Perceived Hospital Preparedness Is Negatively Associated With Pandemic-Induced Psychological Vulnerability in Primary Care Employees: A Multicentre Cross-Sectional Observational Study

OBJECTIVE

The COVID-19 pandemic had a profound negative impact on the psychological wellbeing of healthcare providers (HPs), but little is known about the factors that positively predict mental health of primary care staff during these dire situations.

METHODS

We conducted an online questionnaire survey among 702 emergency department workers across 10 hospitals in Switzerland and Belgium following the first COVID-19 wave in 2020, to explore their psychological vulnerability, perceived concerns, self-reported impact and level of pandemic workplace preparedness. Participants included physicians, nurses, psychologists and nondirect care employees (administrative staff). We tested for predictors of psychological vulnerability through both an exploratory cross-correlation with rigorous correction for multiple comparisons and model-based path modelling.

RESULTS

Findings showed that the self-reported impact of COVID-19 at work, concerns about contracting COVID-19 at work, and a lack of personal protective equipment were strong positive predictors of Depression, Anxiety, and Stress, and low Resilience. Instead, knowledge of the degree of preparedness of the hospital/department, especially in the presence of a predetermined contingency plan for an epidemic and training sessions about protective measures, showed the opposite effect, and were associated with lower psychological vulnerability. All effects were confirmed after accounting for confounding factors related to gender, age, geographical location and the role played by HPs in the hospital/department.

CONCLUSIONS

Difficult working conditions during the pandemic had a major impact on the psychological wellbeing of emergency department HPs, but this effect might have been lessened if they had been informed about adequate measures for minimizing the risk of exposure.

Cognitive exertion affects the appraisal of one's own and other people's pain

Correctly evaluating others' pain is a crucial prosocial ability. In both clinical and private settings, caregivers assess their other people's pain, sometimes under the effect of poor sleep and high workload and fatigue. However, the effect played by such cognitive strain in the appraisal of others' pain remains unclear. Fifty participants underwent one of two demanding tasks, involving either working memory (Experiment 1: N-Back task) or cognitive interference (Experiment 2: Stroop task). After each task, participants were exposed to painful laser stimulations at three intensity levels (low, medium, high), or video-clips of patients experiencing three intensity levels of pain (low, medium, high). Participants rated the intensity of each pain event on a visual analogue scale. We found that the two tasks influenced rating of both one's own and others' pain, by decreasing the sensitivity to medium and high events. This was observed either when comparing the demanding condition to a control (Stroop), or when modelling linearly the difficulty/performance of each depleting task (N-Back). We provide converging evidence that cognitive exertion affects the subsequent appraisal of one's own and likewise others' pain.

Distraction and cognitive control independently impact parietal and prefrontal response to pain

Previous studies found that distracting someone through a challenging activity leads to hypoalgesia, an effect mediated by parietal and prefrontal processes. Other studies suggest that challenging activities affect the ability to regulate one's aching experiences, due to partially-common neural substrate between cognitive control and pain at the level the medial prefrontal cortex. We investigated effects of distraction and cognitive control on pain by delivering noxious stimulations during or after a Stroop paradigm (requiring high cognitive load) or a neutral condition. We found less intense and unpleasant subjective pain ratings during (compared to after) task execution. This hypoalgesia was associated with enhanced activity at the level of the dorsolateral prefrontal cortex and the posterior parietal cortex, which also showed negative connectivity with the insula. Furthermore, multivariate pattern analysis revealed that distraction altered the neural response to pain, by making it more similar to that associated with previous Stroop tasks. All these effects were independent of the nature of the task which, instead, led to a localized neural modulation around the anterior cingulate cortex. Overall, our study underscores the role played by two facets of human executive functions, which exert independent influence in the neural response of pain.

The Effect of Uncertainty on Pain Decisions for Self and Others

Background

Estimating others’ pain is a challenging inferential process, associated with a high degree of uncertainty. While much is known about uncertainty’s effect on self‐regarding actions, its impact on other‐regarding decisions for pain have yet to be characterized.

