by Jennifer FortunatoIn chapter 10 of The Encultured Brain, the author of the chapter, Erin Finley, writes about how trauma evolves into post-traumatic stress disorder (PTSD) by focusing on six variables that are implicated in this experience: cultural environment, stress, horror, dislocation, grief, and cultural mediators. The author starts off the chapter by describing what trauma is. They describe trauma as beginning with sensory and perceptual experience of danger that may or may not come as a shock. To understand how trauma morphs into PTSD, the author states that we need to look not just at one aspect or use of definition of PTSD but integrate biological, social, physiological and cultural factors into our understanding of the disease.
Finley then starts to delve into the six variables of the PTSD experience. The first variable cultural experience which takes into account local social structure, patterns of kin relationships, historical and political context, physical environment and local worldviews and norms. Finley emphasizes that the cultural experience plays a critical role in the experience of trauma. PTSD is characterized by hyperarousal, reexperiencing, and avoidance or numbing all of which can be stigmatized by others. The next variable of stress is discussed in the cultural context. Where soldiers who have extended combat experience have a rewiring of the stress experience due to time spent under intense and potentially life-threatening conditions. This is exemplified in veterans returning from deployment who describe their responses to stimuli as having unprecedented vigilance. Finley then describes research related to this and concludes that it is normal for those who experience a highly stressful environment for a long while to adapt to that way of living and for it to remain after returning to safety. Understanding cultural differences in the stress response might provide a way to understand how individuals respond to stressful events. The third variable, horror, is the one that is most likely to reemerge as a recurrent nightmare and/or intrusive memories. Finley describes horror as an emotion so powerful that it can overwhelm an individual’s capacity for immediate sense-making or cognitive processing. Those with PTSD may not recover without intervention from outside help. Horror can be understood in the cultural context as a challenge to deeply held beliefs about the self and world that may pose a painful challenge to individual identity. Dislocation, the fourth variable, is an estrangement from those around you, an earlier mode of perception, from feeling at home in the world or sense of self. Veterans can have an emotional flattening of their emotions where the way that they react to the world around them has diminished. Biologically, stressed brains will bypass cognitive thinking to go immediately to rapid action and response. This can be shaped by an individual’s personal history and cultural expectations of themselves. Veterans may respond in ways that are culturally appropriate, however, the way in which they do so may not be appropriate. This may in turn further alienate them from close friends and family. However, how the friends and family perceive these responses by veterans to stimuli can reduce this alienation. The next variable, grief, is a part of a natural mourning process when losing someone close to you. Veterans may feel a sense of personal responsibility for the death of a fellow soldier or even for surviving the same event that killed another soldier. Grief can also result from a loss of self or norms after returning to civilian life. These losses whether tangible, like loss of a life, or intangible, like loss of the sense of self, can exacerbate senses of grief in veterans. The last variable is cultural mediators. This is the role of cultural tools and processes to help mediate the relationship of the other trauma variables. This can be best understood through evidence-based cognitive behavioral therapy which has been proven to reduce trauma symptoms over a long period of time. Cognitive behavioral therapy can assist in helping veterans return to civilian life and manage symptoms of PTSD and the, often accompanying, symptoms of anxiety and depression. Having other ways to express emotion can help in reducing dislocation and stress. Also, social support is critical in helping reduce the experience of trauma. Social support can be found in kin relationships, support groups for survivors, and personal role models. Finley ends the chapter with a section on the neuroanthropological view of trauma and how it can assist in understanding PTSD. Neuroanthropology can facilitate the comparison of trauma responses across cultural contexts to better understand the relationship between culture and trauma. It can also help us understand the relationship between cognitive and neurophysiological responses to trauma. Using neuroanthropology as an interdisciplinary framework for understanding PTSD and trauma can help us find more meaningful, focused, and effective ways for understanding PTSD. My questions for the class are: 1. Early in the chapter, Finley mentions that this discussion is solely based on the experiences of male combat veterans and that the inclusion of female combat veterans is an important missing factor. Do you think the analysis of trauma and PTSD would change? How so? 2. How would you design a study to look at trauma from a neuroanthropological view? How would a more laboratory-focused and a more ethnographic-focused study differ?
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by Jennifer FortunatoIn this paper the author, Dr. Katherine Amato, discusses the relevance of the gut microbiota to the ecology and evolution of humans and non-human primates. Amato initially discusses how the gut microbiome is an important, yet understudied, factor in biological models, including humans and non-human primates. This paper suggests that researchers should incorporate the gut microbiome into their research to expand our perspective on and test the importance of the gut microbiome in human ecology and evolution. It does so by first reviewing current knowledge about the gut microbiome and its evolutionary role, then discusses the multitude of possible impacts that the gut microbiome can have on diet, energetics, disease resistance and cognition while also suggesting areas of future research.
