The Google Health Digital Well-Being Study: Protocol for a Digital Device Use and Well-Being Study.

BACKGROUND: The impact of digital device use on health and well-being is a pressing question. However, the scientific literature on this topic, to date, is marred by small and unrepresentative samples, poor measurement of core constructs, and a limited ability to address the psychological and behavioral mechanisms that may underlie the relationships between device use and well-being. Recent authoritative reviews have made urgent calls for future research projects to address these limitations. The critical role of research is to identify which patterns of use are associated with benefits versus risks and who is more vulnerable to harmful versus beneficial outcomes, so that we can pursue evidence-based product design, education, and regulation aimed at maximizing benefits and minimizing the risks of smartphones and other digital devices. OBJECTIVE: The objective of this study is to provide normative data on objective patterns of smartphone use. We aim to (1) identify how patterns of smartphone use impact well-being and identify groups of individuals who show similar patterns of covariation between smartphone use and well-being measures across time; (2) examine sociodemographic and personality or mental health predictors and which patterns of smartphone use and well-being are associated with pre-post changes in mental health and functioning; (3) discover which nondevice behavior patterns mediate the association between device use and well-being; (4) identify and explore recruitment strategies to increase and improve the representation of traditionally underrepresented populations; and (5) provide a real-world baseline of observed stress, mood, insomnia, physical activity, and sleep across a representative population. METHODS: This is a prospective, nonrandomized study to investigate the patterns and relationships among digital device use, sensor-based measures (including both behavioral and physiological signals), and self-reported measures of mental health and well-being. The study duration is 4 weeks per participant and includes passive sensing based on smartphone sensors, and optionally a wearable (Fitbit), for the complete study period. The smartphone device will provide activity, location, phone unlocks and app usage, and battery status information. RESULTS: At the time of submission, the study infrastructure and app have been designed and built, the institutional review board of the University of Oregon has approved the study protocol, and data collection is underway. Data from 4182 enrolled and consented participants have been collected as of March 27, 2023. We have made many efforts to sample a study population that matches the general population, and the demographic breakdown we have been able to achieve, to date, is not a perfect match. CONCLUSIONS: The impact of digital devices on mental health and well-being raises important questions. The Digital Well-Being Study is designed to help answer questions about the association between patterns of smartphone use and well-being. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49189.

Adolescent Social Communication Through Smartphones: Linguistic Features of Internalizing Symptoms and Daily Mood.

The increasing use of smartphone technology by adolescents has led to unprecedented opportunities to identify early indicators of shifting mental health. This intensive longitudinal study examined the extent to which differences in mental health and daily mood are associated with digital social communication in adolescence. In a sample of 30 adolescents (ages 11-15 years), we analyzed 22,152 messages from social media, email, and texting across one month. Lower daily mood was associated with linguistic features reflecting self-focus and reduced temporal distance. Adolescents with lower daily mood tended to send fewer positive emotion words on a daily basis, and more total words on low mood days. Adolescents with lower daily mood and higher depression symptoms tended to use more future focus words. Dynamic linguistic features of digital social communication that relate to changes in mental states may represent a novel target for passive detection of risk and early intervention in adolescence.

Intensive Longitudinal Assessment of Adolescents to Predict Suicidal Thoughts and Behaviors.

OBJECTIVE: Suicide is a leading cause of death among adolescents. However, there are no clinical tools to detect proximal risk for suicide. METHOD: Participants included 13- to 18-year-old adolescents (N = 103) reporting a current depressive, anxiety, and/or substance use disorder who owned a smartphone; 62% reported current suicidal ideation, with 25% indicating a past-year attempt. At baseline, participants were administered clinical interviews to assess lifetime disorders and suicidal thoughts and behaviors (STBs). Self-reports assessing symptoms and suicide risk factors also were obtained. In addition, the Effortless Assessment of Risk States (EARS) app was installed on adolescent smartphones to acquire daily mood and weekly suicidal ideation severity during the 6-month follow-up period. Adolescents completed STB and psychiatric service use interviews at the 1-, 3-, and 6-month follow-up assessments. RESULTS: K-means clustering based on aggregates of weekly suicidal ideation scores resulted in a 3-group solution reflecting high-risk (n = 26), medium-risk (n = 47), and low-risk (n = 30) groups. Of the high-risk group, 58% reported suicidal events (ie, suicide attempts, psychiatric hospitalizations, emergency department visits, ideation severity requiring an intervention) during the 6-month follow-up period. For participants in the high-risk and medium-risk groups (n = 73), mood disturbances in the preceding 7 days predicted clinically significant ideation, with a 1-SD decrease in mood doubling participants' likelihood of reporting clinically significant ideation on a given week. CONCLUSION: Intensive longitudinal assessment through use of personal smartphones offers a feasible method to assess variability in adolescents' emotional experiences and suicide risk. Translating these tools into clinical practice may help to reduce the needless loss of life among adolescents.

Reintroducing the Effortless Assessment Research System (EARS).

