Psychophysiological Evidence for Fear Extinction Learning via Mental Imagery

Imagery-based extinction procedures have long been used in the treatments of fear-related conditions. The assumption here is that imagery can substitute for the perceptual stimuli in the extinction process. Yet, experimental validations of this assumption have been limited in number and some have relied exclusively on measures of autonomic reactivity without consideration of conscious feelings of fear. The current investigation sought to assess whether imagery-based exposure could lead to extinction of conditioned fear to the corresponding perceptual stimulus. Conditioned fear responses were measured by both a physiological (i.e., skin conductance response/SCR) and a subjective (i.e., self-reported fear) measure. Participants (N = 56) first underwent perceptual differential fear conditioning, then imagery extinction, then to perceptual extinction. SCR evidence was found for successful fear conditioning, generalization of fear from viewing to imagery, and most importantly, the absence of differential fear after imagery extinction upon re-exposure to the conditioned perceptual stimulus. Self-reported fear confirmed the acquisition and generalization of fear and provided evidence of a significant reduction in differential fear conditioning across extinction. Consistent with clinical evidence of the efficacy of imagery extinction and the existing limited experimental literature, the current study offers support for fear extinction to perceptual stimuli via imagery exposure.

Calcineurin Participation in Hebbian and Homeostatic Plasticity Associated With Extinction

In nature, animals need to adapt to constant changes in their environment. Learning and memory are cognitive capabilities that allow this to happen. Extinction, the reduction of a certain behavior or learning previously established, refers to a very particular and interesting type of learning that has been the basis of a series of therapies to diminish non-adaptive behaviors. In recent years, the exploration of the cellular and molecular mechanisms underlying this type of learning has received increasing attention. Hebbian plasticity (the activity-dependent modification of the strength or efficacy of synaptic transmission), and homeostatic plasticity (the homeostatic regulation of plasticity) constitute processes intimately associated with memory formation and maintenance. Particularly, long-term depression (LTD) has been proposed as the underlying mechanism of extinction, while the protein phosphatase calcineurin (CaN) has been widely related to both the extinction process and LTD. In this review, we focus on the available evidence that sustains CaN modulation of LTD and its association with extinction. Beyond the classic view, we also examine the interconnection among extinction, Hebbian and homeostatic plasticity, as well as emergent evidence of the participation of kinases and long-term potentiation (LTP) on extinction learning, highlighting the importance of the balance between kinases and phosphatases in the expression of extinction. Finally, we also integrate data that shows the association between extinction and less-studied phenomena, such as synaptic silencing and engram formation that open new perspectives in the field.

Social Integrating Robots Suggest Mitigation Strategies for Ecosystem Decay

We develop here a novel hypothesis that may generate a general research framework of how autonomous robots may act as a future contingency to counteract the ongoing ecological mass extinction process. We showcase several research projects that have undertaken first steps to generate the required prerequisites for such a technology-based conservation biology approach. Our main idea is to stabilise and support broken ecosystems by introducing artificial members, robots, that are able to blend into the ecosystem’s regulatory feedback loops and can modulate natural organisms’ local densities through participation in those feedback loops. These robots are able to inject information that can be gathered using technology and to help the system in processing available information with technology. In order to understand the key principles of how these robots are capable of modulating the behaviour of large populations of living organisms based on interacting with just a few individuals, we develop novel mathematical models that focus on important behavioural feedback loops. These loops produce relevant group-level effects, allowing for robotic modulation of collective decision making in social organisms. A general understanding of such systems through mathematical models is necessary for designing future organism-interacting robots in an informed and structured way, which maximises the desired output from a minimum of intervention. Such models also help to unveil the commonalities and specificities of the individual implementations and allow predicting the outcomes of microscopic behavioural mechanisms on the ultimate macroscopic-level effects. We found that very similar models of interaction can be successfully used in multiple very different organism groups and behaviour types (honeybee aggregation, fish shoaling, and plant growth). Here we also report experimental data from biohybrid systems of robots and living organisms. Our mathematical models serve as building blocks for a deep understanding of these biohybrid systems. Only if the effects of autonomous robots onto the environment can be sufficiently well predicted can such robotic systems leave the safe space of the lab and can be applied in the wild to be able to unfold their ecosystem-stabilising potential.

Steller’s sea cow genome suggests this species began going extinct before the arrival of Paleolithic humans

Anthropogenic activity is the top factor directly related to the extinction of several animal species. The last Steller’s sea cow (Hydrodamalis gigas) population on the Commander Islands (Russia) was wiped out in the second half of the 18th century due to sailors and fur traders hunting it for the meat and fat. However, new data suggests that the extinction process of this species began much earlier. Here, we present a nuclear de novo assembled genome of H. gigas with a 25.4× depth coverage. Our results demonstrate that the heterozygosity of the last population of this animal is low and comparable to the last woolly mammoth population that inhabited Wrangel Island 4000 years ago. Besides, as a matter of consideration, our findings also demonstrate that the extinction of this marine mammal starts along the North Pacific coastal line much earlier than the first Paleolithic humans arrived in the Bering sea region.

An emerging consensus in palaeoanthropology: demography was the main factor responsible for the disappearance of Neanderthals

The causes of Neanderthal disappearance about 40,000 years ago remain highly contested. Over a dozen serious hypotheses are currently endorsed to explain this enigmatic event. Given the relatively large number of contending explanations and the relatively large number of participants in the debate, it is unclear how strongly each contender is supported by the research community. What does the community actually believe about the demise of Neanderthals? To address this question, we conducted a survey among practicing palaeo-anthropologists (total number of respondents = 216). It appears that received wisdom is that demography was the principal cause of the demise of Neanderthals. In contrast, there is no received wisdom about the role that environmental factors and competition with modern humans played in the extinction process; the research community is deeply divided about these issues. Finally, we tested the hypothesis that palaeo-anthropologists’ stand in the debate co-varies with their socio-political views and attitudes. We found no evidence for such a correlation.

