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

Impaired facial emotion recognition in relation to social behaviours in de novo Parkinson's disease

Facial emotion recognition (FER) is a crucial component of social cognition and is essential in social-interpersonal behaviour regulation. Although FER impairment is well-established in advanced PD, data about FER at the time of diagnosis and its relationship with social behavioural problems in daily life are lacking. The aim was to examine FER at the time of PD diagnosis compared to a matched healthy control (HC) group and to associate FER with indices of social behavioural problems. In total, 142 de novo, treatment-naïve PD patients and 142 HC were included. FER was assessed by the Ekman 60 faces test (EFT). Behavioural problems in PD patients were assessed using the Dysexecutive Questionnaire (DEX-self and DEX-proxy) and the Apathy Evaluation Scale (AES-self). PD patients had significantly lower EFT-total scores (p = .001) compared to HC, with worse recognition of Disgust (p = .001) and Sadness (p = .016). Correlational analyses yielded significant correlations between AES-self and both EFT-total (rs = .28) and Fear (rs = .22). Significant negative correlations were found between DEX-proxy and both EFT-total (rs = -.28) and Anger (rs = -.26). Analyses of DEX-subscales showed that proxy ratings were significantly higher than patient-ratings for the Social Conventions subscale (p = .047). This DEX-proxy subscale had the strongest correlation with EFT-total (rs = -.29). Results show that de novo PD patients already show impaired FER compared to HC. In addition, lower FER is linked to self-reported apathy and proxy-reported social-behavioural problems, especially concerning social conventions. These findings validate the importance of the inclusion of social cognition measures in the neuropsychological assessment even in early PD.

Tango and physiotherapy interventions in Parkinson's disease: a pilot study on efficacy outcomes on motor and cognitive skills

Pharmacological treatments in Parkinson's disease (PD), albeit effective in alleviating many motor symptoms, have limited effects in non-motor signatures as cognitive impairment, as well as in other aspects included postural instability. Consequently, complementary interventions are nowadays a prerogative of clinical practice managing PD symptomatology. In this pilot longitudinal study, we recruited twenty-four PD patients participating in one of two interventions: adapted Argentine Tango or group-based physiotherapy. Participants underwent a motor and neuropsychological evaluation before and after four months of activities, carried out twice a week. We found a general stabilization of motor and cognitive abilities, with significant improvements in several motor skills, mainly pertaining to static and dynamic balance, similarly in both groups. At cognitive level, we measured a significant improvement in both groups in the Action Naming task. Interestingly, only PD patients in the Tango group improved their performance in the test measuring facial emotion recognition. These findings highlight the crucial role that physical activities have in the stabilization and slowdown of disease's progression in PD. They further highlight the beneficial effects of a group-based physical intervention, which, especially in the case of Tango, could lead to behavioral ameliorations in domains other than the motor, such as emotion recognition.

Perception of emotionally incongruent cues: evidence for overreliance on body vs. face expressions in Parkinson's disease

Individuals with Parkinson's disease (PD) may exhibit impaired emotion perception. However, research demonstrating this decline has been based almost entirely on the recognition of isolated emotional cues. In real life, emotional cues such as expressive faces are typically encountered alongside expressive bodies. The current study investigated emotion perception in individuals with PD (n = 37) using emotionally incongruent composite displays of facial and body expressions, as well as isolated face and body expressions, and congruent composite displays as a baseline. In addition to a group of healthy controls (HC) (n = 50), we also included control individuals with schizophrenia (SZ) (n = 30), who display, as in PD, similar motor symptomology and decreased emotion perception abilities. The results show that individuals with PD showed an increased tendency to categorize incongruent face-body combinations in line with the body emotion, whereas those with HC showed a tendency to classify them in line with the facial emotion. No consistent pattern for prioritizing the face or body was found in individuals with SZ. These results were not explained by the emotional recognition of the isolated cues, cognitive status, depression, or motor symptoms of individuals with PD and SZ. As real-life expressions may include inconsistent cues in the body and face, these findings may have implications for the way individuals with PD and SZ interpret the emotions of others.

Neurocognitive Impairment and Social Cognition in Parkinson's Disease Patients

In addition to motor symptoms, neurocognitive impairment (NCI) affects patients with prodromal Parkinson's disease (PD). NCI in PD ranges from subjective cognitive complaints to dementia. The purpose of this review is to present the available evidence of NCI in PD and highlight the heterogeneity of NCI phenotypes as well as the range of factors that contribute to NCI onset and progression. A review of publications related to NCI in PD up to March 2023 was performed using PubMed/Medline. There is an interconnection between the neurocognitive and motor symptoms of the disease, suggesting a common underlying pathophysiology as well as an interconnection between NCI and non-motor symptoms, such as mood disorders, which may contribute to confounding NCI. Motor and non-motor symptom evaluation could be used prognostically for NCI onset and progression in combination with imaging, laboratory, and genetic data. Additionally, the implications of NCI on the social cognition of afflicted patients warrant its prompt management. The etiology of NCI onset and its progression in PD is multifactorial and its effects are equally grave as the motor effects. This review highlights the importance of the prompt identification of subjective cognitive complaints in PD patients and NCI management.

