The effect of sleep restriction on empathy for pain: An fMRI study in younger and older adults

Age and sleep both affect emotional functioning. Since sleep patterns change over the lifespan, we investigated the effects of short sleep and age on empathic responses. In a randomized cross-over experimental design, healthy young and older volunteers (n = 47 aged 20–30 years and n = 39 aged 65–75 years) underwent functional magnetic resonance imaging (fMRI) after normal sleep or night sleep restricted to 3 hours. During fMRI, participants viewed pictures of needles pricking a hand (pain) or Q-tips touching a hand (control), a well-established paradigm to investigate empathy for pain. There was no main effect of sleep restriction on empathy. However, age and sleep interacted so that sleep restriction caused increased unpleasantness in older but not in young participants. Irrespective of sleep condition, older participants showed increased activity in angular gyrus, superior temporal sulcus and temporo-parietal junction compared to young. Speculatively, this could indicate that the older individuals adopted a more cognitive approach in response to others’ pain. Our findings suggest that caution in generalizability across age groups is needed in further studies of sleep on social cognition and emotion.

Imaging empathy and prosocial emotions

Empathy is a multi-faceted construct with important implications for social behavior. Based on a selective review of the neuroscientific evidence collected in humans, the present paper discusses the neural representations underlying affect sharing, its relation to mentalizing, the importance of self-other distinction, the distinction between empathy, sympathy and compassion, and how these phenomena are linked to prosocial behavior. Apart from reviewing the literature, we also highlight open questions and how they might be addressed by a research approach that tries to integrate across these diverse constructs.

Is decision making in hypoxia affected by pre-acclimatisation? A randomized controlled trial

INTRODUCTION

Decision making is impaired in hypoxic environments, which may have serious or even lethal consequences for mountaineers. An acclimatisation period prior to high altitude exposures may help to overcome adverse effects of hypoxia. Thus, we investigated possible effects of short-term pre-acclimatisation on decision making in hypoxia.

METHODS

In a randomized controlled study design, 52 healthy participants were allocated to a hypoxia group (HG: short-term pre-acclimatisation by the use of intermittent hypoxia 7×1h at F_iO₂=12.6%, equivalent to 4500m) or a control group (CG: sham pre-acclimatisation 7×1h at F_iO₂=20.9%, equivalent to 600m). The number of risky decisions was assessed using the Game of Dice Task at four time points during a 12-hours stay in hypoxia (F_iO₂=12.6%).

RESULTS

42 (HG: 27, CG: 25) participants completed the study. The number of risky decisions was significantly (p=0.048 as determined by 4×2 ANCOVA) reduced in the hypoxia group compared to the control group, partial η²=0.11, when the age-effect on decision making was controlled. Self-reported positive affective valence prior to decision making was negatively related to the number of risky decisions, r<-0.38.

CONCLUSION

Short-term pre-acclimatisation might influence decision making in hypoxia in a positive way and might be considered as a risk-reducing preparation method prior to exposures to hypoxic environments. Positive affective states seem to have a medium-sized protective effect against risky decision making.

Default mode network deactivation during emotion processing predicts early antidepressant response

Several previous functional magnetic resonance imaging (fMRI) studies have demonstrated the predictive value of brain activity during emotion processing for antidepressant response, with a focus on clinical outcome after 6-8 weeks. However, longitudinal studies emphasize the paramount importance of early symptom improvement for the course of disease in major depressive disorder (MDD). We therefore aimed to assess whether neural activity during the emotion discrimination task (EDT) predicts early antidepressant effects, and how these predictive measures relate to more sustained response. Twenty-three MDD patients were investigated once with ultrahigh-field 7T fMRI and the EDT. Following fMRI, patients received Escitalopram in a flexible dose schema and were assessed with the Hamilton Depression Rating Scale (HAMD) before, and after 2 and 4 weeks of treatment. Deactivation of the precuneus and posterior cingulate cortex (PCC) during the EDT predicted change in HAMD scores after 2 weeks of treatment. Baseline EDT activity was not predictive of HAMD change after 4 weeks of treatment. The precuneus and PCC are integral components of the default mode network (DMN). We show that patients who exhibit stronger DMN suppression during emotion processing are more likely to show antidepressant response after 2 weeks. This is, to our knowledge, the first study to show that DMN activity predicts early antidepressant effects. However, DMN deactivation did not predict response at 4 weeks, suggesting that our finding is representative of early, likely treatment-related, yet unspecific symptom improvement. Regardless, early effects may be harnessed for optimization of treatment regimens and patient care.

