Biology subjects

Aglioti, S. M.

Publications and source records attributed to Aglioti, S. M..

11 recordsLinked to original sources

bioRxiv2025

Differential Effects of Meditation States and Traits on the Neural Mechanisms of Pain Processing

ObjectivesThe main objective of the present study was to explore the effects of different types of meditation on the neurophysiologic mechanisms of pain processing. MethodsEEG responses to electric median nerve stimulation were recorded in short-term and long-term meditators (STM, LTM) during rest and three forms of meditation engaging attentional and affective regulation in different ways: focused attention meditation (FAM), open monitoring meditation (OMM) and loving kindness meditation (LKM). EEG responses were analysed in the time- and time-frequency domains to compute local components, and temporal and spatial synchronizations of multi-spectral pain-related oscillations (PROs) in order to characterize bottom-up processes, pro-active modulation of cortical excitability, cognitive/affective appraisal, and the connectivity of performance monitoring (fronto-medial) and attentional (fronto-parietal) networks during pain processing. ResultsSTM manifested a significant decrease in the connectedness of the fronto-medial theta-alpha network and a significant reduction of the P3b during LKM. In contrast, changes in LTM were observed during FAM and OMM. They were characterized by pre-stimulus alpha increase at somatosensory areas, and modulations of fronto-medial and fronto-parietal theta-alpha synchronizations. ConclusionsDifferent meditation states do not influence bottom-up sensory pain processing. However, they significantly alter cognitive/affective pain mechanisms in state- and trait-dependent ways. In novice meditators, a positive emotional disposition during meditation can suppress the distribution and cognitive/affective appraisal of nociceptive signals. In expert meditators, effects of meditation states on pain processing are critically guided by advanced control of internal attention leading to fine-tuned involvement and functional segregation of cognitive control and attention networks.

neuroscience↗

bioRxiv2024

Dopaminergic modulation of behavioral and electrocortical markers of interpersonal performance monitoring in Parkinson's Disease: insights from multivariate and univariate analyses

Effective interpersonal interaction necessitates constant monitoring and adaptation to others actions, a process known as interpersonal performance monitoring, which is influenced by the dopaminergic system and marked by specific electrocortical signatures. To explore the connection between deficits in interpersonal performance monitoring and altered neural markers, we assessed patients with Parkinsons Disease (PD) performing coordination tasks with a virtual partner (VP) under two conditions: on dopaminergic medication (PD ON) and after withdrawal (PD OFF). In Interactive trials, which required adaptation to the VPs actions, PD OFF performance was impaired compared to PD ON. EEG analysis revealed in PD OFF increased midfrontal Delta-Theta activity during Interactive trials. Higher Delta-Theta synchronization was associated with improved performance, suggesting compensatory mechanisms. Multivariate EEG analysis distinguished Interactive from Cued trials, especially in PD OFF. Our findings highlight dopamine s role in modulating electrocortical markers of interpersonal performance monitor, with significant implications for understanding and treating PD.

neuroscience↗

bioRxiv2024

Taking the perspective of an embodied avatar modulates the temporal dynamics of vicarious pain and pleasure: a combined Immersive Virtual Reality and EEG study

Observing negative and positive valence virtual stimuli can influence the onlookers subjective and brain reactivity. However, the relationship between vicarious pain and pleasure, observers perspective taking and cerebral activity remains underexplored. To address this gap, we asked 24 healthy participants to passively observe pleasant, painful, and neutral stimuli delivered to a virtual hand seen from a first-person (1PP) or third-person perspective (3PP) while undergoing time and time-frequency EEG recording. Participants reported a stronger sense of ownership over the virtual hand seen from a 1PP, rated pain and touch valence appropriately, and more intense than the neutral ones. Distinct EEG patterns emerged across early (N2, early posterior negativity, EPN), late (late positive potential, LPP) event-related potentials, and EEG power. The N2 and EPN components showed greater amplitudes for pain and pleasure than neutral stimuli, particularly in 1PP. The LPP component exhibited lower amplitudes for pleasure than pain and neutral stimuli. Further, theta-band power increased, and alpha power decreased for pain and pleasure stimuli viewed from a 1PP versus a 3PP perspective. In the ultra-late time window, we observed decreased theta, alpha, and beta-band power specifically associated with pleasure stimuli. Our study provides novel evidence that perspective-taking modulates the temporal dynamics of vicarious pain and pleasure.

