Testing the domain-specificity of a theory of mind deficit in brain-injured patients: evidence for consistent performance on non-verbal, "reality-unknown" false belief and false photograph tasks

To test the domain-specificity of "theory of mind" abilities we compared the performance of a case-series of 11 brain-lesioned patients on a recently developed test of false belief reasoning () and on a matched false photograph task, which did not require belief reasoning and which addressed problems with existing false photograph methods. A strikingly similar pattern of performance was shown across the false belief and false photograph tests. Patients who were selectively impaired on false belief tasks were also impaired on false photograph tasks; patients spared on false belief tasks also showed preserved performance with false photographs. In some cases the impairment on false belief and false photograph tasks coincided with good performance on control tasks matched for executive demands. We discuss whether the patients have a domain-specific deficit in reasoning about representations common to both false belief and false photograph tasks.     

Does the autistic child have a metarepresentational deficit?

This study examines the claim that autistic children lack a “theory of mind” because of an inability to metarepresent. We argue that if autistic children have a “metarepresentational” deficit in Leslie's (1987, 1988) sense of the term, then they should have difficulty not only with mental representations such as false beliefs, but also with external representations such as photographs. Autistic children's understanding of photographic representations was tested using Zaitchik's (1990) task. This task is modelled on the false belief task (Baron-Cohen, Leslie, & Frith, 1985: Wimmer & Perner, 1983) but involves “false” photographs where a photographic representation does not conform with the current state of the real world. Like Zaitchik (1990) we found that normal 3 and 4-year-olds found this task as difficult as the false belief task. In sharp contrast, however, the autistic children in our study passed the photograph task but failed the false belief task. As both tasks require the ability to decouple, this evidence challenges the view that autistic children lack “metarepresentational” ability in Leslie's sense. However, the results leave open the question of whether autistic children have a metarepresentational ability in the different sense of the term intended by Pylyshyn (1978), that is, representing the relationship between a representation and what it represents.     

The curious incident of the photo that was accused of being false: issues of domain specificity in development, autism, and brain imaging

We resume an exchange of ideas with Uta Frith that started before the turn of the century. The curious incident responsible for this exchange was the finding that children with autism fail tests of false belief, while they pass Zaitchik's (1990) photograph task (Leekam & Perner, 1991). This finding led to the conclusion that children with autism have a domain-specific impairment in Theory of Mind (mental representations), because the photograph task and the false-belief task are structurally equivalent except for the nonmental character of photographs. In this paper we argue that the false-belief task and the false-photograph task are not structurally equivalent and are not empirically associated. Instead a truly structurally equivalent task is the false-sign task. Performance on this task is strongly associated with the false-belief task. A version of this task, the misleading-signal task, also poses severe problems for children with autism (Bowler, Briskman, Gurvidi, & Fornells-Ambrojo, 2005). These new findings therefore challenge the earlier interpretation of a domain-specific difficulty in inferring mental states and suggest that children with autism also have difficulty understanding misleading nonmental objects. Brain imaging data using false-belief, "false"-photo, and false-sign scenarios provide further supporting evidence for our conclusions.     

Where to look first for children's knowledge of false beliefs

Recent research has shown that, although young children have a substantial knowledge of beliefs as internal mental states, they have considerable difficulty in understanding how a false belief can lead to an outcome which is in conflict with a desire. However, this evidence has come from tasks which assume that children follow an experimenter's "implicatures" in conversation and interpret the question "Where will a person (with the false belief) look for the object?" to mean "Where will the person look first?" rather than "Where will the person have to look (or go to look) to find the object?" In our investigation, even 3-year-olds often responded correctly when asked to predict the initial behavior of a story character with a false belief. We discuss these results in terms of the conversational worlds of children and adults.     

Do people automatically track others’ beliefs? Evidence from a continuous measure

Recent findings suggest that tracking others’ beliefs is not always effortful and slow, but may rely on a fast and implicit system. An untested prediction of the automatic belief tracking account is that own and others’ beliefs should be activated in parallel. We tested this prediction measuring continuous movement trajectories in a task that required deciding between two possible object locations. We independently manipulated whether participants’ belief about the object location was true or false and whether an onlooker’s belief about the object location was true or false. Manipulating whether or not the agent’s belief was ever task relevant allowed us to compare performance in an explicit and implicit version of the same task. Movement parameters revealed an influence of the onlooker’s irrelevant belief in the implicit version of the task. This provides evidence for parallel activation of own and others’ beliefs.     