From shared to distinct self-other representations in empathy: evidence from neurotypical function and socio-cognitive disorders

Neuroscientific research has identified two fundamental components of empathy: shared emotional representations between self and other, and self-other distinction. The concept of shared representations suggests that during empathy, we co-represent another person's affect by engaging brain and bodily functions underpinning the first-hand experience of the emotion we are empathizing with. This possible grounding of empathy in our own emotional experiences explains the necessity for self-other distinction, which is the capacity to correctly distinguish between our own affective representations and those related to the other. In spite of the importance of these two components in empathy, several aspects still remain controversial. This paper addresses some of them and focuses on (i) the distinction between shared activations versus representations, raising the question what shared representations entail in terms of the underlying neural mechanisms, (ii) the possible mechanisms behind self-other distinction in the cognitive and the affective domains, and whether they have distinct neural underpinnings and (iii) the consequences associated with a selective impairment of one of the two components, thereby addressing their importance in mental disorders such as autism spectrum disorders, psychopathy and alexithymia.

Attentional biases in healthy adults: Exploring the impact of temperament and gender

BACKGROUND

Attentional biases such as faster attentional orienting toward negative information were consistently replicated in high-anxious and depressive individuals, but findings in healthy individuals are inconsistent so far.

METHODS

Using a dot-probe paradigm, we investigated whether temperament traits and gender, which are linked to (sub)clinical symptoms and attentional processing, influenced attentional biases in healthy adults.

RESULTS

All participants showed protective attentional biases in terms of orienting their attention away from negative information. In both genders higher values of negative affect were compensated with stronger attentional engagement with positive stimuli. This effect was more pronounced in men than in women. Effortful control fulfilled its regulative function in terms of stronger avoidance of negative stimuli only among men.

LIMITATIONS

Reaction times after probe detection provide only a snapshot of attention and allow only for an indirect assessment of visual attention. Future research should emphasize methods that allow for continuous monitoring of attention allocation, therefore results of the present study await replication in psychophysiological or eye-tracking studies.

CONCLUSION

Our results highlight the importance of considering influencing factors such as gender and temperament traits for attentional biases in healthy adults.

Cardiac Output Determination during Intravenous Cardioangiography Using X-ray Fluorescence Analysis

Cardiac output was determined with an indicator dilution technique during digital venous angiography of the left ventricle in 11 patients. The contrast medium injected into the right atrium was used as indicator. During and after the injection of contrast medium one blood sample per second was obtained through a catheter placed in the descending aorta. The samples were analyzed for iodine content with x-ray fluorescence analysis and cardiac output determined ad modum Stewart-Hamilton. Thermodilution was used as a reference method. The results indicate that the indicator dilution method with the use of contrast medium might be used for calibration of videodensitometric methods for blood flow measurements.

The selfless mind: How prefrontal involvement in mentalizing with similar and dissimilar others shapes empathy and prosocial behavior

Engaging in mentalizing, i.e., reflecting on others' thoughts, beliefs and feelings, is known to facilitate later empathy and prosocial behavior. Activation in dorsomedial prefrontal (dmPFC) areas during mentalizing has been shown to predict the extent of prosocial behavior. It is unclear, however, what cognitive process drives these effects: a simulation process in which the own mental states are used as a proxy for those of others (self-projection) or an effortful other-enhancement process in which one's own perspective is overridden. In this fMRI study we examined the effects of mentalizing with similar and dissimilar others on behavioral and brain measures of empathy and prosocial behavior, to assess which cognitive process mediates the facilitative effects of mentalizing. Participants had to mentalize with two fictitious target persons, one of whom was manipulated to have similar thoughts and beliefs as the participant, while the other had dissimilar mental states. We then assessed participants' behavioral and neural responses during an empathy for pain task and a prosocial behavior task. Similarity between participant and target person increased empathy and affiliation ratings, and mentalizing with dissimilar persons evoked increased activation in ventrolateral prefrontal cortex, the extent of which was inversely related with bias towards the similar person in empathy. Responses in two dmPFC regions were also predictive of later variations in subsequent empathy and prosocial behavior, either predicting overall prosociality and empathic concern (lateral dmPFC), or predicting reduced empathic bias towards the similar person and a lower response to self-related stressors in pain matrix areas (medial dmPFC). This pattern of results suggests that generating and enhancing other-related representations while overcoming one's own perspective, rather than enhanced recruitment of self-projection processes, is driving the facilitative effects of mentalizing on later empathic and prosocial responses.

