Understanding the role of social cognition in neurodegenerative Disease: A scoping review on an overlooked problem

Multidimensional assessment of social cognition using non-immersive virtual reality in dementia with Lewy bodies and Alzheimer's disease: an exploratory study

INTRODUCTION

Few studies have focused on social cognition in dementia with Lewy bodies (DLB), even though some brain structures being well known as underlying social cognitive processes are directly impacted in this disease. Furthermore, social cognition processes have been mostly studied independently using evaluations with poor ecological validity. We aimed at studying the ability of a new naturalistic and multidimensional social cognition task to reveal impairments in DLB patients. We chose to compare the profile of these patients with that of Alzheimer's disease (AD) patients, for which social cognition is better preserved.

METHOD

Fifteen patients (DLB: n = 7; AD: n = 8) and 28 healthy controls underwent the REALSoCog task. They encountered several social situations (e.g. control versus transgressions) in a non-immersive virtual city environment allowing the assessment of moral cognition, cognitive and affective theory of mind (ToM), emotional empathy and behavioral intentions.

RESULTS

The main results showed (i) a lower ability to detect transgressions in DLB patients, particularly conventional ones, whereas moral cognition seemed better preserved in AD patients; (ii) a cognitive ToM impairment in both DLB and AD patients, while affective ToM is impaired only in DLB patients; (iii) a decreased emotional empathy specifically observed in DLB patients; (iv) more inappropriate behavioral intentions, mainly in DLB patients, but also in some AD patients.

CONCLUSIONS

This study suggests the feasibility and potential interest of the REALSoCog task in revealing social cognition deficits, particularly for DLB patients by showing different social patterns as compared to AD patients. These results offer interesting clinical perspectives to develop more naturalistic tasks in such populations and for clinical differential diagnosis. Limitations and future perspectives are discussed.

Dynamic and/or multimodal assessments for social cognition in neuropsychology: Results from a systematic literature review

Objective: Despite the prevalence of socio-cognitive disturbances, and their important diagnostic/therapeutic implications, the assessment of these disturbances remains scarce. This systematic review aims to identify available social cognition tools for adult assessment that use multimodal and/or dynamic social cues, specifying their strengths and limitations (e.g. from a methodological, psychometric, ecological, and clinical perspective). Method: An electronic search was conducted in Pubmed, PsychINFO, Embase and Scopus databases for articles published up to the 3th of January 2023 and the first 200 Google Scholar results on the same date. The PRISMA methodology was applied, 3884 studies were screened based on title and abstract and 329 full texts were screened. Articles using pseudo-dynamic methodologies (e.g. morphing), reported only subjective or self-reported measures, or investigated only physiological or brain activity responses were excluded. Results: In total, 149 works were included in this review, representing 65 assessment tools (i.e. 48% studying emotion recognition (n = 31), 32% Theory of Mind (n = 21), 5% empathy (n = 3), 1.5% moral cognition/social reasoning (n = 1), and 14% being multimodal (n = 9)). For each study, the tool's main characteristics, psychometric properties, ecological validity indicators and available norms are reported. The tools are presented according to social-cognitive process assessed and communication channels used. Conclusions: This study highlights the lack of validated and standardized tools. A few tools appear to partially meet some clinical needs. The development of methodologies using a first-person paradigm and taking into account the multidimensional nature of social cognition seems a relevant research endeavour for greater ecological validity.

New directions for studying the aging social-cognitive brain

The study of social cognition has extended across the lifespan with a recent special focus on the impacts of aging on the social-cognitive brain. This review summarizes current knowledge on social perception, theory of mind, empathy, and social behavior from a social-cognitive neuroscience of aging perspective and identifies new directions for studying the aging social-cognitive brain. These new directions highlight the need for (i) standardized operationalization and analysis of social-cognitive constructs; (ii) use of naturalistic paradigms to enhance ecological validity of social-cognitive measures; (iii) application of repeated assessments via single-N designs for robust delineation of social-cognitive processes in the aging brain; (iv) increased representation of vulnerable aging populations in social-cognitive brain research to enhance diversity, promote generalizability, and allow for cross-population comparisons.

