Impaired conscious recognition of negative facial expressions in patients with locked-in syndrome

Facial emotion recognition and judgment of affective scenes in Parkinson's disease

Emotional dysfunctions in Parkinson's disease (PD) remain a controversial issue. While previous investigations showed compromised recognition of expressive faces in PD, no studies evaluated potential deficits in recognizing the emotional valence of affective scenes. This study aimed to investigate both facial emotion recognition performance and the ability to judge affective scenes in PD patients. Forty PD patients (mean age ± SD: 64.50 ± 8.19 years; 27 men) and forty healthy subjects (64.95 ± 8.25 years; 27 men) were included. Exclusion criteria were previous psychiatric disorders, previous Deep Brain Stimulation, and cognitive impairment. Participants were evaluated through the Ekman 60-Faces test and the International Affective Picture System. The accuracy in recognizing the emotional valence of facial expressions and affective scenes was compared between groups using linear mixed models. Pearson's correlation was performed to test the association between accuracy measures. The groups did not differ in sex, age, education, and Mini-Mental State Examination scores. Patients showed a lower recognition accuracy of facial expressions (68.54 % ± 15.83 %) than healthy participants (78.67 % ± 12.04 %; p < 0.001). Specifically, the PD group was characterized by lower recognition of faces expressing fear, sadness, and anger than the control group (all p < 0.020). No difference was detected for faces expressing disgust, surprise, and happiness (all p ≥ 0.25). Furthermore, patients showed lower accuracy in recognizing the emotional valence of affective scenes (66.75 % ± 14.59 %) than healthy subjects (74.83 % ± 12.65 %; p = 0.010). Pearson's correlations indicated that higher accuracy in recognizing the emotional facial expressions was associated with higher accuracy in classifying the valence of affective scenes in patients (r = 0.57, p < 0.001) and control participants (r = 0.57, p < 0.001). Our study suggested maladaptive affective processing in PD, leading patients to misinterpret both facial expressions and the emotional valence of complex evocative scenes.

Boosting brain-computer interfaces with functional electrical stimulation: potential applications in people with locked-in syndrome

Individuals with a locked-in state live with severe whole-body paralysis that limits their ability to communicate with family and loved ones. Recent advances in brain-computer interface (BCI) technology have presented a potential alternative for these people to communicate by detecting neural activity associated with attempted hand or speech movements and translating the decoded intended movements to a control signal for a computer. A technique that could potentially enrich the communication capacity of BCIs is functional electrical stimulation (FES) of paralyzed limbs and face to restore body and facial movements of paralyzed individuals, allowing to add body language and facial expression to communication BCI utterances. Here, we review the current state of the art of existing BCI and FES work in people with paralysis of body and face and propose that a combined BCI-FES approach, which has already proved successful in several applications in stroke and spinal cord injury, can provide a novel promising mode of communication for locked-in individuals.

Massive body-brain disconnection consequent to spinal cord injuries drives profound changes in higher-order cognitive and emotional functions: A PRISMA scoping review

Spinal cord injury (SCI) leads to a massive disconnection between the brain and the body parts below the lesion level representing a unique opportunity to explore how the body influences a person's mental life. We performed a systematic scoping review of 59 studies on higher-order cognitive and emotional changes after SCI. The results suggest that fluid abilities (e.g. attention, executive functions) and emotional regulation (e.g. emotional reactivity and discrimination) are impaired in people with SCI, with progressive deterioration over time. Although not systematically explored, the factors that are directly (e.g. the severity and level of the lesion) and indirectly associated (e.g. blood pressure, sleeping disorders, medication) with the damage may play a role in these deficits. The inconsistency which was found in the results may derive from the various methods used and the heterogeneity of samples (i.e. the lesion completeness, the time interval since lesion onset). Future studies which are specifically controlled for methods, clinical and socio-cultural dimensions are needed to better understand the role of the body in cognition.

External validation of binary machine learning models for pain intensity perception classification from EEG in healthy individuals

Discrimination of pain intensity using machine learning (ML) and electroencephalography (EEG) has significant potential for clinical applications, especially in scenarios where self-report is unsuitable. However, existing research is limited due to a lack of external validation (assessing performance using novel data). We aimed for the first external validation study for pain intensity classification with EEG. Pneumatic pressure stimuli were delivered to the fingernail bed at high and low pain intensities during two independent EEG experiments with healthy participants. Study one (n = 25) was utilised for training and cross-validation. Study two (n = 15) was used for external validation one (identical stimulation parameters to study one) and external validation two (new stimulation parameters). Time-frequency features of peri-stimulus EEG were computed on a single-trial basis for all electrodes. ML training and analysis were performed on a subset of features, identified through feature selection, which were distributed across scalp electrodes and included frontal, central, and parietal regions. Results demonstrated that ML models outperformed chance. The Random Forest (RF) achieved the greatest accuracies of 73.18, 68.32 and 60.42% for cross-validation, external validation one and two, respectively. Importantly, this research is the first to externally validate ML and EEG for the classification of intensity during experimental pain, demonstrating promising performance which generalises to novel samples and paradigms. These findings offer the most rigorous estimates of ML's clinical potential for pain classification.

