Exploring the specificity of age-related differences in theory of mind tasks

Tasks assessing theory of mind (ToM) and non-mental state control tasks were administered to young and older adults to examine previous contradictory findings about age differences in mental state decoding. Age differences were found on a verbal ToM task after controlling for vocabulary levels. Older adults achieved significantly lower scores than did younger adults on static and dynamic visual ToM tasks, and a similar pattern was found on non-ToM control tasks. Rather than a specific ToM deficit, older adults exhibited a more general impairment in the ability to decode cues from verbal and visual information about people.     

Representational and executive selection resources in 'theory of mind': evidence from compromised belief-desire reasoning in old age

Effective belief-desire reasoning requires both specialized representational capacities-the capacity to represent the mental states as such-as well as executive selection processes for accurate performance on tasks requiring the prediction and explanation of the actions of social agents. Compromised belief-desire reasoning in a given population may reflect failures in either or both of these systems. We report evidence supporting this two-process model from belief-desire reasoning tasks conducted with younger and older adult populations. When task inferential complexity is held constant, neither group showed specific difficulty with reasoning about mental state content as compared with non-mental state content. However, manipulations that systematically increase executive performance demands within belief-desire reasoning caused systematic decreases in task performance in both older and younger adult groups. Moreover, the effect of increasing executive demands was disproportionately greater in the older group. Regression analysis indicated that measures of processing speed and inhibition contributed most to explaining variance in accuracy and response times in the belief-desire reasoning tasks. These results are consistent with the idea that compromised belief-desire reasoning in old age is likely the result of age-related decline in executive selection skills that supplement core mental state representational abilities, rather than as a result of failures in the representational system itself.     

Executive and attentional contributions to Theory of Mind deficit in attention deficit/hyperactivity disorder (ADHD)

Attention deficit/hyperactivity disorder (ADHD) in children has been associated with attentional and executive problems, but also with socioemotional difficulties possibly associated with deficits in Theory of Mind (ToM). Socioemotional problems in ADHD are associated with more negative prognoses, notably interpersonal, educational problems, and an increased risk of developing other psychiatric disorders that emphasize the need to clarify the nature of their ToM deficits. In this study, we hypothesized that ToM dysfunction in children with ADHD is largely attributable to their attentional and/or executive deficits. Thirty-one children with ADHD (8–12 years, IQ > 85) and 31 typically developing (TD) children were assessed using executive functions (inhibition, planning, and flexibility) and attentional tasks, as well as two advanced ToM tasks (Reading the Mind in the Eyes and Faux Pas) involving different levels of executive control. Children with ADHD performed more poorly than TD children in attentional, executive function, and ToM tasks. Linear regression analyses conducted in the ADHD group indicated that inhibition scores predicted performance on the “Faux Pas” task the best, while attention scores were the best for predicting performance on the Reading the Mind in the Eyes task. When controlled for inhibition and attentional variables, ToM performance in children with ADHD was actually similar to TD children. Contrarily, controlling for ToM scores did not normalize performance for inhibition and attentional tasks in children with ADHD. This unidirectional relationship suggests that deficits in the EF and attentional domains are responsible for ToM deficits in ADHD, which therefore may contribute to their socioemotional difficulties.     

Constraints on using the dual-task methodology to specify the degree of central executive involvement in cognitive tasks

The dual-task paradigm has been used to examine the role of the central executive in various cognitive tasks. In these studies, performance decrements in primary cognitive tasks performed concurrently with secondary executive tasks have been interpreted as evidence for the involvement of the central executive in those primary tasks. In the present study, we examined the effects of different secondary tasks on performance of three psychometric visuospatial tasks. The decrement in performance of these tasks when they were paired with secondary executive tasks was smallest for the psychometric task considered to most heavily involve the central executive and largest for the task considered least demanding of executive mechanisms. We propose that, when applied to the assessment of central executive involvement, the prevalent simple dual-task logic does not always apply. Special conditions that limit the application of the dual-task methodology include two inherently related factors--a response selection bottleneck and a strategic tradeoff between primary and secondary tasks.     