neuroscience↗

bioRxiv2023

Deep-body feelings: ingestible pills reveal gastric correlates of emotions

Although it is generally held that gastro-intestinal (GI) signals are related to emotions, direct evidence for such a link is currently lacking. One of the reasons why the internal milieu of the GI system is poorly investigated is because visceral organs are difficult to access and monitor. To directly measure the influence of endoluminal markers of GI activity on the emotional experience, we asked a group of healthy male participants to ingest a pill that measured pH, pressure, and temperature of their GI tract while they watched video-clips that consistently induced disgust, fear, happiness, sadness, or a control neutral state. In addition to the objective physiological markers of GI activity, subjective ratings of perceived emotions and visceral (i.e. gastric, respiratory and cardiac) sensations were recorded. We found that when participants observed fearful and disgusting video-clips, they reported to perceive not only cardiac and respiratory sensations but also gastric sensations, such as nausea. Moreover, we found that there was a clear relation between the physiology of the stomach and the perceived emotions. Specifically, when disgusting video-clips were displayed, the more acidic the pH, the more participants reported feelings of disgust and fear; the less acidic the pH, the more they reported happiness. Our findings suggest that gastric signals contribute to unique emotional states and that ingestible pills may open new avenues for exploring the deep-body physiology of emotions.

neuroscience↗

bioRxiv2022

Reputation risk during dishonest social decision-making modulates anterior insular and cingulate cortex activity and connectivity

To explore the neural underpinnings of (dis)honest decision making under quasi-ecological conditions, we used an fMRI adapted version of a card game in which deceptive or truthful decisions are made to an opponent, with or without the risk of getting caught by them. Dishonest decisions were associated to increased activity in a cortico-subcortical circuit including the bilateral anterior cingulate cortex (ACC), anterior insula (AI), left dorsolateral prefrontal cortex, supplementary motor area, and right caudate. Crucially, deceptive immoral decisions under reputation risk enhanced activity of - and functional connectivity between - the bilateral ACC and left AI, suggesting the need for heightened emotional processing and cognitive control when making immoral decisions under reputation risk. Tellingly, more manipulative individuals required less involvement of the ACC during risky self-gain lies but more involvement during other-gain truths, pointing to the need of cognitive control only when going against ones own moral code.

neuroscience↗

bioRxiv2022

The thermoception task: a thermal-imaging based procedure for measuring awareness of changes in peripheral body temperature

Although thermal body signals provide crucial information about the state of an organism, and changes in body temperature may be a sign of affective states (e.g., stress, pain, sexual arousal), research on thermal awareness is limited. Here we developed a task measuring awareness of changes in peripheral body temperature (thermal interoception) and compared it to the classical heartbeat counting task (cardiac interoception). With an infrared lightbulb we delivered stimuli of different temperature intensities to the right hand of 31 healthy participants. Thermal interoceptive accuracy, i.e., the difference between participants real and perceived change in hand temperature, showed good inter-individual variability. We found that thermal interoception did not correlate with (and was generally higher than) cardiac interoception, suggesting that different interceptive channels provide separate contributions to awareness of bodily states. Moreover, the results hint at the great salience of thermal signals and the need for thermoregulation in day-to-day life. Finally, thermal interoceptive accuracy was associated with self-reported awareness of body temperature changes, and with the ability to regulate distress by focusing on body sensations. Our task has the potential to significantly increase current knowledge about the role of interoception in cognition and behavior, particularly in social and emotional contexts.

