Facial emotion decoding in patients with Parkinson's disease

Facial expressions and identities recognition in Parkinson disease

Parkinson's Disease (PD) is associated with motor and non-motor symptoms. Among the latter are deficits in matching, identification, and recognition of emotional facial expressions. On one hand, this deficit has been attributed to a dysfunction in emotion processing. Another explanation (which does not exclude the former) links this deficit with reduced facial expressiveness in these patients, which prevents them from properly understanding or embodying emotions. To disentangle the specific contribution of emotion comprehension and that of facial expression processing in PD's observed deficit with emotions we performed two experiments on non-emotional facial expressions. In Experiment 1, a group of PD patients and a group of Healthy Controls (HC) underwent a task of non-emotional expression recognition in faces of different identity and a task of identity recognition in faces with different expression. No differences were observed between the two groups in accuracies. In Experiment 2, PD patients and Healthy Controls underwent a task where they had to recognize the identity of faces encoded through a non-emotional facial expression, through a rigid head movement, or as neutral. Again, no group differences were observed. In none of the two experiments hypomimia scores had a specific effect on expression processing. We conclude that in PD patients the observed impairment with emotional expressions is likely due to a specific deficit for emotions to a greater extent than for facial expressivity processing.

Facial muscle movements in patients with Parkinson's disease undergoing phonation tests

Purpose

Parkinson's disease (PD) is a serious neurodegenerative disease affecting the elderly. In general, the locomotion deficit, which seriously affects the daily life of patients with PD, usually occurs at a later stage. The mask face symptom meanwhile progressively worsens. However, facial muscle disorders and changes involved in the freezing mask are unclear.

Method

In this study, we recruited 35 patients with PD and 26 age- and sex-balanced controls to undergo phonation tests, while the built-in camera on the laptop recorded their facial expressions during the whole pronunciation process. Furthermore, FaceReader (version 7.0; Noldus Information Technology, Wageningen, Netherlands) was used to analyze changes in PD facial landmark movement and region movement.

Results

The two-tailed Student's t-test showed that the changes in facial landmark movement among 49 landmarks were significantly lower in patients with PD than in the control group (P < 0.05). The data on facial region movement revealed that the eyes and upper lip of patients with PD differed significantly from those in the control group.

Conclusion

Patients with PD had defects in facial landmark movement and regional movement when producing a single syllable, double syllable, and multiple syllables, which may be related to reduced facial expressions in patients with PD.

Deficits in Emotion Recognition and Theory of Mind in Parkinson's Disease Patients With and Without Cognitive Impairments

Background

Emotion recognition and social deficits have been previously reported in Parkinson's disease (PD). However, the extent of these impairments is still unclear and social cognition is excluded from the cognitive domains considered in the current criteria for PD mild cognitive impairment (MCI). This study aims to analyze emotion recognition, affective and cognitive theory of mind in early PD patients classified according to Level II MCI criteria, and to evaluate the prevalence of socio-cognitive deficits in this sample.

Methods

We enrolled 45 participants with PD, classified as cognitively unimpaired (CU; n = 32) or MCI (n = 13) based on a standard neuropsychological assessment. Social cognitive skills were evaluated through validated tests for emotion recognition (i.e., Ekman 60-faces test, Ek60 Test) and mental states attribution (Story-based Empathy Task, SET) and compared to a group of 45 healthy controls (HC). Between-group differences in social tasks were performed, as well as correlation analyses to assess the relationship between social, cognitive, and clinical variables. Finally, the number of patients with social cognitive impairments in both MCI and CU subgroups was computed based on Italian normative data.

Results

Statistical comparison revealed significant differences among groups in the Ek60 test, with MCI obtaining significantly lower scores than HC and CU, especially for negative emotions. Significant differences were detected also in the SET, with lower performance in emotion and intention attribution for both PD groups compared to HC. A significant correlation emerged between the Ek60 test and emotion attribution. Nine patients showed poor performance at social tasks, five of them being classified as PD-CU.

Discussion

Parkinson's disease cognitive profile was characterized by emotion recognition and attribution deficits. These results, as well as the detection of CU patients with isolated socio-cognitive impairments, underline the importance of assessing social cognition in PD as a possible early marker of cognitive decline.

Social Cognition in Patients with Early-Onset Parkinson's Disease

Social cognition (SC) deficits have been linked to Parkinson's disease (PD) but have been less well researched than general cognitive processes, especially in early-onset PD (EOPD), despite this population often having greater social and family demands. Most studies focus on recognition of facial emotion, theory of mind (ToM), and decision-making domains, with limited research reporting on social reasoning. The main objective of this work was to compare SC ability across four domains: emotional processing, social reasoning, ToM, and decision-making between patients with EOPD and healthy controls. Twenty-five nondemented patients with EOPD and 25 controls matched for sex, age, and educational level were enrolled. A battery that included six SC tests was administered to all study participants; a decision-making scale was completed by participants' partners. Statistically significant differences were found between patients with EOPD and controls in all subtests across the four SC domains studied. The EOPD group demonstrated worse performance on all tasks, with large effect sizes. Differences remained significant after adjusting for Montreal Cognitive Assessment (MoCA) test scores for all SC subtests except the decision-making scale and the Iowa gambling task. No significant correlations between SC and other clinical PD variables were found. Our study shows that patients with EOPD perform significantly below controls in multiple SC domains affecting recognition of facial emotion, social reasoning, ToM, and decision-making. Only decision-making seems to be mediated by overall cognitive ability. The confounding or contributing effect of other clinical PD variables should be studied further.

