Browsing by Subject "Social behavior"

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A window onto the psychology of everyday life : assessing students’ daily behaviors using smartphone sensing methods
(2016-12) Harari, Gabriella Marilyn; Gosling, Sam; Pennebaker, James W; Tucker-Drob, Elliot M; Hixon, John G.; Mehl, Matthias R
The purpose of my dissertation is to assess the viability of using smartphone-sensing methods for behavioral data collection in psychological research, and reveal the patterns of social behavior that characterize students’ everyday lives. In Chapter 1, I provide an overview of smartphone sensing methods and discuss the current opportunities for their use in psychological research. In Chapter 2, I describe the two datasets that are used in this dissertation. In Chapter 3, I examine the viability of using smartphone sensing methods for psychological research by assessing participants’ motivations to self-track, their participation preferences, and their compliance rates in using a smartphone sensing application. The results show that students were interested in using self-tracking tools, and were motivated to self-track to maintain productive lifestyles, monitor their well-being, and increase their social life on campus. The results also suggest that students’ compliance in using a self-tracking app was highest when incentives matched students’ motivations to participate. In Chapter 4, I examine the psychometric properties of smartphone-based social behaviors in the context of students’ affiliation behaviors (i.e., ambient conversation, conversation frequency, co-presence with others) and interaction behaviors (i.e., incoming and outgoing calls and text messages, unique and repeated contacts) over time. The results provide estimates of the base rates, interindividual variability, and temporal stability of students’ social behaviors across different time frames (i.e., daily, weekly, times of the day, days of the week). In Chapter 5, I discuss practical considerations for researchers interested in using smartphone sensing for behavioral data collection, and discuss current challenges of the method. Taken together, the results from these studies provide important insights into the behaviors that make up everyday student life and establish the viability of using sensing methods to capture behaviors in psychological research.
Behavioral and neural mechanisms of learning in groups of a social cichlid fish
(2020-09-11) Rodriguez Santiago, Mariana; Hofmann, Hans (Hans A.); Colgin, Laura; Drew, Michael; Curley, James; Gore, Andrea
As animals navigate through their environment, they must integrate external stimuli with previous experience to guide behavioral decisions. In group living animals, these decisions are embedded in a social context that influences their interactions, access to resources, and ultimately, their behavior. To acquire and learn new information that is vital to their survival, individuals must successfully navigate social interactions that are often embedded in dominance hierarchies. Such hierarchies arise from dyadic relationships between dominant and subordinate individuals and confer fitness benefits to those of high rank. A great deal is known regarding the ultimate underpinnings of dominance, especially as it pertains to differences between dominant and subordinate individuals (reviewed in Chapter 1, along with a summary of the social learning field). However, we have much to learn regarding the neurobiological mechanisms through which individuals navigate these social hierarchies in order to learn and acquire new information that is critical for their survival, such as finding food. To begin to address this knowledge gap in understanding the neurobiology of learning in dynamic social groups, I conducted a series of experiments using the African cichlid fish, Astatotilapia burtoni. Males of this species form dominance hierarchies which are vital for gaining territories and access to reproductive opportunities. In chapter 2, I examined the unique social traits that differentiate dominant and subordinate males in social groups, and how these traits influence group learning and decision-making. In chapter 3, I examined the neural activity patterns that drive learning in a social and asocial context by quantifying immediate-early gene expression at different time points during the learning process. Finally, in chapter 4, I examined how these neural activity patterns in key brain regions, the putative homologues of the basolateral amygdala and hippocampus, vary with the extent of social stability during the learning process. Taken together, my research offers important new insights into the behavioral and neural mechanisms underlying social learning and suggests several directions for future study
Cognition in a social world : assessing cognitive variation by sex and dominance status in Gambusia affinis and Astatotilapia burtoni
(2021-02-23) Wallace, Kelly Jean; Hofmann, Hans (Hans A.); Ryan, Michael J. (Michael Joseph), 1953-; Domjan, Michael; Muth, Felicity; Phelps, Steven