Infants attribute false beliefs to a toy crane

The mentalistic view of early theory of mind posits that infants possess a robust and sophisticated understanding of false belief that is masked by the demands of traditional explicit tasks. Much of the evidence supporting this mentalistic view comes from infants’ looking time at events that violate their expectations about the beliefs of a human agent. We conducted a replication of the violation‐of‐expectation procedure, except that the human agent was replaced by an inanimate agent. Infants watched a toy crane repeatedly move toward a box containing an object. In the absence of the crane, the object changed location. When the crane returned, 16‐month‐old infants looked longer when it turned toward the object's new location, consistent with the attribution of a false belief to the crane. These results suggest that infants spontaneously attribute false beliefs to inanimate agents. A video abstract of this article can be viewed at https://youtu.be/qqEPPhd9FDo     

Attributing false beliefs about non-obvious properties at 18 months

Reports that infants in the second year of life can attribute false beliefs to others have all used a search paradigm in which an agent with a false belief about an object’s location searches for the object. The present research asked whether 18-month-olds would still demonstrate false-belief understanding when tested with a novel non-search paradigm. An experimenter shook an object, demonstrating that it rattled, and then asked an agent, “Can you do it?” In response to this prompt, the agent selected one of two test objects. Infants realized that the agent could be led through inference (Experiment 1) or memory (Experiment 2) to hold a false belief about which of the two test objects rattled. These results suggest that 18-month-olds can attribute false beliefs about non-obvious properties to others, and can do so in a non-search paradigm. These and additional results (Experiment 3) help address several alternative interpretations of false-belief findings with infants.     

Attributing false beliefs about non-obvious properties at 18 months

Reports that infants in the second year of life can attribute false beliefs to others have all used a search paradigm in which an agent with a false belief about an object’s location searches for the object. The present research asked whether 18-month-olds would still demonstrate false-belief understanding when tested with a novel non-search paradigm. An experimenter shook an object, demonstrating that it rattled, and then asked an agent, “Can you do it?” In response to this prompt, the agent selected one of two test objects. Infants realized that the agent could be led through inference (Experiment 1) or memory (Experiment 2) to hold a false belief about which of the two test objects rattled. These results suggest that 18-month-olds can attribute false beliefs about non-obvious properties to others, and can do so in a non-search paradigm. These and additional results (Experiment 3) help address several alternative interpretations of false-belief findings with infants.     

Is Language Required to Represent Others’ Mental States? Evidence From Beliefs and Other Representations

An important part of our Theory of Mind—the ability to reason about other people's unobservable mental states—is the ability to attribute false beliefs to others. We investigated whether processing these false beliefs, as well as similar but nonmental representations, is reliant on language. Participants watched videos in which a protagonist hides a gift and either takes a photo of it or writes a text about its location before a second person inadvertently moves the present to a different location, thereby rendering the belief and either the photo or text false. At the same time, participants performed either a concurrent verbal interference task (rehearsing strings of digits) or a visual interference task (remembering a visual pattern). Results showed that performance on false belief trials did not decline under verbal interference relative to visual interference. We interpret these findings as further support for the view that language does not form an essential part of the process of reasoning online (“in the moment”) about false beliefs.     

Experimenter effects on children's understanding of false drawings and false beliefs

Two experiments were conducted in which a variant of J. McGarrigle and M. Donaldson's (1975) "Naughty Teddy" intervention was applied to children's understanding of false drawings and false beliefs. The results showed that preschool children's understanding of the contents of an out-of-date drawing improved when the drawing was made by a capricious agent ("Naughty Snakey" glove puppet) rather than by the experimenter. The children's performance on a false belief task also improved when the events that set up the false belief were the result of the actions of the glove puppet. The results are discussed in terms of the role of children's sensitivity to the pragmatics of interactions in their development of a theory of mind.     

Inhibitory processing in the false belief task: Two conjectures

Although it is well established that four-year-olds outperform three-year-olds on predicting behavior from false beliefs, this is only true when the false belief is coupled with a positive desire. Four-year-olds perform poorly in an otherwise standard false belief task when the protagonist's desire is to avoid rather than to approach a target. We account for this by assuming that the attribution of a false belief involves inhibitory processing. We present two versions of an inhibition model of successful belief-desire reasoning.     

Two reasons to abandon the false belief task as a test of theory of mind

The false belief task has often been used as a test of theory of mind. We present two reasons to abandon this practice. First, passing the false belief task requires abilities other than theory of mind. Second, theory of mind need not entail the ability to reason about false beliefs. We conclude with an alternative conception of the role of the false belief task.     

A reaction time advantage for calculating beliefs over public representations signals domain specificity for ‘theory of mind’

In a task where participants’ overt task was to track the location of an object across a sequence of events, reaction times to unpredictable probes requiring an inference about a social agent’s beliefs about the location of that object were obtained. Reaction times to false belief situations were faster than responses about the (false) contents of a map showing the location of the object (Experiment 1) and about the (false) direction of an arrow signaling the location of the object (Experiment 2). These results are consistent with developmental, neuro-imaging and neuropsychological evidence that there exist domain specific mechanisms within human cognition for encoding and reasoning about mental states. Specialization of these mechanisms may arise from either core cognitive architecture or via the accumulation of expertise in the social domain.     

