Language and alexithymia: Evidence for the role of the inferior frontal gyrus in acquired alexithymia

Studying the social mind: An updated summary of findings from the Vietnam Head Injury Study

Lesion mapping studies allow us to evaluate the potential causal contribution of specific brain areas to human cognition and complement other cognitive neuroscience methods, as several authors have recently pointed out. Here, we present an updated summary of the findings from the Vietnam Head Injury Study (VHIS) focusing on the studies conducted over the last decade, that examined the social mind and its intricate neural and cognitive underpinnings. The VHIS is a prospective, long-term follow-up study of Vietnam veterans with penetrating traumatic brain injury (pTBI) and healthy controls (HC). The scope of the work is to present the studies from the latest phases (3 and 4) of the VHIS, 70 studies since 2011, when the Raymont et al. paper was published (Raymont et al., 2011). These studies have contributed to our understanding of human social cognition, including political and religious beliefs, theory of mind, but also executive functions, intelligence, and personality. This work finally discusses the usefulness of lesion mapping as an approach to understanding the functions of the human brain from basic science and clinical perspectives.

Leptin's Inverse Association with Brain Morphology and Depressive Symptoms - A Discovery and Confirmatory Study Across Two Independent Samples

BACKGROUND

Major Depressive Disorder (MDD) has a complex, bi-directional relationship with metabolic dysfunction, yet the neural correlates of this association are not well understood.

METHOD

In this cross-sectional investigation, we employed a two-step 'discovery and confirmatory' strategy, utilizing two independent samples (Sample 1: 288 participants, Sample 2: 196 participants) to examine the association between circulating indicators of metabolic health (leptin and adiponectin) and brain structures in individuals with MDD.

RESULTS

We found a replicable inverse correlation between leptin levels and cortical surface area within essential brain areas responsible for emotion regulation, such as the left posterior cingulate cortex, right pars orbitalis, right superior temporal gyrus, and right insula (standardized beta coefficient (SBC) ranged: -0.27 to -0.49, puncorrected <0.05). Notably, this relationship was independent of C-Reactive Protein levels. We also identified a significant interaction effect of leptin levels and diagnosis on the cortical surface area of the right superior temporal gyrus (SBC = 0.26 in sample 1, SBC = 0.30 in sample 2, puncorrected < 0.05). We also observed a positive correlation between leptin levels and atypical depressive symptoms in both MDD groups (r = 0.14 in sample 1, r = 0.29 in sample 2, puncorrected < 0.05).

CONCLUSION

The inverse association between leptin and cortical surface area in brain regions that are important for emotion processing and leptin's association with sleep disturbances supports the hypothesis that metabolic processes may be related to emotion regulation. However, the molecular mechanisms through which leptin might exert these effects should be explored further.

Alexithymia modulates emotion concept activation during facial expression processing

Alexithymia is characterized by difficulties in emotional information processing. However, the underlying reasons for emotional processing deficits in alexithymia are not fully understood. The present study aimed to investigate the mechanism underlying emotional deficits in alexithymia. Using the Toronto Alexithymia Scale-20, we recruited college students with high alexithymia (n = 24) or low alexithymia (n = 24) in this study. Participants judged the emotional consistency of facial expressions and contextual sentences while recording their event-related potentials. Behaviorally, the high alexithymia group showed longer response times versus the low alexithymia group in processing facial expressions. The event-related potential results showed that the high alexithymia group had more negative-going N400 amplitudes compared with the low alexithymia group in the incongruent condition. More negative N400 amplitudes are also associated with slower responses to facial expressions. Furthermore, machine learning analyses based on N400 amplitudes could distinguish the high alexithymia group from the low alexithymia group in the incongruent condition. Overall, these findings suggest worse facial emotion perception for the high alexithymia group, potentially due to difficulty in spontaneously activating emotion concepts. Our findings have important implications for the affective science and clinical intervention of alexithymia-related affective disorders.