Social environments are a rich landscape in which individuals must make decisions that may have lasting impacts on condition, resource acquisition (including reproductive opportunities), and ultimately fitness. Often, these decisions require cognitive processes like learned associations, memory, and spatial navigation. Different social environments facilitate cognitive performance (for example, a species with expansive and highly-delineated territories may excel at spatial learning). Within a species, social phenotype (e.g. sex, reproductive state, dominance status) can drive variation in cognition, yet this variation is less explored. Why might social phenotypes differ in cognition? This variation can be driven both by the underlying ecological pressures and by the physiological and neuromolecular mechanisms associated with social behavior and decision-making. This dissertation expands our knowledge on the exciting and growing intersect between cognitive ecology and social neuroscience. This integration is described in a literature analysis in Chapter 1, where I first provide background on each field individually. I then describe the results of an analysis of publications over time for each field and for the subset of publications found in both fields. Lastly, I propose a set of steps for future work in this intersection, highlighting exemplary animal models and topics in this area. In the experimental chapters of my dissertation, I use a uniquely integrative approach to explore the relationship between social phenotype and cognition. In two fish species with well-characterized social dynamics (the western mosquitofish Gambusia affinis and burton’s mouthbrooder Astatotilapia burtoni, an African cichlid), I assess performance on a suite of cognitive tasks. In Chapters 2 & 3, I investigate how and why the sexes differ in cognition in the respective species. In Chapter 4 I investigate how changes in dominance status modulate cognition and behavior, integrating physiological analyses. Throughout, I employ multidimensional analyses that not only quantify performance but additionally assess cognitive style (the way an individual approaches a cognitive task, e.g. exploration, decision speed), providing a comprehensive perspective on the relationship between social behavior and cognition.
Evolution of neuroendocrine mechanisms regulating adaptive behavior
(2011-05) O'Connell, Ashley Lauren; Hofmann, Hans (Hans A.)
All animals must integrate internal and environmental information into an appropriate behavior that ultimately aims to increases fitness. In order to investigate the proximate and ultimate mechanisms underlying adaptive behavior, I examined the role of neuroendocrine molecules at three distinct levels of biological organization. At the level of the individual, I demonstrate that steroid hormone receptors play distinct roles in modulating adaptive behavior, physiology and brain gene expression in dominant and subordinate African cichlid fish. At the level of the social community, I investigate how the behavior and physiology of one individual can affect the behavior, physiology, and brain gene expression of other community members. I found striking covariance patterns that implicate identifiable neuroendocrine pathways as mediators of specific social signals, establishing an important model to investigate the molecular basis of how behavioral phenotypes spread through communities. Finally, I investigate how the neurochemistry of the five major vertebrate classes has changed in a way that covaries with sensory integration, life history, and mating strategy. To address this question, I have laid an important theoretical framework to study the evolution of behavior as well as establishing neuroanatomical brain homologies across vertebrate lineages. I show that variation in where neurochemicals (dopamine, steroids, neuropeptides) are produced in the brain varies across vertebrates while where signals are received (ie receptors) are conserved, providing a novel theory of social brain evolution. In summary, I use a multidisciplinary approach to study hormonal contributions to the proximate and ultimate mechanisms of social behavior on many levels of biological organization and have contributed important novel insights that have significantly increased our understanding of the evolution of behavior and its neural and molecular underpinnings.
Natural history, behavior, and bacterial microbiomes of a socially polymorphic spider, Anelosimus studiosus
(2019-08) Dietrich, Emma Irene; Mueller, Ulrich G.; Gilbert, Lawrence E; Buskirk, Ruth E; Juenger, Thomas E; Leibold, Mathew A
Anelosimus studiosus is a unique spider; throughout its range from Argentina to New England, most adult females are solitary and subsocial (provide maternal care). However, in the northernmost parts of its range in the United States, adult females sometimes live in cooperative aggregations. While this social polymorphism has been well defined in specific regions of A. studiosus’ range, it is not so thoroughly described elsewhere. Therefore, I first describe the aggregative behavior, natural history, and population sex ratios for A. studiosus across a latitudinal gradient in Texas (Chapters 1 and 2). I discovered that A. studiosus tend to aggregate at higher latitudes in Texas, but that this tendency was not correlated with female-biased primary sex ratios, suggesting that outbreeding still occurs in these populations. I then compared the social behavior of A. studiosus from Texas populations to those further east (Alabama and Tennessee) using tests of aggressive tendency (Chapter 3). Individuals from western and eastern populations vary in aggressive tendency, but I was unable to corroborate previous findings that different measures of aggressive tendency correlate. Finally, I used 16S rRNA metagenomics to describe the bacterial microbiome of A. studiosus (Chapter 4). Similar to some spider species but unlike many other animals, A. studiosus do not harbor a consistent, core bacterial community, and instead, their bacterial communities reflect their rearing environment and diet. In all, this dissertation on the socially polymorphic Anelosimus studiosus adds to a growing body of literature on the complexity of animal personalities, and their effect on organismal biology.