Locked-in syndrome revisited

The locked-in syndrome (LiS) is characterized by quadriplegia with preserved vertical eye and eyelid movements and retained cognitive abilities. Subcategorization, aetiologies and the anatomical foundation of LiS are discussed. The damage of different structures in the pons, mesencephalon and thalamus are attributed to symptoms of classical, complete and incomplete LiS and the locked-in plus syndrome, which is characterized by additional impairments of consciousness, making the clinical distinction to other chronic disorders of consciousness at times difficult. Other differential diagnoses are cognitive motor dissociation (CMD) and akinetic mutism. Treatment options are reviewed and an early, interdisciplinary and aggressive approach, including the provision of psychological support and coping strategies is favoured. The establishment of communication is a main goal of rehabilitation. Finally, the quality of life of LiS patients and ethical implications are considered. While patients with LiS report a high quality of life and well-being, medical professionals and caregivers have largely pessimistic perceptions. The negative view on life with LiS must be overthought and the autonomy and dignity of LiS patients prioritized. Knowledge has to be disseminated, diagnostics accelerated and technical support system development promoted. More well-designed research but also more awareness of the needs of LiS patients and their perception as individual persons is needed to enable a life with LiS that is worth living.

Investigating Structure-Function Connectivity in a Patient With Locked-In Syndrome by 7 T Magnetic Resonance Imaging: A Case Report

INTRODUCTION

Functional neuroimaging studies have been conducted to investigate cognitive and behavioral dysfunctions in locked-in syndrome (LIS). This study, we used a multimodal neuroimaging approach to investigate functional and structural connectivity in a LIS patient.

CASE REPORT

A 39-year-old patient who was in a total locked-in state was admitted in our department. The Coma Recovery Scale-Revised score, event-related potential, and ultra-high-field 7 T magnetic resonance imaging (MRI) were used to investigate this patient. White matter connectometry and seed-based resting-state functional connectivity analysis were used to compare the patient with an age-matched, sex-matched healthy control. Diffusion MRI findings indicated that fibers in the brainstem significantly decreased, especially in the cross region of pons, whereas the fibers above the brainstem in the deep brain increased particularly in the posterior cingulate cortex (PCC), the left parietal lobe, and parts of the corpus callosum. Meanwhile, using the PCC as the seed region, the functional connectivity between PCC and left parietal and occipital lobes, right occipital and temporal lobes increased, respectively, especially in the area of left inferior parietal gyrus and the postcentral gyrus, which were in accordance with the most increased fiber density areas observed in diffusion MRI.

CONCLUSIONS

These results provide tentative evidences to reveal the important role of PCC and corpus callosum in the LIS patient. These findings may be informative to the study of patients with LIS.

What the study of spinal cord injured patients can tell us about the significance of the body in cognition

Although in the last three decades philosophers, psychologists and neuroscientists have produced numerous studies on human cognition, the debate concerning its nature is still heated and current views on the subject are somewhat antithetical. On the one hand, there are those who adhere to a view implying 'disembodiment' which suggests that cognition is based entirely on symbolic processes. On the other hand, a family of theories referred to as the Embodied Cognition Theories (ECT) postulate that creating and maintaining cognition is linked with varying degrees of inherence to somatosensory and motor representations. Spinal cord injury induces a massive body-brain disconnection with the loss of sensory and motor bodily functions below the lesion level but without directly affecting the brain. Thus, SCI may represent an optimal model for testing the role of the body in cognition. In this review, we describe post-lesional cognitive modifications in relation to body, space and action representations and various instances of ECT. We discuss the interaction between body-grounded and symbolic processes in adulthood with relevant modifications after body-brain disconnection.

EEG power spectral density in locked-in and completely locked-in state patients: a longitudinal study

Persons with their eye closed and without any means of communication is said to be in a completely locked-in state (CLIS) while when they could still open their eyes actively or passively and have some means of communication are said to be in locked-in state (LIS). Two patients in CLIS without any means of communication, and one patient in the transition from LIS to CLIS with means of communication, who have Amyotrophic Lateral Sclerosis were followed at a regular interval for more than 1 year. During each visit, resting-state EEG was recorded before the brain-computer interface (BCI) based communication sessions. The resting-state EEG of the patients was analyzed to elucidate the evolution of their EEG spectrum over time with the disease's progression to provide future BCI-research with the relevant information to classify changes in EEG evolution. Comparison of power spectral density (PSD) of these patients revealed a significant difference in the PSD's of patients in CLIS without any means of communication and the patient in the transition from LIS to CLIS with means of communication. The EEG of patients without any means of communication is devoid of alpha, beta, and higher frequencies than the patient in transition who still had means of communication. The results show that the change in the EEG frequency spectrum may serve as an indicator of the communication ability of such patients.