Neural correlates of perceptual switching and their association with empathy and alexithymia in individuals with and without autism spectrum disorder

Individuals with autism spectrum disorder (ASD) often show limited empathy (poor recognition of others' emotions) and high alexithymia (poor recognition of own emotions and external thinking), which can negatively impact their social functioning. Previous experimental studies suggest that alterations in cognitive flexibility play key roles in the development of these characteristics in ASD. However, the underlying neural mechanisms that link cognitive flexibility and empathy/alexithymia are still largely unknown. In this study, we examined the neural correlates of cognitive flexibility via functional magnetic resonance imaging during perceptual task-switching in typical development (TD) adults and adults with ASD. We also investigated associations between regional neural activity and psychometric empathy and alexithymia scores among these populations. In the TD group, stronger activation of the left middle frontal gyrus was associated with better perceptual switching and greater empathic concern. Among individuals with ASD, stronger activation of the left inferior frontal gyrus was associated with better perceptual switching, greater empathy, and lower alexithymia. These findings will contribute to develop a better understanding of social cognition, and could be informative for the development of new ASD therapies.

The relationship between alexithymia, interoception, and neural functional connectivity during facial expression processing in autism spectrum disorder

Neural processing differences of emotional facial expressions, while common in autism spectrum disorder (ASD), may be related to co-occurring alexithymia and interoceptive processing differences rather than autism per se. Here, we investigate relationships between alexithymia, interoceptive awareness of emotions, and functional connectivity during observation of facial expressions in youth (aged 8-17) with ASD (n = 28) compared to typically developing peers (TD; n = 37). Behaviorally, we found no significant differences between ASD and TD groups in interoceptive awareness of emotions, though alexithymia severity was significantly higher in the ASD group. In the ASD group, increased alexithymia was significantly correlated with lower interoceptive sensation felt during emotion. Using psycho-physiological interaction (PPI) analysis, the ASD group showed higher functional connectivity between the left ventral anterior insula and the left lateral prefrontal cortex than the TD group when viewing facial expressions. Further, alexithymia was associated with reduced left anterior insula-right precuneus connectivity and reduced right dorsal anterior insula-left ventral anterior insula connectivity when viewing facial expressions. In the ASD group, the degree of interoceptive sensation felt during emotion was positively correlated with left ventral anterior insula-right IFG connectivity when viewing facial expressions. However, across all participants, neither alexithymia nor interoceptive awareness of emotions predicted connectivity between emotion-related brain regions when viewing emotional facial expressions. To summarize, we found that in ASD compared to TD: 1) there is stronger connectivity between the insula and lateral prefrontal cortex; and 2) differences in interhemispheric and within left hemisphere connectivity between the insula and other emotion-related brain regions are related to individual differences in interoceptive processing and alexithymia. These results highlight complex relationships between alexithymia, interoception, and brain processing in ASD.

Speech, language and communication needs and mental health: the experiences of speech and language therapists and mental health professionals

BACKGROUND

While the relationship between speech, language and communication needs (SLCN) and mental health difficulties has been recognized, speech and language therapists (SLTs), and mental health professionals face challenges in assessing and treating children with these co-occurring needs. There exists a gap in the evidence base for best practice for professionals working with children and young people (CYP) who experience difficulties in both areas.

AIMS

To explore the views of SLTs and mental health clinicians about their experiences of working with CYP exhibiting co-occurring SLCN and mental health difficulties.

METHODS & PROCEDURES

Semi-structured interviews were conducted with eight SLTs and six mental health professionals, including psychotherapists, clinical psychologists, play therapists and counsellors, with experience working with CYP with SLCN. Interviews were analysed using reflexive thematic analysis and themes were identified from the data.

OUTCOMES & RESULTS

Participants felt that SLCN and mental health difficulties frequently co-occur. Participants described how CYP with SLCN and mental health issues commonly experience difficulties across and between the domains of language and cognition, emotional well-being and challenging behaviour. Findings suggest that there are organizational limitations in the fields of SLT and mental health that have implications for the efficacy of assessment and treatment of CYP with SLCN and mental health difficulties. Traditional talking therapies were perceived to be inaccessible and ineffective for CYP with SLCN and mental health difficulties. Interventions blending behaviour and emotion programmes with language and communication interventions were considered potentially beneficial.

CONCLUSIONS & IMPLICATIONS

Future research should explore and evaluate current services and service set-up in SLT and mental health. The findings from this study have important implications for the efficacy of treatments provided to this population suggesting that more research needs to be done into effective diagnosis and interventions for this population.