The initial part of this paper discusses the relevance of gut microbiome interactions in early development, the physiology of the body, and diet and nutrition. In early mammal development, the initial establishment of the gut microbiome is during and after birth, through horizontal transfer from the vaginal microbiota and social interactions with the mother and vertical transmission through breast milk, from mother to offspring. Genotype plays a role in the type of microbiota in an individual. For example, monozygotic twins have more similar gut microbiota even after living apart than couples who live together. Yet, the abundance of microbes is primarily driven by diet and physiology. Changes in nutrients can change the abundances of certain taxa of microbes. However, the microbiome can affect what the host eats based of the ability of the microbiota to digest certain compounds. For example, since vertebrates lack the enzyme to digest cellulose it is left for the microbes in your gut to be able to digest it into usable substances. The gut microbiome also interacts with physiology. It can interact with the immune system by reducing inflammation and increasing immune responses to pathogens. The gut microbiome can also interact with the endocrine and nervous system where hormones such as dopamine can affect the function and composition of the gut microbiome. Also, research has shown that administration of certain bacterial strains can positively affect stress, anxiety, and depression. Another interaction of gut microbiota and the nervous system is that the gut microbiome can impact brain development by altering gene expression which could impact cognition. The next part of the paper discusses how the gut microbiome can be relevant to primate ecology and evolution, both in non-human primates and humans. This part specifically discusses feeding ecology and dietary niches, metabolic demands and physiology, disease resistance and health, and cognition, personality, and social behavior. For feeding ecology, in both human and non-human primates, the gut microbiome changes based on the type of food that the organism is eating and might play a role in the ability for these organisms to vary their diet in different environments for different food sources. The metabolic demands and physiology, of both human and non-human primates, interact with the gut microbiome by changing the permeability of the gut to change the nutrient absorption of the host. It is also suggested in the paper that the gut microbiome has an impact on brain size and growth rate due to this changing absorption rate of nutrients where if the microbes increase the absorption rate then that could have led to increased brain size due to the increased energy availability. Amato also discusses the importance of the gut microbiome in disease resistance and health. In both non-human primates and humans, the gut microbiome abundance and diversity can contribute to decreasing infection rates. This is brought up as corresponding to sociality, where taxa who are more social may have high microbial diversity or due to having high microbial diversity sociality is able to be maintained. Finally, Amato discusses non-human primates and human cognition, personality and social behavior in relation to the gut microbiome. Amato cites research done on how changes in the gut microbiome has been shown to affect aggression, anxiety levels, risk-taking, and social hierarchy. Amato also suggests that the human nervous system may have evolved to require microbial exposure for proper social development due to microbial ability to produce neurotransmitters, such as GABA, during early childhood development of the nervous system. Overall, Amato urges researchers to collaborate and connect gut microbiome research with anthropological research so that we can further our understanding of primate ecology and evolution. Amato ends the paper with a multitude of questions such as: “What constitutes as beneficial or a detrimental gut microbiota?” and “Do different gut microbial stable states provide different fitness effects for the host?” that will assist in furthering the field. However, the author does caution that correlations between the gut microbiome diversity and composition does not indicate causality. She recommends that future research of the gut microbiome complements studies of human ecology and evolution through collaboration to answer questions about how the gut microbiome influences human biology. This paper is especially relevant to neuroanthropology as it discusses how the gut microbiome could have impacts on sociality, brain size evolution and cognition. From previous readings in the class (Example: Dunbar and Shultz 2007), we have seen how important all of these factors have been in the evolution of primates. My questions for everyone are: 1. How would you design an experiment to test a gut microbiome and brain interaction using neuroanthropological methods? 2. Would you consider abundance or the type of microbiota more important or are both equally important and why? 3. Do you think the gut microbiome is important in primate ecology and evolution? Or do you think that there are other factors that are more relevant to primate ecology and evolution? Why? by Leah FontaineIn chapter 9 of The Encultured Brain, Rachel S. Brezis talks about her study looking at religious relationships in autistic youth raised in a Jewish family. She begins her chapter by discussing why her study is important and unique from those around it by pointing out that she is looking at neurological diversity rather than cultural diversity. She soon brings up a paper by Jesse M. Bering on the Theory of Mind, our capability to empathize and understand those around us. A leading theme in autistic research has been that all those on the spectrum lack this Theory of Mind. However, Brezis’s study refutes this and uses religion as her basis for understanding if someone possessed the theory.