Sweet basil (Ocimum basilicum) leaf and seed extracts alleviate neuronal dysfunction in aluminum chloride-induced neurotoxicity in Drosophila melanogaster Meigen model

Ocimum basilicum is an important medicinal plant and culinary herb generally known as sweet basil (SB). These plants are effective radical scavengers, that have been employed in treatment of nervous system disorders, and thus, could be beneficial for the management of neurodegenerative diseases (NDs). Current clinical treatments for NDs present several side effects, therefore, there is need to develop new treatments that can mitigate these deadly diseases. Hence, this study investigated the neuroprotective activities of SB leaf and seed in aluminum chloride (AlCl3)-induced toxicity in Drosophila melanogaster. HPLC characterization of the leaves and seeds were carried out. AlCl3-diet was used to induce neurodegeneration and treated flies received SB leaf and seed extracts-supplemented diet. Survival and locomotor performance activities/levels of oxidative biomarkers [reactive oxygen species (ROS), thiobarbituric acid reactive species (TBARS), total thiol, catalase, superoxide dismutase (SOD) and glutathione-S-transferase (GST)], enzymes linked with neurodegeneration (acetylcholinesterase (AChE) and monoamine oxidase (MAO)) were investigated. SB leaf had significantly (p < 0.05) higher polyphenol contents; gallic acid and P-coumaric acid were the most abundant polyphenol in the leaf and seed respectively. Percentage survival and locomotor rates, level/activities of total thiol, catalase, SOD and GST were significantly (p < 0.05) reduced while ROS, TBARS, AChE and MAO activities were significantly (p < 0.05) increased in AlCl3-diet-fed flies. Treatment with SB leaf and seed diet lessened these observed impairments. However, SB leaf had better neuroprotective activities that could be related to the observed higher phenolic constituents. Hence, SB leaf diet may offer improved therapeutic effect in NDs.

The Impact of Parkinson's Disease on Social Communication: An Exploratory Questionnaire Study

Individuals with Parkinson's disease (PD) often show breakdown in the production and interpretation of aspects of social communication. However, there is no current method of assessment for evaluating social communication dysfunction in individuals with PD. The aim of this study was to develop a self-report questionnaire for individuals with PD to identify their social communication skills, and further recognize the impact of PD on social communication. Fifty-one individuals with Parkinson's disease answered 28 survey questions. These questions pertained to emotional expression and perception, social communication, sarcasm/humor, and pragmatic skills. Exploratory factor analysis and reliability analysis were conducted to identify items loading onto the factors and to check the internal consistency of the items. Individuals with PD reported changes in emotional expression and perception, social communication, sarcasm and humor, and pragmatic skill domains post-PD diagnosis. No correlations were found between age or time since diagnosis and emotional expression, social communication, sarcasm, and humor. This study provides self-reported evidence that individuals with PD experience social communication challenges. Future research should further quantify these challenges, study their impact on daily communicative functioning, and use the results to develop social communication interventions that improve the quality of life for persons with PD.

Correlates of Functional Impairment in Patients with the Behavioral Variant of Frontotemporal Dementia: A PRISMA-Compliant Systematic Review

The behavioral variant of frontotemporal dementia (bvFTD) has a devastating effect on multiple domains of daily living. The purpose of this PRISMA-compliant systematic review is to summarize the most important factors associated with functional impairment in this clinical group by critically analyzing the existing literature spanning the period from 2000 to 2023. To be included in the review, a study had to investigate any kind of correlates of functional status in bvFTD patients, using a previously validated instrument of functional assessment. Out of 40 articles assessed for eligibility, 18 met the inclusion criteria. The anatomical pattern of cerebral atrophy at baseline appeared to be the strongest predictor of the rate of functional decline over time, with the frontal-dominant anatomical subtype being associated with a faster rate of functional impairment. Additionally, executive dysfunction as well as apathy appeared to contribute significantly to functional disability in bvFTD patients. A comparative examination of bvFTD in relation to other clinical subtypes of FTD and other types of dementia in general suggests that it is the predominant atrophy of the frontal lobes along with the subsequent unique combination of cognitive and neuropsychiatric manifestations that account for the pronounced functional limitations observed in these individuals, even from the early stages of the disease.