Gaze-speech coordination during social interaction in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) can affect social interaction and communication as well as motor and cognitive processes. Speech is affected in PD, as is the control of voluntary eye movements which are thought to play an important role in 'turn taking' in conversation.

AIMS

This study aimed to measure eye movements during spoken conversation in PD to assess whether differences in patterns of eye gaze are linked to disrupted turn taking and impaired communication efficiency.

METHODS & PROCEDURE

Eleven participants with mild PD and 14 controls completed a two-player guessing game. During each 3 min game turn, one of the players had to guess the names of as many objects as possible based only on the other player's description. Eye movements were recorded simultaneously in both participants using mobile eye trackers along with speech onset and offset times.

OUTCOMES & RESULTS

When people with PD played the role of describer, the other player guessed fewer objects compared to when controls described objects. When guessing objects, people with PD performed just as well as controls. Analysis of eye fixations showed that people with PD made longer periods of fixation on the other player's face relative to controls and a lower number of such 'gaze on face' periods.

CONCLUSIONS & IMPLICATIONS

A combination of oculomotor, cognitive and speech abnormalities may disrupt communication in PD. Better public awareness of oculomotor, speech and other deficits in the condition could improve social connectedness in people with Parkinson's.

WHAT THIS PAPER ADDS

What is already known on this subject? Parkinson's disease is known to affect the control of voluntary eye movements. Direction of eye gaze is important in spoken conversation as a cue to turn-taking, but no studies have examined whether eye movements are different during communication in people with Parkinson's. What this paper adds to existing knowledge? People with Parkinson's showed longer periods of eye fixation during conversations compared to controls. Delays and overlaps between speech turns were also affected in patients. What are the clinical implications of this work? Better knowledge of the effect of the disease on eye gaze control amongst clinicians may help improve communication and social connectedness for patients in the future.

The impact of deep brain stimulation of the subthalamic nucleus on facial emotion recognition in patients with Parkinson's disease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is successful in patients with advanced Parkinson's disease (PD) but may worsen cognitive outcome, including facial emotion recognition (FER). Data-analyses on 59 consecutive PD patients with complete pre- and postoperative assessments, using a sensitive FER test, showed no changes in FER 1 year after STN-DBS surgery, both after group and individual analyses. These findings do however not exclude the impact of FER in and on itself on the outcome after STN-DBS.

Theory of mind in mild cognitive impairment and Parkinson's disease: The role of memory impairment

BACKGROUND

Social cognition is impaired in Parkinson's disease (PD). Whether social cognitive impairment (iSC) is a by-product of the underlying cognitive deficits in PD or a process independent of cognitive status is unknown. To this end, the present study was designed to investigate the weight of specific cognitive deficits in social cognition, considering different mild cognitive impairment subtypes of PD (PD-MCI).

METHODS

Fifty-eight PD patients underwent a neuropsychological battery assessing executive functions, memory, language, and visuospatial domains, together with social cognitive tests focused on theory of mind (ToM). Patients were divided into subgroups according to their clinical cognitive status: amnestic PD-MCI (PD-aMCI, n = 18), non-amnestic PD-MCI (PD-naMCI, n = 16), and cognitively unimpaired (PD-CU, n = 24). Composite scores for cognitive and social domains were computed to perform mediation analyses.

RESULTS

Memory and language impairments mediated the effect of executive functioning in social cognitive deficits in PD patients. Dividing by MCI subgroups, iSC occurred more frequently in PD-aMCI (77.8%) than in PD-naMCI (18.8%) and PD-CU (8.3%). Moreover, PD-aMCI performed worse than PD-CU in all social cognitive measures, whereas PD-naMCI performed worse than PD-CU in only one subtype of the affective and cognitive ToM tests.

CONCLUSIONS

Our findings suggest that ToM impairment in PD can be explained by memory dysfunction that mediates executive control. ToM downsides in the amnesic forms of PD-MCI may suggest that subtle changes in social cognition could partly explain future transitions into dementia. Hence, the evaluation of social cognition in PD is critical to characterize a possible behavioral marker of cognitive decline.

Can the Ability to Recognize Facial Emotions in Individuals With Neurodegenerative Disease be Improved? A Systematic Review and Meta-analysis

BACKGROUND

Facial emotion recognition (FER) is commonly impaired in individuals with neurodegenerative disease (NDD). This impairment has been linked to an increase in behavioral disorders and caregiver burden.