Implicit and explicit false belief development in preschool children

The ability to represent the mental states of other agents is referred to as Theory of Mind (ToM). A developmental breakthrough in ToM consists of understanding that others can have false beliefs about the world. Recently, infants younger than 2 years of age have been shown to pass novel implicit false belief tasks. However, the processes underlying these tasks and their relation to later‐developing explicit false belief understanding, as well as to other cognitive abilities, are not yet understood. Here, we study a battery of implicit and explicit false belief tasks in 3‐ and 4‐year‐old children, relating their performance to linguistic abilities and executive functions. The present data show a significant developmental change from failing explicit false belief tasks at 3 years of age to passing them at the age of 4, while both age groups pass implicit false belief tasks. This differential developmental trajectory is reflected by the finding that explicit and implicit false belief tasks do not correlate. Further, we demonstrate that explicit false belief tasks correlate with syntactic and executive functions, whereas implicit false belief tasks do not. The study thus indicates that the processes underlying implicit false belief tasks are different from later‐developing explicit false belief understanding. Moreover, our results speak for a critical role of syntactic and executive functions for passing standard explicit false belief tasks in contrast to implicit tasks.     

Timing and executive function: Bidirectional interference between concurrent temporal production and randomization tasks

A review of interference effects in concurrent temporal/nontemporal dual-task studies suggests that prospective timing may be related to executive cognitive functions. Executive processes play a supervisory role in behavior by controlling attention, coordinating information, and scheduling actions. In the present research, a timing task was paired with an established executive task in a dual-task paradigm. The timing task required subjects t o generate a series o f 5-sec temporal productions,and the executive task was random number generation. These tasks were performed both separately and concurrently. Comparisons of single-task and dual-task conditions showed that (1) the randomization task interfered with timing by making temporal productions more variable and longer and (2) concurrent timing disrupted randomization performance by making responses less random. This pattern of bidirectional interference supports the idea that timing relies on the same attentional resources used by other executive-level tasks.     

Domain-general contributions to social reasoning: theory of mind and deontic reasoning re-explored

Using older adults and dual-task interference, we examined performance on two social reasoning tasks: theory of mind (ToM) tasks and versions of the deontic selection task involving social contracts and hazardous conditions. In line with performance accounts of social reasoning, evidence from both aging and the dual-task method suggested that domain-general resources contribute to performance of these tasks. Specifically, older adults were impaired relative to younger adults on all types of social reasoning tasks tested; performance varied as a function of the demands these tasks placed on domain-general resources. Moreover, in younger adults, simultaneous performance of a working memory task interfered with younger adults' performance on both types of social reasoning tasks; here too, the magnitude of the interference effect varied with the processing demands of each task. Limits placed on social reasoning by executive functions contribute a great deal to performance, even in old age and in healthy younger adults under conditions of divided attention. The role of potentially non-modular and modular contributions to social reasoning is discussed.     

Acquired ‘theory of mind'' impairments following stroke

The ability to attribute thoughts and feelings to self and others (‘theory of mind') has been hypothesised to have an innate neural basis and a dedicated cognitive mechanism. Evidence in favour of this proposal has come from autism; a brain-based developmental disorder which appears to be characterised by impaired theory of mind, despite sometimes good general reasoning skills/IQ. To date no case of specific acquired theory of mind impairment has been reported. The present study examined theory of mind in adults who had suffered right hemisphere stroke, a group known to show pragmatic and social difficulties. In one study using story materials and two using cartoons, patients' understanding of materials requiring attribution of mental states (e.g. ignorance, false belief) was significantly worse than their understanding of non-mental control materials. Data from healthy elderly subjects, and a small group of left hemisphere patients (who received the tasks in modified form), suggest that this impairment on mental state tasks is not a function of task difficulty. The findings support the notion of a dedicated cognitive system for theory of mind, and suggest a role for the healthy right hemisphere in the attribution of mental states.     

Differential recruitment of executive resources during mind wandering

Recent research has shown that mind wandering recruits executive resources away from the external task towards inner thoughts. No studies however have determined whether executive functions are drawn away in a unitary manner during mind wandering episodes, or whether there is variation in specific functions impacted. Accordingly, we examined whether mind wandering differentially modulates three core executive functions—response inhibition, updating of working memory, and mental set shifting. In three experiments, participants performed one of these three executive function tasks and reported their attentional state as either on-task or mind wandering at random intervals. We found that mind wandering led to poorer performance in the response inhibition and working memory tasks, but not the set-shifting task. These findings suggest that mind wandering does not recruit executive functions in a monolithic manner. Rather, it appears to selectively engage certain executive functions, which may reflect the adaptive maintenance of ongoing task performance.     

