Impaired theory of mind in adults with traumatic brain injury: A replication and extension of findings

Computerized social cognitive training in the subacute phase after traumatic brain injury: A quasi-randomized controlled trial

OBJECTIVES

To assess the usefulness of a computerized tasks module designed for the rehabilitation of social cognition (SC) in acquired brain injury.

METHODS

Quasi-randomized controlled trial (ClinicalTrials.gov:NCT03479970) involving 45 patients with moderate-severe traumatic brain injury (TBI) in a subacute inpatient rehabilitation hospital. The experimental group (n = 28) received treatment with a computerized SC module in combination with a non-SC module. The control group (n = 26) only received a treatment with non-SC module.

RESULTS

Intragroup comparisons showed that the experimental group had better results for all SC measures, except for International Affective Picture System (IAPS). The control group improved for Facial Expressions of cEmotion-Stimuli and Tests (FEEST) and Moving Shapes Paradigm (MSP), showing no changes with respect to pretreatment in IAPS, MSP and Reading the Mind in the Eyes Test (RMET). Intergroup comparisons did not present differences between the two groups for pretreatment measures. Post-treatment comparison showed that the experimental group obtained better results for RMET than the control group.

CONCLUSION

The computerized SC module was useful for the rehabilitation of SC in patients with moderate-severe TBI in the subacute phase. The group that received combined rehabilitative treatment (SC + non-SC) obtained better results for SC than the group that received treatment intended only for non-SC.

Attentional Orienting and Disfluency-Related Memory Boost Are Intact in Adults With Moderate-Severe Traumatic Brain Injury

PURPOSE

Traumatic brain injury (TBI) is associated with a range of cognitive-communicative deficits that interfere with everyday communication and social interaction. Considerable effort has been directed at characterizing the nature and scope of cognitive-communication disorders in TBI, yet the underlying mechanisms of impairment are largely unspecified. The present research examines sensitivity to a common communicative cue, disfluency, and its impact on memory for spoken language in TBI.

METHOD

Fifty-three participants with moderate-severe TBI and 53 noninjured comparison participants listened to a series of sentences, some of which contained disfluencies. A subsequent memory test probed memory for critical words in the sentences.

RESULTS

Participants with TBI successfully remembered the spoken words (b = 1.57, p < .0001) at a similar level to noninjured comparison participants. Critically, participants with TBI also exhibited better recognition memory for words preceded by disfluency compared to words from fluent sentences (b = 0.57, p = .02).

CONCLUSIONS

These findings advance mechanistic accounts of cognitive-communication disorder by revealing that, when isolated for experimental study, individuals with moderate-severe TBI are sensitive to attentional orienting cues in speech and exhibit enhanced recognition of individual words preceded by disfluency. These results suggest that some aspects of cognitive-communication disorders may not emerge from an inability to perceive and use individual communication cues, but rather from disruptions in managing (i.e., attending, weighting, integrating) multiple cognitive, communicative, and social cues in complex and dynamic interactions. This hypothesis warrants further investigation.

Factors related to social inferencing performance in moderate-severe, chronic TBI

OBJECTIVE

Following traumatic brain injury (TBI), deficits in social cognition are common. Social inferencing is a crucial component of social cognition that enables an individual to understand the thoughts, feelings, and intentions of a communication partner when this information is not explicitly stated. Existing literature suggests a variety of factors contribute to social inferencing success (e.g. biological sex, executive functioning), yet findings are not conclusive, largely because these factors have been examined in isolation.

METHOD

In this cross-sectional study, stepwise regression with cross validation was used to examine the extent that several theoretically motivated factors were associated with social inferencing (measured by performance on The Awareness of Social Inference Test [TASIT]) in adult participants with TBI (n = 105). Demographic information, executive functioning, aggression, emotional functioning measures, and participation in society were all examined in relation to social inferencing performance.

RESULTS

The findings confirm the importance of higher-level cognitive skills (i.e. executive functioning) in social inferencing, and advance the literature by underlining the potential importance of productive participation in social inferencing performance.