Aim

The present study exploited models of probabilistic decision‐making to investigate how uncertainty influences the valuation and assessment of another’s pain.

Materials & Methods

We engaged 63 dyads (43 strangers and 20 romantic couples) in a task where individual choices affected the pain delivered to either oneself (the agent) or the other member of the dyad. At each trial, agents were presented with cues predicting a given pain intensity with an associated probability of occurrence. Agents either chose a sure (mild decrease of pain) or risky (50% chance of avoiding pain altogether) management option, before bidding on their choice. A heat stimulation was then issued to the target (self or other). Decision‐makers were then asked to rate the pain administered to the target.

Results

We found that the higher the expected pain, the more risk‐averse agents became, in line with findings in value‐based decision‐making. Furthermore, agents gambled less on another individual’s pain (especially strangers) and placed higher bids on pain relief than they did for themselves. Most critically, the uncertainty associated with expected pain dampened ratings made for strangers’ pain. This contrasted with the effect on an agent’s own pain, for which risk had a marginal hyperalgesic effect.

Discussion & Conclusion

Overall, our results suggested that risk selectively affects decision‐making on a stranger’s suffering, both at the level of assessment and treatment selection, by (1) leading to underestimation, (2) privileging sure options and (3) altruistically allocating more money to insure the treatment’s success.

Significance

Uncertainty biases decision‐making but it is unclear if it affects choice behavior on pain for others. In examining this question, we found individuals were generally risk‐seeking when faced with looming pain, but more so for self; and assigned higher monetary values and subjective ratings on another’s pain. However, uncertainty dampened agents’ assessment of a stranger’s pain, suggesting latent variables may contradict overt altruism. This bias may underlie pain underestimation in clinical settings.

Medical education and distrust modulate the response of insular-cingulate network and ventral striatum in pain diagnosis

Healthcare providers often underestimate patients’ pain, sometimes even when aware of their reports. This could be the effect of experience reducing sensitivity to others pain, or distrust toward patients’ self-evaluations. Across multiple experiments (375 participants), we tested whether senior medical students differed from younger colleagues and lay controls in the way they assess people’s pain and take into consideration their feedback. We found that medical training affected the sensitivity to pain faces, an effect shown by the lower ratings and highlighted by a decrease in neural response of the insula and cingulate cortex. Instead, distrust toward the expressions’ authenticity affected the processing of feedbacks, by decreasing activity in the ventral striatum whenever patients’ self-reports matched participants’ evaluations, and by promoting strong reliance on the opinion of other doctors. Overall, our study underscores the multiple processes which might influence the evaluation of others’ pain at the early stages of medical career.

Does inappropriate behavior hurt or stink? The interplay between neural representations of somatic experiences and moral decisions

Embodied models suggest that moral judgments are strongly intertwined with first-hand somatic experiences, with some pointing to disgust, and others arguing for a role of pain/harm. Both disgust and pain are unpleasant, arousing experiences, with strong relevance for survival, but with distinctive sensory qualities and neural channels. Hence, it is unclear whether moral cognition interacts with sensory-specific properties of one somatic experience or with supramodal dimensions common to both. Across two experiments, participants evaluated ethical dilemmas and subsequently were exposed to disgusting (olfactory) or painful (thermal) stimulations of matched unpleasantness. We found that moral scenarios enhanced physiological and neural activity to subsequent disgust (but not pain), as further supported by an independently validated whole-brain signature of olfaction. This effect was mediated by activity in the posterior cingulate cortex triggered by dilemma judgments. Our results thus speak in favor of an association between moral cognition and sensory-specific properties of disgust.

Atypical processing of social anticipation and feedback in borderline personality disorder

•

Borderline personality disorder (BPD) is characterized by interpersonal dysfunction.

•

In BPD, the superior temporal sulcus is hyperactivated during social anticipation.

•

In BPD, amygdala response to evaluative social feedback is also reduced.

•

Amygdala suppression is induced by anterior cingulate rise during social anticipation.

