The knowledge ("true belief") error in 4- to 6-year-old children: When are agents aware of what they have in view?

The standard view on explicit theory of mind development holds that children around the age of 4 years start to ascribe beliefs to themselves and others, typically tested with false belief (FB) tasks. The present study (N = 95, 53 female, 41 male, Austrian, 41 to 80 months) systematically investigated the puzzling phenomenon that FB achievers (FB+) fail knowledge (often subsumed under "true belief") tasks: Despite the story protagonist witnessing the displacement of an object these children predict that the protagonist will look for it in its original location. We replicate this result in Experiment 1. Interestingly, some of our children indicated uncertainty about the protagonist's awareness of the relevant event. Thus, in Experiment 2 a new active watching condition was designed to help children understand that the protagonist attended to the critical event. This practically eradicated the knowledge error. Experiment 3 successfully replicated these results. Implications for existing explanations, perceptual access reasoning (PAR, Fabricius, Boyer, Weimer, & Carroll, 2010) and pragmatic difficulties (Oktay-Gür & Rakoczy, 2017) are discussed.

Teleology first: Goals before knowledge and belief.

Comparing knowledge with belief can go wrong in two dimensions: If the authors employ a wider notion of knowledge, then they do not compare like with like because they assume a narrow notion of belief. If they employ only a narrow notion of knowledge, then their claim is not supported by the evidence. Finally, we sketch a superior teleological view.

Extended difficulties with counterfactuals persist in reasoning with false beliefs: Evidence for teleology-in-perspective.

Increasing evidence suggests that counterfactual reasoning is involved in false belief reasoning. Because existing work is correlational, we developed a manipulation that revealed a signature of counterfactual reasoning in participants' answers to false belief questions. In two experiments, we tested 3- to 14-year-olds and found high positive correlations (r = .56 and r = .73) between counterfactual and false belief questions. Children were very likely to respond to both questions with the same answer, also committing the same type of error. We discuss different theories and their ability to account for each aspect of our findings and conclude that reasoning about others' beliefs and actions requires similar cognitive processes as using counterfactual suppositions. Our findings question the explanatory power of the traditional frameworks, theory theory and simulation theory, in favor of views that explicitly provide for a relationship between false belief reasoning and counterfactual reasoning.

Why Do Children Who Solve False Belief Tasks Begin to Find True Belief Control Tasks Difficult? A Test of Pragmatic Performance Factors in Theory of Mind Tasks.

The litmus test for the development of a metarepresentational Theory of Mind is the false belief (FB) task in which children have to represent how another agent misrepresents the world. Children typically start mastering this task around age four. Recently, however, a puzzling finding has emerged: Once children master the FB task, they begin to fail true belief (TB) control tasks. Pragmatic accounts assume that the TB task is pragmatically confusing because it poses a trivial academic test question about a rational agent's perspective; and we do not normally engage in such discourse about subjective mental perspectives unless there is at least the possibility of error or deviance. The lack of such an obvious possibility in the TB task implicates that there might be some hidden perspective difference and thus makes the task confusing. In the present study, we test the pragmatic account by administering to 3- to 6-year-olds (N = 88) TB and FB tasks and structurally analogous true and false sign (TS/FS) tasks. The belief and sign tasks are matched in terms of representational and metarepresentational complexity; the crucial difference is that TS tasks do not implicate an alternative non-mental perspective and should thus be less pragmatically confusing than TB tasks. The results show parallel and correlated development in FB and FS tasks, replicate the puzzling performance pattern in TB tasks, but show no trace of this in TS tasks. Taken together, these results speak in favor of the pragmatic performance account.

What's in a Hub?-Representing Identity in Language and Mathematics.

Hubs emerge in structural and resting state network analysis as areas highly connected to other parts of the brain and have been shown to respond to several task domains in functional imaging studies. A cognitive explanation for this multi-functionality is still wanting. We propose, that hubs subserve domain-general meta-cognitive functions, relevant to a variety of domain-specific networks and test this hypothesis for the example of processing explicit identity information. To isolate this meta-cognitive function from the processing of domain-specific context, we investigate the overlapping activations to linguistic identity processes (e.g. Mr. Dietrich is the dentist) on the one hand and numerical identity processes (e.g. do "3 × 8" and "36-12" give the same number) on the other hand. The main question was, whether these overlapping activations would fall within areas, consistently identified as hubs by network-based analyses. Indeed, the two contrasts showed significant conjunctions in the left inferior parietal lobe (IPL), precuneus (PC), and posterior cingulate. Accordingly, identity processing may well be one domain-general meta-cognitive function that hub-areas provide to domain-specific networks. For the parietal lobe we back up our hypothesis further with existing reports of activation peaks for other tasks that depend on identity processing, e.g., episodic recollection, theory of mind, and visual perspective taking.