What Do Palaeo-Anthropologists Believe About the Disappearance of Neanderthals?

The causes of Neanderthal disappearance about 40,000 years ago remain highly contested. Over a dozen serious hypotheses are currently endorsed to explain this enigmatic event. Given the relatively large number of contending explanations and the relatively large number of participants in the debate, it is unclear how strongly each contender is supported by the research community. What does the community actually believe about the demise of Neanderthals? To address this question, we conducted a survey among practicing palaeo-anthropologists (total number of respondents = 216). It appears that received wisdom is that demography was the principal cause of the demise of Neanderthals. In contrast, there is no received wisdom about the role that environmental factors and competition with modern humans played in the extinction process; the research community is deeply divided about these issues. Finally, we tested the hypothesis that palaeo-anthropologists’ stand in the debate co-varies with their socio-political views and attitudes. We found no evidence for such a correlation.

Comparison of the Effects of Deep Brain Stimulation of the Prelimbic Cortex and Basolateral Amygdala for Facilitation of Extinction Process of Conditioned Fear

Background: The study of the biological basis of fear in animal models has progressed considerably because of the energy and space that the brain devotes to this basic emotion. Electrical stimulation targets several structures of the brain to examine its behavioral effects and to understand the role of different regions in underlying mechanisms of fear processing and anxiety in preclinical models. Objectives: In this study, the effects of high-frequency deep brain stimulation (DBS) of the basolateral amygdala (BLA) and prelimbic (PL) sub-region of the prefrontal cortex were evaluated on the extinction process of conditioned fear. Methods: This study was performed on 35 male Wistar rats in the weight range of 220 – 250 g. After selecting the animals, they were separated into five groups. Then, we did stereotactic surgery on rats for electrode implantation. After recovery, some rats were conditioned, followed by a 10-day treatment schedule via high-frequency DBS in the BLA or PL. Next, freezing behavior was measured as a predicted response dedicated to extinction, without shock (re-exposure). In addition, we used ELISA and Western blot to estimate blood serum corticosterone levels and c-Fos protein expression. Results: The mean freezing time recorded for the PL group was significantly lower than that of both the BLA group and the PC group (P < 0.01). The BLA group and PC group were also significantly different (P < 0.001). Corticosterone results indicated that the PL group had significantly higher serum corticosterone levels compared with both the BLA group and the PC group (P < 0.01). In addition, the BLA group revealed a significant reduction in c-Fos expression compared with the PC (P < 0.001). Conclusions: This study provides further evidence for the contribution of the prelimbic cortex and amygdala both in acquisition and extinction processes during contextual fear conditioning. However, the PL stimulation by high-frequency DBS might be more involved in the extinction process and play a more important role as an enhancer.

Vicarious conditioned fear acquisition and extinction in child–parent dyads

The biological mechanisms involved in fear transmission within families have been scarcely investigated in humans. Here we studied (1) how children acquired conditioned fear from observing their parent, or a stranger, being exposed to a fear conditioning paradigm, and (2) the subsequent fear extinction process in these children. Eighty-three child-parent dyads were recruited. The parent was filmed while undergoing a conditioning procedure where one cue was paired with a shock (CS + Parent) and one was not (CS −). Children (8 to 12 years old) watched this video and a video of an adult stranger who underwent conditioning with a different cue reinforced (CS + Stranger). Children were then exposed to all cues (no shocks were delivered) while skin conductance responses (SCR) were recorded. Children exhibited higher SCR to the CS + Parent and CS + Stranger relative to the CS −. Physiological synchronization between the child’s SCR during observational learning and the parent’s SCR during the actual process of fear conditioning predicted higher SCR for the child to the CS + Parent. Our data suggest that children acquire fear vicariously and this can be measured physiologically. These data lay the foundation to examine observational fear learning mechanisms that might contribute to fear and anxiety disorders transmission in clinically affected families.

The Anthropocene Dialogues on Climate Change to Human Health of Homosapiens in India

The Anthropocene has succeeded the 11700 years old Holocene epoch from 1945. Biological annihilation about 6th mass extinction from Holocene to present is well marked but less documented though the human dominance over bio-geo-hydro spheres has been established. IUCN is the footage of the floral/ faunal species from mammals to microorganisms. Many natural disasters, killer IAS and pandemic viruses are targeting human immune system. The 21st century virulent diseases are the HIV/AIDS, SARS, MERS, Swine flu. Corona viruses are not novice whereas COVID-19 viruses are mutation of old corona viruses. It is necessary to study the COVID-19 as one of the players of the 6th Mass extinction. Present work envisages the 6th mass extinction processes in India from the Holocene to present epoch. There is gradual endangering the aboriginal species, pathogens and viral species. The geospatial extinction process of 1200 years gathered from different sources and synchronized in the India’s time frame. The present outbreak of the killer COVID-19 has triggered threat to very human existence in mid latitudes affecting 5.0 millon and fatalities 325K people over 215 countries and two ships in the globe and 101 thousand confirmed cases and 3.3K people in India (till 20.05.2020).The pandemic has paralyzed the human’s social, economic, political activities and deteriorated world economy since last four months. The viral invasion is geospatially delimiting the climate change, extreme events, economy, sociology and mass immunity of the vibrant urban demography.