•

Atypical frontolimbic interactions may contribute to interpersonal dysfunction in BPD.

Background-

Borderline personality disorder (BPD) is characterized by maladaptive social functioning, and widespread negativity biases. The neural underpinnings of these impairments remain elusive. We thus tested whether BPD patients show atypical neural activity when processing social (compared to non-social) anticipation, feedback, and particularly, how they relate to each other.

Methods-

We acquired functional MRI data from 21 BPD women and 24 matched healthy controls (HCs) while they performed a task in which cues and feedbacks were either social (neutral faces for cues; happy or angry faces for positive and negative feedbacks, respectively) or non-social (dollar sign; winning or losing money for positive and negative feedbacks, respectively). This task allowed for the analysis of social anticipatory cues, performance-based feedback, and their interaction.

Results-

Compared to HCs, BPD patients expressed increased activation in the superior temporal sulcus during the processing of social cues, consistent with elevated salience associated with an upcoming social event. BPD patients also showed reduced activation in the amygdala while processing evaluative social feedback. Importantly, perigenual anterior cingulate cortex (pgACC) activity during the presentation of the social cue correlated with reduced amygdala activity during the presentation of the negative social feedback in the BPD patients.

Conclusions-

These neuroimaging results clarify how BPD patients express altered responses to different types of social stimuli (i.e. social anticipatory cues and evaluative feedback) and uncover an atypical relationship between frontolimbic regions (pgACC-amygdala) over the time span of a social interaction. These findings may help to explain why BPD patients suffer from pervasive difficulties adapting their behavior in the context of interpersonal relationships and should be considered while designing better-targeted interventions.

Pain management decisions in emergency hospitals are predicted by brain activity during empathy and error monitoring

OBJECTIVE

Pain undertreatment, or oligoanalgesia, is frequent in the emergency department (ED), with major medical, ethical, and financial implications. Across different hospitals, healthcare providers have been reported to differ considerably in the ways in which they recognise and manage pain, with some prescribing analgesics far less frequently than others. However, factors that could explain this variability remain poorly understood. Here, we used neuroscience approaches for neural signal modelling to investigate whether individual decisions in the ED could be explained in terms of brain patterns related to empathy, risk-taking, and error monitoring.

METHODS

For 15 months, we monitored the pain management behaviour of 70 ED nurses at triage, and subsequently invited 33 to a neuroimaging study involving three well-established tasks probing relevant cognitive and affective dimensions. Univariate and multivariate regressions were used to predict pain management decisions from neural activity during these tasks.

RESULTS

We found that the brain signal recorded when empathising with others predicted the frequency with which nurses documented pain in their patients. In addition, neural activity sensitive to errors and negative outcomes predicted the frequency with which nurses denied analgesia by registering potential side-effects.

CONCLUSIONS

These results highlight the multiple processes underlying pain management, and suggest that the neural representations of others' states and one's errors play a key role in individual treatment decisions. Neuroscience models of social cognition and decision-making are a powerful tool to explain clinical behaviour and might be used to guide future educational programs to improve pain management in ED.

Does my pain affect your disgust? Cross-modal influence of first-hand aversive experiences in the appraisal of others' facial expressions

BACKGROUND

Embodied models of social cognition argue that others' affective states are processed by re-enacting a sensory-specific representation of the same state in the observer. However, neuroimaging studies suggest that a reliable part of the representation shared between self and others is supramodal and relates to dimensions such as Unpleasantness or arousal, common to qualitatively different experiences. Here we investigated whether representations of first-hand pain and disgust influenced the subsequent evaluation of facial expressions in Modality-specific fashion, or in terms of Unpleasantness or arousal.

METHODS

Thirty volunteers were subjected to thermal painful and olfactory disgusting events, and subsequently were asked to classify computer-generated faces expressing pain (characterized by high Unpleasantness and arousal), disgust (high Unpleasantness and low arousal), surprise (low Unpleasantness and high arousal) and hybrid combinations thereof.

