perception hypothesis comes from a re-analysis of previous work, which confirmed that color contrast elicits color overspecification when detected in a given display, but not when detected across monochrome trials. Experiment 2 revealed that even atypical colors (which are often overspecified) are only mentioned if there is color contrast. In Experiment 3, participants named a target color faster in monochrome than in polychrome displays, suggesting that the effect of color contrast is not analogous to ease of production. We conclude that the tendency to overspecify color in polychrome displays is not a bottom-up effect driven by the visual salience of color as a property, but possibly a learned communicative strategy. We discuss the implications of our account for pragmatic theories of referential communication and models of audience design, challenging the view that overspecification is a form of egocentric behavior.

Abstract

Similes require two different pragmatic skills: appreciating the intended similarity and deriving a scalar implicature (e.g., “Lucy is like a parrot” normally implies that Lucy is not a parrot), but previous studies overlooked this second skill. In Experiment 1, preschoolers (N = 48; ages 3–5) understood “X is like a Y” as an expression of similarity. In Experiment 2 (N = 99; ages 3–6, 13) and Experiment 3 (N = 201; ages 3–5 and adults), participants received metaphors (“Lucy is a parrot”) or similes (“Lucy is like a parrot”) as clues to select one of three images (a parrot, a girl or a parrot-looking girl). An early developmental trend revealed that 3-year-olds started deriving the implicature “X is not a Y,” whereas 5-year-olds performed like adults.

Abstract

A psychophysical analysis of referential communication establishes a causal link between a visual stimulus and a speaker’s perception of this stimulus, and between the speaker’s internal representation and their reference production. Here, I argue that, in addition to visual perception and language, social cognition plays an integral part in this complex process, as it enables successful speaker-listener coordination. This pragmatic analysis of referential communication tries to explain the redundant use of color adjectives. It is well documented that people use color words when it is not necessary to identify the referent; for instance, they may refer to “the blue star” in a display of shapes with a single star. This type of redundancy challenges influential work from cognitive science and philosophy of language, suggesting that human communication is fundamentally efficient. Here, I explain these seemingly contradictory findings by confirming the visual efficiency hypothesis: redundant color words can facilitate the listener’s visual search for a referent, despite making the description unnecessarily long. Participants’ eye movements revealed that they were faster to find “the blue star” than “the star” in a display of shapes with only one star. A language production experiment further revealed that speakers are highly sensitive to a target’s discriminability, systematically reducing their use of redundant color adjectives as the color of the target became more pervasive in a display. It is concluded that a referential expression’s efficiency should be based not only on its informational value, but also on its discriminatory value, which means that redundant color words can be more efficient than shorter descriptions.

Abstract

Pragmatic theories and computational models of reference must account for people’s frequent use of redundant color adjectives (e.g., referring to a single triangle as “the blue triangle”). The standard pragmatic view holds that the informativity of a referential expression depends on pragmatic contrast: Color adjectives should be used to contrast competitors of the same kind to preempt an ambiguity (e.g., between several triangles of different colors), otherwise they are redundant. Here we propose an alternative to the standard view, the incremental efficiency hypothesis, according to which the efficiency of a referential expression must be calculated incrementally over the entire visual context. This is the first theoretical account of referential efficiency that is sensitive to the incrementality of language processing, making different cross-linguistic predictions depending on word order. Experiment 1 confirmed that English speakers produced more redundant color adjectives (e.g., “the blue triangle”) than Spanish speakers (e.g., “el triángulo azul”), but both language groups used more redundant color adjectives in denser displays where it would be more efficient. In Experiments 2A and 2B, we used eye tracking to show that pragmatic contrast is not a processing constraint. Instead, incrementality and efficiency determine that English listeners establish color contrast across categories (BLUE SHAPES > TRIANGULAR ONE), whereas Spanish listeners establish color contrast within a category (TRIANGLES > BLUE ONE). Spanish listeners, however, reversed their visual search strategy when tested in English immediately after. Our results show that speakers and listeners of different languages exploit word order to increase communicative efficiency.