执行功能与心理理论关系的元分析:抑制控制和灵活转换的作用

心理理论的发展对个体社会化具有重要意义。研究通过元分析的方法,表明执行功能能够有效预测个体心理理论的发展水平(r=0.37,p0.001),且具有跨文化和跨人群的稳定性;同时,在个体的毕生发展中,执行功能均与心理理论存在显著相关,证明了执行功能的表达说;但在不同的发展阶段(Q1=411.75,p10.001,df1=90;Q2=219.49,p20.001,df2=50),心理理论的发展会受到执行功能不同成分的影响:0~3岁时抑制控制起关键作用;3~12岁时,心理理论受到抑制控制和灵活转换的共同影响;青春期阶段,灵活转换的作用明显;而到了成年期,抑制控制与灵活转换均会对心理理论产生积极影响。     

Theory of Mind Deficit in Schizophrenia and Associated Cognitive Functions

This study examined the Theory of Mind (ToM) ability of schizophrenic persons in association with other cognitive functions like memory, executive functioning and attention. Results showed evidence of relationship between ToM and cognitive functions i.e. executive function, working memory and intelligence but no uniform predictive model was found across all the ToM tasks. It was also noted that predicting variables related to different cognitive domains varied markedly for schizophrenia and control groups. It seems that there are multiple cognitive pathways to ToM mechanism, although these different forms may not have an additive effect.     

音乐训练对大学生执行功能的影响

近年来大量研究发现音乐训练对认知能力的具有积极影响,一些理论认为音乐训练的广泛迁移效应是通过执行功能起中介作用,但音乐训练与执行功能的关系至今仍存争议。研究将执行功能分为抑制控制、工作记忆和认知灵活性三个子成分,并将抑制控制进一步细分为注意抑制和反应抑制,同时区分工作记忆中主动性控制和反应性控制两种认知过程。通过对比音乐组和控制组在执行功能各任务（Go/No-go, Stroop, AX-CPT, Task-switching）上的行为表现来系统考察音乐训练与执行功能的关系。结果表明音乐训练对执行功能不同子成分的影响具有差异性,其促进效应主要体现在抑制控制中的注意抑制和工作记忆中的主动性控制,对抑制控制中的反应抑制、工作记忆中的反应性控制和认知灵活性影响较小。     

Evidence of Poor Planning in Children with Attention Deficits

This study examined the planning performance of children with attention deficits, and also investigated the possible interactions between inattention and anxiety in the performance of executive function tasks. A group of 98 children (grades 4 and 6), derived from an initial group of 550, were assigned to an attention difficulties group (AD) and a control group (n = 49 each) based on their scores on a variety of cognitive attention measures and teacher scales of attention and hyperactivity. The two groups were matched on age, gender, parental education, non-verbal and verbal ability. They were compared on Crack-the-Code (C-t-C) action-planning task, embedded and ambiguous figures and Theory of Mind tasks. Analyses indicated that the failure of AD children on cognitive performance measures is linked to planning impairments. The co-occurrence of anxiety, in turn, did not interact with inattention to affect planning performance differentially. Implications of these findings for the current discussion about the cognitive and emotional processes underlying impaired performance among children with attention deficits on executive control tasks are discussed.     

More dissociations and interactions within central executive functioning: a comprehensive latent-variable analysis

The present study examined the separability of six executive functions (verbal storage-and-processing coordination, visuospatial storage-and-processing coordination, dual-task coordination, strategic retrieval, selective attention, and shifting) and their relationships, by means of confirmatory factor analysis. A set of tasks thought to primarily assess each target function was administered to 180 participants. The results demonstrated that five of the six functions initially considered were distinguishable albeit related constructs, with one of these functions combining inhibitory and strategic retrieval processes. The analyses failed to reveal a single dual-task coordination ability underlying performance on the dual-tasks. These findings provide further support for the fractionation of the central executive into several functions and also stress the need to approach executive functioning in terms of both dissociations within general functions and specific interactions between some of these functions.     

Theory of mind in spina bifida: Relationship with intellectual and executive functioning

This article investigates emotion recognition ability, a central aspect of Theory of Mind (ToM), in a group of individuals with spina bifida myelomeningocele (SBM) experiencing executive function deficits, and examine associations between emotion recognition, and intellectual and executive functioning. A total of 38 adult subjects with SBM were included in this study, participating in a randomized controlled trial evaluating the effects of a cognitive rehabilitation intervention for executive dysfunction. Reading the Mind in the Eyes Test (RMET) was used as a measure of emotion recognition, and neuropsychological tests and questionnaires were utilized as executive function measures. One third of the participants performed poorer on the emotion recognition task compared to normative data. Emotion recognition may represent an area being affected in adults with SBM, and it is related to verbal IQ. Findings also suggest that executive functions and emotion recognition ability in adults with SBM are independent.     