Cosmetic appreciation and emotional processing in patients with a peripheral facial palsy: A systematic review

Background; The goal of this review is 1) to summarize the studies assessing PFP by casual observers, patients themselves and the cosmetic appreciation of the PFP and 2) to summarize the studies assessing whether there is a difference in emotional recognition/processing of facial emotions and/or cognitive tasks in patients with a PFP. Materials and Methods; A multi-database systematic literature search was performed using the following databases: Pubmed, Embase, Medline, and The Cochrane Library from the earliest date of each database up to December 2019. Population of interest consisted of patients with a PFP and studies that investigated cosmetic appreciation and/or emotional recognition and/or emotional processing in these patients. Two authors rated the methodological quality of the included studies independently using the 'Newcastle - Ottawa Quality Assessment Scale' for nonrandomised studies' (NOS). Two authors extracted the outcome data regarding cosmetic appreciation and/or emotional recognition/processing from the included studies. Results; Twelve hundred and thirty-two studies were found of which eleven studies met the inclusion criteria. Most studies were assessed to be of 'fair' to 'good' methodological quality. The Cohen's kappa (between author RL and SP) was 0.68. Two studies investigated emotional processing and/or emotional recognition. Nine studies investigated cosmetic appreciation in both patients and casual observers. Important findings of this systematic review are that there is a correlation between the perceived severity of the PFP of the patients and the ratings by casual observers. Secondly there seems to be a laterality difference in cosmetic appreciation and thirdly there might to be a decreased emotional recognition and processing in patients with a PFP. Conclusion; Emotional recognition and cosmetic appreciation in patients with a PFP is an under investigated area, in which further studies are needed to substantiate the findings in current literature.

Facial emotion detection in Vestibular Schwannoma patients with and without facial paresis

This study investigates whether there exist differences in facial emotion detection accuracy in patients suffering from Vestibular Schwannoma (VS) due to their facial paresis. Forty-four VS patients, half of them with, and half of them without a facial paresis, had to classify pictures of facial expressions as being emotional or non-emotional. The visual information of images was systematically manipulated by adding different levels of visual noise. The study had a mixed design with emotional expression (happy vs. angry) and visual noise level (10% to 80%) as repeated measures and facial paresis (present vs. absent) and degree of facial dysfunction as between subjects' factors. Emotion detection accuracy declined when visual information declined, an effect that was stronger for anger than for happy expressions. Overall, emotion detection accuracy for happy and angry faces did not differ between VS patients with or without a facial paresis, although exploratory analyses suggest that the ability to recognize emotions in angry facial expressions was slightly more impaired in patients with facial paresis. The findings are discussed in the context of the effects of facial paresis on emotion detection, and the role of facial mimicry, in particular, as an important mechanism for facial emotion processing and understanding.

Complex Scenes From the International Affective Picture System (IAPS)

Complex scenes from standardized stimuli databases such as the International Affective Picture System (IAPS) are organized dimensionally rather than discretely. Further, the potentially unique function of socially relevant scenes is often overlooked. This study sought to identify discrete categories of complex scenes from the IAPS and to explore if there were qualitative features that make the emotional content of some social scenes identifiable with higher levels of agreement. One hundred and three participants (53.4% female, mean age 24.4) judged 118 IAPS scenes as reflecting fear, happy, sad, or neutral. A second judgment study was conducted with a separate group of participants (N = 117; 79.2% female; mean age 30.41) to further characterize valid affective scenes across the full range of basic emotions. Sixty images received agreement on their emotional category from >70% of judges and were considered valid. IAPS identifier codes for these images are available for reference (along with the supplementary material from the second judgment study), organized by emotional and social content. An incidental observation was such that compared to nonsocial scenes, lower agreement rates were observed for social scenes across the board. Qualitative features of social scenes that were classified into emotional categories based on higher levels of agreement are discussed.

My body, your emotions: Viscerosomatic modulation of facial expression discrimination

Interoception reflects the ability to observe one's innermost bodily states. Here, we assessed whether interoceptive accuracy (IA) is related to the empathic ability to discriminate others' emotions. Participants (N = 111) completed a heartbeat tracking task, as well as an emotional go/no-go task with fearful and disgusted faces. Empathic facial mimicry during the go/no-go task was measured using electromyography (EMG) of the Corrugator Supercilii muscle. Higher IA was associated with higher perceptual sensitivity for emotional faces but was unrelated to response bias. Individuals higher in IA had stronger coupling between facial EMG and task performance. IA and facial EMG were associated with Go but not with NoGo trials, consistent with a specific modulation of perceptual sensitivity. These results suggest that tuning into one's own viscerosomatic signals relates to empathic mimicry and perception of others' emotional states.