RESULTS

Thermal and olfactory events were associated with comparable Unpleasantness ratings and heart rate (but stronger galvanic response was found for painful temperatures). Furthermore, we found that the appraisal of facial expressions was biased by the prior stimulus, with more frequent pain classifications following thermal stimuli, and more frequent disgust classifications following olfactory stimuli. Critically, this modulation was cross-modal in nature, as each first-hand stimulation influenced in comparable fashion facial traits diagnostic of both pain and disgust, without instead generalizing to features of surprise.

CONCLUSION

Overall, these data support the presence of shared coding between one's aversive experiences and the appraisal of others' facial responses, which is best describable as supramodal representation of the Unpleasantness of the experience.

SIGNIFICANCE

These results extend previous findings about common representational coding between the experience of first-hand and others' pain. In particular, they highlight that reliable part of the information shared is supramodal in nature and relates to a broad dimension of Unpleasantness common also to painless aversive states such as disgust.

Sensory-specific predictive models in the human anterior insula

Expectations affect the subjective experience of pain by increasing sensitivity to noxious events, an effect underlain by brain regions such as the insula. However, it has been debated whether these neural processes operate on pain-specific information or on more general signals encoding expectation of unpleasant events. To dissociate these possibilities, two independent studies ( Sharvit et al., 2018, Pain; Fazeli and Büchel, 2018, J. Neurosci) implemented a cross-modal expectancy paradigm, testing whether responses to pain could also be modulated by the expectation of similarly unpleasant, but painless, events. Despite their differences, the two studies report remarkably convergent (and in some cases complementary) findings. First, the middle-anterior insula response to noxious stimuli is modulated only by expectancy of pain but not of painless adverse events, suggesting coding of pain-specific information. Second, sub-portions of the middle-anterior insula mediate different aspects of pain predictive coding, related to expectancy and prediction error. Third, complementary expectancy effects are also observed for other negative experiences (i.e., disgust), suggesting that the insular cortex holds prospective models of a wide range of events concerning their sensory-specific features. Taken together, these studies have strong theoretical implications on the functional properties of the insular cortex.

Beyond unpleasantness. Social exclusion affects the experience of pain, but not of equally-unpleasant disgust

Seminal theories posit that social and physical suffering underlie partly-common representational code. It is unclear, however, if this shared information reflects a modality-specific component of pain, or alternatively a supramodal code for properties common to many aversive experiences (unpleasantness, salience, etc.). To address this issue, we engaged participants in a gaming experience in which they were excluded or included by virtual players. After each game session, participants were subjected to comparably-unpleasant painful or disgusting stimuli. Subjective reports and cardiac responses revealed a reduced sensitivity to pain following exclusion relative to inclusion, an effect which was more pronounced in those participants who declared to feel more affected by the gaming manipulation. Such modulation was not observed for disgust. These findings indicate that the relationship between social and physical suffering does not generalize to disgust, thus suggesting a shared representational code at the level of modality-specific components of pain.

The good, the bad, and the suffering. Transient emotional episodes modulate the neural circuits of pain and empathy

People's sensitivity to first-hand pain is affected by their ongoing emotions, with positive states (joy, amusement) exerting analgesic-like effects, and negative states (sadness, fear) often enhancing the subjective experience. It is however less clear how empathetic responses to others' pain are affected by one's own emotional state. Following embodied accounts that posit a shared representational code between self and others' states, it is plausible that pain empathy might be influenced by emotions in the same way as first-hand pain. Alternatively, other theories in psychology suggest that social resources (including empathetic reactions) might be enhanced by positive states, but inhibited by negative states, as only in the former case, one's mindset is sufficiently broad to take into consideration others' needs. To disambiguate between these opposing predictions, we conducted two experiments in which volunteers observed positive, neutral, or negative video clips, and subsequently either received painful thermal stimuli on their own body (first-hand pain), or observed images of wounded hands (others' pain). We measured subjective pain ratings as well as physiological responses and brain activity using fMRI. We found that, contrary to the case of first-hand pain, others' pain produced weaker galvanic responses and lower neural activity in anterior insula and middle cingulate cortex following negative (relative to neutral and positive) videos. Such inhibition was partially counteracted by personal empathy traits, as individuals with higher scores retained greater sensitivity to others' pain after negative emotion induction, in both behavioral and neural responses in medial prefrontal cortex. Furthermore, multivoxel pattern analysis confirmed similar neural representation for first-hand and others' pain in anterior insula, with representation similarity increasing the more the video preceding the observation of others' suffering was positive. These findings speak against the idea that emotion induction affects first-hand and others' pain in an isomorphic way, but rather supports the idea that contrary to negative emotions, positive emotions favors a broader access to social resources.