Working memory and the control of action: evidence from task switching.

A series of 7 experiments used dual-task methodology to investigate the role of working memory in the operation of a simple action-control plan or program involving regular switching between addition and subtraction. Lists requiring switching were slower than blocked lists and showed 2 concurrent task effects. Demanding executive tasks impaired performance on both blocked and switched lists, whereas articulatory suppression impaired principally the switched condition. Implications for models of task switching and working memory and for the Vygotskian concept of verbal control of action are discussed.     

Susceptibility of spatial and verbal working memory to demands of the central executive

We used a dual-task paradigm to examine the degree to which domain-specific spatial and verbal subsystems depend on the domain-general central executive. Forty participants were asked to retain spatial or verbal information while performing a concurrent secondary task related to simple arithmetic. The secondary tasks consisted of three cognitive processes: single-digit addition, a digit-carrying operation, and digit reading. The single-digit addition and carry operation include central executive functioning, while digit reading relies solely on the phonological loop. The single-digit addition caused a performance decrement on the spatial working memory task, while the digit reading impaired performance on the verbal working memory task. The carry operation interfered with recall accuracy on both working memory tasks. The spatial working memory task was significantly correlated with the verbal working memory task only when the secondary task was more demanding on the central executive. Our results suggest that spatial working memory rather than verbal working memory is susceptible to failure of central executive functioning and that the central executive plays an important role in regulating the cognitive demands of different domains.     

Book reviews

Results from past studies show that the central executive, as conceptualised in the working memory model of Baddeley and Hitch (), plays an important role in simple mental arithmetic. According to this model the central executive is viewed as a unitary system. Recent research, however, suggests that the “central executive” can be fractionated in more autonomous executive functions, such as inhibition, response selection, planning, and input monitoring. In four experiments we studied the role of two possible executive functions (input monitoring and response selection) in solving simple sums. Subjects solved one‐digit sums (e.g., 5 + 7) in a single‐task condition as well as in dual‐task conditions. The results show that secondary tasks, which require a choice, impair the calculation of simple sums. On the other hand, an increased degree of input monitoring in the secondary tasks does not seem to impair the calculation of the sums. These findings show that response selection is strongly involved in simple arithmetic and may be one of the core executive processes in mental arithmetic.     

An fMRI study of the social competition in healthy subjects

Social interaction requires the ability to infer another person’s mental state (Theory of Mind, ToM) and also executive functions. This fMRI study aimed to identify the cerebral correlates activated by ToM during a specific social interaction, the human-human competition. In this framework, we tested a conflict resolution task (Stroop) adapted to a virtual situation of competition. The participants were instructed to play in order to win either against a human-like competitor (human-human competition) or against a non-human competitor (human-machine competition). Only the human-human competition requires ToM as this type of competition is performed under social interaction. We identified first the classical network of executive regions activated by Stroop. Secondly, we identified the social (human-human) competition regions, represented by the bilateral superior and inferior frontal gyri, the anterior cingulate, the insula, the superior and anterior temporal, the hippocampus, the fusiform gyrus, the cuneus and the precuneus. Finally, we identified the executive regions that were modulated by the human-human competition, i.e., the executive control regions additionally activated when mentalizing in the context of social competition. They constituted a network predominant to the right and composed of the superior and middle frontal, anterior cingulate, insula and fusiform gyrus. We suggest that our experimental paradigm may be useful in exploration of the cerebral correlates of social adjustments in several situations such as psychiatric disorders presenting executive and social dysfunctions.     

The Role of Memory in the Tower of London Task

The Tower of London (TOL) task is widely used as a neuropsychological test of planning. Relatively little is known of the cognitive components of the task, and in particular the role of memory in performance. The current studies on normal adults looked at the role of verbal and spatial working memory in the TOL. The effects of verbal and visuospatial dual-task manipulations on TOL performance were examined in an experiment with 36 participants. Both verbal and visuospatial executive secondary tasks caused poorer performance on the TOL; however, concurrent articulatory suppression enhanced performance. The results suggest that executive and spatial components are important in the task, and raise questions about the role of preplanning in the TOL.