Executive function and children's understanding of false belief: how specific is the relation?

The present study examined developmental relations among understanding false belief, understanding “false” photographs, performance on the Dimensional Change Card Sort (DCCS), and performance on a picture–sentence verification task in 69 3–5-year-old children. Results showed that performance on the DCCS predicted performance on false belief questions even after controlling for children's age and verbal ability. However, neither performance on the picture–sentence verification task, nor performance on the “false” photograph task predicted false belief understanding. Implications of these findings are discussed in the context of suggestions that understanding false belief reflects a general understanding of representation, propositional negation, and the ability to use higher order rules.     

Children's understanding of false beliefs that result from developmental misconceptions

Most studies of false belief have focused on beliefs about specific and arbitrary facts. The purpose of this research was to extend the study of false belief to false beliefs that result from the general misconceptions that characterize young children's understanding of the world. Three experiments, employing diverse methods, examined preschool children's ability to attribute false beliefs with respect to a variety of cognitive-developmental acquisitions: Level 2 perspective taking, appearance/reality, line of sight, and biological principles of growth and innate potential. Children showed some but incomplete mastery with respect to each of these new forms of false belief, and the level of performance was in most instances comparable to that found with standard measures. Despite this equivalence in overall difficulty, new and standard forms of false belief were not correlated in any of the three experiments.     

Action anticipation through attribution of false belief by 2-year-olds

Two-year-olds engage in many behaviors that ostensibly require the attribution of mental states to other individuals. Yet the overwhelming consensus has been that children of this age are unable to attribute false beliefs. In the current study, we used an eyetracker to record infants' looking behavior while they watched actions on a computer monitor. Our data demonstrate that 25-month-old infants correctly anticipate an actor's actions when these actions can be predicted only by attributing a false belief to the actor.     

Reliability and generalizability of an acted-out false belief task in 3-year-olds

The current study tested the reliability and generalizability of a narrative act-out false belief task held to reveal Theory of Mind (ToM) competence at 3 years of age, before children pass verbal standard false belief tasks (the “Duplo task”; Rubio-Fernández & Geurts, 2013, Psychological Science). We conducted the task across two labs with methodologically improved matched control conditions. Further, we administered an analogue intensionality version to assess the scope of ToM competence in the Duplo task. 72 3-year-olds participated in a Duplo change-of-location task, a Duplo intensionality task, and half of them in a matched verbal standard change-of-location task, receiving either false belief or matched true belief scenarios. Children performed at chance in the false belief Duplo location change and intensionality tasks as well as in the standard false belief task. There were no differences to the standard task, and performance correlated across all three false belief tasks, revealing a rather unified competence and no task advantage. In the true belief conditions of both Duplo tasks, children performed at ceiling and significantly different from the false belief conditions, while they were at chance in the true belief condition of the standard task. The latter indicates that a pragmatic advantage of the Duplo task compared to the standard task holds only for the true belief scenarios. Our study shows that the Duplo task measures the same ToM competence as the standard task and rejects a notion of earlier false belief understanding on the group level in 3-year-old children.     

Processing demands in belief‐desire reasoning: inhibition or general difficulty?

Most 4-year-olds can predict the behavior of a person who wants an object but is mistaken about its location. More difficult is predicting behavior when the person is mistaken about location and wants to avoid the object. We tested between two explanations for children's difficulties with avoidance false belief: the Selection Processing model of inhibitory processing and a General Difficulty account. Children were presented with a false belief task and a control task, in which belief attribution was as difficult as in the false belief task. Predicting behavior in light of the character's desire to avoid the object added more difficulty in the false belief task. This finding is consistent with the Selection Processing model, but not with the General Difficulty account.     

Guessing versus choosing – and seeing versus believing – in false belief tasks

Three‐ and 4‐year‐old children were tested using videos of puppets in various versions of a theory of mind change‐of‐location situation, in order to answer several questions about what children are doing when they pass false belief tests. To investigate whether children were guessing or confidently choosing their answer to the test question, a condition in which children were forced to guess was also included, and measures of uncertainty were compared across conditions. To investigate whether children were using simpler strategies than an understanding of false belief to pass the test, we teased apart the seeing‐knowing confound in the traditional change‐of‐location task. We also investigated relations between children's performance on true and false belief tests. Results indicated that children appeared to be deliberately choosing, not guessing, in the false belief tasks. Children performed just as well whether the protagonist gained information about the object visually or verbally, indicating that children were not using a simple rule based on seeing to predict the protagonist's behaviour. A true belief condition was significantly easier for children than a false belief condition as long as it was of low processing demands. Children's success rate on the different versions of the standard false belief task was influenced by factors such as processing demands of the stories and the child's verbal abilities.