OBJECTIVE

To identify interventions targeting the improvement of FER ability in individuals with NDD and investigate the magnitude of the efficacy of the interventions. We also wanted to explore the duration of the effects of the intervention and their possible impacts on behavioral and psychological symptoms of dementia and caregiver burden.

METHOD

We included 15 studies with 604 individuals who had been diagnosed with NDD. The identified interventions were categorized into three types of approach (cognitive, neurostimulation, and pharmacological) as well as a combined approach (neurostimulation with pharmacological).

RESULTS

The three types of approaches pooled together had a significant large effect size for FER ability improvement (standard mean difference: 1.21, 95% CI = 0.11, 2.31, z = 2.15, P = 0.03). The improvement lasted post intervention, in tandem with a decrease in behavioral disorders and caregiver burden.

CONCLUSION

A combination of different approaches for FER ability improvement may be beneficial for individuals with NDD and their caregivers.

Social cognition in hyperkinetic movement disorders: a systematic review

Numerous lines of research indicate that our social brain involves a network of cortical and subcortical brain regions that are responsible for sensing and controlling body movements. However, it remains unclear whether movement disorders have a systematic impact on social cognition. To address this question, we conducted a systematic review examining the influence of hyperkinetic movement disorders (including Huntington disease, Tourette syndrome, dystonia, and essential tremor) on social cognition. Following the PRISMA guidelines and registering the protocol in the PROSPERO database (CRD42022327459), we analyzed 50 published studies focusing on theory of mind (ToM), social perception, and empathy. The results from these studies provide evidence of impairments in ToM and social perception in all hyperkinetic movement disorders, particularly during the recognition of negative emotions. Additionally, individuals with Huntington's Disease and Tourette syndrome exhibit empathy disorders. These findings support the functional role of subcortical structures (such as the basal ganglia and cerebellum), which are primarily responsible for movement disorders, in deficits related to social cognition.

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.

Longitudinal assessment of social cognition in de novo Parkinson's disease patients and its relationship with dopaminergic innervation

BACKGROUND

Social Cognition (SC) has been scarcely studied in Parkinson's disease (PD), and findings in early disease are controversial. SC encompasses different capacities such as facial emotion recognition (FER); Theory of Mind (ToM), the ability to understand other people's intentions (cognitive-ToM) and emotions (affective-ToM); and self-monitoring, the ability to regulate one's own behavior in social contexts. A relationship between dopaminergic deficit and SC in PD has been suggested.

OBJECTIVES

To prospectively assess, over a two-year period, SC in newly diagnosed drug-naïve, cognitively normal and non-depressed PD patients. Furthermore, we aimed to evaluate the relationship between SC and Fluorodopa (Positron Emission Tomography) Ki uptake, which is a marker of dopaminergic depletion.

METHODS

We compared SC performance between 25 de novo PD patients and 20 healthy controls (HC), and within-patients at baseline and two-year follow-up. The SC assessment included FER, ToM, as well as self-monitoring measures. The relationship between SC and dopaminergic innervation was also assessed in patients.

RESULTS

SC scores did not differ between PD and HC groups at baseline, nor between baseline and follow-up evaluation in PD. A significant positive correlation between self-monitoring and Fluorodopa Ki uptake in the left pallidum in PD patients was found at baseline. At follow-up, ToM (stories) positively correlated with Fluorodopa Ki uptake in the right thalamus and the left putamen.

CONCLUSION

SC appears to be preserved in de novo PD and remains stable in the short-term. Although more evidence is needed, our results support a relationship between dopamine innervation in subcortical regions and SC.

Emotional Sentence Processing in Parkinson's Disease

PURPOSE

Emotional processing allows us to predict our own and others' behavior, communicate our wants and needs, and understand those of others. Thus, deficits in emotional processing can negatively impact one's quality of life. While changes in emotional processing across several domains (e.g., prosody, faces) in Parkinson's disease (PD) are widely accepted, there is a dearth of literature, with equivocal results, regarding how emotional language processing is affected by PD. This study investigated emotional sentence processing in this population.

METHOD

Eighteen persons with PD and 22 healthy adults (HAs) completed a language task in which they rated sentences on their pleasantness (valence), and a battery of cognitive tasks and mood measures that were examined as factors influencing performance. As an interaction between emotionality and concreteness during processing has been indicated in prior research, concreteness of sentence stimuli was also manipulated.

RESULTS

Individuals with PD rated negatively valenced sentences as less negative and positively-valenced sentences as less positive than HAs. The PD group also demonstrated a reduced overall range of valence rating scores. Sentence concreteness did not influence ratings. Results for positive sentences could be explained by individual differences in working memory (WM), whereas individual differences in WM, depression, and group explained differences in ratings to negative sentences.

CONCLUSIONS

Our study provides one of few accounts of emotional language processing deficits in PD, particularly beyond the word level. Individuals with PD may experience difficulty perceiving and assessing the intensity of the emotional content of language, and deficits may disproportionately impact processing of sentences about negative situations.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21313713.

