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Keeping appropriate interpersonal distance is an evolutionary conserved behavior that can be adapted based on learning. Detailed knowledge on how interpersonal space is represented in the brain and whether such representation is genetically influenced is lacking. We measured brain function using functional magnetic resonance imaging in 294 twins (71 monozygotic, 76 dizygotic pairs) performing a distance task where neural responses to human figures were compared to cylindrical blocks. Proximal viewing distance of human figures was compared to cylinders facilitated responses in the occipital face area (OFA) and the superficial part of the amygdala, which is consistent with these areas playing a role in monitoring interpersonal distance. Using the classic twin method, we observed a genetic influence on interpersonal distance related activation in the OFA, but not in the amygdala. Results suggest that genetic factors may influence interpersonal distance monitoring via the OFA whereas the amygdala may play a role in experience-dependent adjustments of interpersonal distance.

The objective of this study was the determination of major and trace elements in the bee pollen samples from the whole territory of Republic of Kosovo. Pollen, as a natural plant product, is exposed to different contaminations absorbed by plants from the soil through the root system or with water intake, as well as to pollutants of different origins, including anthropogenic ones, deposited directly on pollen. In total 67 pollen samples were collected in 2019. The samples were analyzed for 27 macro and microelements by using ICP-AES and ICP-MS. The mean content of major elements in bee pollen was 4065, 3455, 1375 and 549 mg/kg for K, P, Ca and Mg, respectively. The range of the contents for some potentially toxic elements was 11.9-139.1, 1.9-16, 0.11-6.25, 0.01-0.329 and 0.001-0.38 mg/kg for Zn, Cu, Pb, Cd and As, respectively. Three groups of elements of mixed origin were identified through factor analysis: the first and the third Factors, are mostly of geogenic origin (Ag, Li, Al, Fe, Ca, Sr, K, Mg and P and Co, Ni, Cr, Cu and Mn) and the second Factor association is related to anthropogenic processes (Sb, As, Pb, Tl, Sn and Cd).

Nociceptive processing in the human brain is complex and involves several brain structures and varies across individuals. Determining the structures that contribute to interindividual differences in nociceptive processing is likely to improve our understanding of why some individuals feel more pain than others. Here, we found specific parts of the cerebral response to nociception that are under genetic influence by employing a classic twin-design. We found genetic influences on nociceptive processing in the midcingulate cortex and bilateral posterior insula. In addition to brain activations, we found genetic contributions to large-scale functional connectivity (FC) during nociceptive processing. We conclude that additive genetics influence specific brain regions involved in nociceptive processing. The genetic influence on FC during nociceptive processing is not limited to core nociceptive brain regions, such as the dorsal posterior insula and somatosensory areas, but also involves cognitive and affective brain circuitry. These findings improve our understanding of human pain perception and increases chances to find new treatments for clinical pain.

Individuals who engage in nonsuicidal self-injury (NSSI) have demonstrated higher pain thresholds and tolerance compared with individuals without NSSI. The objective of the study was to assess which aspects of the pain regulatory system that account for this augmented pain perception. In a cross-sectional design, 81 women, aged 18-35 (mean [SD] age, 23.4 [3.9]), were included (41 with NSSI and 40 healthy controls). A quantitative sensory testing protocol, including heat pain thresholds, heat pain tolerance, pressure pain thresholds, conditioned pain modulation (assessing central down-regulation of pain), and temporal summation (assessing facilitation of pain signals) was used. Thermal pain stimuli were assessed during fMRI scanning and NSSI behaviors and clinical symptoms were self-assessed. NSSI participants demonstrated higher pain thresholds during heat and pressure pain compared to controls. During conditioned pain modulation, NSSI participants showed a more effective central down-regulation of pain for NSSI participants. Temporal summation did not differ between the groups. There were no correlations between pain outcomes and NSSI behaviors or clinical characteristics. The fMRI analyses revealed increased activity in the primary and secondary somatosensory cortex in NSSI participants, compared to healthy controls, which are brain regions implicated in sensory aspects of pain processing. The findings suggest segregated inhibitory mechanisms for pain and emotion in NSSI, as pain insensitivity was linked to enhanced inhibitory control of pain in spite of significant impairments in emotion regulation. This may represent an endophenotype associated with a greater risk for developing self-injurious behavior.

Understanding the neural basis for individual differences in the conditioned skin conductance response (SCR) may inform on autonomic regulation in fear-related psychopathology. Previous region-of-interest (ROI) analyses have implicated the amygdala in regulating conditioned SCR, but whole brain analyses are lacking. This study examined correlations between individual differences in conditioned SCR and neural activity throughout the whole brain by using data from a large functional magnetic resonance imaging study (N = 285). Results show that conditioned SCR correlates with activity in the dorsal anterior cingulate cortex/anterior midcingulate cortex, anterior insula, bilateral temporoparietal junction, right frontal operculum, bilateral dorsal premotor cortex, right superior parietal lobe and midbrain. A ROI analysis replicated a correlation between amygdala activity and conditioned SCR, but amygdala contribution to SCR was modest compared with other regions. We suggest that implicated neural regions belong to a large-scale midcingulo-insular network related to salience detection and autonomic-interoceptive processing. Altered activity within this network may underlie individual differences in conditioned SCR and autonomic aspects of psychopathology.