This paper reintroduces the Effortless Assessment Research System (EARS), 4 years and 10,000 participants after its initial launch. EARS is a mobile sensing tool that affords researchers the opportunity to collect naturalistic, behavioral data via participants' naturalistic smartphone use. The first section of the paper highlights improvements made to EARS via a tour of EARS's capabilities-the most important of which is the expansion of EARS to the iOS operating system. Other improvements include better keyboard integration for the collection of typed text; full control of survey design and administration for research teams; and the addition of a researcher-facing EARS dashboard, which facilitates survey design, the enrollment of participants, and the tracking of participants. The second section of the paper goes behind the scenes to describe 3 challenges faced by the EARS developers-remote participant enrollment and tracking, keeping EARS running in the background, and continuous attention and effort toward data protection-and how those challenges shaped the design of the app.

Finding the "self" in self-regulation: The identity-value model.

Many psychological theories suggest a link between self-regulation and identity, but until now a mechanistic account that suggests ways to improve self-regulation has not been put forth. The identity-value model (IVM) connects the idea from social psychology, that aspects of identity such as core values and group affiliations hold positive subjective value, to the process-focused account from decision-making and behavioral economics, that self-regulation is driven by a dynamic value integration across a range of choice attributes. Together, these ideas imply that goal-directed behaviors that are identity-relevant are more likely to be enacted because they have greater subjective value than identity-irrelevant behaviors. A central hypothesis, therefore, is that interventions that increase the degree to which a target behavior is perceived as self-relevant will improve self-regulation. Additionally, identity-based changes in self-regulation are expected to be mediated by changes in subjective value and its underlying neural systems. In this paper, we define the key constructs relevant to the IVM, explicate the model and delineate its boundary conditions, and describe how it fits with related theories. We also review disparate results in the research literature that might share identity-related value as a common underlying mechanism of action. We close by discussing questions about the model whose answers could advance the study of self-regulation.

Self-Control as Value-Based Choice.

Self-control is often conceived as a battle between "hot" impulsive processes and "cold" deliberative ones. Heeding the angel on one shoulder leads to success; following the demon on the other leads to failure. Self-control feels like a duality. What if that sensation is misleading, and, despite how they feel, self-control decisions are just like any other choice? We argue that self-control is a form of value-based choice wherein options are assigned a subjective value and a decision is made through a dynamic integration process. We articulate how a value-based choice model of self-control can capture its phenomenology and account for relevant behavioral and neuroscientific data. This conceptualization of self-control links divergent scientific approaches, allows for more robust and precise hypothesis testing, and suggests novel pathways to improve self-control.

Does inhibitory control training transfer?: behavioral and neural effects on an untrained emotion regulation task.

Inhibitory control (IC) is a critical neurocognitive skill for successfully navigating challenges across domains. Several studies have attempted to use training to improve neurocognitive skills such as IC, but few have found that training generalizes to performance on non-trained tasks. We used functional magnetic resonance imaging (fMRI) to investigate the effect of IC training on a related but untrained emotion regulation (ER) task with the goal of clarifying how training alters brain function and why its effects typically do not transfer across tasks. We suggest hypotheses for training-related changes in activation relevant to transfer effects: the strength model and several plausible alternatives (shifting priorities, stimulus-response automaticity, scaffolding). Sixty participants completed three weeks of IC training and underwent fMRI scanning before and after. The training produced pre- to post-training changes in neural activation during the ER task in the absence of behavioral changes. Specifically, individuals in the training group demonstrated reduced activation during ER in the left inferior frontal gyrus and supramarginal gyrus, key regions in the IC neural network. This result is less consistent with the strength model and more consistent with a motivational account. Implications for future work aiming to further pinpoint mechanisms of training transfer are discussed.

Learning to play it safe (or not): stable and evolving neural responses during adolescent risky decision-making.

Adolescent decision-making is a topic of great public and scientific interest. However, much of the neuroimaging research in this area contrasts only one facet of decision-making (e.g., neural responses to anticipation or receipt of monetary rewards). Few studies have directly examined the processes that occur immediately before making a decision between two options that have varied and unpredictable potential rewards and penalties. Understanding adolescent decision-making from this vantage point may prove critical to ameliorating risky behavior and improving developmental outcomes. In this study, participants aged 14-16 years engaged in a driving simulation game while undergoing fMRI. Results indicated activity in ventral striatum preceded risky decisions and activity in right inferior frontal gyrus (rIFG) preceded safe decisions. Furthermore, participants who reported higher sensation-seeking and sensitivity to reward and punishment demonstrated lower rIFG activity during safe decisions. Finally, over successive games, rIFG activity preceding risky decisions decreased, whereas thalamus and caudate activity increased during positive feedback (taking a risk without crashing). These results indicate that regions traditionally associated with reward processing and inhibition not only drive risky decision-making in the moment but also contribute to learning about risk tradeoffs during adolescence.

But do you think I'm cool? Developmental differences in striatal recruitment during direct and reflected social self-evaluations.

