What I think she thinks about my paralysed body: Social inferences about disability-related content in anosognosia for hemiplegia.

The neuropsychological disorder of anosognosia for hemiplegia (AHP) can offer unique insights into the neurocognitive processes of body consciousness and representation. Previous studies have found associations between selective social cognition deficits and anosognosia. In this study, we examined how such social cognition deficits may directly interact with representations of one's body as disabled in AHP. We used a modified set of previously validated Theory of Mind (ToM) stories to create disability-related content that was related to post-stroke paralysis and to investigate differences between right hemisphere damage patients with (n = 19) and without (n = 19) AHP. We expected AHP patients to perform worse than controls when trying to infer paralysis-related mental states in the paralysis-related ToM stories and explored whether such differences depended on the inference patients were asked to perform (e.g. self or other referent perspective-taking). Using an advanced structural neuroimaging technique, we expected selective social cognitive deficits to be associated with posterior parietal cortex lesions and deficits in self-referent perspective-taking in paralysis-related mentalising to be associated with frontoparietal disconnections. Group- and individual-level results revealed that AHP patients performed worse than HP controls when trying to infer paralysis-related mental states. Exploratory lesion analysis results revealed some of the hypothesised lesions, but also unexpected white matter disconnections in the posterior body and splenium of the corpus collosum associated with a self-referent perspective-taking in paralysis-related ToM stories. The study has implications for the multi-layered nature of body awareness, including abstract, social perspectives and beliefs about the body.

Topographic mapping of the sensorimotor qualities of empathic reactivity: A psychophysiological study in people with spinal cord injuries.

The experience of empathy for pain is underpinned by sensorimotor and affective dimensions which, although interconnected, are at least in part behaviorally and neurally distinct. Spinal cord injuries (SCI) induce a massive, below-lesion level, sensorimotor body-brain disconnection. This condition may make it possible to test whether sensorimotor deprivation alters specific dimensions of empathic reactivity to observed pain. To explore this issue, we asked SCI people with paraplegia and healthy controls to observe videos of painful or neutral stimuli administered to a hand (intact) or a foot (deafferented). The stimuli were displayed by means of a virtual reality set-up and seen from a first person (1PP) or third person (3PP) visual perspective. A number of measures were recorded ranging from explicit behaviors like explicit verbal reports on the videos, to implicit measures of muscular activity (like EMG from the corrugator and zygomatic muscles that may represent a proxy of sensorimotor empathy) and of autonomic reactivity (like the electrodermal response and Respiratory Sinus Arrhythmia that may represent a general proxy of affective empathy). While no across group differences in explicit verbal reports about the pain stimuli were found, SCI people exhibited reduced facial muscle reactivity to the stimuli applied to the foot (but not the hand) seen from the 1PP. Tellingly, the corrugator activity correlated with SCI participants' neuropathic pain. There were no across group differences in autonomic reactivity suggesting that SCI lesions may affect sensorimotor dimensions connected to empathy for pain.

Normative data beyond the total scores: a process score analysis of the Rey's 15 word test in healthy aging and Alzheimer's Disease.

BACKGROUND: The Rey's 15 words test is currently the most frequently used task in Italy to detect memory deficits in AD. The current standardised version is however quite outdated and lacks some cognitive indexes which may highlight problems in recall or encoding processes. The aim of the study was to update the normative data of the test and to consider some variables which were not accounted for in the original study, that is, recognition, learning rate and forgetfulness. We also adopted the process scores approach to ascertain the effects of serial position (primacy and recency). METHODS: Three hundred ninety-six healthy participants were recruited. To detect any variables useful for intercepting the early stages of dementia, a group of 208 patients in the very early stage of AD was also recruited. Linear models were used to calculate the corrections scores for age, education, and gender, and ROCs were used to calculate cut-offs based on the maximum sum of sensitivity and specificity and the positive and negative predictive values. RESULTS: All main indexes showed excellent Area Under the Curve (0.90-1), strong sensitivity and PPVs for distinguishing between the HCs and AD participants. However, the Intrusions index performed poorly in all parameters. CONCLUSION: The study provides updated, normative data which may be reliably used as a cognitive marker to detect early AD. The strength of the study is the large sample size and the number of indexes which make it possible to explore the utility of memory test process scores.

Examining the role of self-reported somatosensory sensations in body (dis)ownership: A scoping review and empirical study of patients with a disturbed sense of limb ownership.