Abstract

Language and Theory of Mind come together in communication, but their relationship has been intensely contested. I hypothesize that pragmatic markers connect language and Theory of Mind and enable their co-development and co-evolution through a positive feedback loop, whereby the development of one skill boosts the development of the other. I propose to test this hypothesis by investigating two types of pragmatic markers: demonstratives (e.g., ‘this’ vs. ‘that’ in English) and articles (e.g., ‘a’ vs. ‘the’). Pragmatic markers are closed-class words that encode non-representational information that is unavailable to consciousness, but accessed automatically in processing. These markers have been associated with implicit Theory of Mind because they are used to establish joint attention (e.g., ‘I prefer that one’) and mark shared knowledge (e.g., ‘We bought the house’ vs. ‘We bought a house’). Here I develop a theoretical account of how joint attention (as driven by the use of demonstratives) is the basis for children’s later tracking of common ground (as marked by definite articles). The developmental path from joint attention to common ground parallels language change, with demonstrative forms giving rise to definite articles. This parallel opens the possibility of modelling the emergence of Theory of Mind in human development in tandem with its routinization across language communities and generations of speakers. I therefore propose that, in order to understand the relationship between language and Theory of Mind, we should study pragmatics at three parallel timescales: during language acquisition, language use, and language change.

Abstract

This study investigated the extent to which 3- and 4-year-old children may rely on associative memory representations to pass an unexpected-contents false-belief task. In Experiment 1, 4-year-olds performed at chance in both a standard Smarties task and a modified version highlighting the secrecy of the contents of the tube. These results were interpreted as evidence that having to infer the answer to a false-belief question (without relying on memory representations) is generally difficult for preschool children. In Experiments 2a, 2b, and 2c, 3-year-olds were tested at 3-month intervals during their first year of preschool and showed better performance in a narrative version of the Smarties task (chance level) than in the standard version (below-chance level). These children performed even better in an associative version of the narrative task (above-chance level) where they could form a memory representation associating the protagonist with the expected contents of a box. The results of a true-belief control suggest that some of these children may have relied on their memory of the protagonist’s preference for the original contents of the box (rather than their understanding of what the protagonist was expecting to find inside). This suggests that when 3-year-olds passed the associative unexpected-contents task, some may have been keeping track of the protagonist’s initial preference and not only (or not necessarily) of the protagonist’s false belief. These results are interpreted in the light of current accounts of Theory of Mind development and failed replications of verbal false-belief tasks.

Abstract

The Violation-of-Expectation paradigm is a widespread paradigm in infancy research that relies on looking time as an index of surprise. This methodological review aims to increase the reliability of future VoE studies by proposing to standardize reporting practices in this literature. I review 15 VoE studies on false-belief reasoning, which used a variety of experimental parameters. An analysis of the distribution of p-values across experiments suggests an absence of p-hacking. However, there are potential concerns with the accuracy of their measures of infants’ attention, as well as with the lack of a consensus on the parameters that should be used to set up VoE studies. I propose that (i) future VoE studies ought to report not only looking times (as a measure of attention) but also looking-away times (as an equally important measure of distraction); (ii) VoE studies must offer theoretical justification for the parameters they use, and (iii) when parameters are selected through piloting, pilot data must be reported in order to understand how parameters were selected. Future VoE studies ought to maximize the accuracy of their measures of infants’ attention since the reliability of their results and the validity of their conclusions both depend on the accuracy of their measures.

Abstract

There is an ongoing debate, both in philosophy and psychology, as to whether people are able to automatically infer what others may know, or whether they can only derive belief inferences by deploying cognitive resources. Evidence from laboratory tasks, often involving false beliefs or visual-perspective taking, has suggested that belief inferences are cognitively costly, controlled processes. Here we suggest that in everyday conversation, belief reasoning is pervasive and therefore potentially automatic in some cases. To test this hypothesis, we conducted two pre-registered self-paced reading experiments (N1 = 91, N2 = 89). The results of these experiments showed that participants slowed down when a stranger commented ‘That greasy food is bad for your ulcer’ relative to conditions where a stranger commented on their own ulcer or a friend made either comment – none of which violated participants’ common-ground expectations. We conclude that Theory of Mind models need to account for belief reasoning in conversation as it is at the center of everyday social interaction