CONCLUSION

This study innovatively highlights factors linked with social inferencing skills and, in doing so, how deficits in social inferencing might manifest in the lives of individuals with TBI.

Dynamic Emotion Recognition and Social Inference Ability in Traumatic Brain Injury: An Eye-Tracking Comparison Study

Emotion recognition and social inference impairments are well-documented features of post-traumatic brain injury (TBI), yet the mechanisms underpinning these are not fully understood. We examined dynamic emotion recognition, social inference abilities, and eye fixation patterns between adults with and without TBI. Eighteen individuals with TBI and 18 matched non-TBI participants were recruited and underwent all three components of The Assessment of Social Inference Test (TASIT). The TBI group were less accurate in identifying emotions compared to the non-TBI group. Individuals with TBI also scored lower when distinguishing sincere and sarcastic conversations, but scored similarly to those without TBI during lie vignettes. Finally, those with TBI also had difficulty understanding the actor's intentions, feelings, and beliefs compared to participants without TBI. No group differences were found for eye fixation patterns, and there were no associations between fixations and behavioural accuracy scores. This conflicts with previous studies, and might be related to an important distinction between static and dynamic stimuli. Visual strategies appeared goal- and stimulus-driven, with attention being distributed to the most diagnostic area of the face for each emotion. These findings suggest that low-level visual deficits may not be modulating emotion recognition and social inference disturbances post-TBI.

Facial affect recognition in context in adults with and without TBI

Introduction

Several studies have reported impaired emotion recognition in adults with traumatic brain injury (TBI), but studies have two major design features that limit application of results to real-world contexts: (1) participants choose from among lists of basic emotions, rather than generating emotion labels, and (2) images are typically presented in isolation rather than in context. To address these limitations, we created an open-labeling task with faces shown alone or in real-life scenes, to more closely approximate how adults with TBI label facial emotions beyond the lab.

Methods

Participants were 55 adults (29 female) with moderate to severe TBI and 55 uninjured comparison peers, individually matched for race, sex, and age. Participants viewed 60 photographs of faces, either alone or in the pictured person's real-life context, and were asked what that person was feeling. We calculated the percent of responses that were standard forced-choice-task options, and also used sentiment intensity analysis to compare verbal responses between the two groups. We tracked eye movements for a subset of participants, to explore whether gaze duration or number of fixations helped explain any group differences in labels.

Results

Over 50% of responses in both groups were words other than basic emotions on standard affect tasks, highlighting the importance of eliciting open-ended responses. Valence of labels by participants with TBI was attenuated relative to valence of Comparison group labels, i.e., TBI group responses were less positive to positive images and the same was true for negative images, although the TBI group responses had higher lexical diversity. There were no significant differences in gaze duration or number of fixations between groups.

Discussion

Results revealed qualitative differences in affect labels between adults with and without TBI that would not have emerged on standard forced-choice tasks. Verbal differences did not appear to be attributable to differences in gaze patterns, leaving open the question of mechanisms of atypical affect processing in adults with TBI.

Socio-demographic and political predictors of Theory of Mind in adulthood

Individual differences in Theory of Mind (ToM)-the ability to understand the mental states of others-are theorised to be predicted by socio-demographic and political factors. However, inconsistent findings on the relationships between various socio-demographic predictors and ToM, as well as a paucity of research on political predictors of ToM, have left a gap in the literature. Using a recently validated self-report measure of ToM in a large sample (N = 4202) we investigated the unique contributions of age, sex, socio-economic status, and political beliefs to ToM in adults. Except for age, all variables were correlated with ToM, but when accounting for the variance of other predictors in statistical analyses, political beliefs was no longer associated with ToM. Dominance analysis revealed that participant sex was the most important predictor of ToM. These findings help to address theoretical discrepancies in the existing literature and inform future methods and directions in social cognition research.