Patients with a disturbed sense of limb ownership (DSO) offer a unique window of insight into the multisensory processes contributing to the sense of body ownership. A limited amount of past research has examined the role of sensory deficits in DSO, and even less is known regarding the role of patient self-reported somatosensory sensations in the pathogenesis of DSO. To address this lack of knowledge we first conducted a systematic scoping review following PRISMA-SR guidelines, examining current research into somatosensory deficits and patient self-reported somatosensory sensations in patients with DSO. Eighty studies, including 277 DSO patients, were identified. The assessment of sensory deficits was generally limited in scope and quality, and deficits in tactile sensitivity and proprioception were most frequently found. The reporting of somatosensory sensations was even less frequent, with instances of paraesthesia (pins-and-needles), stiffness/rigidity, numbness and warmth, coldness and heaviness amongst the deficits recorded. In a second part of the study, we sought to directly address the lack of evidence concerning the impact of patient self-reported somatosensory sensations in DSO by measuring DSO and self-reported somatosensory sensations in a large (n = 121) sample of right-hemisphere stroke patients including N = 65 with DSO and N = 56 hemiplegic controls. Results show that feelings of coldness and stiffness modulate DSO symptoms. Sense of heaviness and numbness are more frequent in patients with DSO but do not have a clear impact on disownership symptomology. Although preliminary, these results suggest a role of subjective sensations about the felt body in the sense of limb ownership.

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.

Effects of the social context on the neurophysiological correlates of observed error monitoring.

Monitoring the motor performance of others, including the correctness of their actions, is crucial for the human behavior. However, while performance (and error) monitoring of the own actions has been studied extensively at the neurophysiological level, the corresponding studies on monitoring of others' errors are scarce, especially for ecological actions. Moreover, the role of the context of the observed action has not been sufficiently explored. To fill this gap, the present study investigated electroencephalographic (EEG) indices of error monitoring during observation of images of interrupted reach-to-grasp actions in social (an object held in another person's hand) and non-social (an object placed on a table) contexts. Analysis in time- and time-frequency domain showed that, at the level of conscious error awareness, there were no effects of the social context (observed error positivity was present for erroneous actions in both contexts). However, the effects of the context were present at the level of hand image processing: observing erroneous actions in the non-social context was related to larger occipito-temporal N1 and theta activity, while in the social context this pattern was reversed, i.e., larger N1 and theta activity were present for the correct actions. These results suggest that, in case of easily predictable ecological actions, action correctness is processed as early as at the level of hand image perception, since the hand posture conveys information about the action (e.g., motor intention). The social context of actions might make the correct actions more salient, possibly through the saliency of the correctly achieved common goal.

A fronto-insular-parietal network for the sense of body ownership.

Neuropsychological disturbances in the sense of limb ownership provide unique opportunities to study the neurocognitive basis of body ownership. Previous small sample studies that showed discrete cortical lesions cannot explain why multisensory, affective, and cognitive manipulations alter disownership symptoms. We tested the novel hypothesis that disturbances in the sense of limb ownership would be associated not only with discrete cortical lesions but also with disconnections of white-matter tracts supporting specific functional networks. We drew on an advanced lesion-analysis and Bayesian statistics approach in 49 right-hemisphere patients (23 with and 26 without limb disownership). Our results reveal that disturbances in the sense of ownership are associated with lesions in the supramarginal gyrus and disconnections of a fronto-insular-parietal network, involving the frontal-insular and frontal inferior longitudinal tracts, confirming previous disconnection hypotheses. Together with previous behavioral and neuroanatomical results, these findings lead us to propose that the sense of body ownership involves the convergence of bottom-up, multisensory integration, and top-down monitoring of sensory salience based on contextual demands.

Temporal judgments of actions following unilateral brain damage.

Sense of time is a complex construct, and its neural correlates remain to date in most part unknown. To complicate the frame, physical attributes of the stimulus, such as its intensity or movement, influence temporal perception. Although previous studies have shown that time perception can be compromised after a brain lesion, the evidence on the role of the left and right hemispheres are meager. In two experiments, the study explores the ability of temporal estimation of multi-second actions and non-biological movements in 33 patients suffering from unilateral brain lesion. Furthermore, the modulatory role of induced embodiment processes is investigated. The results reveal a joint contribution of the two hemispheres depending not only on different durations but also on the presence of actions. Indeed, the left hemisphere damaged patients find it difficult to estimate 4500 ms or longer durations, while the right hemisphere damaged patients fail in 3000 ms durations. Furthermore, the former fail when a biological action is shown, while the latter fail in non-biological movement. Embodiment processes have a modulatory effect only after right hemisphere lesions. Among neuropsychological variables, only spatial neglect influences estimation of non-biological movement.

