Physicians prescribe fewer analgesics during night shifts than day shifts.

Adequate pain management is one of the biggest challenges of the modern healthcare system. Physician perception of patient subjective pain, which is crucial to pain management, is susceptible to a host of potential biases. Here we explore the timing of physicians' work as a previously unrecognized source of systematic bias in pain management. We hypothesized that during night shifts, sleep deprivation, fatigue, and stress would reduce physicians' empathy for others' pain, leading to underprescription of analgesics for patient pain relief. In study 1, 67 resident physicians, either following a night shift or not, performed empathy for pain assessment tasks and simulated patient scenarios in laboratory conditions. As predicted, following a night shift, physicians showed reduced empathy for pain. In study 2, we explored this phenomenon in medical decisions in the field. We analyzed three emergency department datasets from Israel and the United States that included discharge notes of patients arriving with pain complaints during 2013 to 2020 (n = 13,482). Across all datasets, physicians were less likely to prescribe an analgesic during night shifts (compared to daytime shifts) and prescribed fewer analgesics than generally recommended by the World Health Organization. This effect remained significant after adjusting for patient, physician, type of complaint, and emergency department characteristics. Underprescription for pain during night shifts was particularly prominent for opioids. We conclude that night shift work is an important and previously unrecognized source of bias in pain management, likely stemming from impaired perception of pain. We consider the implications for hospitals and other organizations employing night shifts.

Intonation Units in Spontaneous Speech Evoke a Neural Response.

Spontaneous speech is produced in chunks called intonation units (IUs). IUs are defined by a set of prosodic cues and presumably occur in all human languages. Recent work has shown that across different grammatical and sociocultural conditions IUs form rhythms of ∼1 unit per second. Linguistic theory suggests that IUs pace the flow of information in the discourse. As a result, IUs provide a promising and hitherto unexplored theoretical framework for studying the neural mechanisms of communication. In this article, we identify a neural response unique to the boundary defined by the IU. We measured the EEG of human participants (of either sex), who listened to different speakers recounting an emotional life event. We analyzed the speech stimuli linguistically and modeled the EEG response at word offset using a GLM approach. We find that the EEG response to IU-final words differs from the response to IU-nonfinal words even when equating acoustic boundary strength. Finally, we relate our findings to the body of research on rhythmic brain mechanisms in speech processing. We study the unique contribution of IUs and acoustic boundary strength in predicting delta-band EEG. This analysis suggests that IU-related neural activity, which is tightly linked to the classic Closure Positive Shift (CPS), could be a time-locked component that captures the previously characterized delta-band neural speech tracking.SIGNIFICANCE STATEMENT Linguistic communication is central to human experience, and its neural underpinnings are a topic of much research in recent years. Neuroscientific research has benefited from studying human behavior in naturalistic settings, an endeavor that requires explicit models of complex behavior. Usage-based linguistic theory suggests that spoken language is prosodically structured in intonation units. We reveal that the neural system is attuned to intonation units by explicitly modeling their impact on the EEG response beyond mere acoustics. To our understanding, this is the first time this is demonstrated in spontaneous speech under naturalistic conditions and under a theoretical framework that connects the prosodic chunking of speech, on the one hand, with the flow of information during communication, on the other.

Effects of social presence on behavioral, neural, and physiological aspects of empathy for pain.

In mediated interactions (e.g. video calls), less information is available about the other. To investigate how this affects our empathy for one another, we conducted an electroencephalogram study, in which 30 human participants observed 1 of 5 targets undergoing painful electric stimulation, once in a direct interaction and once in a live, video-mediated interaction. We found that observers were as accurate in judging others' pain and showed as much affective empathy via video as in a direct encounter. While mu suppression, a common neural marker of empathy, was not sensitive to others' pain, theta responses to others' pain as well as skin conductance coupling between participants were reduced in the video-mediated condition. We conclude that physical proximity with its rich social cues is important for nuanced physiological resonance with the other's experience. More studies are warranted to confirm these results and to understand their behavioral significance for remote social interactions.