Designing evidence-based support aids for social media access for individuals with moderate-severe traumatic brain injury: A preliminary acceptability study

Background

Adults with traumatic brain injury (TBI) report significant barriers to using current social media platforms, including cognitive overload and challenges in interpreting social cues. Rehabilitation providers may be tasked with helping to address these barriers.

Objectives

To develop technological supports to increase social media accessibility for people with TBI-related cognitive impairments and to obtain preliminary data on the perceived acceptability, ease of use, and utility of proposed technology aids.

Methods

We identified four major barriers to social media use among individuals with TBI: sensory overload, memory impairments, misreading of social cues, and a lack of confidence to actively engage on social media platforms. We describe the process of developing prototypes of support aids aimed at reducing these specific social media barriers. We created mock-ups of these prototypes and asked 46 community-dwelling adults with TBI (24 females) to rate the proposed aids in terms of their acceptability, ease of use, and utility.

Results

Across all aids, nearly one-third of respondents agreed they would use the proposed aids frequently, and the majority of respondents rated the proposed aids as easy to use. Respondents indicated that they would be more likely to use the memory and post-writing aids than the attention and social cue interpretation aids.

Conclusions

Findings provide initial support for social-media-specific technology aids to support social media access and social participation for adults with TBI. Results from this study have design implications for future development of evidence-based social media support aids. Future work should develop and deploy such aids and investigate user experience.

The epidemiology of pediatric traumatic brain injury presenting at a referral center in Moshi, Tanzania

Background

Over 95% of childhood injury deaths occur in low- and middle-income countries (LMICs). Patients with severe traumatic brain injury (TBI) have twice the likelihood of dying in LMICs than in high-income countries (HICs). In Africa, TBI estimates are projected to increase to upwards of 14 million new cases in 2050; however, these estimates are based on sparse data, which underscores the need for robust injury surveillance systems. We aim to describe the clinical factors associated with morbidity and mortality in pediatric TBI at the Kilimanjaro Christian Medical Centre (KCMC) in Moshi, Tanzania to guide future prevention efforts.

Methods

We conducted a secondary analysis of a TBI registry of all pediatric (0–18 years of age) TBI patients presenting to the KCMC emergency department (ED) between May 2013 and April 2014. The variables included demographics, acute treatment and diagnostics, Glasgow Coma Scores (GCSs, severe 3–8, moderate 9–13, and mild 14–15), morbidity at discharge as measured by the Glasgow Outcome Scale (GOS, worse functional status 1–3, better functional status 4–6), and mortality status at discharge. The analysis included descriptive statistics, bivariable analysis and multivariable logistic regression to report the predictors of mortality and morbidity. The variables used in the multivariable logistic regression were selected according to their clinical validity in predicting outcomes.

Results

Of the total 419 pediatric TBI patients, 286 (69.3%) were male with an average age of 10.12 years (SD = 5.7). Road traffic injury (RTI) accounted for most TBIs (269, 64.4%), followed by falls (82, 19.62%). Of the 23 patients (5.58%) who had alcohol-involved injuries, most were male (3.6:1). Severe TBI occurred in 54 (13.0%) patients. In total, 90 (24.9%) patients underwent TBI surgery. Of the 21 (5.8%) patients who died, 11 (55.0%) had severe TBI, 6 (30.0%) had moderate TBI (GCS 9–13) and 3 (15.0%) presented with mild TBI (GCS>13). The variables most strongly associated with worse functional status included having severe TBI (OR = 9.45) and waiting on the surgery floor before being moved to the intensive care unit (ICU) (OR = 14.37).

Conclusions

Most pediatric TBI patients were males who suffered RTIs or falls. Even among children under 18 years of age, alcohol was consumed by at least 5% of patients who suffered injuries, and more commonly among boys. Patients becoming unstable and having to be transferred from the surgery floor to the ICU could reflect poor risk identification in the ED or progression of injury severity. The next steps include designing interventions to reduce RTI, mitigate irresponsible alcohol use, and improve risk identification and stratification in the ED.