WHAT THIS PAPER ADDS

What is already known on the subject Research suggests that CYP with SLCN, such as developmental language disorder (DLD), are likely to experience mental health difficulties including depression, anxiety and poor emotional well-being. CYP who experience difficulties with SLCN and poor mental health are not well understood and this area remains under-researched. This has implications for clinician knowledge and therefore the effective diagnosis and treatment of children and adolescents experiencing SLCN and mental health difficulties. In addition, little is known about the accessibility of talking therapies to CYP presenting with SLCN and mental health difficulties. What this paper adds to existing knowledge SLCN issues are understood by SLTs and mental health issues are understood by mental health professionals, but where these co-occur difficulties exist for the diagnostic process, with professionals perceiving that CYP in this category are often undiagnosed or misdiagnosed. Organizational boundaries between SLT and mental health were perceived to contribute to a lack of understanding of SLCN and mental health needs, which has implications for effective diagnosis and treatment. Traditional talking therapies were thought to be inaccessible for CYP with SLCN and mental health difficulties. Interventions used in both SLT and psychotherapy were perceived as clinically useful if combined. What are the potential or actual clinical implications of this work? This paper highlights implications for the accessibility and efficacy of the assessment and treatment provided to this population and to the organization of services currently treating this group of CYP. A direction for future research would be to undertake service evaluations and intervention-based studies.

Furthering the language hypothesis of alexithymia: An integrated review and meta-analysis

Alexithymia, including the inability to identify and express one's own feelings, is a subclinical condition responsible for some of the socioemotional symptoms seen across a range of psychiatric conditions. The language hypothesis of alexithymia posits a language-mediated disruption in the development of discrete emotion concepts from ambiguous affective states, exacerbating the risk of developing alexithymia in language-impaired individuals. To provide a critical evaluation, a systematic review and meta-analysis of 29 empirical studies of language functioning in alexithymia was performed. A modest association was found between alexithymia and multi-domain language deficits (r = -0.14), including structural language, pragmatics, and propensity to use emotional language. A more theoretically-relevant subsample analysis comparing alexithymia levels in language-impaired and typical individuals revealed larger effects, but a limited number of studies adopted this approach. A synthesis of 11 emotional granularity studies also found an association between alexithymia and reduced emotional granularity (r = -0.10). Language impairments seem to increase the risk of alexithymia. Heterogeneous samples and methods suggest the need for studies with improved alexithymia assessments.

Interindividual differences in interoception modulate behavior and brain responses in emotional inference

Emotional experiences are proposed to arise from contextualized perception of bodily responses, also referred to as interoceptive inferences. The recognition of emotions benefits from adequate access to one's own interoceptive information. However, direct empirical evidence of interoceptive inferences and their neural basis is still lacking. In the present fMRI study healthy volunteers performed a probabilistic emotion classification task with videotaped dynamically unfolding facial expressions. In a first step, we aimed to determine functional areas involved in the processing of dynamically unfolding emotional expressions. We then tested whether individuals with higher interoceptive accuracy (IAcc), as assessed by the Heartbeat detection task (HDT), or higher interoceptive sensitivity (IS), as assessed by the Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), benefit more from the contextually given likelihood of emotional valence and whether brain regions reflecting individual IAcc and/or IS play a role in this. Individuals with higher IS benefitted more from the biased probability of emotional valence. Brain responses to more predictable emotions elicited a bilateral activity pattern comprising the inferior frontal gyrus and the posterior insula. Importantly, individual IAcc scores positively covaried with brain responses to more surprising and less predictable emotional expressions in the insula and caudate nucleus. We show for the first time that IAcc score is associated with enhanced processing of interoceptive prediction errors, particularly in the anterior insula. A higher IS score seems more likely to be associated with a stronger weighting of attention to interoceptive changes processed by the posterior insula and ventral prefrontal cortex.

High-definition transcranial direct current stimulation modulates eye gaze on emotional faces in college students with alexithymia: An eye-tracking study

BACKGROUND

Atypical eye gaze on emotional faces is a core feature of alexithymia. The inferior frontal gyrus (IFG) is considered to be the neurophysiological basis of alexithymia-related emotional face fixation. Our aim was to examine whether anodal high-definition transcranial direct current stimulation (HD-tDCS) administered to the right (r)IFG would facilitate eye gaze of emotional faces in alexithymia individuals.