Grasp-specific high-frequency broadband mirror neuron activity during reach-and-grasp movements in humans.

Broadly congruent mirror neurons, responding to any grasp movement, and strictly congruent mirror neurons, responding only to specific grasp movements, have been reported in single-cell studies with primates. Delineating grasp properties in humans is essential to understand the human mirror neuron system with implications for behavior and social cognition. We analyzed electrocorticography data from a natural reach-and-grasp movement observation and delayed imitation task with 3 different natural grasp types of everyday objects. We focused on the classification of grasp types from high-frequency broadband mirror activation patterns found in classic mirror system areas, including sensorimotor, supplementary motor, inferior frontal, and parietal cortices. Classification of grasp types was successful during movement observation and execution intervals but not during movement retention. Our grasp type classification from combined and single mirror electrodes provides evidence for grasp-congruent activity in the human mirror neuron system potentially arising from strictly congruent mirror neurons.

Are there positive effects of having a sibling with special needs? Empathy and prosociality of twins of children with non-typical development.

This study examined whether typically developing (TD) twins of non-TD children demonstrate enhanced empathy and prosociality. Of 778 Hebrew-speaking Israeli families who participated in a twin study, 63 were identified to have a non-TD child with a TD twin, and 404 as having both twins TD. TD twins of non-TD children (27% males) were compared to the rest of the cohort of TD children (46% males) on measures of empathy and prosociality. Participants were 11 years old. TD twins of non-TD children scored significantly higher than TD twins of TD children in a measure of cognitive empathy (d = .43). No differences were found in emotional empathy and prosociality. The specificity of the positive effect on cognitive empathy is discussed.

Mirroring in the Human Brain: Deciphering the Spatial-Temporal Patterns of the Human Mirror Neuron System.

Embodied theories of cognition emphasize the central role of sensorimotor transformations in the representation of others' actions. Support for these theories is derived from the discovery of the mirror neuron system (MNS) in primates, from noninvasive techniques in humans, and from a limited number of intracranial studies. To understand the neural dynamics of the human MNS, more studies with precise spatial and temporal resolutions are essential. We used electrocorticography to define activation patterns in sensorimotor, parietal and/or frontal neuronal populations, during a viewing and grasping task. Our results show robust high gamma activation for both conditions in classic MNS sites. Furthermore, we provide novel evidence for 2 different populations of neurons: sites that were only active for viewing and grasping ("pure mirroring") and sites that were also active between viewing and grasping, and perhaps serve a more general attentional role. Lastly, a subgroup of parietal electrodes showed earlier peaks than all other regions. These results highlight the complexity of spatial-temporal patterns within the MNS and provide a critical link between single-unit research in monkeys and noninvasive techniques in human.

Effects of prefrontal cortex damage on emotion understanding: EEG and behavioural evidence.

Humans are highly social beings that interact with each other on a daily basis. In these complex interactions, we get along by being able to identify others' actions and infer their intentions, thoughts and feelings. One of the major theories accounting for this critical ability assumes that the understanding of social signals is based on a primordial tendency to simulate observed actions by activating a mirror neuron system. If mirror neuron regions are important for action and emotion recognition, damage to regions in this network should lead to deficits in these domains. In the current behavioural and EEG study, we focused on the lateral prefrontal cortex including dorsal and ventral prefrontal cortex and utilized a series of task paradigms, each measuring a different aspect of recognizing others' actions or emotions from body cues. We examined 17 patients with lesions including (n = 8) or not including (n = 9) the inferior frontal gyrus, a core mirror neuron system region, and compared their performance to matched healthy control subjects (n = 18), in behavioural tasks and in an EEG observation-execution task measuring mu suppression. Our results provide support for the role of the lateral prefrontal cortex in understanding others' emotions, by showing that even unilateral lesions result in deficits in both accuracy and reaction time in tasks involving the recognition of others' emotions. In tasks involving the recognition of actions, patients showed a general increase in reaction time, but not a reduction in accuracy. Deficits in emotion recognition can be seen by either direct damage to the inferior frontal gyrus, or via damage to dorsal lateral prefrontal cortex regions, resulting in deteriorated performance and less EEG mu suppression over sensorimotor cortex.

