Social Network Effects on Health and Emotional Wellbeing

Humans’ social relationships determine to a large degree their trajectories in life. Despite strong evidence for the impact of interpersonal relations on wellbeing, the causal links between the two are not yet fully understood. This dissertation offers a new perspective on the mechanisms through which social ties influence negative (excessive drinking) and positive (participation in recreational activities) health behaviors. In three studies employing a unique combination of social network, fMRI, and experience-sampling methods, we propose that health decisions are the result of complex computations involving prior social experiences, perceived social norms, social comparison processes, and current feelings of connections. Each chapter of this dissertation discusses one of these three studies. Chapter 1 provides evidence that past social experiences shape valuations of new information by showing that pairs of students that drink often together tend to have more similar neural responses to novel alcohol cues in regions associated with affective self-generated thought. In addition, this Chapter suggests that researchers must consider the intricate interplay between individuals’ personal goals and their communities’ norms to understand the influence of social environments on neural representations. The degree to which students aligned their neural response patterns to alcohol with those of their peers depended on interactions between their individual motives for drinking and their group’s approval of this behavior. Chapter 2 presents novel findings that people spontaneously represent social information from multiple networks (e.g., popularity and leadership) at a neural level in social cognition (right TPJ, dmPFC) and valuation (vmPFC) regions. Importantly, individuals who display higher neural sensitivity to status differences are also more likely to align their drinking behavior with their group norms in daily life. Together, our results provide insight into the neural mechanisms through which social comparison processes shape conformity and suggest social cognition and valuation regions as important hubs orchestrating this process. While Chapter 1 and Chapter 2 focus on the influence of social ties on drinking, Chapter 3 discusses the protective role of close relations during difficult times. We provide evidence that close college friendships, even if afar, helped young adults cope with the stress of the COVID-19 pandemic. Follow-up between- and within-individual analyses reveal that this buffering effect could be explained by differences in the quality of online interactions (e.g., via phone, text messaging), instances of personal disclosure, and participation in enjoyable activities. All in all, this dissertation advances our understanding of why measures of social wellbeing are the best predictor of health trajectories in life, by highlighting the important role social ties play in shaping valuation of new information, guiding behavior to meet social goals, and protecting against stress by allowing people to engage in recreational activities

Momentary associations between affect and alcohol use in the daily lives of college students

Objective: Alcohol is theorized to be motivated by desires to regulate negative affect and/or to enhance positive affect. We tested the association between momentary affect and alcohol use in the daily lives of college students, hypothesizing that alcohol use would be more likely to follow increases in positive affect and that alcohol use would not be strongly associated with negative affect. Method: Using two ecological momentary assessment (EMA) studies consisting of two prompts per day for 28 days, we used multilevel hurdle models to test for lagged associations between positive and negative affect and alcohol use. There were 108 participants (60.19%; mean age = 20.20, SD=1.69) in EMA study 1 and 268 participants (60.03%women, mean age = 20.22, SD=1.96) in EMA study 2. To provide context for the affect-alcohol associations, we collected data on whether participants drank alone or with others at each drinking occasion and the drinking motives of participants using the Drinking Motives Questionnaire. Results: Alcohol use was more likely to occur following increases in positive affect. No significant associations emerged between fluctuations in negative affect and alcohol use. This pattern of findings was observed across both ecological momentary assessment studies. The majority of alcohol use occurred in social contexts. Conclusions: College students who report primarily social and enhancement motives for drinking and who seldom drink alone are more likely to drink following increases in positive affect

Purpose in life, neural alcohol cue reactivity and daily alcohol use in social drinkers