Social cognition training improves recognition of distinct facial emotions and decreases misattribution errors in healthy individuals

Facial emotion recognition is a key component of social cognition. Impaired facial emotion recognition is tied to poor psychological wellbeing and deficient social functioning. While previous research has demonstrated the potential for social cognition training to improve overall facial emotion recognition, questions remain regarding what aspects of emotion recognition improve. We report results from a randomized controlled trial that evaluates whether computerized social cognition training can improve recognition of distinct facial emotions in healthy participants. This investigation was designed to better understand the therapeutic potential of social cognition training for individuals with neuropsychiatric disorders. Fifty-five healthy adult participants were randomly assigned to an internet-based intervention during which they either completed social cognition training (SCT) or played control computer games (CON) for 10.5 h over 2-3 weeks. Facial emotion recognition was measured with the Penn ER-40, which was conducted before and after training. The following variables were collected and analyzed: facial emotion recognition accuracy for each emotion (i.e., anger, fear, happy, neutral (no emotional expression), and sad), reaction times for each emotion, and response error types (i.e., frequency of an emotion being chosen incorrectly, frequency of an emotion being missed, and frequency of an emotion being confused for another particular emotion). ANOVAs and t-tests were used to elucidate intervention effects both within and between groups. Results showed that the SCT group improved their accuracy for angry and neutral faces. They also improved their reaction times for neutral, fearful, and sad faces. Compared to the CON group, the SCT group had significantly faster reaction times to neutral faces after training. Lastly, the SCT group decreased their tendency to confuse angry faces for no emotional expression and to confuse no emotional expression for sad faces. In contrast, the CON group did not significantly improve their accuracy or reaction times on any emotional expression, and they did not improve their response error types. We conclude that social cognition training can improve recognition of distinct emotions in healthy participants and decrease response error patterns, suggesting it has the potential to improve impaired emotion recognition and social functioning in individuals with facial emotion recognition deficits.

Social decision-making in Parkinson's disease

INTRODUCTION

Parkinson's Disease (PD) commonly affects cognition and communicative functions, including the ability to perceive socially meaningful cues from nonverbal behavior and spoken language (e.g., a speaker's tone of voice). However, we know little about how people with PD use social information to make decisions in daily interactions (e.g., decisions to trust another person) and whether this ability rests on intact cognitive functions and executive/decision-making abilities in nonsocial domains.

METHOD

Non-demented adults with and without PD were presented utterances that conveyed differences in speaker confidence or politeness based on the way that speakers formulated their statement and their tone of voice. Participants had to use these speech-related cues to make trust-related decisions about interaction partners while playing the Trust Game. Explicit measures of social perception, nonsocial decision-making, and related cognitive abilities were collected.

RESULTS

Individuals with PD displayed significant differences from control participants in social decision-making; for example, they showed greater trust in game partners whose voice sounded confident and who explicitly stated that they would cooperate with the participant. The PD patients displayed relative intact social perception (speaker confidence or politeness ratings) and were unimpaired on a nonsocial decision-making task (the Dice game). No obvious relationship emerged between measures of social perception, social decision-making, or cognitive functioning in the PD sample.

CONCLUSIONS

Results provide evidence of alterations in decision-making restricted to social contexts in PD individuals with relatively preserved cognition with minimal changes in social perception. Researchers and practitioners interested in how PD affects social perception and cognition should include assessments that emulate social interactions, as non-interactive tasks may fail to detect the full impact of the disease on those affected.

Affective forecasting in Parkinson's disease

OBJECTIVES

While emotional responses experienced in-the-moment appear to remain intact in Parkinson's disease (PD), no study has tested whether this extends to the prediction of future emotional responses. The present study aimed to provide the first assessment of affective forecasting capacity in this cohort.

METHODS

A positively and negatively valenced affective forecasting task and broader clinical battery were completed by a PD group (ns = 28 and 37, respectively) and a demographically matched neurotypical control group (ns = 38 and 39, respectively).

RESULTS

No group differences emerged on the two tasks, with the two groups underestimating their level of happiness and overestimating their level of negative affect to a similar degree. Affective forecasting error scores were unrelated to clinical characteristics.

CONCLUSIONS

Given that affective forecasting relies on self-projection into the future, a skill shown to often be disrupted in this cohort, impairments were expected. However, this study provides initial evidence that this may not be the case. These findings are potentially important given that how we think about and envisage the future affectively is a major determinant of goal-directed behavior. Further work is now needed to establish whether these findings are robust and generalize to other types of affective stimuli.

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.

Action and emotion perception in Parkinson's disease: A neuroimaging meta-analysis

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The neural substrates for action and emotion perception deficits in PD are still unclear.