Bipolar Spectrum Symptoms in Patients with Fibromyalgia: A Dimensional Psychometric Evaluation of 120 Patients.

BACKGROUND: Fibromyalgia Syndrome (FMS) is characterized by chronic widespread pain, fatigue, unrefreshing sleep and cognitive dysfunction. Depressive and manic symptoms are often reported in FMS patients' history. The aim of this study was to evaluate the prevalence of bipolar spectrum symptoms (BSS) and to correlate these with quality of life (QoL) scores and antidepressant treatment. METHODS: From October 2017 to July 2018, a battery of QoL questionnaires (FIQ, PSQI and SF-12) was administered to 120 FMS patients after a clinical examination. The MOODS-SR lifetime questionnaire was then remotely administered to the patients included in the study. RESULTS: The presence of depressive and manic lifetime symptoms was found, in line with the results of the available literature. A correlation was found between the history of depressive symptoms and the severity of FIQ and SF-12 scores. Despite a low statistical strength, a trend toward a correlation between a history of manic symptoms and SNRI treatment was detected. CONCLUSIONS: The correlation between the MOOD-depressive domains and poor QoL is in line with the available literature. Further studies are needed to corroborate these findings and to elucidate the relationship between manic symptoms and SNRI treatment.

The 'healthy side' of anosognosia for hemiplegia: Increased sense of agency for the unimpaired limb or motor compensation?

OBJECTIVES: Anosognosic patients show a lack of awareness for their hemiplegia coupled with a distorted sense of agency for the actions performed by the plegic limbs. Since anosognosia is often associated with right brain damage, this hemisphere seems to play a dominant role in monitoring awareness for motor actions. Therefore, we would expect that anosognosic patients show distorted awareness and sense of agency also for actions performed with the unimpaired limb. METHOD: To test this hypothesis, we induced illusory actions that could be congruent or incongruent with a preceding verbal command. A group of 16 right brain-damaged patients performed this task and then rated i) their ability to anticipate the actions, ii) their sense of agency and iii) their sense of ownership for each limb. Measures of awareness, neglect and motor impairment were also considered for the patient group. RESULTS: Following incongruent actions with the unimpaired limb, less aware patients showed a relatively mild distortion in all three aspects. In addition, we also found a crucial relationship between motor impairment (for the plegic limb) and sense of agency for both plegic and healthy limbs. CONCLUSION: Although the distortion linked to both limbs supports the initial hypothesis that the right hemisphere is responsible for monitoring awareness for action for the whole body, our data also suggest that the observed distortion may be linked to a motor compensatory phenomenon, not necessarily related to awareness processes.

Motor awareness: a model based on neurological syndromes.

Motor awareness is a complex, multifaceted construct involving the awareness of both (i) one's motor state while executing a movement or remaining still and (ii) one's motor abilities. The analysis of neurological syndromes associated with motor disorders suggests the existence of various different components which are, however, integrated into a model of motor awareness. These components are: (i) motor intention, namely, a conscious desire to perform an action; (ii) motor monitoring and error recognition, that is, the capacity to check the execution of the action and identify motor errors; and (iii) a general awareness of one's own motor abilities and deficits, that is, the capacity to recognize the general state of one's motor abilities about the performance of specific actions and the potential consequences of motor impairment. Neuroanatomical correlates involving the parietal and insular cortices, the medial and lateral frontal regions, and subcortical structures (basal ganglia and limbic system) support this multi-component model. Specific damage (or disconnections) to these structures results in a number of different disorders in motor awareness, such as anosognosia for hemiplegia and apraxia, and a number of symptoms which are specific to motor intention disorders (e.g., the Anarchic Hand Syndrome and Tourette's Syndrome) or motor monitoring (e.g., Parkinson's and Huntington's diseases). All of these clinical conditions are discussed in the light of a motor awareness model.

Electrophysiological correlates of action monitoring in brain-damaged patients: A systematic review.

Action monitoring is crucial to the successful execution of an action and understanding the actions of others. It is often impaired due to brain lesions, in particular after stroke. This systematic review aims to map the literature on the neurophysiological correlates of action monitoring in patients with brain lesions. Eighteen studies were identified and divided into two groups: studies on monitoring of one's own actions and studies on monitoring of the actions of others. The first group included EEG studies on monitoring of self-performed erroneous and correct actions. Impaired error detection (decreased error-related negativity) was observed in patients with lesions in the performance-monitoring network, as compared to healthy controls. Less consistent results were shown for error positivity and behavioral error monitoring performance. The second group of studies on monitoring of others' actions reported decreased mu frequency suppression, impaired readiness potential in the affected hemisphere and decreased EEG indices of error observation (observed error positivity and theta power) in stroke patients. As a whole, these results indicate distinct patterns of impaired neurophysiological activity related to monitoring one's own versus others' actions in patients with brain lesions. EEG recordings of this dissociation in the same patients might be a useful index of motor recovery, and therefore, potentially also beneficial in rehabilitation protocols.