Neuromolecular mechanisms of social cognition in a cichlid fish
(2016-08) Weitekamp, Chelsea Anne; Hofmann, Hans (Hans A.); Cummings, Molly E; Ryan, Michael J; Bolnick, Daniel I; Gore, Andrea C
When interacting with conspecifics, individuals make decisions that integrate, in real-time, the behavior of their social partners with stored experiences from past interactions (learning and memory) and predictions of future behavior. This ability can be referred to as social cognition, defined as awareness of and knowledge about conspecifics, and measured by examining an individual’s perception of and insight into its own and others’ social interactions and relationships. The study of social cognition depends critically on understanding how the brain processes social information. However, the neural and molecular substrates subserving these processes are only poorly understood. To begin to address this knowledge gap, I conducted a series of experiments using territorial male African cichlid fish, Astatotilapia burtoni. I focused on three brain regions critical to social decision-making in vertebrates: the preoptic area and homologs of the amygdala and hippocampus. In Chapter 1, I examined the mechanisms underlying same-sex pair bonding in the context of the Dear Enemy effect and identified a role for the oxytocin receptor homolog in the amygdala and hippocampus. In Chapter 2, I studied the hormonal processes of the Dear Enemy effect as males gained familiarity. Then, I demonstrated that Dear Enemy males will engage in cooperative defense against an intruder. I identified neural correlates of cooperative behavior in the amygdala and preoptic area, as well as within dopaminergic neuron populations. In Chapter 3, I manipulated social context during territory defense to examine how the brain responds to the social environment. I found that blocking D2 dopamine receptors inhibits territory defense in the context of a reproductive opportunity, but not in the context of cooperative defense. Further, I identified differences between social contexts in candidate gene expression levels in the preoptic area. In summary, my data offer novel insight into the neuromolecular mechanisms underlying social cognition in a cichlid fish and suggest several directions for future study.
Sex steroid hormones regulate responses to social challenge and opportunity in the convict cichlid, Amatitliana nigrofasciata
(2011-05) Sessa, Anna Kristina; Hofmann, Hans (Hans A.)
Steroid hormones play an important role in modulating behavioral responses to various social stimuli. However, relatively little is known about how hormones respond to social stimuli and their modulation of subsequent behavior. Variation in the hormonal regulation of behavior across species has complicated the overall understanding of the hormone-behavior dynamic. In order to further elucidate the interplay of hormones and behavior in social situations, we exposed males of the monogamous convict cichlid Amatitliana nigrofasciata to three social stimuli: gravid female, intruder male and nonsocial neutral stimulus. We used a repeated exposure paradigm to create behavioral profiles and explore how sex steroid hormones respond to and regulate social behavior. Results show clear behavioral profiles in different social situations with 11-KT acting as the active androgen, increasing in response to social stimuli. Pharmacological manipulations using androgen and estrogen receptor agonists and antagonists exposed complex control over digging behavior based on social context, showed a unique decrease in aggressive behavior due to blocking the androgen receptors and a ubiquitous drug effect on vertical display. Results create well defined context-specific behavior profiles and extends our understanding of particular social behavior and how sex steroid hormones are involved in social situations and the behavioral response.