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We addressed this issue via coordinate-based meta-analyses of previous fMRI data.

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PD patients exhibit decreased response in the basal ganglia.

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PD patients exhibit a trend toward decreased response in the parietal areas.

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PD patients exhibit a trend toward increased activation in the posterior cerebellum.

Patients with Parkinson disease (PD) may show impairments in the social perception. Whether these deficits have been consistently reported, it remains to be clarified which brain alterations subtend them. To this aim, we conducted a neuroimaging meta-analysis to compare the brain activity during social perception in patients with PD versus healthy controls. Our results show that PD patients exhibit a significantly decreased response in the basal ganglia (putamen and pallidum) and a trend toward decreased activity in the mirror system, particularly in the left parietal cortex (inferior parietal lobule and intraparietal sulcus). This reduced activation may be tied to a disruption of cognitive resonance mechanisms and may thus constitute the basis of impaired others’ representations underlying action and emotion perception. We also found increased activation in the posterior cerebellum in PD, although only in a within-group analysis and not in comparison with healthy controls. This cerebellar activation may reflect compensatory mechanisms, an aspect that deserves further investigation. We discuss the clinical implications of our findings for the development of novel social skill training programs for PD patients.

Representations of facial expressions since Darwin

Darwin's book on expressions of emotion was one of the first publications to include photographs (Darwin, The expression of the emotions in Man and animals, 1872). The inclusion of expression photographs meant that readers could form their own opinions and could, like Darwin, survey others for their interpretations. As such, the images provided an evidence base and an 'open source'. Since Darwin, increases in the representativeness and realism of emotional expressions have come from the use of composite images, colour, multiple views and dynamic displays. Research on understanding emotional expressions has been aided by the use of computer graphics to interpolate parametrically between different expressions and to extrapolate exaggerations. This review tracks the developments in how emotions are illustrated and studied and considers where to go next.

Motor symptom asymmetry predicts non-motor outcome and quality of life following STN DBS in Parkinson's disease

Risk factors for long-term non-motor symptoms and quality of life following subthalamic nucleus deep brain stimulation (STN DBS) have not yet been fully identified. In the present study, we investigated the impact of motor symptom asymmetry in Parkinson's disease. Data were extracted for 52 patients with Parkinson's disease (half with predominantly left-sided motor symptoms and half with predominantly right-sided ones) who underwent bilateral STN and a matched healthy control group. Performances for cognitive tests, apathy and depression symptoms, as well as quality-of-life questionnaires at 12 months post-DBS were compared with a pre-DBS baseline. Results indicated a deterioration in cognitive performance post-DBS in patients with predominantly left-sided motor symptoms. Performances of patients with predominantly right-sided motor symptoms were maintained, except for a verbal executive task. These differential effects had an impact on patients' quality of life. The results highlight the existence of two distinct cognitive profiles of Parkinson's disease, depending on motor symptom asymmetry. This asymmetry is a potential risk factor for non-motor adverse effects following STN DBS.

Moving beyond emotions in Parkinson's disease

OBJECTIVE

Emotion recognition is a fundamental neurocognitive capacity that is a critical predictor of interpersonal function and, in turn, mental health. Although people with Parkinson's disease (PD) often exhibit difficulties recognizing emotions, almost all studies to date have focused on basic emotions (happiness, sadness, anger, surprise, fear, and disgust), with little consideration of how more cognitively complex self-conscious emotions such as contempt, embarrassment, and pride might also be affected. Further, the few studies that have considered self-conscious emotions have relied on high intensity, static stimuli. The aim of the present study was to therefore provide the first examination of how self-conscious emotion recognition is affected by PD using a dynamic, dual-intensity measure that more closely captures how emotion recognition judgements are made in daily life.

METHOD

People with PD (n = 42) and neurotypical controls (n = 42) completed a validated measure of self-conscious facial emotion recognition. For comparative purposes, in addition to a broader clinical test battery, both groups also completed a traditional static emotion recognition measure and a measure of self-conscious emotional experience.

RESULTS

Relative to controls, the PD group did not differ in their capacity to recognize basic emotions but were impaired in their recognition of self-conscious emotions. These difficulties were associated with elevated negative affect and poorer subjective well-being.

CONCLUSIONS

Difficulties recognizing self-conscious emotions may be more problematic for people with PD than difficulties recognizing basic ones, with implications for interventions focused on helping people with this disorder develop and maintain strong social networks.

PRACTITIONER POINTS

This is the first direct investigation into how the recognition of self-conscious emotion is affected in Parkinson's disease using dynamic, dual-intensity stimuli, thus providing an important extension to prior literature that has focused solely on basic emotion recognition and/or relied on static, high-intensity stimuli. Results revealed preserved basic facial emotional recognition coexisting with impairment in all three self-conscious emotions assessed, therefore suggesting that the latter stimuli type may function as a more sensitive indicator of Parkinson's disease-related social cognitive impairment. Problems with self-conscious emotion recognition in people with Parkinson's disease were associated with poorer broader subjective well-being and increased negative affect. This aligns with the broader literature linking interpersonal difficulties with poorer clinical outcomes in this cohort.