Are you looking at me? Mu suppression modulation by facial expression direction.

Although we encounter numerous expressive faces on a daily basis, those that are not aimed at us will often be disregarded. Facial expressions aimed at our direction appear far more relevant and evoke an engaging affective experience, while the exact same expressions aimed away from us may not. While the importance of expression directionality is intuitive and commonplace, the neural mechanisms underlying this phenomenon are largely unknown. In the current study we measured EEG mu rhythm suppression, an established measure of mirror neuron activity, while participants viewed short video clips of dynamic facial expressions. Critically, the videos portrayed facial emotions which turned towards or away from the viewer, thus manipulating their degree of social relevance. Mirroring activity increased as a function of social relevance such that expressions turning toward the viewer resulted in increased sensorimotor activation (i.e., stronger mu suppression) compared to identical expressions turning away from the viewer. Additional analyses confirmed that expressions turning toward the viewer were perceived as more relevant and engaging than expressions turning away from the viewer, a finding not explained by perceived intensity or recognition accuracy. Mirror sensorimotor mechanisms may play a key role in determining the relevance of perceived facial expressions.

Training-induced recovery of low-level vision followed by mid-level perceptual improvements in developmental object and face agnosia.

Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental stage of the adult visual system, can overcome such developmental impairments. Here, we visually trained LG, a developmental object and face agnosic individual. Prior to training, at the age of 20, LG's basic and mid-level visual functions such as visual acuity, crowding effects, and contour integration were underdeveloped relative to normal adult vision, corresponding to or poorer than those of 5-6 year olds (Gilaie-Dotan, Perry, Bonneh, Malach & Bentin, 2009). Intensive visual training, based on lateral interactions, was applied for a period of 9 months. LG's directly trained but also untrained visual functions such as visual acuity, crowding, binocular stereopsis and also mid-level contour integration improved significantly and reached near-age-level performance, with long-term (over 4 years) persistence. Moreover, mid-level functions that were tested post-training were found to be normal in LG. Some possible subtle improvement was observed in LG's higher-order visual functions such as object recognition and part integration, while LG's face perception skills have not improved thus far. These results suggest that corrective training at a post-developmental stage, even in the adult visual system, can prove effective, and its enduring effects are the basis for a revival of a developmental cascade that can lead to reduced perceptual impairments.

Mirror-neuron system recruitment by action observation: effects of focal brain damage on mu suppression.

Mu suppression is the attenuation of EEG power in the alpha frequency range (8-12 Hz), recorded over the sensorimotor cortex during execution and observation of motor actions. Based on this dual characteristic mu suppression is thought to signalize activation of a human analogue of the mirror neuron system (MNS) found in macaque monkeys. However, much uncertainty remains concerning its specificity and full significance. To further explore the hypothesized relationship between mu suppression and MNS activation, we investigated how it is affected by damage to cortical regions, including areas where the MNS is thought to reside. EEG was recorded in 33 first-event stroke patients during observation of video clips showing reaching and grasping hand movements. We examined the modulation of EEG oscillations at central and occipital sites, and analyzed separately the lower (8-10 Hz) and higher (10-12 Hz) segments of the alpha/mu range. Suppression was determined relative to observation of a non-biological movement. Normalized lesion data were used to investigate how damage to regions of the fronto-parietal cortex affects the pattern of suppression. The magnitude of mu suppression during action observation was significantly reduced in the affected hemisphere compared to the unaffected hemisphere. Differences between the hemispheres were significant at central (sensorimotor) sites but not at occipital (visual) sites. Total hemispheric volume loss did not correlate with mu suppression. Suppression in the lower mu range in the unaffected hemisphere (C3) correlated with lesion extent within the right inferior parietal cortex. Our lesion study supports the role of mu suppression as a marker of MNS activation, confirming previous studies in normal subjects.