neuroscience↗

bioRxiv2022

Selective influence of dopamine on electrocortical signatures of error monitoring: a combined EEG and immersive virtual reality study in Parkinson's disease

Detecting errors in ones own and others actions is likely linked to the discrepancy between intended or expected and produced or observed output. To detect and process the occurrence of salient events seems associated to the release of dopamine, the balance of which is profoundly altered in Parkinsons disease (PD). EEG studies in healthy participants indicate that the occurrence of errors in observed actions triggers a variety of electrocortical indices (like mid-frontal theta activity, error-related delta and the Error Positivity, oPe), that seem to map different aspects of error detection and performance monitoring. Whether these indices are differently modulated by dopamine in the same individual has never been investigated. To explore this issue, we recorded EEG markers of error detection by asking healthy controls (HCs) and PD patients to observe ecological reach-to-grasp a glass actions performed by a virtual arm seen in first person perspective. PD patients were tested under their dopaminergic medication ( on-condition), and after dopaminergic withdrawal ( off-condition). HCs showed a clear oPe and an increase of delta and theta power during the observation of erroneous vs. correct actions. In PD patients, oPe and delta responses were always preserved. Crucially, however, an error-related increase of theta power was found in on but not in off state PD patients. Thus, different EEG error signatures may index the activity of independent systems and error related theta power is selectively modulated by dopamine depletion. Our findings may pave the way to the discovery of dopamine-related biomarkers of higher-order motor cognition dysfunctions that may have crucial theoretical and clinical implications. Significance StatementDopaminergic neurons respond to salient events during performance monitoring. Yet, the impact of dopamine depletion on the human reactivity to observed errors is still unclear. We recorded EEG in patients with Parkinsons Disease (PD) under dopaminergic treatment ( on-condition) and medication withdrawal ( off-condition) while they observed correct and erroneous goal-related actions performed by a virtual limb. Analysis of Error Positivity (oPe) and theta and delta power increase, markers of physiological error-monitoring, indicates that while the formers were intact, the latter was preserved in the on and altered in the off condition. Thus, different EEG markers of error monitoring likely rely on independent circuits. Moreover, mid-frontal theta activity alterations may represent a marker of dopamine-related neurophysiological impairments of higher-order cognition.

neuroscience↗

bioRxiv2021

The monitoring system is attuned to others' actions during dyadic motor interactions

Successful interpersonal motor interactions necessitate the simultaneous monitoring of our own and our partners actions. To characterize the dynamics of the action monitoring system for tracking self and other behaviors during dyadic synchronous interactions, we combined EEG recordings and immersive Virtual Reality in two tasks where participants were asked to coordinate their actions with those of a Virtual Partner (VP). The two tasks differed in the features to be monitored: the Goal task required participants to predict and monitor the VPs reaching goal; the Spatial task required participants to predict and monitor the VPs reaching trajectory. In both tasks, the VP performed unexpected movement corrections to which the participant needed to adapt. By comparing the neural activity locked to the detection of unexpected changes in the VP action (other-monitoring) or to the participants action-replanning (self-monitoring), we show that during interpersonal interactions the monitoring system is more attuned to others than to ones own actions. Additionally, distinctive neural responses to VPs unexpected goals and trajectory corrections were found: goal corrections were reflected both in early fronto-central and later posterior neural responses while trajectory deviations from the expected movement were reflected only in later and posterior responses. Since these responses were locked to the partners behavior and not to ones own, our results indicate that during interpersonal interactions the action monitoring system is dedicated to evaluating the partners movements. Hence, our results reveal an eminently social role of the monitoring system during motor interactions. Significance StatementNon-verbal synchronous interpersonal interactions require the monitoring of both our actions and those of our partners. Understanding the neural underpinnings of this ability with a focus on the dynamics between self- and other-monitoring is fundamental to the comprehension of social coordination. By combining EEG and immersive Virtual Reality we demonstrate that the monitoring system is more attuned to others actions than to our own. In two tasks, we show that the neural activity associated with unexpected corrections in the goal or the trajectory of an action are locked to the partners actions rather than to the participants subsequent adaptation. This pattern of results highlights a social mode adopted by the monitoring system to handle motor interactions.