Temperament differentially influences early information processing in men and women: Preliminary electrophysiological evidence of attentional biases in healthy individuals

Preferential processing of threat-related information is a robust finding in anxiety disorders. The observation that attentional biases are also present in healthy individuals suggests factors other than clinical symptoms to play a role. Using a dot-probe paradigm while event-related potentials were recorded in 59 healthy adults, we investigated whether temperament and gender, both related to individual variation in anxiety levels, influence attentional processing. All participants showed protective attentional biases in terms of enhanced attention engagement with positive information, indexed by larger N1 amplitudes in positive compared to negative conditions. Taking gender differences into account, we observed that women showed enhanced attention engagement with negative compared to neutral information, indicated by larger P2 amplitudes in congruent than in incongruent negative conditions. Attentional processing was influenced by the temperament traits negative affect and effortful control. Our results emphasize that gender and temperament modulate attentional biases in healthy adults.

Neurobiological differences in mental rotation and instrument interpretation in airline pilots

Airline pilots and similar professions require reliable spatial cognition abilities, such as mental imagery of static and moving three-dimensional objects in space. A well-known task to investigate these skills is the Shepard and Metzler mental rotation task (SMT), which is also frequently used during pre-assessment of pilot candidates. Despite the intuitive relationship between real-life spatial cognition and SMT, several studies have challenged its predictive value. Here we report on a novel instrument interpretation task (IIT) based on a realistic attitude indicator used in modern aircrafts that was designed to bridge the gap between the abstract SMT and a cockpit environment. We investigated 18 professional airline pilots using fMRI. No significant correlation was found between SMT and IIT task accuracies. Contrasting both tasks revealed higher activation in the fusiform gyrus, angular gyrus, and medial precuneus for IIT, whereas SMT elicited significantly stronger activation in pre- and supplementary motor areas, as well as lateral precuneus and superior parietal lobe. Our results show that SMT skills per se are not sufficient to predict task accuracy during (close to) real-life instrument interpretation. While there is a substantial overlap of activation across the task conditions, we found that there are important differences between instrument interpretation and non-aviation based mental rotation.

Performance monitoring during a minimal group manipulation

The on-going (self-)monitoring of our behaviour is inextricably intertwined with the surrounding social context. In this study, we investigated whether a minimal group paradigm assigning individuals to arbitrary group categories is powerful enough to induce changes in behavioural, psychophysiological and event-related potential correlates of performance monitoring. Following arbitrary group assignment based on ostensible task performance and a group identification task, 22 volunteers performed a flanker-task during both in-group and out-group contexts, while electroencephalography was performed. More errors were committed in the out-group compared with the in-group context. Error-related negativity amplitudes were larger for in-group compared with out-group errors. However, subsequent processing reflected in late Pe amplitudes and stimulus-driven conflict reflected in N2 amplitudes were not affected by the group context. Heart rate deceleration (during both correct and incorrect trials) tended to be more pronounced during the out-group compared with the in-group context. This surprising observation was corroborated by subjective ratings of performance satisfaction, in which participants reported higher satisfaction with their out-group performance. This study identified specific stimulus evaluation processes to be affected by a minimal group manipulation and demonstrated thereby transient top-down effects of a social context manipulation on performance monitoring.