Neural Correlates of Facial Expression Recognition in Earthquake Witnesses

Major adverse events, like an earthquake, trigger different kinds of emotional dysfunctions or psychiatric disorders in the exposed subjects. Recent literature has also shown that exposure to natural disasters can increase threat detection. In particular, we previously found a selective enhancement in the ability to read emotional facial expressions in L’Aquila earthquake witnesses, suggesting hypervigilance to stimuli signaling a threat. In light of previous neuroimaging data showing that trauma exposure is related to derangement of resting-state brain activity, in the present study we investigated the neurofunctional changes related to the recognition of emotional faces in L’Aquila earthquake witnesses. Specifically, we tested the relationships between accuracy in recognizing facial expressions and activity of the visual network (VN) and of the default-mode network (DMN). Resting-state functional connectivity (FC) with the main hub of the VN (primary, ventral, right-dorsal, and left-dorsal visual cortices) and DMN (posterior cingulate/precuneus, medial prefrontal, and right and left inferior parietal cortices) was investigated through a seed-based functional magnetic resonance imaging (fMRI) analysis in both earthquake-exposed subjects and non-exposed persons who did not live in an earthquake-affected area. The results showed that, in earthquake-exposed subjects, there is a significant reduction in the correlation between accuracy in recognizing facial expressions and the FC of the dorsal seed of the VN with the right inferior occipito-temporal cortex and the left lateral temporal cortex, and of two parietal seeds of DMN, i.e., lower parietal and medial prefrontal cortex, with the precuneus bilaterally. These findings suggest that a functional modification of brain systems involved in detecting and interpreting emotional faces may represent the neurophysiological basis of the specific “emotional expertise” observed in the earthquake witnesses.

The effects of Botulinum toxin on the detection of gradual changes in facial emotion

When we feel sad or depressed, our face invariably “drops”. Conversely, when we try to cheer someone up, we might tell them “keep your smile up”, so presupposing that modifying the configuration of their facial muscles will enhance their mood. A crucial assumption that underpins this hypothesis is that mental states are shaped by information originating from the peripheral neuromotor system — a view operationalised as the Facial Feedback Hypothesis. We used botulinum toxin (BoNT-A) injected over the frown area to temporarily paralyse muscles necessary to express anger. Using a pre-post treatment design, we presented participants with gradually changing videos of a face morphing from neutral to full-blown expressions of either anger or happiness and asked them to press a button as soon as they had detected any change in the display. Results indicate that while all participants (control and BoNT-A) improved their reaction times from pre-test to post-test, the BoNT-A group did not when detecting anger in the post-test. We surmise that frown paralysis disadvantaged participants in their ability to improve the detection of anger. Our finding suggests that facial feedback causally affects perceptual awareness of changes in emotion, as well as people’s ability to use perceptual information to learn.

Diffusion tensor imaging reveals diffuse white matter injuries in locked-in syndrome patients

Locked-in syndrome (LIS) is a state of quadriplegia and anarthria with preserved consciousness, which is generally triggered by a disruption of specific white matter fiber tracts, following a lesion in the ventral part of the pons. However, the impact of focal lesions on the whole brain white matter microstructure and structural connectivity pathways remains unknown. We used diffusion tensor magnetic resonance imaging (DT-MRI) and tract-based statistics to characterise the whole white matter tracts in seven consecutive LIS patients, with ventral pontine injuries but no significant supratentorial lesions detected with morphological MRI. The imaging was performed in the acute phase of the disease (26 ± 13 days after the accident). DT-MRI-derived metrics were used to quantitatively assess global white matter alterations. All diffusion coefficient Z-scores were decreased for almost all fiber tracts in all LIS patients, with diffuse white matter alterations in both infratentorial and supratentorial areas. A mixture model of two multidimensional Gaussian distributions was fitted to cluster the white matter fiber tracts studied in two groups: the least (group 1) and most injured white matter fiber tracts (group 2). The greatest injuries were revealed along pathways crossing the lesion responsible for the LIS: left and right medial lemniscus (98.4% and 97.9% probability of belonging to group 2, respectively), left and right superior cerebellar peduncles (69.3% and 45.7% probability) and left and right corticospinal tract (20.6% and 46.5% probability). This approach demonstrated globally compromised white matter tracts in the acute phase of LIS, potentially underlying cognitive deficits.

Cognitive and Emotional Empathy in Individuals with Spinal Cord Injury

Background

Empathy has been conceptualized as comprising a cognitive and an emotional component, the latter being further divided into direct and indirect aspects, which refer, respectively, to the explicit evaluation of the observer's feelings while attending someone in an emotional situation and to the physiological response of the observer. Empathy has been previously investigated in several neurological disorders.

Objective

This study is aimed at investigating empathy in patients with spinal cord injury (SCI). We hypothesize that, due to deafferentation following their injury, SCI patients will display difficulty in the processing of emotional stimuli and blunted empathic responses as compared to healthy controls.