Fear Spreading Across Senses: Visual Emotional Events Alter Cortical Responses to Touch, Audition, and Vision

Attention and perception are potentiated for emotionally significant stimuli, promoting efficient reactivity and survival. But does such enhancement extend to stimuli simultaneously presented across different sensory modalities? We used functional magnetic resonance imaging in humans to examine the effects of visual emotional signals on concomitant sensory inputs in auditory, somatosensory, and visual modalities. First, we identified sensory areas responsive to task-irrelevant tones, touches, or flickers, presented bilaterally while participants attended to either a neutral or a fearful face. Then, we measured whether these responses were modulated by the emotional content of the face. Sensory responses in primary cortices were enhanced for auditory and tactile stimuli when these appeared with fearful faces, compared with neutral, but striate cortex responses to the visual stimuli were reduced in the left hemisphere, plausibly as a consequence of sensory competition. Finally, conjunction and functional connectivity analyses identified 2 distinct networks presumably responsible for these emotional modulatory processes, involving cingulate, insular, and orbitofrontal cortices for the increased sensory responses, and ventrolateral prefrontal cortex for the decreased sensory responses. These results suggest that emotion tunes the excitability of sensory systems across multiple modalities simultaneously, allowing the individual to adaptively process incoming inputs in a potentially threatening environment.

Cross-modal and modality-specific expectancy effects between pain and disgust

Pain sensitivity increases when a noxious stimulus is preceded by cues predicting higher intensity. However, it is unclear whether the modulation of nociception by expectancy is sensory-specific ("modality based") or reflects the aversive-affective consequence of the upcoming event ("unpleasantness"), potentially common with other negative events. Here we compared expectancy effects for pain and disgust by using different, but equally unpleasant, nociceptive (thermal) and olfactory stimulations. Indeed both pain and disgust are aversive, associated with threat to the organism, and processed in partly overlapping brain networks. Participants saw cues predicting the unpleasantness (high/low) and the modality (pain/disgust) of upcoming thermal or olfactory stimulations, and rated the associated unpleasantness after stimuli delivery. Results showed that identical thermal stimuli were perceived as more unpleasant when preceded by cues threatening about high (as opposed to low) pain. A similar expectancy effect was found for olfactory disgust. Critically, cross-modal expectancy effects were observed on inconsistent trials when thermal stimuli were preceded by high-disgust cues or olfactory stimuli preceded by high-pain cues. However, these effects were stronger in consistent than inconsistent conditions. Taken together, our results suggest that expectation of an unpleasant event elicits representations of both its modality-specific properties and its aversive consequences.

How the brain predicts people's behavior in relation to rules and desires. Evidence of a medio-prefrontal dissociation

Forming and updating impressions about others is critical in everyday life and engages portions of the dorsomedial prefrontal cortex (dMPFC), the posterior cingulate cortex (PCC) and the amygdala. Some of these activations are attributed to "mentalizing" functions necessary to represent people's mental states, such as beliefs or desires. Evolutionary psychology and developmental studies, however, suggest that interpersonal inferences can also be obtained through the aid of deontic heuristics, which dictate what must (or must not) be done in given circumstances. We used fMRI and asked 18 participants to predict whether unknown characters would follow their desires or obey external rules. Participants had no means, at the beginning, to make accurate predictions, but slowly learned (throughout the experiment) each character's behavioral profile. We isolated brain regions whose activity changed during the experiment, as a neural signature of impression updating: whereas dMPFC was progressively more involved in predicting characters' behavior in relation to their desires, the medial orbitofrontal cortex and the amygdala were progressively more recruited in predicting rule-based behavior. Our data provide evidence of a neural dissociation between deontic inference and theory-of-mind (ToM), and support a differentiation of orbital and dorsal prefrontal cortex in terms of low- and high-level social cognition.