Background and AimAlcohol craving is an urge to consume alcohol that commonly precedes drinking; however, craving does not lead to drinking for all people under all circumstances. The current study measured the correlation between neural reactivity and alcohol cues as a risk, and purpose in daily life as a protective factor that may influence the link between alcohol craving and the subsequent amount of consumption.DesignObservational study that correlated functional magnetic resonance imaging (fMRI) data on neural cue reactivity and ecological momentary assessments (EMA) on purpose in life and alcohol use.SettingTwo college campuses in the United States.ParticipantsA total of 54 college students (37 women, 16 men, and 1 other) recruited via campus-based groups from January 2019 to October 2020.MeasurementsParticipants underwent fMRI while viewing images of alcohol; we examined activity within the ventral striatum, a key region of interest implicated in reward and craving. Participants then completed 28 days of EMA and answered questions about daily levels of purpose in life and alcohol use, including how much they craved and consumed alcohol.FindingsA significant three-way interaction indicated that greater alcohol cue reactivity within the ventral striatum was associated with heavier alcohol use following craving in daily life only when people were previously feeling a lower than usual sense of purpose. By contrast, individuals with heightened neural alcohol cue reactivity drank less in response to craving if they were feeling a stronger than their usual sense of purpose in the preceding moments (binteraction = −0.086, P < 0.001, 95% CI = −0.137, −0.035).ConclusionsNeural sensitivity to alcohol cues within the ventral striatum appears to be a potential risk for increased alcohol use in social drinkers, when people feel less purposeful. Enhancing daily levels of purpose in life may promote alcohol moderation among social drinkers who show relatively higher reactivity to alcohol cues.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/175062/1/add16012.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175062/2/add16012-sup-0001-3_add16012-sup.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175062/3/add16012_am.pd

Neural moderators of social influence susceptibility on drinking

Objectives: Conversations shape health behaviors. However, individuals vary in susceptibility to conversational influence and in their neural responses that track such influences. We examined whether activity in brain regions associated with social rewards and making sense of others’ minds was related to drinking following conversations about alcohol. We studied ten social groups of college students (total N = 104 students; 4760 total observations) across two University campuses. Methods: We collected whole-brain fMRI data while participants viewed photographs of the faces of peers with whom they tended to drink at varying frequencies (i.e., drinking vs. non-drinking peers). Next, using mobile diaries, we tracked alcohol-related conversations and alcohol use twice daily for 28 days. Results: On average, talking about alcohol was associated with a higher probability of drinking the following day. Controlling for baseline drinking, participants who responded more strongly to drinking peers—with whom they drank more frequently— in brain regions associated with social rewards and mentalizing showed higher susceptibility to conversational influence on drinking. Conversely, stronger neural responses to non-drinking peers—with whom they drank less frequently—decoupled the link between alcohol conversations and next-day drinking. Conclusions: These findings conceptually replicate prior findings linking peer conversations and drinking behavior in a longitudinal, ecologically valid setting, and provide new evidence that brain sensitivity to peers may exacerbate or buffer conversational susceptibility to drink

Mindful attention promotes control of brain network dynamics for self-regulation and discontinues the past from the present.

Mindful attention is characterized by acknowledging the present experience as a transient mental event. Early stages of mindfulness practice may require greater neural effort for later efficiency. Early effort may self-regulate behavior and focalize the present, but this understanding lacks a computational explanation. Here we used network control theory as a model of how external control inputs-operationalizing effort-distribute changes in neural activity evoked during mindful attention across the white matter network. We hypothesized that individuals with greater network controllability, thereby efficiently distributing control inputs, effectively self-regulate behavior. We further hypothesized that brain regions that utilize greater control input exhibit shorter intrinsic timescales of neural activity. Shorter timescales characterize quickly discontinuing past processing to focalize the present. We tested these hypotheses in a randomized controlled study that primed participants to either mindfully respond or naturally react to alcohol cues during fMRI and administered text reminders and measurements of alcohol consumption during 4 wk postscan. We found that participants with greater network controllability moderated alcohol consumption. Mindful regulation of alcohol cues, compared to ones own natural reactions, reduced craving, but craving did not differ from the baseline group. Mindful regulation of alcohol cues, compared to the natural reactions of the baseline group, involved more-effortful control of neural dynamics across cognitive control and attention subnetworks. This effort persisted in the natural reactions of the mindful group compared to the baseline group. More-effortful neural states had shorter timescales than less effortful states, offering an explanation for how mindful attention promotes being present

Psychological distance intervention reminders reduce alcohol consumption frequency in daily life

Abstract Modifying behaviors, such as alcohol consumption, is difficult. Creating psychological distance between unhealthy triggers and one’s present experience can encourage change. Using two multisite, randomized experiments, we examine whether theory-driven strategies to create psychological distance—mindfulness and perspective-taking—can change drinking behaviors among young adults without alcohol dependence via a 28-day smartphone intervention (Study 1, N = 108 participants, 5492 observations; Study 2, N = 218 participants, 9994 observations). Study 2 presents a close replication with a fully remote delivery during the COVID-19 pandemic. During weeks when they received twice-a-day intervention reminders, individuals in the distancing interventions reported drinking less frequently than on control weeks—directionally in Study 1, and significantly in Study 2. Intervention reminders reduced drinking frequency but did not impact amount. We find that smartphone-based mindfulness and perspective-taking interventions, aimed to create psychological distance, can change behavior. This approach requires repeated reminders, which can be delivered via smartphones