Considering the Role of Human Empathy in AI-Driven Therapy.

Recent breakthroughs in artificial intelligence (AI) language models have elevated the vision of using conversational AI support for mental health, with a growing body of literature indicating varying degrees of efficacy. In this paper, we ask when, in therapy, it will be easier to replace humans and, conversely, in what instances, human connection will still be more valued. We suggest that empathy lies at the heart of the answer to this question. First, we define different aspects of empathy and outline the potential empathic capabilities of humans versus AI. Next, we consider what determines when these aspects are needed most in therapy, both from the perspective of therapeutic methodology and from the perspective of patient objectives. Ultimately, our goal is to prompt further investigation and dialogue, urging both practitioners and scholars engaged in AI-mediated therapy to keep these questions and considerations in mind when investigating AI implementation in mental health.

Beyond physical sensations: investigating empathy and prosocial behavior in vicarious pain responders.

Empathy, the capacity to share others' emotional experiences, has been proposed as a key motivation for altruistic behavior in both humans and animals. Sharing another's emotional experience may generate a self-embodied simulation of their emotional state, fostering understanding and promoting prosocial behavior. Vicarious pain responders report sensing physical pain when observing others in pain. Whether this ability extends to emotional experiences remains unexplored. Using both questionnaires and ecologically valid behavioral tasks, we explored whether vicarious pain responders differ from nonresponders in empathic abilities and prosocial behavior. Participants watched video clips of people describing a negative emotional life event. We operationalized several empathic abilities and responses (empathic accuracy, affective synchrony, emotional reaction, and empathic motivation) based on participants' and targets' responses during and after watching the videos. Participants were also engaged in a donation task measuring tendency for prosocial behavior. Findings reveal that compared to nonresponders, vicarious pain responders exhibit enhanced empathic accuracy, intensified emotional reactions to others' emotional pain, and a greater motivation to communicate with the target. This study marks the first behavioral evidence showcasing vicarious pain responders' empathic abilities, reactions, and motivation in response to nonphysical pain of others, expanding our knowledge of this phenomenon and its association with broader empathic abilities.

Don't stand so close to me: a behavioral and ERP study of preferred interpersonal distance.

The space between people, or interpersonal distance, creates and defines the dynamics of social interactions. Given that invasion of one's interpersonal space may trigger threat and anxiety, a critical question is if high vulnerability to social anxiety (SA) is associated with avoidance and attentional biases when anticipating invasion to one's interpersonal space. Therefore, the current study sought to examine the behavioral mechanisms, time course and neural correlates underlying the threat of interpersonal distance invasion with a focus on different SA levels, using both a behavioral and an ERP experiment. Preferred interpersonal distance was assessed using a paradigm that involves responding to different virtual protagonists (friend or stranger) approaching the participant by indicating where one would like the protagonist to stop. In addition, participants' level of social anxiety was measured. The behavioral experiment indicated that levels of SA predicted one's preferred interpersonal distance such that higher SA individuals preferred further distance from a stranger. At the neural level, across groups, early (N1) but not late (LPP) differences were found between stranger and friend conditions. Importantly, SA individuals were characterized by attenuated early ERP responses, suggesting less attentional resources allocated to social stimuli. The results suggest that high SA individuals feel discomfort earlier than others in social engagement, which may lead them to stand further away, thus creating less communicative social interactions.

Midfrontal theta as an index of conflict strength in approach-approach vs avoidance-avoidance conflicts.

The seminal theory of motivational conflicts distinguishes between approach-approach (AP-AP) conflicts, in which a decision is made between desirable alternatives, and avoidance-avoidance (AV-AV) conflicts, in which a decision is made between undesirable alternatives. The behavioral differences between AP-AP and AV-AV conflicts are well documented: abundant research showed that AV-AV conflicts are more difficult to resolve than AP-AP ones. However, there is little to no research looking into the neural underpinnings of the differences between the two conflict types. Here, we show that midfrontal theta, an established neural marker of conflict, distinguished between the two conflict types such that midfrontal theta power was higher in AV-AV conflicts than in AP-AP conflicts. We further demonstrate that higher midfrontal theta power was associated with shorter decision times on a single-trial basis, indicating that midfrontal theta played a role in promoting successful controlled behavior. Taken together, our results show that AP-AP and AV-AV conflicts are distinguishable on the neural level. The implications of these results go beyond motivational conflicts, as they establish midfrontal theta as a measure of the continuous degree of conflict in subjective decisions.