Selecting category specific visual information: Top-down and bottom-up control of object based attention

The ability to select, within the complexity of sensory input, the information most relevant for our purposes is influenced by both internal settings (i.e., top-down control) and salient features of external stimuli (i.e., bottom-up control). We here investigated using fMRI the neural underpinning of the interaction of top-down and bottom-up processes, as well as their effects on extrastriate areas processing visual stimuli in a category-selective fashion. We presented photos of bodies or buildings embedded into frequency-matched visual noise to the subjects. Stimulus saliency changed gradually due to an altered degree to which photos stood-out in relation to the surrounding noise (hence generating stronger bottom-up control signals). Top-down settings were manipulated via instruction: participants were asked to attend one stimulus category (i.e., "is there a body?" or "is there a building?"). Highly salient stimuli that were inconsistent with participants' attentional top-down template activated the inferior frontal junction and dorsal parietal regions bilaterally. Stimuli consistent with participants' current attentional set additionally activated insular cortex and the parietal operculum. Furthermore, the extrastriate body area (EBA) exhibited increased neural activity when attention was directed to bodies. However, the latter effect was found only when stimuli were presented at intermediate saliency levels, thus suggesting a top-down modulation of this region only in the presence of weak bottom-up signals. Taken together, our results highlight the role of the inferior frontal junction and posterior parietal regions in integrating bottom-up and top-down attentional control signals.

Cognitive and affective theory of mind share the same local patterns of activity in posterior temporal but not medial prefrontal cortex

Understanding emotions in others engages specific brain regions in temporal and medial prefrontal cortices. These activations are often attributed to more general cognitive 'mentalizing' functions, associated with theory of mind and also necessary to represent people's non-emotional mental states, such as beliefs or intentions. Here, we directly investigated whether understanding emotional feelings recruit similar or specific brain systems, relative to other non-emotional mental states. We used functional magnetic resonance imaging with multivoxel pattern analysis in 46 volunteers to compare activation patterns in theory-of-mind tasks for emotions, relative to beliefs or somatic states accompanied with pain. We found a striking dissociation between the temporoparietal cortex, that exhibited a remarkable voxel-by-voxel pattern overlap between emotions and beliefs (but not pain), and the dorsomedial prefrontal cortex, that exhibited distinct (and yet nearby) patterns of activity during the judgment of beliefs and emotions in others. Pain judgment was instead associated with activity in the supramarginal gyrus, middle cingulate cortex and middle insular cortex. Our data reveal for the first time a functional dissociation within brain networks sub-serving theory of mind for different mental contents, with a common recruitment for cognitive and affective states in temporal regions, and distinct recruitment in prefrontal areas.

Integration of Error Agency and Representation of Others' Pain in the Anterior Insula

A crucial feature of socially adaptive behavior is the ability to recognize when our actions harm other individuals. Previous research demonstrates that dorsal mediofrontal cortex (dMFC) and anterior insula (AI) are involved in both action monitoring and empathy for pain. Here, we tested whether these regions could integrate monitoring of error agency with the representation of others' pain. While undergoing event-related fMRI, participants played a visual task in turns with a friend placed outside the scanner, who would receive painful stimulation in half of the error trials. Brain activity was enhanced in dMFC and AI for painful compared with nonpainful errors. Left AI and dorsolateral pFC also exhibited a significant interaction with agency and increased responses when painful errors were caused by oneself. We conclude that AI is crucial for integrating inferences about others' feeling states with information about action agency and outcome, thus generating an affective signal that may guide subsequent adjustment.