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

Social cognition (SC) is the set of socio-cognitive processes that guide automatic and voluntary behaviors by modulating behavioral responses, it includes both cognitive (Theory of the mind - ToM) and affective aspects (Empathy). SC also includes representations of internal somatic states, self-knowledge, perception of others, communication with others and interpersonal motivations. SC is relevant in daily life and reflects the neural complexity of social processing. The purpose of this scoping review is to evaluate the role of SC in neurological disorders, also considering the pathophysiological mechanisms underlying SC and potential assessment tools. The included studies were carried out between 2010 and 2019 and were found on PubMed, Scopus, Cochrane, and Web of Sciences databases, using the combined terms "social cognition"; "dementia"; "multiple sclerosis"; "parkinson", "amyotrophic lateral sclerosis", "neurodegenerative disease". Our review has shown that different SC domains are affected by several neurological conditions, with regards to dementia and amyotrophic lateral sclerosis. Further studies are needed to investigate the association between cognitive and social deficits, for a better management of patients with neurological disorders.

A new experimental evidence that olfactory bulb lesion may be a causative factor for substantia nigra degeneration; preliminary study

Background: Anosmia has been considered as the first diagnostic criteria of Parkinson disease (PD), we investigated the effect of the olfactory bulbectomy (OBX) on histopathological features of the substantia nigra in an animal model.Methods: Twenty-seven male rats were used in this study. Animals were divided into three groups as five (control), six SHAM and sixteen study (OBL) groups. Nothing was done in the control group, the only burr hole was done in the SHAM group, OBL was not applied, and bilateral OBL was performed in the study group, and followed ten weeks, then animals were decapitated. Olfactory bulb volumes were measured by macro anatomically. The olfactory bulbs and substantia nigra sections were analyzed by a stereological method to evaluate olfactory glomerulus and neuron density of substantia nigra per cubic centimeter and compared with statistically.Results: The mean olfactory bulb volume, degenerated olfactory glomerulus density and degenerated neuron density of substantia nigra were measured as:(4.14 ± 0.20) mm³, (1 ± 1)/mm³ and (7 ± 2)/mm³ in control (Group I); (3.6 ± 0.16)/mm³, (4 ± 1)/mm³ and(32 ± 7)/mm³ in SHAM (Group II) and (2.2 ± 0.9)/mm³, (112 ± 18)/mm³ and (1543 ± 115)/mm³in study group (Group III). Diminished olfactory bulb volume was observed in Group III animals.Conclusions: We concluded that OBL may lead to the degeneration of substantia nigra.

Social perceptual function in parkinson's disease: A meta-analysis

Social perceptual impairment is a common presenting feature of Parkinson's disease (PD) that has the potential to contribute considerably to disease burden. The current study reports a meta-analytic integration of 79 studies which shows that, relative to controls, PD is associated with a moderate emotion recognition deficit (g = -0.57, K = 73), and that this deficit is robust and almost identical across facial and prosodic modalities. However, the magnitude of this impairment does appear to vary as a function of task and emotion type, with deficits generally greatest for identification tasks (g = -0.65, K = 54), and for negative relative to other basic emotions. With respect to clinical variables, dopaminergic medication, deep brain stimulation, and a predominant left side onset of motor symptoms are each associated with greater social perceptual difficulties. However, the magnitude of social perceptual impairment seen for the four atypical parkinsonian conditions is broadly comparable to that associated with PD. The theoretical and practical implications of these findings are discussed.

Social Cognition Dysfunctions in Neurodegenerative Diseases: Neuroanatomical Correlates and Clinical Implications

Social cognitive function, involved in the perception, processing, and interpretation of social information, has been shown to be crucial for successful communication and interpersonal relationships, thereby significantly impacting mental health, well-being, and quality of life. In this regard, assessment of social cognition, mainly focusing on four key domains, such as theory of mind (ToM), emotional empathy, and social perception and behavior, has been increasingly evaluated in clinical settings, given the potential implications of impairments of these skills for therapeutic decision-making. With regard to neurodegenerative diseases (NDs), most disorders, characterized by variable disease phenotypes and progression, although similar for the unfavorable prognosis, are associated to impairments of social cognitive function, with consequent negative effects on patients' management. Specifically, in some NDs these deficits may represent core diagnostic criteria, such as for behavioral variant frontotemporal dementia (bvFTD), or may emerge during the disease course as critical aspects, such as for Parkinson's and Alzheimer's diseases. On this background, we aimed to revise the most updated evidence on the neurobiological hypotheses derived from network-based approaches, clinical manifestations, and assessment tools of social cognitive dysfunctions in NDs, also prospecting potential benefits on patients' well-being, quality of life, and outcome derived from potential therapeutic perspectives of these deficits.