Materials and Methods

20 patients with spinal cord injury (SCI) (12 males and 8 females, mean age = 50.9, standard deviation (SD) = 16.1 years; mean education = 10.9, SD = 4.1 years) were included in the study and compared to 20 matched healthy subjects. Participants were investigated using the State-Trait Anxiety Inventory (Form Y) (STAI-Y), the Beck Depression Scale, and the Toronto Alexithymia Scale. Moreover, participants were further evaluated by means of the Interpersonal Reactivity Index (IRI), which explores both cognitive and emotional aspects of empathy, and through an experimental protocol based on the use of a modified version of the computerized Multifaceted Empathy Test (MET) to evaluate emotional (direct and indirect) empathy and the ability to judge the valence of complex emotional scenes.

Results

As compared to healthy controls, SCI patients reported higher scores on the Perspective-Taking subscale of the IRI, while, on the modified MET, they were less accurate in identifying the valence of neutral scenes, notwithstanding their spared direct and indirect emotional empathy ability. Furthermore, we found a significant negative correlation between the time interval since injury and the direct emotional empathy scores on the positive images, as well as a negative correlation with the indirect emotional empathy scores on both positive and neutral images, indicating a blunting of the empathic responses as time elapses.

Conclusion

Results suggest that SCI patients, when analyzing the meaning of emotional stimuli, tend to rely on a cognitive empathy strategy rather than on emotion simulation.

Cortical Brain Changes in Patients With Locked-In Syndrome Experiencing Hallucinations and Delusions

Previous evidence suggests that hallucinations and delusions may be detected in patients with the most severe forms of motor disability including locked-in syndrome (LIS). However, such phenomena are rarely described in LIS and their presence may be underestimated as a result of the severe communication impairment experienced by the patients. In this study, we retrospectively reviewed the clinical history and the neuroimaging data of a cohort of patients with LIS in order to recognize the presence of hallucinations and delusions and to correlate it with the pontine damage and the presence of any cortical volumetric changes. Ten patients with LIS were included (5 men and 5 women, mean age 50.1 ± 14.6). According to the presence of indicators of symptoms, these patients were categorized as hallucinators (n = 5) or non-hallucinators (n = 5). MRI images of patients were analyzed using Freesurfer 6.0 software to evaluate volume differences between the two groups. Hallucinators showed a selective cortical volume loss involving the fusiform (p = 0.001) and the parahippocampal (p = 0.0008) gyrus and the orbital part of the inferior frontal gyrus (p = 0.001) in the right hemisphere together with the lingual (p = 0.01) and the fusiform gyrus (p = 0.01) in the left hemisphere. Moreover, a volumetric decrease of bilateral anterior portions of the precuneus was recognized in the hallucinators (right p = 0.01; left p = 0.001) as compared to non-hallucinators. We suggested that the presence of hallucinations and delusions in some LIS patients could be accounted for by the combination of a damage of the corticopontocerebellar pathways with cortical changes following the primary brainstem injury. The above areas are embedded within cortico-cortical and cortico-subcortical loops involved in self-monitoring and have been related to the presence of hallucinations in other diseases. The two main limitations of our study are the small sample of included patients and the lack of a control group of healthy individuals. Further studies would be of help to expand this field of research in order to integrate existing theories about the mechanisms underlying the generation of hallucinations and delusions in neurological patients.

Post-earthquake Distress and Development of Emotional Expertise in Young Adults

After a natural disaster like an earthquake about 15% of the population experience a post-traumatic stress disorder (PTSD). However, even those without a diagnosis of PTSD can suffer from disorders of the affective sphere, including anxiety, depression and alteration of emotion recognition. The objective of this study was to investigate the neuropsychological and emotional profile of students living in the earthquake-affected areas of L'Aquila, Italy. A group of students living in L'Aquila at the time of the 2009 earthquake was recruited, and compared to a control group of students not living in any earthquake-affected areas. Participants were assessed by means of the Beck Depression Inventory (BDI) scale, the State-Trait Anxiety Inventory (STAI), the Insomnia Severity Index (ISI), the Intolerance of Uncertainty Scale Short Form, the Uncertainty Response Scale (URS), the Anxiety Sensitivity Index 3 (ASI-3), and the Eysenck Personality Questionnaire-Revised Short Form (EPQ-RS). Participants also took part in two behavioral experiments aimed at evaluating their ability to recognize facial expressions (by means of the Ekman and Friesen Pictures of Facial Affect) and to evaluate emotionally evocative scenes (by means of the International Affective Picture System (IAPS)). Results showed that students living in the earthquake-affected areas had a general increase of anxiety and anticipation of threats. Moreover, students living in the earthquake-affected areas showed a significantly higher overall accuracy in recognizing facial expressions as compared to controls. No significant differences between the two groups were detected in the evaluation of emotionally evocative scenes. The novel result lies in the greater accuracy of earthquake victims in recognizing facial expressions, despite the lack of differences from controls in evaluating affective evocative scenes. The trauma exposure may have increased vigilance for threats in earthquake victims, leading them to systematically pay attention to potential signs of approaching threats, such as emotional facial expressions, thus progressively developing particular "emotional expertise."