Disentangling self- and fairness-related neural mechanisms involved in the ultimatum game: an fMRI study

Rejections of unfair offers in the ultimatum game (UG) are commonly assumed to reflect negative emotional arousal mediated by the anterior insula and medial prefrontal cortex. We aimed to disentangle those neural mechanisms associated with direct personal involvement ('I have been treated unfairly') from those associated with fairness considerations, such as the wish to discourage unfair behavior or social norm violations ('this person has been treated unfairly'). For this purpose, we used fMRI and asked participants to play the UG as responders either for themselves (myself) or on behalf of another person (third party). Unfair offers were equally often rejected in both conditions. Neuroimaging data revealed a dissociation between the medial prefrontal cortex, specifically associated with rejections in the myself condition, thus confirming its role in self-related emotional responses, and the left anterior insula, associated with rejections in both myself and third-party conditions, suggesting a role in promoting fair behavior also toward third parties. Our data extend the current understanding of the neural substrate of social decision making, by disentangling the structures sensitive to direct emotional involvement of the self from those implicated in pure fairness considerations.

“She” Is Not Like “I”: The Tie between Language and Action Is in Our Imagination

Embodied theories hold that understanding what another person is doing requires the observer to map that action directly onto his or her own motor representation and simulate it internally. The human motor system may, thus, be endowed with a “mirror matching” device through which the same motor representation is activated, when the subject is either the performer or the observer of another's action (“self-other shared representation”). It is suggested that understanding action verbs relies upon the same mechanism; this implies that motor responses to these words are automatic and independent of the subject of the verb. In the current study, participants were requested to read silently and decide on the syntactic subject of action and nonaction verbs, presented in first (1P) or third (3P) person, while TMS was applied to the left hand primary motor cortex (M1). TMS-induced motor-evoked potentials were recorded from hand muscles as a measure of cortico-spinal excitability. Motor-evoked potentials increased for 1P, but not for 3P, action verbs or 1P and 3P nonaction verbs. We provide novel demonstration that the motor simulation is triggered only when the conceptual representation of a word integrates the action with the self as the agent of that action. This questions the core principle of “mirror matching” and opens to alternative interpretations of the relationship between conceptual and sensorimotor processes.

Thalamic-insular dysconnectivity in schizophrenia: evidence from structural equation modeling

Structural and functional studies have shown that schizophrenia is often associated with frontolimbic abnormalities in the prefrontal and mediotemporal regions. It is still unclear, however, if such dysfunctional interaction extends as well to relay regions such as the thalamus and the anterior insula. Here, we measured gray matter volumes of five right-hemisphere regions in 68 patients with schizophrenia and 77 matched healthy subjects. The regions were amygdala, thalamus, and entorhinal cortex (identified as anomalous by prior studies on the same population) and dorsolateral prefrontal cortex and anterior insula (isolated by voxel-based morphometry analysis). We used structural equation modeling and found altered path coefficients connecting the thalamus to the anterior insula, the amygdala to the DLPFC, and the entorhinal cortex to the DLPFC. In particular, patients exhibited a stronger thalamus-insular connection than healthy controls. Instead, controls showed positive entorhinal-DLPFC and negative amygdalar-DLPFC connections, both of which were absent in the clinical population. Our data provide evidence that schizophrenia is characterized by an impaired right-hemisphere network, in which intrahemispheric communication involving relay structures may play a major role in sustaining the pathophysiology of the disease.

Is the body in the eye of the beholder? Visual processing of bodies in individuals with anomalous anatomical sensory and motor features

Neuropsychological and neuroimaging studies suggest distinct body representations involved in coding one's and others' body. Other influential theories, however, instead posit a unique model behind coding multisensory information about one's own body and visual information about others. An efficient way to further investigate this issue can be through testing individuals with anomalous anatomical and sensorimotor bodily features. In these people, the representation of their own body is held to be different with respect to the average population due to the peculiar properties of their body, and any experimental finding supposedly mediated by this representation should reflect such difference. We reviewed the most relevant studies reporting individuals with anomalous anatomical and sensorimotor bodily features engaged in (a) handedness task, (b) visual processing of biological motion and (c) visual processing of body shape. The performance in all three kinds of cognitive processes is affected by anomalous body features of the tested populations. However, the reviewed data are also in favor of a body model extrapolated by visual experience of others which mediates processing of biological stimuli and which operates in parallel, or as an alternative, to the representation of one's own body. In light of these results, pure visual and pure embodied accounts behind visual processing of biological stimuli should be reconsidered.