METHOD

Forty individuals with alexithymia were equally assigned to anodal or sham HD-tDCS of the rIFG according to the principle of randomization. The individuals then completed a free-viewing eye tracking task (including happy, sad, and neutral faces) before and after 5 consecutive days of stimulation (twice a day).

RESULTS

The results showed that twice a day anodal HD-tDCS of the rIFG significantly increased the fixation time and fixation count of the eye area on happy and neutral faces, but there was no significant effect on sad faces. According to the temporal-course analysis, after the intervention, the fixation time on neutral faces increased significantly at almost all time points of the eye tracking task. For happy faces, the improvement was demonstrated between 500 and 1000 ms and between 2500 and 3500 ms. For sad faces, the fixation time improved but not significantly.

CONCLUSIONS

Applying high-dose anodal HD-tDCS to the rIFG selectively facilitated eye gaze in the eye area of neutral and happy faces in individuals with alexithymia, which may improve their face processing patterns.

Alexithymia in autism: cross-sectional and longitudinal associations with social-communication difficulties, anxiety and depression symptoms

BACKGROUND

Alexithymia (difficulties in identifying and describing emotion) is a transdiagnostic trait implicated in social-emotional and mental health problems in the general population. Many autistic individuals experience significant social-communication difficulties and elevated anxiety/depression and alexithymia. Nevertheless, the role of alexithymia in explaining individual variability in the quality/severity of social-communication difficulties and/or anxiety and depression symptoms in autism remains poorly understood.

METHODS

In total, 337 adolescents and adults (autism N = 179) were assessed for alexithymia on the Toronto Alexithymia Scale and for social-communication difficulties, anxiety and depression symptoms. A total of 135 individuals (autism N = 76) were followed up 12-24 months later. We used regression models to establish cross-sectional and longitudinal associations between alexithymia, social-communication difficulties, anxiety and depression symptoms.

RESULTS

Autistic individuals reported significantly higher alexithymia than comparison individuals (p < 0.001, r effect size = 0.48), with 47.3% of autistic females and 21.0% of autistic males meeting cut-off for clinically relevant alexithymia (score ⩾61). Difficulties in describing feelings were particularly associated with current self-reported social-communication difficulties [p < 0.001, β = 0.57, 95% confidence interval (CI) 0.44-0.67] and predicted later social-communication difficulties (p = 0.02, β = 0.43, 95% CI 0.07-0.82). Difficulties in identifying feelings were particularly associated with current anxiety symptom severity (p < 0.001, β = 0.54, 95% CI 0.41-0.77) and predicted later anxiety (p = 0.01; β = 0.31, 95% CI 0.08-0.62).

CONCLUSIONS

Our findings suggest that difficulties in identifying v. describing emotion are associated with differential clinical outcomes in autism. Psychological therapies targeting emotional awareness may improve social-communication and anxiety symptoms in autism, potentially conferring long-term benefits.

The process of emotion identification: Considerations for psychiatric disorders

Emotional regulation is important for mental health and behavioral regulation. A relevant precursor to emotional regulation may involve identification of one's emotions. Here, we propose a model of seven components that may provide a foundation for emotion identification. These factors include baseline mood, monitoring, physiological responses, interoception, past personal experiences regarding emotions/metacognition, context, and labeling. We additionally examine how deficits in different components may contribute to the concept of alexithymia, which is defined by difficulty identifying and describing one's own emotions. Ultimately, we explore how the model may support a relationship between specific psychiatric disorders and alexithymia. The proposed model may help explain emotional identification impairment in multiple psychiatric disorders and guide future research and treatment development efforts.

Consumers in the Face of COVID-19-Related Advertising: Threat or Boost Effect?