Emotional Egocentricity Bias Across the Life-Span

In our daily lives, we often have to quickly estimate the emotions of our conspecifics in order to have successful social interactions. While this estimation process seems quite easy when we are ourselves in a neutral or equivalent emotional state, it has recently been shown that in case of incongruent emotional states between ourselves and the others, our judgments can be biased. This phenomenon, introduced to the literature with the term Emotional Egocentricity Bias (EEB), has been found to occur in young adults and, to a greater extent, in children. However, how the EEB changes across the life-span from adolescence to old age has been largely unexplored. In this study, we recruited 114 female participants subdivided in four cohorts (adolescents, young adults, middle-aged adults, older adults) to examine EEB age-related changes. Participants were administered with a recently developed paradigm which, by making use of visuo-tactile stimulation that elicits conflicting feelings in paired participants, allows the valid and reliable exploration of the EEB. Results highlighted a U-shape relation between age and EEB, revealing enhanced emotional egocentricity in adolescents and older adults compared to young and middle-aged adults. These results are in line with the neuroscientific literature which has recently shown that overcoming the EEB is associated with a greater activation of a portion of the parietal lobe, namely the right Supramarginal Gyrus (rSMG). This is an area that reaches full maturation by the end of adolescence and goes through an early decay. Thus, the age-related changes of the EEB could be possibly due to the life-span development of the rSMG. This study is the first one to show the quadratic relation between age and the EEB and set a milestone for further research exploring the neural correlates of the life-span development of the EEB. Future studies are needed in order to generalize these results to the male population and to explore gender differences related to the aging of socio- emotional processes.

Subjective Memory Complaints and Conversion to Dementia in Patients with Subjective Cognitive Decline and Patients with Mild Cognitive Impairment

Abstract. Background: Subjective cognitive complaints and their clinical significance are discussed controversially. Objectives: To determine the clinical validity of subjective cognitive complaints among subjects with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). Design: Longitudinal study with one follow up examination at a University based out-patient memory clinic. Participants: A clinical sample of patietns with SCD and MCI (n = 141), aged 50 and older, who came to the memory outpatient clinic. Results: No significant differences between converters and non converters regarding subjective cognitive complaints were detected. MCI patients had a higher risk than the patients with SCD developing AD (OR = 7.3 [CI 0.9 to 61.2]. Verbal memory testing using the Verbal Selektive Reminding Test (VSRT) showed better diagnostic validity than subjective cognitive complaints using the Forgetfulness Assessment Inventory (FAI) in predicting conversion to dementia. Conclusion: Verbal memory testing was superior in predicting conversion to dementia compared to subjective cognitive complaints.

Reflections on empathy in medical education: What can we learn from social neurosciences?

The role of empathy in human social interaction has been examined in several research fields, including medical education (ME) and social neuroscience (SN). SN yields insights into empathy based on neurobiological processes, and such information may also be relevant to ME. In this reflection article, the authors first critically review current definitions and concepts of empathy in ME and link them to recent SN findings. In the light of recent evidence from SN, research in ME regarding the positive and negative effects of empathy for physicians and patients is discussed, as well as the question whether (future) physicians differ from the general population with regard to empathic skills. Commonly used SN paradigms and ME approaches to assess empathy are contrasted, a joint approach is advocated, and implications for further interdisciplinary studies are outlined. Finally, the authors delineate the contribution of SN to the question of whether empathy is teachable, and argue that SN findings represent a potential for new ME training approaches. In conclusion, the authors discuss how the incorporation of perspectives on empathy from different research areas would benefit ME, and suggest the translation and integration of such findings into ME research approaches.

Micro-CT analyses of historical bone samples presenting with osteomyelitis

OBJECTIVE

Osteomyelitis is an inflammation of the bone marrow mainly caused by bacteria such as Staphylococcus aureus. It typically affects long bones, e.g. femora, tibiae and humeri. Recently micro-computed tomography (μCT) techniques offer the opportunity to investigate bone micro-architecture in great detail. Since there is no information on long bone microstructure in osteomyelitis, we studied historic bone samples with osteomyelitis by μCT.

MATERIALS AND METHODS

We investigated 23 femora of 22 individuals suffering from osteomyelitis provided by the Collection of Anatomical Pathology, Museum of Natural History, Vienna (average age 44 ±19 years); 9 femora from body donors made available by the Department of Applied Anatomy, Medical University of Vienna (age range, 56-102 years) were studied as controls. Bone microstructure was assessed by μCT VISCOM X 8060 II with a minimal resolution of 18 μm.