Mistaken max befriends Duplo girl: No difference between a standard and an acted-out false belief task.

With their Duplo task, Rubio-Fernández and Geurts (2013) challenged the assumption that children under 4 years of age cannot pass the standard false belief test. In an attempt to replicate this task on a sample of 73 children aged 32-51 months, we added a standard change of location false belief task as well as a Duplo true belief task. Performance on the latter is crucial for interpreting answers in the Duplo false belief task as to whether they reflect evidence for understanding or merely exhibit a difference in guessing rate. We found (a) a greater variability of response types in both Duplo tasks, (b) no evidence that responses in the Duplo tasks reveal earlier competence than those in the standard false belief test, and (c) a reassuring correlation between false belief tasks, suggesting that the Duplo task does pick up understanding of belief in light of the standard test.

Reduced spontaneous perspective taking in schizophrenia.

Judgments about another person's visual perspective are impaired when the self-perspective is inconsistent with the other-perspective. This is a robust finding in healthy samples as well as in schizophrenia (SZ). Studies show evidence for the existence of a reverse effect, where an inconsistent other-perspective impairs the self-perspective. Such spontaneous perspective taking processes are not yet explored in SZ. In the current fMRI experiment, 24 healthy and 24 schizophrenic participants performed a visual perspective taking task in the scanner. Either a social or a non-social stimulus was presented and their visual perspectives were consistent or inconsistent with the self-perspective of the participant. We replicated previous findings showing that healthy participants show increased reaction times when the human avatar's perspective is inconsistent to the self-perspective. Patients with SZ, however, did not show this effect, neither in the social nor in the non-social condition. BOLD responses revealed similar patterns in occipital areas and group differences were identified in the middle occipital gyrus. These findings suggest that patients with SZ are less likely to spontaneously compute the visual perspectives of others.

The role of the IPL in person identification.

We investigate the brain activations when identifying a newly encountered individual as being the same as a person previously perceived, a fundamental but seldom acknowledged process. In an identity condition, two faces had to be identified as the same person in contrast to a control condition, in which two faces had to be recognised as belonging to similar looking twins. Our results demonstrate an increase of neural activation in frontal as well as in parietal areas including the left inferior parietal lobe and the precuneus during identification. We introduce mental files theory to model this process as a linking of co-referential files and identify important connections to other domains in neurological and cognitive science (e.g., delusional misidentification syndromes, theory of mind).

Belief and Counterfactuality: A Teleological Theory of Belief Attribution.

The development and relation of counterfactual reasoning and false belief understanding were examined in 3- to 7-year-old children (N = 75) and adult controls (N = 14). The key question was whether false belief understanding engages counterfactual reasoning to infer what somebody else falsely believes. Findings revealed a strong correlation between false belief and counterfactual questions even in conditions in which children could commit errors other than the reality bias (r p  = .51). The data suggest that mastery of belief attribution and counterfactual reasoning is not limited to one point in development but rather develops over a longer period. Moreover, the rare occurrence of reality errors calls into question whether young children's errors in the classic false belief task are indeed the result of a failure to inhibit what they know to be actually the case. The data speak in favor of a teleological theory of belief attribution and challenges established theories of belief attribution.

Measuring visual perspective taking in the brain with avatars and arrows: Which question are we asking?

There is an ongoing debate about the involvement of Theory of Mind (ToM) processes in Visual Perspective Taking (VPT). In an fMRI study (Schurz et al., 2015), we borrowed the positive features from a novel VPT task - which is widely used in behavioral research - to study previously overlooked experimental factors in neuroimaging studies. However, as Catmur et al. (2016) rightly argue in a comment on our work, our data do not speak strongly to questions discussed in the original behavioral studies, in particular the issue of implicit mentalizing. We appreciate the clarification of these interpretational limitations of our study, but would like to point out the differences between questions emerging from behavioral and neuroimaging research on VPT. Different from what Catmur et al. (2016) discuss, our study was not intended as a test of implicit mentalizing. In fact, the terms "automatic" and "implicit mentalizing" were never mentioned in our manuscript. Our study addressed a methodological gap between ToM and VPT research, which we identified in two previous meta-analyses on the topics (Schurz et al., 2013, 2014). With this difference in mind we show that the critical points levelled by Catmur et al. (2016) cease to apply.

The robustness and generalizability of findings on spontaneous false belief sensitivity: a replication attempt.