Laterality of motor symptom onset and facial expressivity in Parkinson disease using face digitization

The onset of motor symptoms in Parkinson disease (PD) is typically unilateral. Previous work has suggested that laterality of motor symptoms may also influence non-motor symptoms including cognition and emotion perception. In line with hemispheric differences in emotion processing, we tested whether left side/right brain motor onset was associated with worse expression of facial affect when compared to right side/left brain motor onset. We evaluated movement changes associated with facial affect in 30 patients with idiopathic PD (15 left-sided motor onset, 15 right-sided motor onset) and 20 healthy controls. Participants were videotaped while posing three facial expressions: fear, anger, and happiness. Expressions were digitized and analyzed using software that extracted three variables: two measures of dynamic movement change (total entropy and entropy percent change) and a measure of time to initiate facial expression (latency). The groups did not differ in overall amount of movement change or percentchange. However, left-sided onset PD patients were significantly slower in initiating anger and happiness facial expressions than were right-sided onset PD patients and controls. Our results indicated PD patients with left-sided symptom onset had greater latency in initiating two of three facial expressions, which may reflect laterality effects in intentional behaviour.

Evidence for a vocal signature in the rat and its reinforcing effects: a key role for the subthalamic nucleus

Although rodents have a well-structured vocal form of communication, like humans and non-human primates, there is, to date, no evidence for a vocal signature in the well-known 50- and 22-kHz ultrasonic vocalizations (USVs) emitted by rats. Here, we show that rats can recognize the identity of the USV emitter since they choose to preferentially self-administer playback of 50-kHz USVs emitted by a stranger rat over those of their cagemate. In a second experiment, we show that only stranger, but not familiar, 50-kHz USVs reduce cocaine self-administration. Finally, to study the neurobiological substrate of these processes, we have shown that subthalamic nucleus (STN)-lesioned rats did not lever press much for any USV playback, whatever their emotional valence, nor did they seem able to differentiate familiar from stranger peer. Advocating for the existence of a vocal signature in rats, these results highlight the importance of ultrasonic communication in the socio-affective influence of behaviour, such as the influence of proximal social factors on drug consumption and confirm the role of the STN on this influence.

Evidence for a vocal signature in the rat and its reinforcing effects: a key role for the subthalamic nucleus

Although rodents have a well-structured vocal form of communication, like humans and non-human primates, there is, to date, no evidence for a vocal signature in the well-known 50- and 22-kHz ultrasonic vocalizations (USVs) emitted by rats. Here, we show that rats can recognize the identity of the USV emitter since they choose to preferentially self-administer playback of 50-kHz USVs emitted by a stranger rat over those of their cagemate. In a second experiment, we show that only stranger, but not familiar, 50-kHz USVs reduce cocaine self-administration. Finally, to study the neurobiological substrate of these processes, we have shown that subthalamic nucleus (STN)-lesioned rats did not lever press much for any USV playback, whatever their emotional valence, nor did they seem able to differentiate familiar from stranger peer. Advocating for the existence of a vocal signature in rats, these results highlight the importance of ultrasonic communication in the socio-affective influence of behaviour, such as the influence of proximal social factors on drug consumption and confirm the role of the STN on this influence.

Social Cognition and Cognitive Decline in Patients with Parkinson's Disease

Social cognition (SC) comprises an array of cognitive and affective abilities such as social perception, theory of mind, empathy, and social behavior. Previous studies have suggested the existence of deficits in several SC abilities in Parkinson disease (PD), although not unanimously.

OBJECTIVE

The aim of this study is to assess the SC construct and to explore its relationship with cognitive state in PD patients.

METHOD

We compare 19 PD patients with cognitive decline, 27 cognitively preserved PD patients, and 29 healthy control (HC) individuals in social perception (static and dynamic emotional facial recognition), theory of mind, empathy, and social behavior tasks. We also assess processing speed, executive functions, memory, language, and visuospatial ability.

RESULTS

PD patients with cognitive decline perform worse than the other groups in both facial expression recognition tasks and theory of mind. Cognitively preserved PD patients only score worse than HCs in the static facial expression recognition task. We find several significant correlations between each of the SC deficits and diverse cognitive processes.

CONCLUSIONS

The results indicate that some components of SC are impaired in PD patients. These problems seem to be related to a global cognitive decline rather than to specific deficits. Considering the importance of these abilities for social interaction, we suggest that SC be included in the assessment protocols in PD.