The COVID-19 pandemic has prompted the production of a vast amount of COVID-19-themed brand commercials, in an attempt to exploit the salience of the topic to reach more effectively the consumers. However, the literature has produced conflicting findings of the effectiveness of negative emotional contents in advertisings. The present study aims at exploring the effect of COVID-19-related contents on the hemodynamic brain correlates of the consumer approach or avoidance motivation. Twenty Italian participants were randomly assigned to two different groups that watched COVID-19-related or non-COVID-19-related commercials. The hemodynamic response [oxygenated (O₂Hb) and deoxygenated hemoglobin modulations] within the left and right prefrontal cortices (PFC) was monitored with Functional Near-Infrared Spectroscopy (fNIRS) while brand commercials were presented, as the prefrontal lateralization was shown to be indicative of the attitude toward the brand and of the approach-avoidance motivation. First, the findings showed that the COVID-19-related contents were able to prompt emotional processing within the PFC to a higher extent compared to contents non-related to COVID-19. Moreover, the single-channel analysis revealed increased O₂Hb activity of the left dorsolateral PFC compared to the left pars triangularis Broca’s area in the group of participants that watched the COVID-19-related commercials, suggesting that the commercials may have driven participants to dedicate more attention toward the processing of the emotional components compared to the semantic meaning conveyed by the ad. To conclude, despite expressing unpleasant emotions, commercials referring to the highly emotional pandemic experience may benefit the advertising efficacy, increasing the capability to reach customers.

Neural correlates of compassion - An integrative systematic review

Compassion is a psychological construct that has received increasing attention in recent years. Even though a lot of work has been done to identify neural correlates of empathy across studies, such work has not been properly done on neural correlates of compassion. Therefore, the aim was to systematically review the literature on neural correlates of compassion. We have searched through PsycINFO, PubMed and Web of Science for relevant articles published between 1985 and 2020. We included the studies (n = 35) examining the relationship between brain structure or function and compassion. Screening was performed by two authors, between whom a level of agreement was calculated. The quality of the studies was assessed by measures used in other studies as well by measures specific for our study aims. This study was conducted under PRISMA guidelines. Our analysis revealed that the most frequent neural associations with compassion across all analysed studies can be found in the orbital part of the left inferior frontal gyrus, in the right cerebellum, the bilateral middle temporal gyrus, in the bilateral insula and the right caudate nucleus. Our findings suggest that people displaying a lower compassion tend to have either lower neural activity or a grey matter volume in neural areas associated with reward.

Atypical interoception as a common risk factor for psychopathology: A review

The inadequacy of a categorial approach to mental health diagnosis is now well-recognised, with many authors, diagnostic manuals and funding bodies advocating a dimensional, trans-diagnostic approach to mental health research. Variance in interoception, the ability to perceive one's internal bodily state, is reported across diagnostic boundaries, and is associated with atypical functioning across symptom categories. Drawing on behavioural and neuroscientific evidence, we outline current research on the contribution of interoception to numerous cognitive and affective abilities (in both typical and clinical populations), and describe the interoceptive atypicalities seen in a range of psychiatric conditions. We discuss the role that interoception may play in the development and maintenance of psychopathology, as well as the ways in which interoception may differ across clinical presentations. A number of important areas for further research on the role of interoception in psychopathology are highlighted.

The relationship between alexithymia and theory of mind: A systematic review

Theory of Mind (ToM), the ability to represent the mental states of oneself and others, is an essential social skill disrupted across many psychiatric conditions. The transdiagnostic nature of ToM impairment means it is plausible that ToM impairment is related to alexithymia (difficulties identifying and describing one's own emotions), as alexithymia is seen across psychiatric conditions. Whilst many studies have examined links between alexithymia and ToM, results are mixed. Therefore, the purpose of this systematic review is to provide a taxonomy of ToM tests and assess their relationship with alexithymia. Tests are grouped according to whether they assess propensity to engage spontaneously in ToM or accuracy of ToM inferences, with tests further subdivided into those that do, and do not, require emotion recognition. A review of 63 suitable studies suggests that alexithymia is often associated with reduced ToM, and inaccurate ToM when tasks require emotion recognition. This latter finding appears due to impaired emotion recognition, rather than ToM impairment per se. Further directions and considerations for future research are discussed.

Increased Global-Brain Functional Connectivity Is Associated with Dyslipidemia and Cognitive Impairment in First-Episode, Drug-Naive Patients with Bipolar Disorder

Objectives

Previous researches have demonstrated that abnormal functional connectivity (FC) is associated with the pathophysiology of bipolar disorder (BD). However, inconsistent results were obtained due to different selections of regions of interest in previous researches. This study is aimed at examining voxel-wise brain-wide functional connectivity (FC) alterations in the first-episode, drug-naive patient with BD in an unbiased way.