The current fMRI study investigates the neural foundations of evaluating oneself and others during early adolescence and young adulthood. Eighteen early adolescents (ages 11-14, M=12.6) and 19 young adults (ages 22-31, M=25.6) evaluated whether academic, physical, and social traits described themselves directly (direct self-evaluations), described their best friend directly (direct other-evaluations), described themselves from their best friend's perspective (reflected self-evaluations), or in general could change over time (control malleability-evaluations). Compared to control evaluations, both adolescents and adults recruited cortical midline structures during direct and reflected self-evaluations, as well as during direct other-evaluations, converging with previous research. However, unique to this study was a significant three-way interaction between age group, evaluative perspective, and domain within bilateral ventral striatum. Region of interest analyses demonstrated a significant evaluative perspective by domain interaction within the adolescent sample only. Adolescents recruited greatest bilateral ventral striatum during reflected social self-evaluations, which was positively correlated with age and pubertal development. These findings suggest that reflected social self-evaluations, made from the inferred perspective of a close peer, may be especially self-relevant, salient, or rewarding to adolescent self-processing--particularly during the progression through adolescence - and this feature persists into adulthood.

Training-induced changes in inhibitory control network activity.

Despite extensive research on inhibitory control (IC) and its neural systems, the questions of whether IC can be improved with training and how the associated neural systems change are understudied. Behavioral evidence suggests that performance on IC tasks improves with training but that these gains do not transfer to other tasks, and almost nothing is known about how activation in IC-related brain regions changes with training. Human participants were randomly assigned to receive IC training (N = 30) on an adaptive version of the stop-signal task (SST) or an active sham-training (N = 30) during 10 sessions across 3 weeks. Neural activation during the SST before and after training was assessed in both groups using functional magnetic resonance imaging. Performance on the SST improved significantly more in the training group than in the control group. The pattern of neuroimaging results was consistent with a proactive control model such that activity in key parts of the IC network shifted earlier in time within the trial, becoming associated with cues that anticipated the upcoming need for IC. Specifically, activity in the inferior frontal gyrus decreased during the implementation of control (i.e., stopping) and increased during cues that preceded the implementation of IC from pretraining to post-training. Also, steeper behavioral improvement in the training group correlated with activation increases during the cue phase and decreases during implementation in the dorsolateral prefrontal cortex. These results are the first to uncover the neural pathways for training-related improvements in IC and can explain previous null findings of IC training transfer.

'Like me?': ventromedial prefrontal cortex is sensitive to both personal relevance and self-similarity during social comparisons.

Social comparisons are an important means by which we gain information about the self, but little is known about the neural mechanisms underlying comparative social judgment, as most prior functional magnetic resonance imaging research on this topic has investigated judgments of self or others in isolation. Ventromedial prefrontal cortex (vmPFC) has routinely been implicated in social cognitive tasks that rely on such absolute judgments about the self or others, but it is unclear whether activity in this region is modulated by personal relevance of social stimuli or self-similarity of judgment targets. Using functional magnetic resonance imaging, we demonstrate that these forces interact to determine vmPFC response during social comparisons, as well as neural activity in the bilateral anterior insulae. Comparisons between the self and similar others exhibit a unique response in this region when compared with other judgment contexts, suggesting that the special psychological status afforded to these social comparisons is indexed by activity in the vmPFC and insula.

Longitudinal change in the neural bases of adolescent social self-evaluations: effects of age and pubertal development.

Self-evaluations undergo significant transformation during early adolescence, developing in parallel with the heightened complexity of teenagers' social worlds. Intuitive theories of adolescent development, based in part on animal work, suggest that puberty is associated with neural-level changes that facilitate a "social reorientation" (Nelson et al., 2005). However, direct tests of this hypothesis using neuroimaging are limited in humans. This longitudinal fMRI study examined neurodevelopmental trajectories associated with puberty, self-evaluations, and the presumed social reorientation during the transition from childhood to adolescence. Participants (N = 27, mean age = 10.1 and 13.1 years at time points one and two, respectively) engaged in trait evaluations of two targets (the self and a familiar fictional other), across two domains of competence (social and academic). Responses in ventromedial PFC increased with both age and pubertal development during self-evaluations in the social domain, but not in the academic domain. These results suggest that changes in social self-evaluations are intimately connected with biology, not just peer contexts, and provide important empirical support for the relationship between neurodevelopment, puberty, and social functioning.

Flexible visual processing of spatial relationships.

Visual processing breaks the world into parts and objects, allowing us not only to examine the pieces individually, but also to perceive the relationships among them. There is work exploring how we perceive spatial relationships within structures with existing representations, such as faces, common objects, or prototypical scenes. But strikingly, there is little work on the perceptual mechanisms that allow us to flexibly represent arbitrary spatial relationships, e.g., between objects in a novel room, or the elements within a map, graph or diagram. We describe two classes of mechanism that might allow such judgments. In the simultaneous class, both objects are selected concurrently. In contrast, we propose a sequential class, where objects are selected individually over time. We argue that this latter mechanism is more plausible even though it violates our intuitions. We demonstrate that shifts of selection do occur during spatial relationship judgments that feel simultaneous, by tracking selection with an electrophysiological correlate. We speculate that static structure across space may be encoded as a dynamic sequence across time. Flexible visual spatial relationship processing may serve as a case study of more general visual relation processing beyond space, to other dimensions such as size or numerosity.