An Examination of Social Inferencing Skills in Males and Females Following Traumatic Brain Injury

OBJECTIVE

This study examines sex differences in social inferencing deficits after traumatic brain injury (TBI), and examines the odds of males and females being impaired while controlling for potential confounders.

DESIGN

Cross-sectional survey.

SETTING

Outpatient.USA and a University in Canada.

PARTICIPANTS

One hundred five participants with TBI (60 males, 45 females) and 105 healthy controls (HC; 57 males, 48 females).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The Awareness of Social Inference Test (TASIT), which includes 1) Emotional Evaluation Test (EET), 2) Social Inference-Minimal (SI-M) test, and 3) Social Inference-Enriched (SI-E) test.

RESULTS

Within the HC sample, males and females performed similarly on all three TASIT subtests. Within the TBI group, males had significantly lower scores than females on EET (P = 0.03), SI-M (P=0.01) and SI-E (P=0.04). Using impairment cutoffs derived from the HC sample, significantly more males with TBI (30%) were impaired on the EET than females(16.7%); impairment was similar between males and females on SI-M and SI-E. When adjusting for executive functioning and education, the odds of being impaired on the EET did not significantly differ for males and females (OR = 0.47; 95% CI: 0.16 - 1.40; P = 0.18).

CONCLUSIONS

While more males with TBI have emotion perception deficits than females, the difference appears to be driven by education and executive functioning. Research is needed in larger samples with more definitive norms to better understand social inferencing impairments in males and females with TBI, and translation to interpersonal behaviors.

Unravelling moral cognition in acquired brain injury: a scoping review

Background:

Acquired brain injury (ABI) is accompanied by impairments in social, emotional, cognitive and behavioural skills and highly prevalent in the population. Social and emotional skills are crucial for moral cognition, but the extent to which moral cognition contributes to social competence deficits in people with ABI is largely unclear.

Method:

To provide more insight on this topic, we conducted a scoping review according to the PRISMA guidelines. After screening 1269 articles that we obtained via PubMed and Scopus, we found 27 articles on moral cognition in ABI.

Results:

We encountered four important topics across these studies which include traumatic brain injury (TBI) versus non-TBI, the influence of the different approaches used to measure moral cognition in ABI, the role of age of onset and the role of location of the injury. Overall, evidence suggests that the earlier the brain damage occurred, the more this leads to impairments in moral cognitive functioning. The location of the injury furthermore seems to differentially affect the way impairments are manifested. Finally, we found that the use of different measurement approaches can heavily influence the interpretation of the impairment.

Conclusion:

We conclude that impairments in moral cognition in people with ABI are derived from a complex interplay between the age of onset, the location and the approach used to index moral cognition.

Understanding Traumatic Brain Injury in Females: A State-of-the-Art Summary and Future Directions

In this report, we identify existing issues and challenges related to research on traumatic brain injury (TBI) in females and provide future directions for research. In 2017, the National Institutes of Health, in partnership with the Center for Neuroscience and Regenerative Medicine and the Defense and Veterans Brain Injury Center, hosted a workshop that focused on the unique challenges facing researchers, clinicians, patients, and other stakeholders regarding TBI in women. The goal of this "Understanding TBI in Women" workshop was to bring together researchers and clinicians to identify knowledge gaps, best practices, and target populations in research on females and/or sex differences within the field of TBI. The workshop, and the current literature, clearly highlighted that females have been underrepresented in TBI studies and clinical trials and have often been excluded (or ovariectomized) in preclinical studies. Such an absence in research on females has led to an incomplete, and perhaps inaccurate, understanding of TBI in females. The presentations and discussions centered on the existing knowledge regarding sex differences in TBI research and how these differences could be incorporated in preclinical and clinical efforts going forward. Now, a little over 2 years later, we summarize the issues and state of the science that emerged from the "Understanding TBI in Women" workshop while incorporating updates where they exist. Overall, despite some progress, there remains an abundance of research focused on males and relatively little explicitly on females.