Methods

A total of 35 patients with BD and 37 age-, sex-, and education-matched healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI). Global-brain FC (GFC) was applied to analyze the image data. Support vector machine (SVM) was adopted to probe whether GFC abnormalities could be used to identify the patients from the controls.

Results

Patients with BD exhibited increased GFC in the left inferior frontal gyrus (LIFG), pars triangularis and left precuneus (PCu)/superior occipital gyrus (SOG). The left PCu belongs to the default mode network (DMN). Furthermore, increased GFC in the LIFG, pars triangularis was positively correlated with the triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) and negatively correlated with the scores of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) coding test and Stroop color. Increased GFC values in the left PCu/SOG can be applied to discriminate patients from controls with preferable sensitivity (80.00%), specificity (75.68%), and accuracy (77.78%).

Conclusions

This study found increased GFC in the brain regions of DMN; LIFG, pars triangularis; and LSOG, which was associated with dyslipidemia and cognitive impairment in patients with BD. Moreover, increased GFC values in the left PCu/SOG may be utilized as a potential biomarker to differentiate patients with BD from controls.

Evaluation of alexithymia in individuals with chronic pain in a Mexican population: Alexithymia in a Mexican population

INTRODUCTION

Alexithymia is the difficulty in identifying and describing feelings. Several studies have suggested that chronic pain can be linked to alexithymia. The aims of this study were to determine the presence of alexithymia in a sample of Mexican individuals who attended public health services, to assess if alexithymia is higher in medically ill individuals with pain than in those without pain, and to determine which alexithymia dimensions are more affected by the presence of pain.

METHODS

Demographic and clinical features were evaluated in 250 Mexican outpatients of the General Hospital of Comalcalco, Tabasco. Pain was evaluated using the Visual Analogue Scale for Pain Assessment (VAS-P) and alexithymia was evaluated using the Toronto Alexithymia Scale (TAS-20).

RESULTS

38.8% of the sample was identified with probable/definite alexithymia and up to 61.2% of individuals were currently experiencing pain. Individuals with pain exhibited higher scores in the TAS-20 dimensions: difficulty describing feelings (p = 0.02), difficulty identifying feelings (p < 0.001) and higher total TAS-20 score (p < 0.001). Also, Probable/definite alexithymia was more frequently reported in individuals with pain (49% vs. 21.6%, p < 0.001).

CONCLUSIONS

Our results show that a large proportion of individuals who attend public health services in a Mexican population present pain. We also identified that pain could be associated with alexithymia, in particular with a difficulty in describing and identifying feelings. An early identification and treatment of alexithymia could help in reducing the clinical burden of chronic pain in Mexican outpatients.

Functional connectivity density alterations in middle-age retinal detachment patients

OBJECTIVE

Middle-age patients with retinal detachment (RD) exhibit a loss of visual information, and previous studies of functional magnetic resonance imaging (fMRI) have demonstrated abnormal spontaneous activity in the RD brain. Therefore, this study assessed changes in local functional connectivity density (lFCD) and long-range functional connectivity density (longFCD) in middle-age RD patients during resting-state FC.

METHODS

In total, 32 middle-age patients with RD (18 men and 14 women), and 32 age-, sex-, and education-matched normal controls (NCs) (18 men and 14 women) were recruited and underwent functional magnetic resonance examination in the resting state. Two-sample t test was performed to compare lFCD and longFCD between groups. Receiver operating characteristic (ROC) curves were generated to distinguish middle-age RD patients from NCs.

RESULTS

Compared with NCs, middle-age RD patients demonstrated increased lFCD values in the right inferior temporal gyrus, and increased longFCD values in the bilateral inferior frontal gyri, left superior and middle frontal gyrus, bilateral inferior temporal gyri, and left cerebellum posterior lobe. Middle-age RD patient exhibited decreased lFCD values in the left cuneus, right lingual gyrus, and left middle frontal gyrus. They also had lower longFCD values in the left lingual gyrus and left inferior occipital gyrus. ROC curve analysis showed excellent accuracy of the specific areas under the curve.