RESULTS

In the osteomyelitic femora, most prominent alterations were seen in the cortical compartment. In 71.4% of the individuals with osteomyelitis, cortical porosity occurred. 57.1% of the individuals showed cortical thinning. In 42.9% trabecularisation of cortical bone was observed.

CONCLUSION

Osteomyelitis is associated with severe alterations of cortical bone structure otherwise typically observed at old age such as cortical porosity and cortical thinning.

A functional polymorphism in the prodynorphin gene affects cognitive flexibility and brain activation during reversal learning

Whether the opioid system plays a role in the ability to flexibly adapt behavior is still unclear. We used fMRI to investigate the effect of a nucleotide tandem repeat (68-bp VNTR) functional polymorphism of the prodynorphin (PDYN) gene on cerebral activation during a reversal learning task in which participants had to flexibly adapt stimulus-response associations. Past studies suggested that alleles with 3 or 4 repeats (HH genotype) of this polymorphism are associated with higher levels of dynorphin peptides than alleles with 1 or 2 repeats (LL genotype). On the behavioral level, the HH group made more perseverative errors than the LL group. On the neural level, the HH group demonstrated less engagement of left orbitofrontal cortex (lOFC) and cortico-striatal circuitry, and lower effective connectivity of lOFC with anterior midcingulate cortex and anterior insula/ventrolateral prefrontal cortex during reversal learning and processing negative feedback. This points to a lower ability of the HH genotype to monitor or adapt to changes in reward contingencies. These findings provide first evidence that dynorphins may contribute to individual differences in reversal learning, and that considering the opioid system may shed new light on the neurochemical correlates of decision-making and behavioral regulation.

Item Response Model Investigation of the (German) Interpersonal Reactivity Index Empathy Questionnaire

Abstract. The interpersonal reactivity index (IRI) is a widely used personality questionnaire for measuring empathy. We investigated the psychometric properties of the German version using the partial credit model. If this model fits the data, the raw-scores are fair measures of the latent construct. Only in such a case, further analyses based on the raw-scores are accurate and valid. The results showed model fit only for the subscale empathic concern. The subscales perspective taking and fantasy consisted of two theoretically explainable sub-dimensions. For the subscale personal distress, no model fit could be achieved. Our study provides important information on the psychometric qualities of the IRI that has been repeatedly used to assess, for example, group differences. It demonstrates that these analyses were not warranted by the psychometric quality of the questionnaire. Our results provide direct suggestions (e.g., theoretically explainable sub-dimensions) for further developments of the IRI to overcome this limitation.

Neuroanatomical profiles of alexithymia dimensions and subtypes

Alexithymia, a major risk factor for a range of psychiatric and neurological disorders, has been recognized to comprise two dimensions, a cognitive dimension (difficulties identifying, analyzing, and verbalizing feelings) and an affective one (difficulties emotionalizing and fantasizing). Based on these dimensions, the existence of four distinct alexithymia subtypes has been proposed, but never empirically tested. In this study, 125 participants were assigned to four groups corresponding to the proposed alexithymia subtypes: Type I (impairment on both dimensions), Type II (impairment on the cognitive, but not the affective dimension), Type III (impairment on the affective, but not the cognitive dimension), and Lexithymics (no impairment on either dimension). By means of voxel-based morphometry, associations of the alexithymia dimensions and subtypes with gray and white matter volumes were analyzed. Type I and Type II alexithymia were characterized by gray matter volume reductions in the left amygdala and the thalamus. The cognitive dimension was further linked to volume reductions in the right amygdala, left posterior insula, precuneus, caudate, hippocampus, and parahippocampus. Type III alexithymia was marked by volume reduction in the MCC only, and the affective dimension was further characterized by larger sgACC volume. Moreover, individuals with the intermediate alexithymia Types II and III showed gray matter volume reductions in distinct regions, and had larger corpus callosum volumes compared to Lexithymics. These results substantiate the notion of a differential impact of the cognitive and affective alexithymia dimensions on brain morphology and provide evidence for separable neuroanatomical representations of the different alexithymia subtypes.