Theory of mind in adults with traumatic brain injury: A meta-analysis

Studies of abnormal theory of mind (ToM) performance in adult patients with traumatic brain injury (TBI) have reported inconsistent results. Therefore, we conducted a meta-analysis to characterize ToM performance in adult patients with TBI. Random-effects models were employed to estimate the overall effect size and the differential effect sizes across different ToM aspects. Based on a sample of 28 studies (1031 patients and 865 healthy controls), the meta-analytic findings revealed that ToM was significantly impaired in adult patients with TBI compared to healthy controls (g = -1.13). Besides, patients with TBI showed significant impairments in individual ToM tasks, as well as for different stimulus modes and contents involved in these ToM tasks. A meta-regression indicated a positive association between ToM performance and Glasgow Coma Scale score. The results of the current meta-analysis suggest that the performance in ToM tasks may be a good predictor of functional outcomes in adults with TBI, which is important for the identification of targets for cognitive interventions and the development of useful training intervention programs.

Sex-based differences in expectations for social communication after TBI

Sex-based differences have been reported in several TBI outcome studies, including studies of social functioning. In some studies, social outcomes have been evaluated via perceptual judgments on questionnaires, which may be influenced by stereotypes about acceptable behaviour for men and women. To explore potential sex-based rater bias in social judgments, we asked 68 typical undergraduates (34 women) to identify problematic behaviour for men vs. women on a widely used questionnaire for TBI social outcome, the LaTrobe Communication Questionnaire. Results revealed more consensus among raters of both sexes about acceptable behaviours for men than behaviours for women, and women were more critical than men when judging persons of either sex. These findings support the importance of considering sex in TBI social outcome research, past and future, not only sex of the participant but also sex of the person judging social outcome. Sex-based differences here also have implications for social evaluations in clinic, where female clinicians are often judging male patients. Future research should consider gender (the social construct), as well as sex (the biological construct), as both may contribute to perceived social outcome after TBI.

Anosognosia for theory of mind deficits: A single case study and a review of the literature

Being aware of one's own ability to interact socially is crucial to everyday life. After a brain injury, patients may lose their capacity to understand others' intentions and beliefs, that is, the Theory of Mind (ToM). To date, the debate on the association between ToM and other cognitive deficits (in particular executive functions and behavioural disorders) remains open and data regarding awareness of ToM deficits are meagre. By means of an ad-hoc neuropsychological battery of tests, we report on a patient who suffers from ToM deficits and is not aware of these disorders, although aware of his other symptoms. The study is accompanied by a review of the literature (PRISMA guidelines) demonstrating that ToM deficits are independent of executive functions. Furthermore, an advanced lesion analysis including tractography was executed. The results indicate that: i) ToM deficits can be specific and independent of other cognitive symptoms; ii) unawareness may be specific for ToM impairment and not involve other disorders and iii) the medial structures of the limbic, monitoring and attentional systems may be involved in anosognosia for ToM impairment.

Cognitive and Affective Theory of Mind in Healthy Aging

BACKGROUND

Previous studies on the effect of healthy aging on Theory of Mind (ToM) have produced mixed results. A possible explanation may be that different ToM components and types of inference have not systematically been considered. This study examined the effect of aging on ToM by assessing both first and second order cognitive and affective components within a single task.

METHODS

We compared performance of young (M = 18.3y) and older adults (M = 61.0y) on the Yoni task. This task allows for a within-subject assessment of both first and second order cognitive and affective ToM.

RESULTS

We observed that older adults had longer reaction times than young adults across cognitive and affective first order items. For second order items, this age difference was larger for affective than cognitive items. Results showed no indications that these findings could be explained by age differences in speed/accuracy trade-offs.

CONCLUSION

Our findings suggest that decision processes underlying ToM are slower in older adults on both first and second order inferences, but that age differences in these processes between cognitive and affective ToM are selective to second order inferences. We propose that the observed age differences may be associated with cortical and mental changes that occur with aging.

