Sensory and Intellectual Pleasure-Seeking in H. D. Thoreau’s Walden: A Phylogenetic and Ontogenetic Developmental Paradigm

Nautinnonhaun tärkeä rooli ihmisen käyttäytymisessä on tiedostettu antiikin filosofiasta lähtien, ja 1900-luvun jälkipuoliskolla sille on annettu tieteellinen pohja neurofysiologisten tutkimusten kautta. Tämän tutkielman teoreettinen viitekehys perustuu neurofysiologiseen käyttäytymisteoriaan, jonka pohjalta ihmisen nautinnonhakumenetelmät on jaettu kahteen yläkategoriaan: aistinautintoihin ja älyllisiin nautintoihin. Tämän kahtiajaon pohjalta on tunnistettu fylogeneettinen ja ontogeneettinen ihmisen kehitysmalli, jonka mukaan ihmisen kehityshistoriassa aistinautinnot edeltävät älyllisiä nautintoja sekä laji- että yksilötasolla. Tätä teoreettista viitekehystä käyttäen analysoidaan Henry David Thoreaun klassikkokirjan henkilöhahmojen edistystä kehitysmallin puitteissa. Alek Therienin käyttäytyminen esitetään kirjassa lapsenomaisena ja hänen nautinnonhakunsa pääosin aistien kautta tapahtuvana. Thoreau kuvaa hänen älyllistä kehitystään eläimen tasolla olevaksi ja toteaa saman pitävän paikkansa useimpien ihmisten kohdalla. Thoreau tunnistaa itsessään ihmisen kehitysmallin aistinautintojen hakijasta älyllisten nautintojen hakijaksi, ja Walden itsessään voidaankin nähdä Thoreaun pyrkimyksenä edistää tätä kehitystä sekä muissa ihmisissä että hänessä itsessään. Thoreau kritisoi teoksessaan voimakkaasti materialismia. Osasyy tähän kritiikkiin on materialististen halujen hidastava vaikutus ihmisen älylliseen kehittymiseen. Älyllisen toiminnan tuloksilla on potentiaalisesti suurempi ja pitkäkestoisempi vaikutus ihmiskunnan kehitykseen, kun taas aistinautinnot nähdään ainoastaan ihmisrotua ylläpitävänä mekanismina ja ohikiitävän nautinnon saavuttamistapana. Walden sinänsä on todiste tästä: kirjoittamalla tämän kirjan Thoreau on vaikuttanut miljooniin ihmisiin tavalla, jota pelkkä aistinautintojen haku ei olisi mahdollistanut. Opiskelijan kannalta tässä tutkielmassa esitetyn kehitysmallin tunnistaminen itsessä auttaa määrittämään omia nautinnonhakumenetelmiä, henkilökohtaista kehitystä mallin viitekehyksessä sekä sitä kautta soveltuvuutta opiskelun edellyttämään pitkitettyyn älylliseen toimintaan.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Psycholinguistic dataset on language use in 1145 novels published in English and Dutch

This dataset includes psycholinguistic data on 694 English-language and 451 Dutch-language novels, acquired with computerised analysis of digitised novels published mainly between 1800 and 2018. The English-language novels have a total word count of 66.9 million words, while the Dutch-language novels comprise 49.6 million words, therefore offering large, representative samples for both languages. The data provided in this article include 93 linguistic and psycholinguistic outcome variables for the English-language novels, acquired using Linguistic Inquiry and Word Count (LIWC) version 2015, and 68 linguistic and psycholinguistic outcome variables for the Dutch-language novels, acquired using Linguistic Inquiry and Word Count (LIWC) version 2001. The dataset also includes word frequencies (unigram and bigram) for each novel. The metadata for each novel include year of publication, authors’ nationality, sex, age at publication, and sexual orientation (the latter only in the English-language dataset), making it possible for researchers to study the data along these parameters. The use of these data can help researchers illuminate how word use reflects psychological processes in more than two centuries of literary art in English and in contemporary Dutch novels

Schizophrenia: The new etiological synthesis

Schizophrenia has been an evolutionary paradox: it has high heritability, but it is associated with decreased reproductive success. The causal genetic variants underlying schizophrenia are thought to be under weak negative selection. To unravel this paradox, many evolutionary explanations have been suggested for schizophrenia. We critically discuss the constellation of evolutionary hypotheses for schizophrenia, highlighting the lack of empirical support for most existing evolutionary hypotheses—with the exception of the relatively well supported evolutionary mismatch hypothesis. It posits that evolutionarily novel features of contemporary environments, such as chronic stress, low-grade systemic inflammation, and gut dysbiosis, increase susceptibility to schizophrenia. Environmental factors such as microbial infections (e.g., Toxoplasma gondii) can better predict the onset of schizophrenia than polygenic risk scores. However, researchers have not been able to explain why only a small minority of infected people develop schizophrenia. The new etiological synthesis of schizophrenia indicates that an interaction between host genotype, microbe infection, and chronic stress causes schizophrenia, with neuroinflammation and gut dysbiosis mediating this etiological pathway. Instead of just alleviating symptoms with drugs, the parasite x genotype x stress model emphasizes that schizophrenia treatment should focus on detecting and treating possible underlying microbial infection(s), neuroinflammation, gut dysbiosis, and chronic stress.</p