Social distancing in nature : insights from vampire bats
(2021-01-21) Stockmaier, Sebastian; Ryan, Michael J. (Michael Joseph), 1953-; Bolnick, Daniel; Meyers, Lauren E; Phelps, Steven M
I am broadly interested in how animals change their social behaviors in response to infection and how these changes affect pathogen spread across groups or populations. Hence, my research integrates ideas from behavioral ecology, epidemiology, and immunology to better understand the ultimate and proximate consequences of social distancing. In my first chapter, I synthesize literature on pathogen-induced changes in sociality in non-human animals and in humans. These include active and passive changes in pathogen-exposed and unexposed group members, occurring both before and after individuals develop an active infection. Behavioral changes that reduce social interactions and thus pathogen spread include changes driven by infectious hosts, such as sickness behaviors and active self-isolation, as well as changes driven by healthy hosts, including active avoidance or exclusion of infectious individuals and proactive social distancing in the face of pathogenic threats. I review what is known about underlying mechanism and consider implications for evolution and epidemiology. I also highlight the value of studying social distancing behaviors in non-human animals to better understand how these behaviors alter traits relevant to human public health, including pathogen spread and virulence. The remaining three chapters present my experimental work on common vampire bats (Desmodus rotundus) in Panama. In my second chapter, I established a method to experimentally induce transient symptoms of sickness in vampire bats by using injections of lipopolysaccharide (LPS). LPS injections mimic a bacterial infection including physiological, as well as behavioral symptoms (commonly termed ‘sickness behaviors’) in vampire bats (Stockmaier et al., 2018). Importantly, vampire bats also expressed a form a social distancing by reducing their allogrooming efforts towards others in this study (Stockmaier et al., 2018). In my third chapter I explored how this social distancing behavior in vampire bats is affected by what type of behavior is observed (allogrooming versus food sharing), how sociality as a biological trait is defined (e.g. network degree versus mean edge strength), and the type of relationship between two interacting individuals (kin versus non-kin relationship). Immune-challenged bats experienced a greater reduction in grooming than food sharing which potentially bestows greater fitness benefits (Stockmaier et al., 2020a). I also found that sickness effects on social behaviors might vary with relationship type because the immune challenge had smaller effects on mother-offspring interactions (Stockmaier et al., 2020a). Finally, I found that sickness effects depend on how a social interaction is defined (e.g. number of grooming partners versus grooming duration). I found that sickness reduced the number of grooming partners but less so the overall duration of social encounters (Stockmaier et al., 2020a). This reduction in grooming partners could be driven by reduced movement but could be augmented by reduced social vocalizations. When isolated, vampire bats produce contact calls that attract highly associated group mates. In my fourth chapter I explore whether LPS injections affect contact calling behavior. I show that LPS-induced sickness behavior mainly reduces the number of contact calls produced by isolated vampire bats (Stockmaier et al., 2020b). This effect is relevant for pathogen transmission in social animals that rely on vocalizations to maintain physical contact.
The effects of gestational exposure to endocrine-disrupting chemicals on the adult social behavior in male and female rats
(2018-06-13) Reilly, Michael Patrick; Gore, Andrea C., 1964-; Crews, David; Vasquez, Karen; Dominguez, Juan; Richburg, John
Endocrine disrupting chemicals (EDC) exposures during critical periods of development influence neuronal development and the manifestation of sexually dimorphic behaviors that emerge in adulthood. Among these behaviors, social information processing is sexually dimorphic and regulated by sex steroids. Oxytocin and vasopressin serve as primary neurotransmitters mediating these behaviors; these neuroendocrine circuits are hormone sensitive and potential targets of prenatal EDC exposures. In dissertation, I assess the effects of gestational exposure to EDCs on the social behavior of male and females later in adulthood. A weakly estrogenic PCB mixture, Aroclor 1221, was administered to pregnant Sprague-Dawley rat dams during the time when the hypothalamus undergoes sexual differentiation. The brains of these animals were also used to quantify the presence of oxytocin or vasopressin in the two main regions of production: the paraventricular nucleus (PVN) and the supraoptic nucleus (SON). Another experiment extended this treatment paradigm to encompass a longer period of gestational development, added another EDC treatment group (Vinclozolin), and looked at similar behavioral outcomes. Lastly, I provide a novel way of modeling complex social behaviors in a laboratory setting. Through all of this work, we show that the sexes are differentially susceptible to endocrine disruption by PCBs or vinclozolin. Additionally, we provide evidence that the traditional choice models of social behavior in the rodent may not be reflective of how an animal behaves in a more complex, naturalistic, environment.