Development of the Italian Version of the Near-Death Experience Scale

Near-death experiences (NDEs) have been defined as any conscious perceptual experience occurring in individuals pronounced clinically dead or who came very close to physical death. They are frequently reported by patients surviving a critical injury and, intriguingly, they show common features across different populations. The tool traditionally used to assess NDEs is the NDE Scale, which is available in the original English version. The aim of this study was to develop the Italian version of the NDE Scale and to assess its reliability in a specific clinical setting. A process of translation of the original scale was performed in different stages in order to obtain a fully comprehensible and accurate Italian translation. Later, the scale was administered to a convenience sample of patients who had experienced a condition of coma and were, at the time of assessment, fully conscious and able to provide information as requested by the scale. Inter-rater and test–retest reliability, assessed by the weighted Cohen’s kappa (K_w), were estimated. A convenience sample of 20 subjects [mean age ± standard deviation (SD) 51.6 ± 17.1, median time from injury 3.5 months, interquartile range (IQR) 2–10] was included in the study. Inter-rater [K_w 0.77 (95% CI 0.67–0.87)] and test–retest reliability [K_w 0.96 (95% CI 0.91–1.00)] showed good to excellent values for the total scores of the Italian NDE Scale and for subanalyses of each single cluster of the scale. An Italian Version of the NDE Scale is now available to investigate the frequency of NDE, the causes for NDE heterogeneity across different life-threatening conditions, and the possible neural mechanisms underlying NDE phenomenology.

Facial expressions as a model to test the role of the sensorimotor system in the visual perception of the actions

A long-term debate concerns whether the sensorimotor coding carried out during transitive actions observation reflects the low-level movement implementation details or the movement goals. On the contrary, phonemes and emotional facial expressions are intransitive actions that do not fall into this debate. The investigation of phonemes discrimination has proven to be a good model to demonstrate that the sensorimotor system plays a role in understanding actions acoustically presented. In the present study, we adapted the experimental paradigms already used in phonemes discrimination during face posture manipulation, to the discrimination of emotional facial expressions. We submitted participants to a lower or to an upper face posture manipulation during the execution of a four alternative labelling task of pictures randomly taken from four morphed continua between two emotional facial expressions. The results showed that the implementation of low-level movement details influence the discrimination of ambiguous facial expressions differing for a specific involvement of those movement details. These findings indicate that facial expressions discrimination is a good model to test the role of the sensorimotor system in the perception of actions visually presented.

Emotions Are Rising: The Growing Field of Affect Neuropsychology

Thirty years ago, the neuropsychology of emotion started to emerge as a mainstream topic. Careful examination of individual patients showed that emotion, like memory, language, and so on, could be differentially affected by brain disorders, especially in the right hemisphere. Since then, there has been accelerating interest in uncovering the neural architecture of emotion, and the major steps in this process of discovery over the past 3 decades are detailed in this review. In the 1990s, magnetic resonance imaging (MRI) scans provided precise delineation of lesions in the amygdala, medial prefrontal cortex, insula and somatosensory cortex as underpinning emotion disorders. At the same time, functional MRI revealed activation that was bilateral and also lateralized according to task demands. In the 2000s, converging evidence suggested at least two routes to emotional responses: subcortical, automatic and autonomic responses and slower, cortical responses mediating cognitive processing. The discovery of mirror neurons in the 1990s reinvigorated older views that simulation was the means to recognize emotions and empathize with others. More recently, psychophysiological research, revisiting older Russian paradigms, has contributed new insights into how autonomic and other physiological indices contribute to decision making (the somatic marker theory), emotional simulation, and social cognition. Finally, this review considers the extent to which these seismic changes in understanding emotional processes in clinical disorders have been reflected in neuropsychological practice. (JINS, 2017, 23, 719-731).

Facial emotion recognition, theory of mind and the role of facial mimicry in depression

BACKGROUND

This study examined whether acutely (aMDD) and remitted depressed patients (rMDD) show deficits in the two aspects of social cognition - facial emotion recognition (FER) and reasoning - when using ecologically valid material. Furthermore, we examined whether reduced facial mimicry mediates the association between depressive symptoms and FER, and whether FER deficits and reasoning deficits are associated.

METHOD

In 42 aMDD, 43 rMDD, and 39 healthy controls (HC) FER was assessed using stimuli from the Amsterdam Dynamic Facial Expression Set, reasoning by the Movie for the Assessment of Social Cognition. Furthermore, the activity of Zygomaticus Major and Corrugator supercilii were recorded.

RESULTS

aMDD recognized happy faces less accurately, were less confident recognizing happiness and anger and found it more difficult to recognize happiness, anger and fear than HC. rMDD were less confident recognizing anger and found it more difficult to recognize happiness, anger and fear than HC. Reduced mimicry did not explain FER deficits. aMDD but not rMDD showed impaired reasoning.

LIMITATIONS

The stimulus material was comparably easy to decode. Therefore, it is possible that the FER deficits of aMDD and rMDD patients are more pronounced than demonstrated in this study.

CONCLUSIONS

aMDD show deficits in FER and reasoning, whereas rMDD only show mild impairments in the recognition of emotional expressions. There must be other processes - besides mimicry - that serve the accurate recognition of emotional facial expressions.