CONCLUSION

Our results reveal that middle-age RD patients exhibited variations of binarized lFCD and longFCD in specific brain areas, which provides insight into the pathological mechanism of RD patients with acute visual loss.

The Prevalence and Characteristics of Alexithymia in Adults Following Brain Injury: A Meta-Analysis

Alexithymia is the inability to identify and describe one's own emotions. Some research suggests that organic alexithymia may occur after acquired brain injury (ABI). However, the results in the literature are inconsistent, when comparisons are made against healthy controls. Furthermore, a precise estimate of alexithymia prevalence in the ABI population has not yet been reported. Consequently, this meta-analysis aimed to estimate the prevalence and characteristics of alexithymia in ABI, as measured by the Toronto Alexithymia Scale-20 (TAS-20). Based on 22 unique ABI samples, a series of random-effects meta-analyses estimated moderate to large positive effect sizes (i.e., greater alexithymia in ABI samples) for the TAS-20 total scale (Hedges' g = 1.00, 95% CI [0.75, 1.35]), as well as the subscales: difficulty identifying feelings (Hedges' g = 0.92, 95% CI [0.66, 1.17]), difficulty describing feelings (Hedges' g = 0.69, 95% CI [0.50, 0.87]) and externally oriented thinking (Hedges' g = 0.75, 95% CI [0.64, 0.85]). Furthermore, a meta-regression identified a larger effect size (TAS-20 total scale score) for traumatic brain injury (TBI) samples, in comparison to non-TBI samples. Finally, the prevalence of clinically significant levels of alexithymia (TAS-20 total scale ≥ 68.4; i.e., two SDs above the general population mean) in ABI patients was estimated at 15.2%. We interpreted the results to suggest that ABI may have a substantial negative impact on affective processing abilities and, thus, comprehensive assessment of emotional functioning deficits following ABI should be considered by practitioners.

Alexithymia

Humans are highly adept at differentiating, regulating, and responding to their emotions. At the core of all these functions is emotional awareness: the conscious feeling states that are central to human mental life. Disrupted emotional awareness-a subclinical construct commonly referred to as alexithymia-is present in a range of psychiatric and neurological disorders and can have a deleterious impact on functional outcomes and treatment response. This chapter is a selective review of the current state of the science on alexithymia. We focus on two separate but related issues: (i) the functional deficits associated with alexithymia and what they reveal about the importance of emotional awareness for shaping normative human functioning, and (ii) the neural correlates of alexithymia and what they can inform us about the biological bases of emotional awareness. Lastly, we outline challenges and opportunities for alexithymia research, focusing on measurement issues and the potential utility of formal computational models of emotional awareness for advancing the fields of clinical and affective science.

No Words for Feelings? Not Only for My Own: Diminished Emotional Empathic Ability in Alexithymia

The present study has been designed to disentangle cognitive and emotional dimensions of empathy in a group of mentally healthy and highly alexithymic individuals (ALEX, n = 24) and well-matched controls (n = 26) through questionnaire Interpersonal Reactivity Index (IRI) and Multifaceted Empathy Task (MET) used during the fMRI and after the fMRI. Simultaneously, Skin Conductance Response (SCR) has been acquired as an implicit measure of emotional reaction. Results show an impaired emotional empathic ability in alexithymic individuals, with lower levels of SCR and higher activation in prefrontal brain regions such as the ventrolateral prefrontal cortex (VLPFC) and inferior frontal gyrus (IFG). Cognitive empathy was not impaired in the alexithymic group and the results were accompanied by a higher activation left IFG. The study leads to the conclusion that alexithymia does not only involve a diminished ability to identify and describe one's own emotions. Furthermore, it is related to a deeper disability of emotion regulation, which becomes visible through impaired emotional concern for others and higher levels of personal distress.

The association between communication impairments and acquired alexithymia in chronic stroke patients

INTRODUCTION

Language dysfunction has recently been suggested to be one route to alexithymia, an impairment in recognizing and communicating one's own emotions. Neuropsychological evidence is needed to investigate the possibility that acquired language problems could underlie acquired alexithymia.