The relationship between empathy and executive functions among young adolescents.

Empathy and executive functions (EFs) are multimodal constructs that enable individuals to cope with their environment. Both abilities develop throughout childhood and are known to contribute to social behavior and academic performance in young adolescents. Notably, mentalizing and EF activate shared frontotemporal brain areas, which in previous studies of adults led researchers to suggest that at least some aspects of empathy depend on intact EF mechanisms. Despite the substantial development that empathy and EF undergo during adolescence, no study to date has systematically examined the associations between components of empathy and EF in this age group. Here, we explore these associations using data from an online battery of tasks, collected as part of a longitudinal twin study (N = 593; Mage 11.09 ± 0.2; 53.46% female, Israeli adolescents from Jewish decent). Using a confirmatory factor analysis, we quantified the associations between the main components of empathy (mentalizing and interpersonal concern) and of EF (working memory [WM], inhibition and shifting [IaS]). We found that WM was related to both mentalizing and interpersonal concern, whereas IaS were related to mentalizing but not to interpersonal concern. We also discuss the genetic and environmental contributions to individual differences in each factor. Our findings show both similarities and differences from previous findings in adults, suggesting that the ongoing brain maturation processes and environmental age-dependent experiences in adolescence may affect the developing relation between cognitive and emotional development. These results have implications for better understanding and treating clinical populations demonstrating executive or emotional deficits, specifically during adolescence. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Mood congruency affects physiological synchrony but not empathic accuracy in a naturalistic empathy task.

Empathy is a crucial aspect of our daily lives, as it enhances our wellbeing and is a proxy for prosocial behavior. It encompasses two related but partially distinct components: cognitive and affective empathy. Both are susceptible to context, biases and an individual's physiological state. Few studies have explored the effects of a person's mood on these empathy components, and results are mixed. The current study takes advantage of an ecological, naturalistic empathy task - the empathic accuracy (EA) task - in combination with physiological measurements to examine and differentiate between the effects of one's mood on both empathy components. Participants were induced with positive or negative mood and presented videos of targets narrating autobiographical negative stories, selected from a Chinese empathy dataset that we developed (now publicly available). The stories were conveyed in audio-only, visual-only and full-video formats. Participants rated the target's emotional state while watching or listening to their stories, and physiological measures were taken throughout the process. Importantly, similar measures were taken from the targets when they narrated the stories, allowing a comparison between participants' and targets' measures. We found that in audio-only and visual-only conditions, participants whose moods were congruent with the target showed higher physiological synchrony than those with incongruent mood, implying a mood-congruency effect on affective empathy. However, there was no mood effect on empathic accuracy (reflecting cognitive empathy), suggesting a different influence of mood on the two empathy components.

Mu rhythm suppression over sensorimotor regions is associated with greater empathic accuracy.

When people encounter others' emotions, they engage multiple brain systems, including parts of the sensorimotor cortex associated with motor simulation. Simulation-related brain activity is commonly described as a 'low-level' component of empathy and social cognition. It remains unclear whether and how sensorimotor simulation contributes to complex empathic judgments. Here, we combine a naturalistic social paradigm with a reliable index of sensorimotor cortex-based simulation: electroencephalography suppression of oscillatory activity in the mu frequency band. We recruited participants to watch naturalistic video clips of people ('targets') describing emotional life events. In two experiments, participants viewed these clips (i) with video and sound, (ii) with only video or (iii) with only sound and provided continuous ratings of how they believed the target felt. We operationalized 'empathic accuracy' as the correlation between participants' inferences and targets' self-report. In Experiment 1 (US sample), across all conditions, right-lateralized mu suppression tracked empathic accuracy. In Experiment 2 (Israeli sample), this replicated only when using individualized frequency-bands and only for the visual stimuli. Our results provide novel evidence that sensorimotor representations-as measured through mu suppression-play a role not only in low-level motor simulation, but also in higher-level inferences about others' emotions, especially when visual cues are crucial for accuracy.