Social and non-social working memory in neurodegeneration

Although social functioning relies on working memory, whether a social-specific mechanism exists remains unclear. This undermines the characterization of neurodegenerative conditions with both working memory and social deficits. We assessed working memory domain-specificity across behavioral, electrophysiological, and neuroimaging dimensions in 245 participants. A novel working memory task involving social and non-social stimuli with three load levels was assessed across controls and different neurodegenerative conditions with recognized impairments in: working memory and social cognition (behavioral-variant frontotemporal dementia); general cognition (Alzheimer's disease); and unspecific patterns (Parkinson's disease). We also examined resting-state theta oscillations and functional connectivity correlates of working memory domain-specificity. Results in controls and all groups together evidenced increased working memory demands for social stimuli associated with frontocinguloparietal theta oscillations and salience network connectivity. Canonical frontal theta oscillations and executive-default mode network anticorrelation indexed non-social stimuli. Behavioral-variant frontotemporal dementia presented generalized working memory deficits related to posterior theta oscillations, with social stimuli linked to salience network connectivity. In Alzheimer's disease, generalized working memory impairments were related to temporoparietal theta oscillations, with non-social stimuli linked to the executive network. Parkinson's disease showed spared working memory performance and canonical brain correlates. Findings support a social-specific working memory and related disease-selective pathophysiological mechanisms.

A scoping review of neurodegenerative manifestations in explainable digital phenotyping

Neurologists nowadays no longer view neurodegenerative diseases, like Parkinson's and Alzheimer's disease, as single entities, but rather as a spectrum of multifaceted symptoms with heterogeneous progression courses and treatment responses. The definition of the naturalistic behavioral repertoire of early neurodegenerative manifestations is still elusive, impeding early diagnosis and intervention. Central to this view is the role of artificial intelligence (AI) in reinforcing the depth of phenotypic information, thereby supporting the paradigm shift to precision medicine and personalized healthcare. This suggestion advocates the definition of disease subtypes in a new biomarker-supported nosology framework, yet without empirical consensus on standardization, reliability and interpretability. Although the well-defined neurodegenerative processes, linked to a triad of motor and non-motor preclinical symptoms, are detected by clinical intuition, we undertake an unbiased data-driven approach to identify different patterns of neuropathology distribution based on the naturalistic behavior data inherent to populations in-the-wild. We appraise the role of remote technologies in the definition of digital phenotyping specific to brain-, body- and social-level neurodegenerative subtle symptoms, emphasizing inter- and intra-patient variability powered by deep learning. As such, the present review endeavors to exploit digital technologies and AI to create disease-specific phenotypic explanations, facilitating the understanding of neurodegenerative diseases as "bio-psycho-social" conditions. Not only does this translational effort within explainable digital phenotyping foster the understanding of disease-induced traits, but it also enhances diagnostic and, eventually, treatment personalization.

Differentiation of claustrum resting-state functional connectivity in healthy aging, Alzheimer's disease, and Parkinson's disease

The claustrum is a sheet-like of telencephalic gray matter structure whose function is poorly understood. The claustrum is considered a multimodal computing network due to its reciprocal connections with almost all cortical areas as well as subcortical structures. Although the claustrum has been involved in several neurodegenerative diseases, specific changes in connections of the claustrum remain unclear in Alzheimer's disease (AD), and Parkinson's disease (PD). Resting-state fMRI and T1-weighted structural 3D images from healthy elderly (n = 15), AD (n = 16), and PD (n = 12) subjects were analyzed. Seed-based FC analysis was performed using CONN FC toolbox and T1-weighted images were analyzed with the Computational Anatomy Toolbox for voxel-based morphometry analysis. While we observed a decreased FC between the left claustrum and sensorimotor cortex, auditory association cortex, and cortical regions associated with social cognition in PD compared with the healthy control group (HC), no significant difference was found in alterations in the FC of both claustrum comparing the HC and AD groups. In the AD group, high FC of claustrum with regions of sensorimotor cortex and cortical regions related to cognitive control, including cingulate gyrus, supramarginal gyrus, and insular cortex were demonstrated. In addition, the structural results show significantly decreased volume in bilateral claustrum in AD and PD compared with HC. There were no significant differences in the claustrum volumes between PD and AD groups so the FC may offer more precise findings in distinguishing changes for claustrum in AD and PD.

Validity and diagnostics of the Reading the Mind in the Eyes Test (RMET) in non-demented amyotrophic lateral sclerosis (ALS) patients

Background

The aim of this study was to explore the construct validity and diagnostic properties of the Reading the Mind in the Eyes Test (RMET) in non-demented patients with amyotrophic lateral sclerosis (ALS).