METHOD

This project examined data from a large group of chronic stroke patients (N = 118) to test whether self-reported or behavioral measures of language and communication problems were associated with alexithymia. We also examined the impact of hemisphere of damage on alexithymia.

RESULTS

We found no differences in alexithymia levels for patients with observed language impairments on brief tests of picture naming, comprehension, and reading vs unimpaired patients. However, self-reported communication difficulties were found to be associated with higher scores of alexithymia, even after controlling for depression and anxiety. Patients with left- versus right-hemisphere damage did not differ in their alexithymia scores.

CONCLUSIONS

We found partial support for the language hypothesis of alexithymia. We discuss potential reasons for the discrepant findings between the self-report and objective language measures and suggest that self-report measures may be more sensitive to milder, more pragmatic language impairments, as opposed to the severe structural language impairments measured by the cognitive screening tests.

Different Aspects of Emotional Awareness in Relation to Motor Cognition and Autism Traits

Emotion is inherently embodied, formulated through bodily sensation, as well as expressed and regulated through action. Both expressing one’s own emotions and understanding the emotional actions of others are common areas of difficulty in autism. Moreover, reduced emotional awareness is also thought to be problematic in autism, and such difficulties may be mediated by impaired motor cognition. We aimed to examine how intensity of emotional experience and ability to differentiate between one’s own emotions relates to motor empathy and autistic traits. We hypothesized that greater motor cognition would be associated with greater emotional intensity and more refined emotion differentiation. Participants from the general population (N = 160) completed the Actions and Feelings Questionnaire (AFQ), a self-report measure assessing motor cognition, alongside the Broad Autism Phenotype Questionnaire and an emotion elicitation task. Motor cognition was significantly associated with more intense emotional experiences but not with ability to differentiate between similar emotions. Autistic traits, particularly social aloofness, predicted less emotion differentiation and lower scores on the animation subscale of the AFQ. We suggest that whereas as intensity of experience may be dependent on sensorimotor representation of emotions, differentiation requires additional cognitive functions such as language understanding. A dissociation between awareness of intensity and differentiation may be critical for understanding emotional difficulties in autism.

Addressing Evidence Linking Secondary Alexithymia to Aberrant Humor Processing

In this review, we explore current literature and assess evidence linking secondary (acquired) alexithymia to aberrant humor processing, in terms of their neurobiological underpinnings. In addition, we suggest a possible common neuropathological substrate between secondary alexithymia and deficits in humor appreciation, by drawing on neurophysiologic and neuroradiological evidence, as well as on a recent and unique single-case study showing the cooccurrence of secondary alexithymia and deficit in humor appreciation. In summary, what emerges from the literature is that the cortical midline structures, in particular the medial prefrontal cortex (mPFC), the anterior cingulate cortex (ACC), and the insular cortex, seem to play a crucial role in the expression of both alexithymia and defective humor processing, while though to a lesser extent, a right hemisphere and bilateral frontoparietal contribution becomes evident. Neurobiological evidence of secondary alexithymia and aberrant humor processing points to the putative role of ACC/mPFC and the insular cortex in representing crucial processing nodes whose damage may produce both the above clinical conditions. We believe that the association of secondary alexithymia and aberrant humor processing, especially humor appreciation deficit, and their correlation with specific brain regions, mainly ACG/mPFC, as emerged from the literature, may be of some heuristic importance. Increased awareness on this topic may be of aid for neurosurgeons when accessing emotion-relevant structures, as well as for neuropsychologists to intensify their efforts to plan evidence-based neurorehabilitative interventions to alleviate the deleterious effects of such interpersonal communication deficits.

The Role of Language in Alexithymia: Moving Towards a Multiroute Model of Alexithymia

Alexithymia is characterized by difficulty identifying and describing one’s own emotion. Identifying and describing one’s emotion involves several cognitive processes, so alexithymia may result from a number of impairments. Here we propose the alexithymia language hypothesis—the hypothesis that language impairment can give rise to alexithymia—and critically review relevant evidence from healthy populations, developmental disorders, adult-onset illness, and acquired brain injury. We conclude that the available evidence is supportive of the alexithymia–language hypothesis, and therefore that language impairment may represent one of multiple routes to alexithymia. Where evidence is lacking, we outline which approaches will be useful in testing this hypothesis.