Disconnections in personal neglect.

Personal neglect is a disorder in the perception and representation of the body that causes the patients to behave as if the contralesional side of their body does not exist. This clinical condition has not been adequately investigated in the past as it has been considered a symptom of unilateral spatial neglect, which has mainly been studied with reference to extrapersonal space. Only a few studies with small samples have investigated the neuroanatomical correlates of personal neglect, and these have mainly focused on discrete cortical lesions and modular accounts, as well as being based on the hypothesis that this disorder is associated with somatosensory and spatial deficits. In the present study, we tested the novel hypothesis that personal neglect may be associated not only with discrete cortical and subcortical lesions, but also with disconnections of white matter tracts. We performed an advanced lesion analyses in a large sample of 104 right hemisphere damaged patients, 72 of whom were suffering from personal neglect. Results from the analyses of the grey and white matter were controlled for co-occurrent clinical variables such as extrapersonal neglect, anosognosia for hemiplegia and motor deficits, along with other lesion-related variables such as lesion size and the interval from the lesion onset to neuroimaging recordings. Our results reveal that personal neglect is associated with lesions in a medial network which involves the temporal cortex (Heschl's gyrus), the ventro-lateral nuclei of the thalamus and the fornix. This suggests that personal neglect involves a convergence between sensorimotor processes, spatial representation and the processing of self-referred information (episodic memory).

Awareness is in the eye of the observer: Preserved third-person awareness of deficit in anosognosia for hemiplegia.

In recent decades, the research traditions of (first-person) embodied cognition and of (third-person) social cognition have approached the study of self-awareness with relative independence. However, neurological disorders of self-awareness offer a unifying perspective to empirically investigate the contribution of embodiment and social cognition to self-awareness. This study focused on a neuropsychological disorder of bodily self-awareness following right-hemisphere damage, namely anosognosia for hemiplegia (AHP). A previous neuropsychological study has shown AHP patients, relative to neurological controls, to have a specific deficit in third-person perspective taking and allocentric stance (the other unrelated to the self) in higher order mentalizing tasks. However, no study has tested if verbal awareness of motor deficits is influenced by perspective-taking and centrism and identified the related anatomical correlates. Accordingly, two novel experiments were conducted with right-hemisphere stroke patients with (n = 17) and without AHP (n = 17) that targeted either their own (egocentric, experiment 1) or another stooge patients (allocentric, experiment 2) motor abilities from a first-or-third person perspective. In both experiments, neurological controls showed no significant difference in perspective-taking, suggesting that social cognition is not a necessary consequence of right-hemisphere damage. More specifically, experiment 1 found AHP patients more aware of their own motor paralysis (egocentric stance) when asked from a third compared to a first-person perspective, using both group level and individual level analysis. In experiment 2, AHP patients were less accurate than controls in making allocentric judgements about the stooge patient, but with only a trend towards significance and with no difference between perspectives. As predicted, deficits in egocentric and allocentric third-person perspective taking were associated with lesions in the middle frontal gyrus, superior temporal and supramarginal gyri, and white matter disconnections were more prominent with deficits in allocentricity. Behavioural and neuroimaging results demonstrate the intersecting relationship between bodily self-awareness and self-and-other-directed metacognition or mentalisation.

The evaluation of capacity in dementia: ethical constraints and best practice. A systematic review.

The progressive ageing of a population leads to an increase in the number of people suffering from cognitive deterioration. This requires particular attention in terms of the necessity to assess these people's cognitive functions and their capacity to make decisions. The present systematic review analyses the clinical and ethical aspects of any assessment of capacity, with a specific focus on the capacity of the individual to give informed consent for medical treatment and also with regard to their testamentary capacity. The results indicate that the concepts of capacity, competence and decision-making need to be better clarified, ad-hoc devised tools are required and a multidisciplinary, clinical and legal approach to assessments of capacity needs to be adopted. This is crucial to guarantee that the two ethical principles of capacity assessment are adhered to: respect for an individual's autonomy and the protection of fragile individuals.