Frontoparietal functional connectivity moderates the link between time spent on social media and subsequent negative affect in daily life

Abstract Evidence on the harms and benefits of social media use is mixed, in part because the effects of social media on well-being depend on a variety of individual difference moderators. Here, we explored potential neural moderators of the link between time spent on social media and subsequent negative affect. We specifically focused on the strength of correlation among brain regions within the frontoparietal system, previously associated with the top-down cognitive control of attention and emotion. Participants (N = 54) underwent a resting state functional magnetic resonance imaging scan. Participants then completed 28 days of ecological momentary assessment and answered questions about social media use and negative affect, twice a day. Participants who spent more than their typical amount of time on social media since the previous time point reported feeling more negative at the present moment. This within-person temporal association between social media use and negative affect was mainly driven by individuals with lower resting state functional connectivity within the frontoparietal system. By contrast, time spent on social media did not predict subsequent affect for individuals with higher frontoparietal functional connectivity. Our results highlight the moderating role of individual functional neural connectivity in the relationship between social media and affect

Mindfulness Promotes Control of Brain Network Dynamics for Self-Regulation and Discontinues the Past from the Present

Mindfulness is characterized by attentiveness to the present experience with nonjudgmental awareness and acceptance. Practicing mindfulness alters brain function to support the executive regulation of thoughts, feelings, and behavior. While early stages of practice are thought to require greater "neural effort" for later efficiency, current evidence relies on circular definitions of effort based on functional activity magnitude. Here we used network control theory as a model of how external control inputs, which operationalize effort, can distribute changes in neural activity across the macro-scale structural brain network. Further, we inferred the intrinsic timescale of activity to operationalize present-centered activity as shorter momentary timescales that discontinue the past and update the present. To explain effects of mindful regulation on alcohol consumption, we applied these methods to a randomized controlled intervention study with resting-state and task fMRI data. The task primed participants to either mindfully respond or naturally react to alcohol cues. Mobile text interventions and measurements of alcohol consumption were administered using ecological momentary assessments during the subsequent 4 weeks. We hypothesized that neural states of mindfulness require greater effort to enact and sustain. This effort may support deautomatized habitual natural reactions, discontinued processing, and updated present-centered neural dynamics. We found that mindful regulation of alcohol cues, compared to the natural reactions of the benchmark group, involved more effortful control of neural dynamics across cognitive control and attention networks. This effort persisted in the natural reactions of the mindful group compared to the benchmark group. Using resting-state fMRI, we found that more effortful neural states tended to occur over shorter timescales than less effortful states. Our findings provide an explanation for how neural dynamics with altered effort and stability, such as mindful states, tend to center the present experience

Study protocol: Social Health Impact of Network Effects (SHINE) Study

Humans are a fundamentally social species whose well-being depends on how we connect with and relate to one another. As such, scientific understanding of factors that promote health and well-being requires insight into causal factors present at multiple levels of analysis, ranging from brain networks that dynamically reconfigure across situations to social networks that allow behaviors to spread from person to person. The Social Health Impacts of Network Effects (SHINE) study takes a multilevel approach to investigate how interactions between the mind, brain, and community give rise to well-being. The SHINE protocol assesses multiple health and psychological variables, with particular emphasis on alcohol use, how alcohol-related behavior can be modified via self-regulation, and how thoughts, feelings, and behaviors unfold in the context of social networks. An overarching aim is to derive generalizable principles about relationships that promote well-being by applying multilayer mathematical models and explanatory approaches such as network control theory. The SHINE study includes data from 711 college students recruited from social groups at two universities in the northeastern United States of America, prior to and during the COVID-19 pandemic. Participants completed at least one of the following study components: baseline self-reported questionnaires and social network characterization, self-regulation intervention assignment (mindful attention or perspective taking), functional and structural neuroimaging, ecological momentary assessment, and longitudinal follow-ups including questionnaires and social network characterization. The SHINE dataset enables integration across modalities, levels of analysis, and timescales to understand young adults’ well-being and health-related decision making. Our goal is to further our understanding of how individuals can change their thoughts, feelings, and behaviors, and of how these changes unfold in the context of social networks