Covid-19: Fat, Obesity, Inflammation, Ethnicity, and Sex Differences

Although obesity is known to be a risk factor for COVID-19 severity, there is an urgent need to distinguish between different kinds of fat-visceral and subcutaneous fat-and their inflammation status in COVID-19. These different fat types have partially diverging biochemical roles in the human body, and they are differentially associated with SARS-CoV-2, which targets the angiotensin-converting enzyme 2 (ACE2) for cell entry. ACE2 is highly expressed in adipose tissue, especially in visceral fat, suggesting an important role for this tissue in determining COVID-19 disease severity. In this perspective article, we discuss group differences in the amount of visceral fat levels and the extent of inflammation in adipocytes of visceral fat tissue, which may, in part, drive population, cross-national, ethnic, and sex differences in COVID-19 disease. It is vital to steer the scientific community's attention to the effects of visceral fat in creating individual and population differences in COVID-19 severity. This can help researchers unravel the reasons for the reported population, ethnic, and sex differences in COVID-19 severity and mortality

The obesity paradox predicts the second wave of COVID-19 to be severe in western countries

Funding Information: This work was funded by the Latvian Council of Science grants lzp-2018/1-0393 (I.A.K.), lzp-2018/2-0057 (T.K.), and lzp-2020/2-0271 (T.K.). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.While COVID-19 infection and mortality rates are soaring in Western countries, Southeast Asian countries have successfully avoided the second wave of the SARS-CoV-2 pandemic despite high population density. We provide a biochemical hypothesis for the connection between low COVID-19 incidence, mortality rates, and high visceral adiposity in Southeast Asian populations. The SARS-CoV-2 virus uses angiotensin-converting enzyme 2 (ACE2) as a gateway into the human body. Although the highest expression levels of ACE2 are found in people’s visceral adipose tissue in Southeast Asia, this does not necessarily make them vulnerable to COVID-19. Hypothetically, high levels of visceral adiposity cause systemic inflammation, thus decreasing the ACE2 amount on the surface of both visceral adipocytes and alveolar epithelial type 2 cells in the lungs. Extra weight gained during the pandemic is expected to increase visceral adipose tissue in Southeast Asians, further decreasing the ACE2 pool. In contrast, weight gain can increase local inflammation in fat depots in Western people, leading to worse COVID-related outcomes. Because of the biological mechanisms associated with fat accumulation, inflammation, and their differential expression in Southeast Asian and Western populations, the second wave of the pandemic may be more severe in Western countries, while Southeast Asians may benefit from their higher visceral fat depots.publishersversionPeer reviewe

Extra-pair paternity explains cooperation in a bird species

In many social animals, females mate with multiple males, but the adaptive value of female extra-pair mating is not fully understood. Here, we tested whether male pied flycatchers (Ficedula hypoleuca) engaging in extra-pair copulations with neighboring females were more likely to assist their neighbors in antipredator defense. We found that extra-pair sires joined predator-mobbing more often, approached predators more closely, and attacked predators more aggressively than males without extra-pair offspring in the neighboring nest. Extra-pair mating may incentivize males to assist in nest defense because of the benefits that this cooperative behavior has on their total offspring production. For females, this mating strategy may help recruit more males to join in antipredator defense, offering better protection and ultimately improving reproductive success. Our results suggest a simple mechanism by which extra-pair mating can improve reproductive success in breeding birds. In summary, males siring extra-pair offspring in neighboring nests assist neighbors in antipredator defense more often than males without extra-pair offspring.publishedVersio

Toxoplasma gondii and Psychopathology: Latent Infection Is Associated with Interpersonal Sensitivity, Psychoticism, and Higher Testosterone Levels in Men, but Not in Women

Objective The ability of parasites to hijack the nervous system, manipulating the host's physiology and behavior in ways that enhance the parasite's fitness while damaging host fitness, is a topic of ongoing research interest in evolutionary biology, but is largely overlooked in mental health research. Nevertheless, recent evidence has shown that Toxoplasma gondii infection can change host testosterone levels and influence the development of some psychiatric disorders. Here, we tested this hypothesis in a mixed sample of 213 non-clinical subjects.Methods Participants (n(males) = 108, n(females) = 105) provided 5 ml of blood to quantify testosterone levels and Toxoplasma gondii antibodies. The Symptom Checklist-90-Revised was used to assess psychopathological symptoms.Results The results showed that Toxoplasma-infected men had higher testosterone levels and scored higher in Interpersonal Sensitivity and Psychoticism symptoms than non-infected men. Toxoplasma-infected women did not differ from control women.Conclusions Framed in an evolutionary framework, the findings suggest that the elevated testosterone levels and the expression of psychopathological symptoms can be seen as the result of the manipulation exerted by Toxoplasma gondii either to reach its definitive host or to increase its spread. Future research can benefit from integrating insights from evolutionary biology and parasite-host interactions with physiology, immunology, and mental health to develop a better understanding of mental health etiology.</div