Brezis includes a section talking about autism where she details the three main themes when patients are being diagnosed. The first centers around social interaction and any inability when dealing with it. The second is any disruption in language or communication. The third has to do with the need for a routine and therefore an inability to both handle and perform spontaneously. The also brings up one of the leading discoveries in autism research suggests a lack of connectivity throughout the brain as a whole. After looking into several other theories about autism, she does take a step back to remind that the emic perspective of autistic people shouldn’t be silenced in this research. This emic theme continues throughout the rest of her chapter. Throughout the rest of the chapter, Brezis details and describes her study, but does so in a much more scientific way that in a religious studies way. Her perspective on religion only goes as far as the Abrahamic religions which is a problem in many western studies. She defines her criteria for religion which is helpful in understanding what she is looking for, but it doesn’t mitigate the fact that she doesn’t acknowledge that she is only using the word religion or religious as being god centric. However, she finds that at least two of the autistic young adults that she studies have some form of personal connection with God. She uses this to show that some people with autism do have the ability to have a self and reflect on it despite Bering’s theory that they couldn’t. Brezis only studied those who were high functioning however, and there was little discussion on how wide of a spectrum autism covers. This chapter was an interesting read and I agree with Brezis’s assertion that this research should be continued, but there were many flaws and components left out of the study that leave gaping holes of understanding. She neglects to give any comparison to how autistic individuals relationships and understanding differ from those in their community. In a religion such a Judaism that doesn’t inforces practice over belief, the rates of how deep others in the community feel on religion should have been included in this study as it was one of the reason for picking it. While I think what Brezis finds is important and should be further looked into, I don’t believe her study has much weight because of the missing components. Questions: - What elements did you think were missing from this study either from a scientific perspective or a cultural one? - In what ways do you think this could further understanding in autism research and categorization of disabilities? Germs in Your Gut Are Talking to Your Brain/Gut bacteria linked to mental well-being and depression4/2/2019 by Kaitlyn MayThe New York Times article, “Germs in Your Gut are Talking to Your Brain,” discusses a newer wave of research exploring the relationship between the microbiome system and the brain. More and more, research in this area is increasing and pointing a critical role of microbiome in neural disorders such as autism, Alzheimer’s, Parkinson’s, depression, and others. The hypothesis is that there are a few species of microbes in the gastrointestinal system that play a key role in the development of neural disease and disorders via the release of chemicals that alter how immune cells work in the brain.
This area of research has been overlooked for years, largely because of the difficulties of studying these species in a lab; the majority of the microbes of the human system cannot survive in a petri dish. A key finding—the discovery of a way to sequence DNA from these microbes—served as a catalyst to the development of this area of research. Even then, little thought was given to the influence of the microbiome on the brain. Prior research indicated that the blood-brain barrier acted as a “sift” for the brain, only allowing small molecules to pass through. The New York Times article goes through seminal studies in this line of research. Each study relates various aspects of the microbiome to a different neurological disorder, such as Alzheimer’s, depression, autism, or seizures. The majority of these studies examine individual strains of bacteria in mouse models. For example, Dr. Costa-Mattioli at Baylor College of Medicine used mouse models of autism to examine how differences in the microbiome affected autism symptomatology. Dr. Costa-Mattioli found that the animals lacked Lactobacillus and adding this strain of bacteria to their diet reduced repetitive and anti-social behaviors. He researches revealed that the bacteria communicated to nerve endings in the intestines, and that these signals would be sent from gut to brain, where they would affect the production of the oxytocin hormone that promotes social bonds. Similarly, examination of the role of the microbiome in epileptic mice on a ketogenic diet identified a key role of the microbiome. A ketogenic diet has long been a key treatment for individuals with epilepsy, as the diet reduces seizures. When this diet was fed to epileptic mice raised free of microbes, these mice did not see a reduction in seizures. However, if they received stool from mice who were on a ketogenic diet, there seizures were reduced. This was because it is the microbiome which communicates to the brain. The research identified two types of gut bacteria which thrive in mice on a ketogenic diet and are potentially the key bacterium which communicate with neurotransmitters to halt electrical activity in the brain. This research could eventually replace diet therapy for epileptics with a pill containing the bacteria needed to communicate to neurotransmitters in the brain. The Penninsi article dives deeper into the relationship between the microbiome and depression. This article details a study that identified the absence of several species of gut bacteria in people with depression, namely Coprococcus and Dialister bacteria. These species were not missing in subjects with a high quality of life, and this persisted in participants of different ages, genders, or different antidepressant use. It is unclear whether the absence is a cause and effect, or a confound, but they were able to demonstrate that gut bacteria affected nerve cell function. Unlike the studies in the New York Times article which examined mice, the Penninsi article demonstrates this effect in humans. These findings could eventually influence treatments for depression. Oral probiotics, for example, could begin to be an accepted treatment for individuals with depression. 1. How might this area of research influence your field? 2. How does this research change the way that you think of the brain? |
AuthorThis blog is group authored by Dr. DeCaro and the students in his ANT 474/574: Neuroanthropology. Archives
April 2019
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