Disorders of Consciousness: Painless or Painful Conditions?-Evidence from Neuroimaging Studies

The experience of pain in disorders of consciousness is still debated. Neuroimaging studies, using functional Magnetic Resonance Imaging (fMRI), Positron Emission Tomography (PET), multichannel electroencephalography (EEG) and laser-evoked potentials, suggest that the perception of pain increases with the level of consciousness. Brain activation in response to noxious stimuli has been observed in patients with unresponsive wakefulness syndrome (UWS), which is also referred to as a vegetative state (VS), as well as those in a minimally conscious state (MCS). However, all of these techniques suggest that pain-related brain activation patterns of patients in MCS more closely resemble those of healthy subjects. This is further supported by fMRI findings showing a much greater functional connectivity within the structures of the so-called pain matrix in MCS as compared to UWS/VS patients. Nonetheless, when interpreting the results, a distinction is necessary between autonomic responses to potentially harmful stimuli and conscious experience of the unpleasantness of pain. Even more so if we consider that the degree of residual functioning and cortical connectivity necessary for the somatosensory, affective and cognitive-evaluative components of pain processing are not yet clear. Although procedurally challenging, the particular value of the aforementioned techniques in the assessment of pain in disorders of consciousness has been clearly demonstrated. The study of pain-related brain activation and functioning can contribute to a better understanding of the networks underlying pain perception while addressing clinical and ethical questions concerning patient care. Further development of technology and methods should aim to increase the availability of neuroimaging, objective assessment of functional connectivity and analysis at the level of individual cases as well as group comparisons. This will enable neuroimaging to truly become a clinical tool to reliably investigate pain in severely brain-injured patients as well as an asset for research.

Does Facial Amimia Impact the Recognition of Facial Emotions? An EMG Study in Parkinson's Disease

According to embodied simulation theory, understanding other people’s emotions is fostered by facial mimicry. However, studies assessing the effect of facial mimicry on the recognition of emotion are still controversial. In Parkinson’s disease (PD), one of the most distinctive clinical features is facial amimia, a reduction in facial expressiveness, but patients also show emotional disturbances. The present study used the pathological model of PD to examine the role of facial mimicry on emotion recognition by investigating EMG responses in PD patients during a facial emotion recognition task (anger, joy, neutral). Our results evidenced a significant decrease in facial mimicry for joy in PD, essentially linked to the absence of reaction of the zygomaticus major and the orbicularis oculi muscles in response to happy avatars, whereas facial mimicry for expressions of anger was relatively preserved. We also confirmed that PD patients were less accurate in recognizing positive and neutral facial expressions and highlighted a beneficial effect of facial mimicry on the recognition of emotion. We thus provide additional arguments for embodied simulation theory suggesting that facial mimicry is a potential lever for therapeutic actions in PD even if it seems not to be necessarily required in recognizing emotion as such.

The Role of Neuroimaging in the Diagnosis, Prognosis and Management of Disorders of Consciousness and Locked-in Syndrome

Disorders of consciousness and locked-in syndrome are two completely different neurological conditions which share unresponsiveness or minimal responsiveness at an observable behavioral level. The key element of disorders of consciousness is the loss of self- and environmental awareness, while the main feature of locked-in syndrome is extreme motor entrapment despite preserved awareness. In both cases accurate diagnosis may come late and patients are at risk of being wrongly diagnosed and missing out on appropriate rehabilitative opportunities. Clinical assessment alone often does not suffice in establishing the correct diagnosis and prognosis. The contribution of advanced neuroimaging techniques is essential in order to properly recognize patients’ conditions and formulate a tailored rehabilitative approach. Neuroimaging findings are also crucial in identifying the neuropathological substrate of the disorders: they contribute to elucidating the dynamics of cortical-subcortical networks in disorders of consciousness and the neural correlates of recently reported non-motor symptoms in locked-in syndrome.

Disembodied Mind: Cortical Changes Following Brainstem Injury in Patients with Locked-in Syndrome

Locked-in syndrome (LIS) following ventral brainstem damage is the most severe form of motor disability. Patients are completely entrapped in an unresponsive body despite consciousness is preserved. Although the main feature of LIS is this extreme motor impairment, minor non-motor dysfunctions such as motor imagery defects and impaired emotional recognition have been reported suggesting an alteration of embodied cognition, defined as the effects that the body and its performances may have on cognitive domains. We investigated the presence of structural cortical changes in LIS, which may account for the reported cognitive dysfunctions. For this aim, magnetic resonance imaging scans were acquired in 11 patients with LIS (6 males and 5 females; mean age: 52.3±5.2SD years; mean time interval from injury to evaluation: 9±1.2SD months) and 44 healthy control subjects matching patients for age, sex and education. Freesurfer software was used to process data and to estimate cortical volumes in LIS patients as compared to healthy subjects. Results showed a selective cortical volume loss in patients involving the superior frontal gyrus, the pars opercularis and the insular cortex in the left hemisphere, and the superior and medium frontal gyrus, the pars opercularis, the insular cortex, and the superior parietal lobule in the right hemisphere. As these structures are typically associated with the mirror neuron system, which represents the neural substrate for embodied simulation processes, our results provide neuroanatomical support for potential disembodiment in LIS.