Materials

A total of 61 consecutive patients and 50 healthy controls (HCs) were administered the 36-item RMET. Additionally, patients underwent a comprehensive assessment of social cognition via the Story-Based Empathy Task (SET), which encompasses three subtests targeting Causal Inference, Emotion Attribution (SET-EA), and Intention Attribution (SET-IA), as well as global cognitive [the Edinburgh Cognitive and Behavioral ALS Screen (ECAS)] and behavioral screening [the Frontal Behavioral Inventory (FBI); the Dimensional Apathy Scale (DAS); the Beck Depression Inventory (BDI); and the State and Trait Anxiety Inventory-Y]. The construct validity of the RMET was tested by regressing it within a stepwise model that encompassed as predictors the abovementioned cognitive and behavioral measures, covarying for demographic and motor confounders. Receiver-operating characteristics (ROC) analyses allowed exploring intrinsic and post-test properties of the RMET both in discriminating patients from HCs and in identifying patients with a defective SET-EA performance.

Results

The RMET was solely predicted by the SET-EA (p = 0.003) and SET-IA (p = 0.005). RMET scores showed high accuracy both in discriminating patients from HCs (AUC = 0.81) and in identifying patients with a defective SET-EA score (AUC = 0.82), with adequate-to-optimal both intrinsic and post-test properties.

Discussion

The RMET is a convergently and divergently valid measure of affective social cognition in non-demented ALS patients, also featuring optimal intrinsic and post-test diagnostic properties in both case-control and case-finding scenarios.

Eine Lücke, die es zu schließen gilt: Die Untersuchung sozial-kognitiver Fähigkeiten an deutschsprachigen Memory-Kliniken

Zusammenfassung: Die Untersuchung sozial-kognitiver Fähigkeiten kann zur Diagnostik kognitiver Störungen beitragen. In diesem Zusammenhang stellt sich die Frage, inwieweit sozial-kognitive Fähigkeiten in deutschsprachigen Memory-Kliniken (MK) untersucht werden. Wir führten dazu eine Befragung in 87 deutschsprachigen MK in Deutschland, österreich und der Schweiz durch. Es zeigte sich, dass die Untersuchung sozial-kognitiver Fähigkeiten mehrheitlich befürwortet wird, jedoch nur selten erfolgt. Die Mehrheit der MK könnte sich jedoch vorstellen, in Zukunft sozial-kognitive Diagnostik durchzuführen, vorausgesetzt, dass hierfür adäquate psychometrische Testverfahren vorliegen. Die Forderung der MK nach psychometrischen sozial-kognitiven Tests gewinnt an Bedeutung angesichts der Tatsache, dass die kürzlich publizierten ICD-11-Kriterien (International Statistical Classification of Diseases and Related Health Problems) die Untersuchung sozial-kognitiver Fähigkeiten bei der Abklärung einer kognitiven Störung empfehlen.

Apathy, Executive Function, and Emotion Recognition Are the Main Drivers of Functional Impairment in Behavioral Variant of Frontotemporal Dementia

Background: The cognitive and neuropsychiatric deficits present in patients with behavioral variant frontotemporal dementia (bvFTD) are associated with loss of functionality in the activities of daily living (ADLs). The main purpose of this study was to examine and explore the association between the cognitive and neuropsychiatric features that might prompt functional impairment of basic, instrumental, and advanced ADL domains in patients with bvFTD. Methods: A retrospective cross-sectional study was conducted with 27 patients with bvFTD in its early stage (<2 years of evolution) and 32 healthy control subjects. A neuropsychological assessment was carried out wherein measures of cognitive function and neuropsychiatric symptoms were obtained. The informant-report Technology-Activities of Daily Living Questionnaire was used to assess the percentage of functional impairment in the different ADL domains. To identify the best determinants, three separate multiple regression analyses were performed, considering each functional impairment as the dependent variable and executive function, emotion recognition, disinhibition, and apathy as independent variables. Results: For the basic ADLs, a model that explains 28.2% of the variability was found, in which the presence of apathy (β = 0.33, p = 0.02) and disinhibition (β = 0.29, p = 0.04) were significant factors. Concerning instrumental ADLs, the model produced accounted for 63.7% of the functional variability, with the presence of apathy (β = 0.71, p < 0.001), deficits in executive function (β = -0.36, p = 0.002), and lack of emotion recognition (β = 0.28, p = 0.017) as the main contributors. Finally, in terms of advanced ADLs, the model found explained 52.6% of the variance, wherein only the presence of apathy acted as a significant factor (β = 0.59, p < 0.001). Conclusions: The results of this study show the prominent and transverse effect of apathy in the loss of functionality throughout all the ADL domains. Apart from that, this is the first study that shows that the factors associated with loss of functionality differ according to the functional domain in patients with bvFTD in its early stage. Finally, no other study has analyzed the impact of the lack of emotion recognition in the functionality of ADLs. These results could guide the planning of tailored interventions that might enhance everyday activities and the improvement of quality of life.