Impaired empathic accuracy following damage to the left hemisphere.

Failing to understand others accurately can be extremely costly. Unfortunately, events such as strokes can lead to a decline in emotional understanding. Such impairments have been documented in stroke patients and are widely hypothesized to be related to right-hemisphere lesions, as well as to the amygdala, and are thought to be driven in part by attentional biases, for example, less fixation on the eyes. Notably, most of the previous research relied on measurements of emotional understanding from simplified cues, such as facial expressions or prosody. We hypothesize that chronic damage to the left hemisphere could hinder empathic accuracy and emotion recognition in naturalistic social settings that require complex language comprehension, even after a patient regains core language capacities. To assess this notion, we use an empathic accuracy task and eye-tracking measurements with chronic stroke patients with either right (N = 13) or left (N = 11) hemispheric damage-together with aged-matched controls (N = 15)-to explore the patients' understanding of others' affect inferred from stimuli that separates audio and visual cues. While we find that patients with right-hemisphere lesions showed visual attention bias compared to the other two groups, we uncover a disadvantage for patients with left-hemisphere lesions in empathic accuracy, especially when only auditory cues are present. These results suggest that patients with left-hemisphere damage have long-lasting difficulties comprehending real-world complex emotional situations.

Motor and attentional mechanisms involved in social interaction--evidence from mu and alpha EEG suppression.

Mu rhythms are EEG oscillations in the 8-13 Hz recorded at sites located roughly over the sensory-motor cortex. There is reliable evidence that the amplitude of mu rhythms is reduced when the participant performs a motor act (mu suppression). Recent studies found mu suppression not only in response to actual movements but also while the participant observes actions executed by someone else. This finding putatively associates the mu suppression to the activity of a mirror neurons system which, in humans, has been suggested to contribute to social skills. In the present study we explored the effects of different levels of social interaction on mu suppression. Participants observed dynamic displays of hand gestures performing actions used in the Rock-Scissors-Paper game. In different blocks, participants passively viewed identical video clips with no game context and in the context of a game, or while being actually engaged in the game either by imagining actions or by actual playing. As a baseline for calculating mu suppression we used a dynamic display of a rolling ball. In addition, to isolate the social aspect of the actual movements, participants performed the same acts outside the game context. Mu suppression was larger while participants were engaged in the social game than when they passively looked at the "opponent" actions or when they performed movements without the game context. This effect was found while viewing the opponent play as well as while actually playing, which supports the view that mu suppression is affected not only by motion, but also by the social context of the motion. However, we did not find differences in mu suppression between perception segments in which the participant did not actually play. Furthermore, in all perception segments occipital alpha suppression was more robust than mu suppression suggesting the involvement of a strong attentional component. While actually playing, however, mu suppression was stronger than alpha suppression.

The influence of anger on empathy and theory of mind.

Social cognition allows humans to understand and predict other people's behavior by inferring or sharing their emotions, intentions and beliefs. Few studies have investigated the impact of one's own emotional state on understanding others. Here, we tested the effect of being in an angry state on empathy and theory of mind (ToM). In a between-groups design we manipulated anger status with different paradigms in three studies (autobiographical recall (N = 45), negative feedback (N = 49), frustration (N = 46)) and checked how this manipulation affected empathic accuracy and performance in the EmpaToM. All paradigms were successful in inducing mild anger. We did not find the expected effect of anger on empathy or ToM performance but observed small behavioral changes. Together, our results validate the use of three different anger induction paradigms and speak for rather weak behavioral effects of mild state anger on empathy and ToM.