The Role of Neuroimaging Techniques in Establishing Diagnosis, Prognosis and Therapy in Disorders of Consciousness

Non-communicative brain damaged patients raise important clinical and scientific issues. Here, we review three major pathological disorders of consciousness: coma, the unresponsive wakefulness syndrome and the minimally conscious state. A number of clinical studies highlight the difficulty in making a correct diagnosis in patients with disorders of consciousness based only on behavioral examinations. The increasing use of neuroimaging techniques allows improving clinical characterization of these patients. Recent neuroimaging studies using positron emission tomography, functional magnetic resonance imaging, electroencephalography and transcranial magnetic stimulation can help assess diagnosis, prognosis, and therapeutic treatment. These techniques, using resting state, passive and active paradigms, also highlight possible dissociations between consciousness and responsiveness, and are facilitating a more accurate understanding of brain function in this challenging population.

Inducing a concurrent motor load reduces categorization precision for facial expressions

Motor theories of expression perception posit that observers simulate facial expressions within their own motor system, aiding perception and interpretation. Consistent with this view, reports have suggested that blocking facial mimicry induces expression labeling errors and alters patterns of ratings. Crucially, however, it is unclear whether changes in labeling and rating behavior reflect genuine perceptual phenomena (e.g., greater internal noise associated with expression perception or interpretation) or are products of response bias. In an effort to advance this literature, the present study introduces a new psychophysical paradigm for investigating motor contributions to expression perception that overcomes some of the limitations inherent in simple labeling and rating tasks. Observers were asked to judge whether smiles drawn from a morph continuum were sincere or insincere, in the presence or absence of a motor load induced by the concurrent production of vowel sounds. Having confirmed that smile sincerity judgments depend on cues from both eye and mouth regions (Experiment 1), we demonstrated that vowel production reduces the precision with which smiles are categorized (Experiment 2). In Experiment 3, we replicated this effect when observers were required to produce vowels, but not when they passively listened to the same vowel sounds. In Experiments 4 and 5, we found that gender categorizations, equated for difficulty, were unaffected by vowel production, irrespective of the presence of a smiling expression. These findings greatly advance our understanding of motor contributions to expression perception and represent a timely contribution in light of recent high-profile challenges to the existing evidence base.

Intrathecal baclofen: effects on spasticity, pain, and consciousness in disorders of consciousness and locked-in syndrome

Disorders of consciousness (DOCs) include coma, vegetative state (VS), and minimally conscious state (MCS). Coma is characterized by impaired wakefulness and consciousness, while VS and MCS are defined by lacking or discontinuous consciousness despite recovered wakefulness. Conversely, locked-in syndrome (LIS) is characterized by quadriplegia and lower cranial nerve paralysis with preserved consciousness. Intrathecal baclofen (ITB) is a useful treatment to improve spasticity both in patients with DOCs and LIS. Moreover, it supports the recovery of consciousness in some patients with VS or MCS. The precise mechanism underlying this recovery has not yet been elucidated. It has been hypothesized that ITB may act by reducing the overload of dysfunctional sensory stimuli reaching the injured brain or by stabilizing the imbalanced circadian rhythms. Although the current indication of ITB is the management of severe spasticity, its potential use in speeding the recovery of consciousness merits further investigation.

Explicit recognition of emotional facial expressions is shaped by expertise: evidence from professional actors

Can reading others' emotional states be shaped by expertise? We assessed processing of emotional facial expressions in professional actors trained either to voluntary activate mimicry to reproduce character's emotions (as foreseen by the "Mimic Method"), or to infer others' inner states from reading the emotional context (as foreseen by "Stanislavski Method"). In explicit recognition of facial expressions (Experiment 1), the two experimental groups differed from each other and from a control group with no acting experience: the Mimic group was more accurate, whereas the Stanislavski group was slower. Neither acting experience, instead, influenced implicit processing of emotional faces (Experiment 2). We argue that expertise can selectively influence explicit recognition of others' facial expressions, depending on the kind of "emotional expertise".

Cognitive rehabilitation in non-communicative brain-damaged patients

Conscious patients with severe motor and speech disorders have great difficulty interacting with the environment and communicating with other people. Several augmentative communication devices are now available to exploit these patients' expressive potential, but their use often demands considerable cognitive effort. Non-communicative patients with severe brain lesions may have, in addition, specific cognitive deficits that hinder the efficient use of augmentative communication methods. Some neuropsychological batteries are now available for testing these patients. On the basis of such cognitive assessments, cognitive rehabilitation training can now be applied, but we underline that this training must be tailored to single patients in order to allow them to communicate autonomously and efficiently.