The effect of directional social cues on saccadic eye movements in Parkinson's disease

There is growing interest in how social processes and behaviour might be affected in Parkinson’s disease. A task which has been widely used to assess how people orient attention in response to social cues is the spatial cueing task. Socially relevant directional cues, such as a picture of someone gazing or pointing to the left or the right have been shown to cause orienting of visual attention in the cued direction. The basal ganglia may play a role in responding to such directional cues, but no studies to date have examined whether similar social cueing effects are seen in people with Parkinson’s disease. In this study, patients and healthy controls completed a prosaccade (Experiment 1) and an antisaccade task (Experiment 2) in which the target was preceded by arrow, eye gaze or pointing finger cues. Patients showed increased errors and response times for antisaccades but not prosaccades. Healthy participants made most anticipatory errors on pointing finger cue trials, but Parkinson's patients were equally affected by arrow, eye gaze and pointing cues. It is concluded that Parkinson's patients have a reduced ability to suppress responding to directional cues, but this effect is not specific to social cues.

Health, social, and economic consequences of rapid eye movement sleep behavior disorder: a controlled national study evaluating societal effects

STUDY OBJECTIVES

Parkinson's disease (PD) causes significant socioeconomic burdens. One of the strongest predictors of PD is rapid eye movement (REM) sleep behavior disorder (RBD; when there is no known other cause of RBD, referred to as idiopathic RBD [iRBD]), but there is no information about its factual welfare burden. We estimated the direct and indirect total costs of iRBD in a national sample of patients, based on a national register-based cohort study with matched controls.

METHODS

Using records from the Danish National Patient Registry, patient's diagnosis with RBD from 2006 to 2016 were identified. We excluded patients with a prior diagnosis of narcolepsy, PD, and other neurodegenerative diseases. We identified and compared randomly chosen controls matched for age, gender, geographic area, and civil status. Direct costs included frequencies of primary and secondary sector contacts and procedures, and medication. Indirect costs included the effect on labor supply. Social-transfer payments were included to illustrate the effect on national accounts.

RESULTS

A total of 246 iRBD patients and 982 matched controls were registered. iRBD patients had significantly higher rates of health-related contacts and of medication use, and higher socioeconomic costs than controls. The total additional direct net healthcare costs after the diagnosis (general practitioner services, hospital services, and medication) and indirect costs (loss of labor market income) was €13,088 for patients compared with controls. Patients already exhibited a negative social- and health-related status several years before the first diagnosis.

CONCLUSIONS

Diagnoses of iRBD have major socioeconomic consequences for patients, their partners, and society.

Recognition of affective prosody in autism spectrum conditions: A systematic review and meta-analysis

LAY ABSTRACT

Differences in understanding others' emotions and attitudes through features in speech (e.g. intonation) have been observed in individuals with autism spectrum conditions, which contribute greatly to their social communication challenges. However, some studies reported that individuals with autism spectrum condition performed comparably to typically developing individuals on affective prosody recognition. Here, we provide a comprehensive review with statistical analysis of 23 existing studies on this topic to examine potential factors that could explain the discrepancies. Compared with typically developing individuals, autism spectrum condition participants generally appeared to encounter more difficulties in affective prosody recognition. But this finding was likely due to the tendency of the existing research to overly focus on deficits in autism. The affective prosody recognition performance in individuals with autism spectrum condition was closely related to the number of answer options offered to them. Moreover, the degree of difficulty in affective prosody recognition encountered by individuals with autism spectrum condition varied across emotions. The findings of this systematic review highlighted the need for further research on affective prosody recognition in autism (e.g. studies that include tonal language speakers and autism spectrum condition individuals with lower cognitive or verbal abilities).

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.

Empathy and Theory of Mind in Alzheimer's Disease: A Meta-analysis

OBJECTIVE

A large literature now shows that Alzheimer's disease (AD) disrupts a number of social cognitive abilities, including social perceptual function and theory of mind (ToM). However, less well understood is how the specific subcomponents of ToM as well as both the broader and specific subcomponents of empathic processing are affected.

METHOD

The current study provides the first meta-analytic review of AD that focuses on both empathy and ToM as broad constructs, as well as their overlapping (cognitive empathy and affective ToM) and distinct (affective empathy and cognitive ToM) subcomponents.

RESULTS

Aggregated across 31 studies, the results revealed that, relative to controls, AD is associated with large-sized deficits in both cognitive ToM (g = 1.09) and affective ToM/cognitive empathy (g = 0.76). However, no statistical differences were found between the AD participants and controls on affective empathic abilities (g = 0.36).

CONCLUSIONS

These data point to a potentially important disconnect between core aspects of social cognitive processing in people with AD. The practical and theoretical implications of these findings are discussed.