Sex and Gender Differences in Emotion Recognition and Theory of Mind After TBI: A Narrative Review and Directions for Future Research

A growing body of literature has examined sex differences in a variety of outcomes from moderate-severe traumatic brain injury (TBI), including outcomes for social functioning. Social functioning is an area in which adults with TBI have significant long-term challenges (1-4), and a better understanding of sex and gender differences in this domain may have a significant clinical impact. This paper presents a brief narrative review of current evidence regarding sex differences in one aspect of social functioning in adults with TBI: social cognition, specifically affect recognition and Theory of Mind (ToM). Data from typical adults and adults with TBI are considered in the broader context of common stereotypes about social skills and behaviors in men vs. women. We then discuss considerations for future research on sex- and gender-based differences in social cognition in TBI, and in adults more generally.

Theory of Mind Impairments Highlighted With an Ecological Performance-Based Test Indicate Behavioral Executive Deficits in Traumatic Brain Injury

Background: In view of the recent literature, the negative impact of traumatic brain injury (TBI) on social cognition remains a debated issue. On one hand, a considerable number of studies reported significant impairments in emotion recognition, empathy, moral reasoning, social problem solving, and mentalizing or theory of mind (ToM) abilities in patients with TBI. On the other hand, the ecological validity of social cognition tasks is still a matter of concern and debate for clinicians and researchers.

Objectives: The objectives of the present study were 2-fold: (1) to assess social cognition in TBI with an ecological performance-based test which focuses on ToM ability, and (2) to study the relationship between performances on this task and behavioral disorders. To this end, 47 patients with moderate to severe TBI in the chronic stage were assessed with a ToM task, the Movie for the Assessment of Social Cognition (MASC), a film displaying social interactions in natural settings and asking for an evaluation of the emotions, thoughts, and intentions of the characters. Behavioral disorders were assessed with the Behavioral Dysexecutive Syndrome Inventory (BDSI), a structured interview of an informant in assessing changes compared with previous behavior in 12 domains.

Results: Patients were significantly less accurate in mental state attribution than a demographically matched group of 38 healthy control subjects. Significant others of patients also reported more behavioral executive problems than controls' relatives on most of the domains of the BDSI. In addition, social cognition performance in the MASC was significantly correlated with behavioral dysexecutive problems rated by proxies on the BDSI.

Conclusions: This study is the first to find association between impairments in mentalizing abilities in the MASC and behavioral impairments in patients with TBI, confirming the added value of this ecological task and that the recognition of social signals is a key element for adequate behavioral functioning.

"To whom did I tell that information?": Relationship between destination memory and theory of mind in traumatic brain injury

Traumatic Brain Injury (TBI) has been widely associated with impairment of social cognition. We therefore investigated the relationship between the ability to infer and predict other's mental states (i.e., Theory of Mind, ToM) and the ability to remember to whom one has sent information (i.e., destination memory). We invited patients with TBI and control subjects, on a destination memory task, to tell proverbs to pictures of celebrities, so as to remember to which celebrity they had previously told the proverbs. Participants also performed affective (i.e., Reading the Mind in the Eyes) and cognitive (i.e., the false belief) tests of ToM. Results demonstrated lower destination memory, affective, and cognitive ToM performance in TBI patients than in control subjects. Critically, analysis demonstrated significant positive correlations between destination memory and first order and second cognitive order ToM in patients with TBI, but no significant correlations between destination memory and affective ToM in these patients. Our results demonstrate a relationship between difficulties of TBI patients to infer and predict cognitive states of interlocutors and difficulties to remember to which interlocutor information has been told.

