The cognitive demands of remembering a speaker's perspective and managing common ground size modulate 8- and 10-year-olds' perspective-taking abilities.

Using "theory of mind" to successfully accommodate differing perspectives during communication requires much more than just acquiring basic theory of mind understanding. Evidence suggests that children's ability to adopt a speaker's perspective continues to develop throughout childhood to adolescence until adulthood. The current study examined the cognitive factors that could account for variations in children's abilities to use a speaker's perspective during language comprehension and whether the same factors contribute to age-related improvements. Our study incorporated into a commonly used communication task two types of memory demands that are frequently present in our everyday communication but have been overlooked in the previous literature: remembering a speaker's perspective and the amount of common ground information. Findings from two experiments demonstrated that both 8- and 10-year-olds committed more egocentric errors when each of these memory demands was high. Our study also found some supporting evidence for the age-related improvement in children's perspective use, with 10-year-olds generally committing fewer egocentric errors compared with 8-year-olds. Interestingly, there was no clear evidence that the memory factors that affected children's perspective use in our experiments were also the factors that drove age-related improvement.

Language complexity modulates 8- and 10-year-olds' success at using their theory of mind abilities in a communication task.

Basic competence in theory of mind is acquired during early childhood. Nonetheless, evidence suggests that the ability to take others' perspectives in communication improves continuously from middle childhood to the late teenage years. This indicates that theory of mind performance undergoes protracted developmental changes after the acquisition of basic competence. Currently, little is known about the factors that constrain children's performance or that contribute to age-related improvement. A sample of 39 8-year-olds and 56 10-year-olds were tested on a communication task in which a speaker's limited perspective needed to be taken into account and the complexity of the speaker's utterance varied. Our findings showed that 10-year-olds were generally less egocentric than 8-year-olds. Children of both ages committed more egocentric errors when a speaker uttered complex sentences compared with simple sentences. Both 8- and 10-year-olds were affected by the demand to integrate complex sentences with the speaker's limited perspective and to a similar degree. These results suggest that long after children's development of simple visual perspective-taking, their use of this ability to assist communication is substantially constrained by the complexity of the language involved.

Remembering visual and linguistic common ground in shared history.

Successful communication requires speakers and listeners to refer to information in their common ground. Shared history is one of the bases for common ground, as information from a communicative episode in the past can be referred to in future communication. However, to draw upon shared history, communicative partners need to have an accurate memory record that they can refer to. The memory mechanism for shared history is poorly understood. The current study investigated the ways in which memory for shared history is prioritised. Two experiments presented a referential communication task followed by a surprise recognition memory task, with the former task serving as an episode of shared history. Experiment 1 revealed superior memory for information that was both seen in the communicators' common ground and referred to, followed by information that was seen but not referred to, and finally by information privileged to the participants. Experiment 2 provided a replication of Experiment 1 and further demonstrated that these co-presence effects are not dependent on the presence of a speaker with a different perspective to the participant.

Why are listeners sometimes (but not always) egocentric? Making inferences about using others' perspective in referential communication.

Theory of Mind (ToM) is the ability to understand others' mental states, and that these mental states can differ from our own. Although healthy adults have little trouble passing conceptual tests of ToM (e.g., the false belief task [1]), they do not always succeed in using ToM [2,3]. In order to be successful in referential communication, listeners need to correctly infer the way in which a speaker's perspective constrains reference and inhibit their own perspective accordingly. However, listeners may require prompts to take these effortful inferential steps. The current study investigated the possibility of embedding prompts in the instructions for listeners to make inference about using a speaker's perspective. Experiment 1 showed that provision of a clear introductory example of the full chain of inferences resulted in large improvement in performance. Residual egocentric errors suggested that the improvement was not simply due to superior comprehension of the instructions. Experiment 2 further dissociated the effect by placing selective emphasis on making inference about inhibiting listeners' own perspective versus using the speaker's perspective. Results showed that only the latter had a significant effect on successful performance. The current findings clearly demonstrated that listeners do not readily make inferences about using speakers' perspectives, but can do so when prompted.

Perspective-taking across cultures: shared biases in Taiwanese and British adults.

The influential hypothesis by Markus & Kitayama (Markus, Kitayama 1991. Psychol. Rev. 98, 224) postulates that individuals from interdependent cultures place others above self in interpersonal contexts. This led to the prediction and finding that individuals from interdependent cultures are less egocentric than those from independent cultures (Wu, Barr, Gann, Keysar 2013. Front. Hum. Neurosci. 7, 1-7; Wu, Keysar. 2007 Psychol. Sci. 18, 600-606). However, variation in egocentrism can only provide indirect evidence for the Markus and Kitayama hypothesis. The current study sought direct evidence by giving British (independent) and Taiwanese (interdependent) participants two perspective-taking tasks on which an other-focused 'altercentric' processing bias might be observed. One task assessed the calculation of simple perspectives; the other assessed the use of others' perspectives in communication. Sixty-two Taiwanese and British adults were tested in their native languages at their home institutions of study. Results revealed similar degrees of both altercentric and egocentric interference between the two cultural groups. This is the first evidence that listeners account for a speaker's limited perspective at the cost of their own performance. Furthermore, the shared biases point towards similarities rather than differences in perspective-taking across cultures.

Just one look: Direct gaze briefly disrupts visual working memory.

Direct gaze is a salient social cue that affords rapid detection. A body of research suggests that direct gaze enhances performance on memory tasks (e.g., Hood, Macrae, Cole-Davies, & Dias, Developmental Science, 1, 67-71, 2003). Nonetheless, other studies highlight the disruptive effect direct gaze has on concurrent cognitive processes (e.g., Conty, Gimmig, Belletier, George, & Huguet, Cognition, 115(1), 133-139, 2010). This discrepancy raises questions about the effects direct gaze may have on concurrent memory tasks. We addressed this topic by employing a change detection paradigm, where participants retained information about the color of small sets of agents. Experiment 1 revealed that, despite the irrelevance of the agents' eye gaze to the memory task at hand, participants were worse at detecting changes when the agents looked directly at them compared to when the agents looked away. Experiment 2 showed that the disruptive effect was relatively short-lived. Prolonged presentation of direct gaze led to recovery from the initial disruption, rather than a sustained disruption on change detection performance. The present study provides the first evidence that direct gaze impairs visual working memory with a rapidly-developing yet short-lived effect even when there is no need to attend to agents' gaze.

Adults see vision to be more informative than it is.

Humans gain a wide range of knowledge through interacting with the environment. Each aspect of our perceptual experiences offers a unique source of information about the world-colours are seen, sounds heard and textures felt. Understanding how perceptual input provides a basis for knowledge is thus central to understanding one's own and others' epistemic states. Developmental research suggests that 5-year-olds have an immature understanding of knowledge sources and that they overestimate the knowledge to be gained from looking. Without evidence from adults, it is not clear whether the mature reasoning system outgrows this overestimation. The current study is the first to investigate whether an overestimation of the knowledge to be gained from vision occurs in adults. Novel response time paradigms were adapted from developmental studies. In two experiments, participants judged whether an object or feature could be identified by performing a specific action. Adult participants found it disproportionately easy to accept looking as a proposed action when it was informative, and difficult to reject looking when it was not informative. This suggests that adults, like children, overestimate the informativeness of vision. The origin of this overestimation and the implications that the current findings bear on the interpretation of children's overestimation are discussed.