Approach to Cognitive Impairment in Parkinson's Disease

Cognitive dysfunction is common in Parkinson's disease (PD) and predicts poor clinical outcomes. It is associated primarily with pathologic involvement of basal forebrain cholinergic and prefrontal dopaminergic systems. Impairments in executive functions, attention, and visuospatial abilities are its hallmark features with eventual involvement of memory and other domains. Subtle symptoms in the premotor and early phases of PD progress to mild cognitive impairment (MCI) which may be present at the time of diagnosis. Eventually, a large majority of PD patients develop dementia with advancing age and longer disease duration, which is usually accompanied by immobility, hallucinations/psychosis, and dysautonomia. Dopaminergic medications and deep brain stimulation help motor dysfunction, but may have potential cognitive side effects. Central acetylcholinesterase inhibitors, and possibly memantine, provide modest and temporary symptomatic relief for dementia, although there is no evidence-based treatment for MCI. There is no proven disease-modifying treatment for cognitive impairment in PD. The symptomatic and disease-modifying role of physical exercise, cognitive training, and neuromodulation on cognitive impairment in PD is under investigation. Multidisciplinary approaches to cognitive impairment with effective treatment of comorbidities, proper rehabilitation, and maintenance of good support systems in addition to pharmaceutical treatment may improve the quality of life of the patients and caregivers.

Effects of Subthalamic Nucleus Deep Brain Stimulation on Facial Emotion Recognition in Parkinson's Disease: A Critical Literature Review

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective therapy for Parkinson's disease (PD). Nevertheless, DBS has been associated with certain nonmotor, neuropsychiatric effects such as worsening of emotion recognition from facial expressions. In order to investigate facial emotion recognition (FER) after STN DBS, we conducted a literature search of the electronic databases MEDLINE and Web of science. In this review, we analyze studies assessing FER after STN DBS in PD patients and summarize the current knowledge of the effects of STN DBS on FER. The majority of studies, which had clinical and methodological heterogeneity, showed that FER is worsening after STN DBS in PD patients, particularly for negative emotions (sadness, fear, anger, and tendency for disgust). FER worsening after STN DBS can be attributed to the functional role of the STN in limbic circuits and the interference of STN stimulation with neural networks involved in FER, including the connections of the STN with the limbic part of the basal ganglia and pre- and frontal areas. These outcomes improve our understanding of the role of the STN in the integration of motor, cognitive, and emotional aspects of behaviour in the growing field of affective neuroscience. Further studies using standardized neuropsychological measures of FER assessment and including larger cohorts are needed, in order to draw definite conclusions about the effect of STN DBS on emotional recognition and its impact on patients' quality of life.

Facial expressions recognition and discrimination in Parkinson's disease

Emotion processing impairment is a common non-motor symptom in Parkinson's Disease (PD). Previous literature reported conflicting results concerning, in particular, the performance for different emotions, the relation with cognitive and neuropsychiatric symptoms and the affected stage of processing. This study aims at assessing emotion recognition and discrimination in PD. Recognition of six facial expressions was studied in order to clarify its relationship with motor, cognitive and neuropsychiatric symptoms. Sensitivity in discriminating happy and fearful faces was investigated to address controversial findings on impairment in early stages of emotion processing. To do so, seventy PD patients were tested with the Ekman 60 Faces test and compared with 46 neurologically unimpaired participants. Patients' performances were correlated with clinical scales and neuropsychological tests. A subsample of 25 PD patients and 25 control participants were also tested with a backward masking paradigm for sensitivity in happiness and fear discrimination. Results showed that PD patients were impaired in facial emotion recognition, especially for fearful expressions. The performance correlated with perceptual, executive and general cognitive abilities, but facial expression recognition deficits were present even in cognitively unimpaired patients. In contrast, patients' sensitivity in backward masking tasks was not reduced as compared to controls. Taken together our data demonstrate that facial emotion recognition, and fear expression in particular, is critically affected by neurodegeneration in PD and related to cognitive abilities; however, it appears before other cognitive impairments. Preserved performances in discriminating shortly presented facial expressions, suggest unimpaired early stages of emotion processing.

A meta-analytic review of prospection deficits in Parkinson's disease

Parkinson's disease (PD) is one of the most common neurodegenerative disorders, and is associated with prominent motor deficits. However, neurocognitive impairment is also a common clinical feature that can contribute greatly to the overall disease burden. In the current study, a meta-analysis was conducted to gain a clearer understanding of how PD affects one of the most functionally important domains of cognition: prospection. The results indicate that, relative to controls, PD is associated with a large deficit in the capacity to engage in planning (g = -0.81, K = 25) and a moderate-sized deficit in prospective memory (g = -0.57, K = 16). Sub-analyses indicated that these deficits are evident for both time and event-based prospective memory, as well as for prospective memory tasks that have relatively limited ecological validity. Significant impairment was also evident for both medicated and non-medicated PD sub-groups, but for planning, these deficits were substantially greater in the unmedicated sub-group. The theoretical and practical implications of these findings are discussed.