Lonely But Not Alone: Neuroticism Mediates the Relationship Between Social Network Size and Loneliness in Individuals With Traumatic Brain Injury

Objectives: Although individuals with traumatic brain injury (TBI) often report higher levels of social isolation, little is known about the factors influencing their self-perception of loneliness. The aim of the current study was to investigate the relationship between loneliness, social network size, and personality variables (neuroticism and extraversion) after TBI, and in particular whether specific personality variables mediate the relationship between social network size and perception of loneliness. Methods: Here, we assessed self-reported loneliness, personality variables, and social network size of 24 individuals with moderate-to-severe TBI and 41 healthy comparison participants. We then carried out a mediation analysis to examine whether personality variables mediated the relationship between loneliness and social network size. Results: Our results indicate that individuals with TBI reported higher levels of loneliness and neuroticism, but there was no group difference in social network size or extraversion. The mediation analysis revealed that the association between social network size and loneliness was mediated by neuroticism, but not by extraversion. Conclusions: Our findings show that neuroticism is an intervening variable in the relationship between social network size and self-perception of loneliness in individuals with moderate-to-severe TBI, and presents a new possible target for clinicians and rehabilitators seeking to address reports of loneliness and social isolation in TBI. (JINS 2019, 25, 266-274).

Do executive function and theory of mind predict pragmatic abilities following traumatic brain injury? An analysis of sincere, deceitful and ironic communicative acts

Quality of life and social integration are strongly influenced by the ability to communicate and previous research has shown that pragmatic ability can be specifically impaired in individuals with traumatic brain injury (TBI). In addition, TBI usually results in damage to the frontotemporal lobes with a consequent impairment of cognitive functions, i.e., attention, memory, executive function (EF) and theory of mind (ToM). The role of the underlying cognitive deficits in determining the communicative-pragmatic difficulties of an individual with TBI is not yet completely clear. This study examined the relationship between the ability to understand and produce various kinds of communicative acts, (i.e., sincere, deceitful and ironic) and the above-mentioned cognitive and ToM abilities following TBI. Thirty-five individuals with TBI and thirty-five healthy controls were given tasks assessing their ability to comprehend and produce sincere, deceitful and ironic communicative acts belonging to the linguistic and extralinguistic scales of the Assessment Battery for Communication (ABaCo), together with a series of EF and ToM tasks. The results showed that, when compared to healthy individuals, participants with TBI performed poorly overall in the comprehension and production of all the pragmatic phenomena investigated, (i.e., sincere, deceitful and ironic communicative acts), and they also exhibited impaired performance at the level of all the cognitive functions examined. Individuals with TBI also showed a decreasing trend in performance in dealing with sincere, deceitful and ironic communicative acts, on both the comprehension and production subscales of the linguistic and extralinguistic scales. Furthermore, a hierarchical regression analysis revealed that - in patients with TBI but not in the controls - EF had a significant effect on the comprehension of linguistic and extralinguistic irony only, while the percentage of explained variance increased with the inclusion of theory of mind. Indeed, ToM had a significant role in determining patients' performance in the extralinguistic production of sincere and deceitful communicative acts, linguistic and extralinguistic comprehension of deceit and the linguistic production of irony. However, with regard to the performance of patients with TBI in the various pragmatic tasks investigated, (i.e., sincere, deceitful and ironic communicative acts), EF was able to explain the pattern of patients' scores in the linguistic and extralinguistic comprehension but not in production ability. Furthermore, ToM seemed not to be able to explain the decreasing trend in the performance of patients in managing the various kinds of communicative acts investigated.

Theory of Mind after Severe Acquired Brain Injury: Clues for Interpretation

Background. Recently, increased interest has been shown in Theory of Mind (ToM) abilities of individuals with severe acquired brain injury (sABI). ToM impairment following sABI can be associated with altered executive functioning and/or with difficulty in decoding and elaborating emotions. Two main theoretical models have been proposed to explain the mechanisms underlying ToM in the general population: Theory Theory and Simulation Theory. This review presents and discusses the literature on ToM abilities in individuals with sABI by examining whether they sustain the applicability of the Theory Theory and/or Simulation Theory to account for ToM deficits in this clinical population. We found 32 papers that are directly aimed at investigating ToM in sABI. Results did not show the univocal predominance of one model with respect to the other in explaining ToM deficits in sABI. We hypothesised that ToM processes could be explained by coinvolvement of the two models, i.e., according to personal experience, cognitive features, or the emotional resources of the persons with sABI.