neuroscience↗

bioRxiv2021

Gut markers of bodily self-consciousness

Bodily self-consciousness, the state of mind that allows humans to be aware of their own body, forms the backdrop for almost every human experience, yet its underpinnings remain elusive. Here we combine an ingestible, minimally invasive capsule with surface electrogastrography to probe if gut physiology correlates with bodily self-consciousness during a virtual bodily illusion. We discover that specific patterns of stomach and bowel activity (temperature, pressure, pH, and gastric peak frequency) covary with specific facets of bodily self-consciousness (feelings of body agency, location, and disembodiment). These results uncover the hitherto untapped potential of minimally invasive probes to study the link between mental and gut states, and reveal a deep visceral pathway to the self-conscious perception of ourselves as embodied beings.

physiology↗

bioRxiv2018

The true size of placebo analgesia: Concordant neural and behavioural measures of placebo analgesia during experimental acute pain

Placebo analgesia refers to the reduction of pain following the administration of an inactive treatment. While most clinical trials compare a drug treatment against a placebo to determine the efficacy of the analgesic, most experimental studies of placebo analgesia do not include a real analgesic condition. A direct comparison of placebo against a real analgesic can inform us about the true size of the placebo effect. To this end, we aimed to provide a robust estimate of placebo analgesia by contrasting the effect of pain relief expectation from an inert cream (vaseline) against a real topical analgesic agent (lidocaine) applied on two different limbs and their respective control conditions. Pain reports and electroencephalography (EEG) responses triggered by laser nociceptive stimulation were collected. Forty typical healthy adults were enrolled in a double-blind randomized within-subject study where a standard placebo induction script of verbal suggestions in a sham medical setting was used to enhance the expectation on treatment outcome. In line with the earliest studies of placebo analgesia, majority (30 of 40) of participants was placebo responders, i.e. they reported lower pain to the placebo treatment. Placebo responders reported low pain and displayed low laser evoked potentials (LEPs) amplitude for both the analgesic and placebo treatment limbs compared to the respective control limbs. Placebo analgesia correlated positively with the amplitude of the LEPs, thus establishing convergent validity of the findings. This study provides a robust estimate of the neural and behavioural measures of placebo analgesia, in comparison to a real analgesic. These estimates can help inform the quantitative criteria for similar neural and behavioural measures in assessing the effectiveness of a real drug in placebo controlled trials.

neuroscience↗

bioRxiv2018

Frontal and occipito-temporal Theta activity as marker of error monitoring in Human-Avatar joint performance.

Discrepancies between sensory predictions and action outcome are at the base of error coding. However, these phenomena have mainly been studied focusing on individual performance. Here, we explored prediction errors during a human-avatar motor interaction and focused on both the classical frontal error-related brain responses and the activity of the action observation network. Our motor interaction paradigm required healthy individuals to synchronize their reach-to-grasp movements with those of a virtual partner in conditions that did (Interactive) or did not require (Cued) movement prediction and adaptation to the partners actions. Crucially, in 30% of the trials the virtual partner suddenly and unpredictably changed its movement trajectory thereby violating the human participants expectation. These changes elicited error-related neuromarkers (ERN/Pe - Theta/Alpha modulations) over fronto-central electrodes mainly during the Interactive condition. Source localization and connectivity analyses showed that the frontal Theta activity induced by violations of the expected interactive movements was in phase with occipito-temporal Theta activity. These results expand current knowledge about the neural correlates of on-line motor interactions linking the frontal error-monitoring system to visual, body motion-related, responses.

neuroscience↗