Neuropsychological perspectives on the mechanisms of imitation

Cognitive neuroscientists have contributed to the understanding of imitation according to their expertise. Neuropsychologists first established over a century ago that lesions to the left hemisphere of right-handed individuals lead to a dramatic reduction of their ability to imitate gestures. In contrast, after frontal lobe damage, patients may experience severe difficulties in inhibiting their imitative tendency. These findings suggested that our tendency to imitate is mostly sustained by the left hemisphere and that we normally manage successfully to keep it under control. Neuropsychologists went on investigating other aspects of gesture imitation. These include the existence of putative mechanisms involved in imitating different types of gestures (e.g. meaningful and meaningless or transitive and intransitive), the strategic control over these mechanisms and whether there are differences in imitation depending on the action goal or the body part used. Based on neuropsychological findings, some cognitive models of gesture imitation have been forwarded, the most influential of which will be reviewed here. In particular, reference will be made to the dual route model and to accounts that associate the imitative deficit to putative degraded body representations.

Velocity control in Parkinson's disease: a quantitative analysis of isochrony in scribbling movements

An experiment was conducted to contrast the motor performance of three groups (N = 20) of participants: (1) patients with confirmed Parkinson Disease (PD) diagnose; (2) age-matched controls; (3) young adults. The task consisted of scribbling freely for 10 s within circular frames of different sizes. Comparison among groups focused on the relation between the figural elements of the trace (overall size and trace length) and the velocity of the drawing movements. Results were analysed within the framework of previous work on normal individuals showing that instantaneous velocity of drawing movements depends jointly on trace curvature (Two-thirds Power Law) and trace extent (Isochrony principle). The motor behaviour of PD patients exhibited all classical symptoms of the disease (reduced average velocity, reduced fluency, micrographia). At a coarse level of analysis both isochrony and the dependence of velocity on curvature, which are supposed to reflect cortical mechanisms, were spared in PD patients. Instead, significant differences with respects to the control groups emerged from an in-depth analysis of the velocity control suggesting that patients did not scale average velocity as effectively as controls. We factored out velocity control by distinguishing the influence of the broad context in which movement is planned--i.e. the size of the limiting frames--from the influence of the local context--i.e. the linear extent of the unit of motor action being executed. The balance between the two factors was found to be distinctively different in PD patients and controls. This difference is discussed in the light of current theorizing on the role of cortical and sub-cortical mechanisms in the aetiology of PD. We argue that the results are congruent with the notion that cortical mechanisms are responsible for generating a parametric template of the desired movement and the BG specify the actual spatio-temporal parameters through a multiplicative gain factor acting on both size and velocity.

Where is a nose with respect to a foot? The left posterior parietal cortex processes spatial relationships among body parts

Neuropsychological studies suggest that patients with left parietal lesions may show impaired localization of parts of either their own or the examiner's body, despite preserved ability to identify isolated body parts. This deficit, called autotopagnosia, may result from damage to the Body Structural Description (BSD), a representation which codes spatial relationships among body parts. We used functional magnetic resonance imaging to identify the neural mechanisms underlying the BSD. Two human body or building parts (factor: STIMULI) were shown to participants who either identified them or evaluated their distance (factor: TASK). The analysis of the interaction between STIMULI and TASK, which isolates the neural mechanism underlying BSD, revealed an activation of left posterior intraparietal sulcus (IPS) when the distance between body parts was evaluated. The results show that the left IPS processes specifically the information about spatial relationships among body parts and thereby suggest that damage to this area may underlie autotopagnosia.