Abstract

A pragmatic account of referential communication is developed which presents an alternative to traditional Gricean accounts by focusing on cooperativeness and efficiency, rather than informativity. The results of four language-production experiments support the view that speakers can be cooperative when producing redundant adjectives, doing so more often when color modification could facilitate the listener's search for the referent in the visual display (Experiment 1a). By contrast, when the listener knew which shape was the target, speakers did not produce redundant color adjectives (Experiment 1b). English speakers used redundant color adjectives more often than Spanish speakers, suggesting that speakers are sensitive to the differential efficiency of prenominal and postnominal modification (Experiment 2). Speakers were also cooperative when using redundant size adjectives (Experiment 3). Overall, these results show how discriminability affects a speaker's choice of referential expression above and beyond considerations of informativity, supporting the view that redundant speakers can be cooperative.

Abstract

It has been generally assumed in the Theory of Mind literature of the past 30 years that young children fail standard false-belief tasks because they attribute their own knowledge to the protagonist (what Leslie and colleagues called a “true-belief default”). Contrary to the traditional view, we have recently proposed that the children's bias is task induced. This alternative view was supported by studies showing that 3 year olds are able to pass a false-belief task that allows them to focus on the protagonist, without drawing their attention to the target object in the test phase. For a more accurate comparison of these two accounts, the present study tested the true-belief default with adults. Four experiments measuring eye movements and response inhibition revealed that (a) adults do not have an automatic tendency to respond to the false-belief question according to their own knowledge and (b) the true-belief response need not be inhibited in order to correctly predict the protagonist's actions. The positive results observed in the control conditions confirm the accuracy of the various measures used. I conclude that the results of this study undermine the true-belief default view and those models that posit mechanisms of response inhibition in false-belief reasoning. Alternatively, the present study with adults and recent studies with children suggest that participants' focus of attention in false-belief tasks may be key to their performance.

Abstract

In standard Theory of Mind tasks, such as the Sally-Anne, children have to predict the behaviour of a mistaken character, which requires attributing the character a false belief. Hundreds of developmental studies in the last 30 years have shown that children under 4 fail standard false-belief tasks. However, recent studies have revealed that bilingual children and adults outperform their monolingual peers in this type of tasks. Bilinguals’ better performance in false-belief tasks has generally been interpreted as a result of their better inhibitory control; that is, bilinguals are allegedly better than monolinguals at inhibiting the erroneous response to the false-belief question. In this review, I challenge the received view and argue instead that bilinguals’ better false-belief performance results from more effective attention management. This challenge ties in with two independent lines of research: on the one hand, recent studies on the role of attentional processes in false-belief tasks with monolingual children and adults; and on the other, current research on bilinguals’ performance in different Executive Function tasks. The review closes with an exploratory discussion of further benefits of bilingual cognition to Theory of Mind development and pragmatics, which may be independent from Executive Function.

Abstract

Categorisation models of metaphor interpretation are based on the premiss that categorisation statements (e.g., ‘Wilma is a nurse’) and comparison statements (e.g., ‘Betty is like a nurse’) are fundamentally different types of assertion. Against this assumption, we argue that the difference is merely a quantitative one: ‘x is a y’ unilaterally entails ‘x is like a y’, and therefore the latter is merely weaker than the former. Moreover, if ‘x is like a y’ licenses the inference that x is not a y, then that inference is a scalar implicature. We defend these claims partly on theoretical grounds and partly on the basis of experimental evidence. A suite of experiments indicates both that ‘x is a y’ unilaterally entails that x is like a y, and that in several respects the non-y inference behaves exactly as one should expect from a scalar implicature. We discuss the implications of our view of categorisation and comparison statements for categorisation models of metaphor interpretation.

Abstract

Over two decades, the director task has increasingly been employed as a test of the use of Theory of Mind in communication, first in psycholinguistics and more recently in social cognition research. A new version of this task was designed to test two independent hypotheses. First, optimal performance in the director task, as established by the standard metrics of interference, is possible by using selective attention alone, and not necessarily Theory of Mind. Second, pragmatic measures of Theory-of-Mind use can reveal that people actively represent the director’s mental states, contrary to recent claims that they only use domain-general cognitive processes to perform this task. The results of this study support both hypotheses and provide a new interactive paradigm to reliably test Theory-of-Mind use in referential communication.