Influential studies showed that 25-month-olds and neurotypical adults take an agent's false belief into account in their anticipatory looking patterns (Southgate et al. 2007 Psychol. Sci.18, 587-592 (doi:10.1111/j.1467-9280.2007.01944.x); Senju et al. 2009 Science325, 883-885 (doi:10.1126/science.1176170)). These findings constitute central pillars of current accounts distinguishing between implicit and explicit Theory of Mind. In our first experiment, which initially included a replication as well as two manipulations, we failed to replicate the original finding in 2- to 3-year-olds (N = 48). Therefore, we ran a second experiment with the sole purpose of seeing whether the effect can be found in an independent, tightly controlled, sufficiently powered and preregistered replication study. This replication attempt failed again in a sample of 25-month-olds (N = 78), but was successful in a sample of adults (N = 115). In all samples, a surprisingly high number of participants did not correctly anticipate the agent's action during the familiarization phase. This led to massive exclusion rates when adhering to the criteria of the original studies and strongly limits the interpretability of findings from the test phase. We discuss both the reliability of our replication attempts as well as the replicability of non-verbal anticipatory looking paradigms of implicit false belief sensitivity, in general.

The practical other: teleology and its development.

We argue for teleology as a description of the way in which we ordinarily understand others' intentional actions. Teleology starts from the close resemblance between the reasoning involved in understanding others' actions and one's own practical reasoning involved in deciding what to do. We carve out teleology's distinctive features more sharply by comparing it to its three main competitors: theory theory, simulation theory, and rationality theory. The plausibility of teleology as our way of understanding others is underlined by developmental data in its favour.

Helping as an early indicator of a theory of mind: Mentalism or Teleology?

This article challenges the claim that young children's helping responses in Buttelmann, Carpenter, and Tomasello's (2009) task are based on ascribing a false belief to a mistaken agent. In our first Study 18- to 32-month old children (N = 28) were more likely to help find a toy in the false belief than in the true belief condition. In Study 2, with 54 children of the same age, we assessed the authors' mentalist interpretation of this result against an alternative teleological interpretation that does not make the assumption of belief ascription. The data speak in favor of our alternative. Children's social competency is based more on inferences about what is likely to happen in a particular situation and on objective reasons for action than on inferences about agents' mental states. We also discuss the need for testing serious alternative interpretations of claims about early belief understanding.

Mental files theory of mind: When do children consider agents acquainted with different object identities?

Mental files theory explains why children pass many perspective taking tasks like the false belief test around age 4 (Perner & Leahy, 2016). It also explains why older children struggle to understand that beliefs about an object depend on how one is acquainted with it (intensionality or aspectuality). If Heinz looks at an object that is both a die and an eraser, but cannot tell by looking that it is an eraser, he will not reach for it if he needs an eraser. Four- to 6-year olds find this difficult (Apperly & Robinson, 1998). We tested 129 35- to 86-month olds with a modified version of Apperly and Robinson's task. Each child faced four tasks resulting from two experimental factors, timing and mode of information. Timing: Children saw Heinz learn the die's location either before or after they learn that the die is an eraser. Mode of information: Heinz learns where the die is either perceptually or verbally. When Heinz' learning is verbal, he never perceives the die at all. We found that Apperly and Robinson's problem occurs only in the seen-after condition, where Heinz sees the die afterchildren had learnt that it was also an eraser. It vanishes when Heinz learns where the die is before children learn that it is also an eraser. The problem also vanishes when Heinz learns where the die is purely verbally (e.g., "The die is in the red box") and never sees it. This evidence lets us refine existing mental files theory, and eliminate several alternatives from the literature.

Great apes are sensitive to prior reliability of an informant in a gaze following task.

Social animals frequently rely on information from other individuals. This can be costly in case the other individual is mistaken or even deceptive. Human infants below 4 years of age show proficiency in their reliance on differently reliable informants. They can infer the reliability of an informant from few interactions and use that assessment in later interactions with the same informant in a different context. To explore whether great apes share that ability, in our study we confronted great apes with a reliable or unreliable informant in an object choice task, to see whether that would in a subsequent task affect their gaze following behaviour in response to the same informant. In our study, prior reliability of the informant and habituation during the gaze following task affected both great apes' automatic gaze following response and their more deliberate response of gaze following behind barriers. As habituation is very context specific, it is unlikely that habituation in the reliability task affected the gaze following task. Rather it seems that apes employ a reliability tracking strategy that results in a general avoidance of additional information from an unreliable informant.

Specifying the brain anatomy underlying temporo-parietal junction activations for theory of mind: A review using probabilistic atlases from different imaging modalities.