The abundances of selected elements in different environmental compartments, namely soil, honey, and bee pollen, was determined in this study. For that purpose, sixteen soil and honey samples, and nine pollen samples were taken in the region of Mitrovica, Kosovo. The concentration of elements was measured by ICP-AES and ICP-MS. Pollution level concentrations of Pb, Zn, As, and Cd were observed in soil. The level of soil pollution was estimated by calculating pollution indices. Pb was also observed at high concentrations in honey, as was Cd and Pb in pollen. Pearson’s correlation coefficients revealed mostly weak and moderate correlations of the concentrations of the eight selected elements among the soil, honey, and pollen samples. Several groups of elements with geogenic and anthropogenic origin were identified by hierarchical cluster analysis. The concentrations of selected heavy metals for soil and honey were compared to those in neighboring countries, and those for pollen with samples from Turkey, Serbia, and Jordan.

Nociceptive processing in the human brain is a signal that enables harm avoidance, with large interindividual variance. The relative contributions of genes and environment to the neural structures that support nociception have not been studied in twins previously. Here, we employed a classic twin-design to determine brain structures influenced by additive genetics. We found genetic influences on nociceptive processing in the midcingulate cortex, bilateral posterior insulae and thalamus. In addition to brain activations, we found genetic contributions to large-scale functional connectivity during nociceptive processing. We conclude that additive genetics influence specific aspects of nociceptive processing, which improves our understanding of human nociceptive processing.

Responding to threats in the environment is crucial for survival. Certain types of threat produce defensive responses without necessitating previous experience and are considered innate, whereas other threats are learned by experiencing aversive consequences. Two important innate threats are whether an encountered stimulus is a member of the same species (social threat) and whether a stimulus suddenly appears proximal to the body (proximal threat). These threats are manifested early in human development and robustly elicit defensive responses. Learned threat, on the other hand, enables adaptation to threats in the environment throughout the life span. A well-studied form of learned threat is fear conditioning, during which a neutral stimulus acquires the ability to eliciting defensive responses through pairings with an aversive stimulus. If innate threats can facilitate fear conditioning, and whether different types of innate threats can enhance each other, is largely unknown. We developed an immersive virtual reality paradigm to test how innate social and proximal threats are related to each other and how they influence conditioned fear. Skin conductance responses were used to index the autonomic component of the defensive response. We found that social threat modulates proximal threat, but that neither proximal nor social threat modulates conditioned fear. Our results suggest that distinct processes regulate autonomic activity in response to proximal and social threat on the one hand, and conditioned fear on the other.

Brain activity can be modelled as a temporal network of interconnected regions. Recently, in network neuroscience, temporal network models have gained popularity and their network properties have been related to cognition and behaviour. Here we demonstrate that calculating nodal properties that are dependent on temporal community structure (such as participation coefficient) in time-varying contexts leads to misleading results due to fluctuations of the community structure over time. Further, we present a temporal extension to the participation coefficient measure (temporal participation coefficient) that circumnavigates this problem by considering all community partitions a node is assigned to through time. Initially, we demonstrate that when controlling for temporal communities, different nodes and time-points are identified as hubs when compared to current approaches. The proposed method allows us to track a node’s integration through time while adjusting for the possible changes in community structure of the overall network

Virtual reality lets the user be immersed in a 3-dimensional environment, which can enhance certain emotional responses to stimuli relative to experiencing them on a flat computer screen. We here tested whether displaying two different types of threats in immersive virtual reality enhanced threat related autonomic responses measured by skin conductance responses (SCRs). We studied innate and learned threat responses because these types of threats have been shown to depend on different neural circuits in animals. Therefore, it is possible that immersive virtual reality may modulate one of these threats but not the other. Innate threat responses were provoked by the sudden appearance of characters at proximal egocentric distance, which were compared to the sudden appearance of distant characters (proximal threat). Learned threat responses were studied by conditioning two of the characters to an electric shock (conditioned threat) and contrasting SCRs to these characters with SCRs to two other characters that were never paired with shock. We found that displaying stimuli in immersive virtual reality enhanced proximal threat responses but not conditioned threat responses. Findings show that immersive virtual reality can enhance an innate type of threat responses without affecting a learned threat response, suggesting that separate neural pathways serve these threat responses. This article is licensed under a Creative Commons Attribution 4.0 International License, http://creativecommons.org/licenses/by/4.0/.

Preparedness theory is one of the most influential ideas in explaining the origin of specific phobias. The theory proposes that fear conditioning is selective to animals that have posed a threat to survival throughout human evolution, and that acquired fear memories to such threats are resistant to extinction. We reviewed fear conditioning studies testing whether autonomic responses conditioned to pictures of snakes and spiders show greater resistance to extinction than neutral cues. We identified 32 fear conditioning experiments published in 23 studies including 1887 participants. Increased resistance to extinction of conditioned responses to snake and spider pictures was found in 10 (31%) of the experiments, whereas 22 (69%) experiments did not support the hypothesis. Thus, the body of evidence suggests that preparedness theory does not explain the origin of specific phobias.