In this quantitative review, we specified the anatomical basis of brain activity reported in the Temporo-Parietal Junction (TPJ) in Theory of Mind (ToM) research. Using probabilistic brain atlases, we labeled TPJ peak coordinates reported in the literature. This was carried out for four different atlas modalities: (i) gyral-parcellation, (ii) sulco-gyral parcellation, (iii) cytoarchitectonic parcellation and (iv) connectivity-based parcellation. In addition, our review distinguished between two ToM task types (false belief and social animations) and a nonsocial task (attention reorienting). We estimated the mean probabilities of activation for each atlas label, and found that for all three task types part of TPJ activations fell into the same areas: (i) Angular Gyrus (AG) and Lateral Occpital Cortex (LOC) in terms of a gyral atlas, (ii) AG and Superior Temporal Sulcus (STS) in terms of a sulco-gyral atlas, (iii) areas PGa and PGp in terms of cytoarchitecture and (iv) area TPJp in terms of a connectivity-based parcellation atlas. Beside these commonalities, we also found that individual task types showed preferential activation for particular labels. Main findings for the right hemisphere were preferential activation for false belief tasks in AG/PGa, and in Supramarginal Gyrus (SMG)/PFm for attention reorienting. Social animations showed strongest selective activation in the left hemisphere, specifically in left Middle Temporal Gyrus (MTG). We discuss how our results (i.e., identified atlas structures) can provide a new reference for describing future findings, with the aim to integrate different labels and terminologies used for studying brain activity around the TPJ. Hum Brain Mapp 38:4788-4805, 2017. © 2017 Wiley Periodicals, Inc.

Systematic Comparison of Brain Imaging Meta-Analyses of ToM with vPT.

In visual perspective taking (vPT) one has to concern oneself with what other people see and how they see it. Since seeing is a mental state, developmental studies have discussed vPT within the domain of "theory of mind (ToM)" but imaging studies have not treated it as such. Based on earlier results from several meta-analyses, we tested for the overlap of visual perspective taking studies with 6 different kinds of ToM studies: false belief, trait judgments, strategic games, social animations, mind in the eyes, and rational actions. Joint activation was observed between the vPT task and some kinds of ToM tasks in regions involving the left temporoparietal junction (TPJ), anterior precuneus, left middle occipital gyrus/extrastriate body area (EBA), and the left inferior frontal and precentral gyrus. Importantly, no overlap activation was found for the vPT tasks with the joint core of all six kinds of ToM tasks. This raises the important question of what the common denominator of all tasks that fall under the label of "theory of mind" is supposed to be if visual perspective taking is not one of them.

Direct and indirect admission of ignorance by children.

Research has shown that children are able to admit their own ignorance directly (i.e., verbally) by 3years of age when they are totally ignorant about what is hidden in a box (total ignorance task) but fail to do so until 5 or 6years of age when having seen different objects without seeing which of them is being hidden (partial exposure task). This study investigated whether an earlier understanding of own ignorance in the partial exposure task is found when using an indirect measure-when children are allowed to either opt out from a risky decision (Experiment 1) or seek clarifying information by peeking inside (Experiment 2). No evidence for an earlier understanding was found in Experiment 1. In Experiment 2, however, 3- and 4-year-olds searched for clarifying information under partial exposure more often when being ignorant than when being knowledgeable. We argue that this discrepancy is related to whether spontaneous information seeking involves metacognitive processes or not.

An evaluation of neurocognitive models of theory of mind.

We review nine current neurocognitive theories of how theory of mind (ToM) is implemented in the brain and evaluate them based on the results from a recent meta-analysis by Schurz et al. (2014), where we identified six types of tasks that are the most frequently used in imaging research on ToM. From theories about cognitive processes being associated with certain brain areas, we deduce predictions about which areas should be engaged by the different types of ToM tasks. We then compare these predictions with the observed activations in the meta-analysis, and identify a number of unexplained findings in current theories. These can be used to revise and improve future neurocognitive accounts of ToM.

Mental files and belief: A cognitive theory of how children represent belief and its intensionality.

We provide a cognitive analysis of how children represent belief using mental files. We explain why children who pass the false belief test are not aware of the intensionality of belief. Fifty-one 3½- to 7-year old children were familiarized with a dual object, e.g., a ball that rattles and is described as a rattle. They observed how a puppet agent witnessed the ball being put into box 1. In the agent's absence the ball was taken from box 1, the child was reminded of it being a rattle, and emphasising its being a rattle it was put back into box 1. Then the agent returned, the object was hidden in the experimenter's hands and removed from box 1, described as a "rattle," and transferred to box 2. Children who passed false belief had no problem saying where the puppet would look for the ball. However, in a different condition in which the agent was also shown that the ball was a rattle they erroneously said that the agent would look for the ball in box 1, ignoring the agent's knowledge of the identity of rattle and ball. Their problems cease with their mastery of second-order beliefs (she thinks she knows). Problems also vanish when the ball is described not as a rattle but as a thing that rattles. We describe how our theory can account for these data as well as all other relevant data in the literature.