Fusing Mobile Phone Sensing and Brain Imaging to Assess Depression in College Students.

As smartphone usage has become increasingly prevalent in our society, so have rates of depression, particularly among young adults. Individual differences in smartphone usage patterns have been shown to reflect individual differences in underlying affective processes such as depression (Wang et al., 2018). In the current study, a positive relationship was identified between smartphone screen time (e.g., phone unlock duration) and resting-state functional connectivity (RSFC) between the subgenual cingulate cortex (sgCC), a brain region implicated in depression and antidepressant treatment response, and regions of the ventromedial/orbitofrontal cortex (OFC), such that increased phone usage was related to stronger connectivity between these regions. This cluster was subsequently used to constrain subsequent analyses looking at individual differences in depressive symptoms in the same cohort and observed partial replication in a separate cohort. Similar analyses were subsequently performed on metrics of circadian rhythm consistency showing a negative relationship between connectivity of the sgCC and OFC. The data and analyses presented here provide relatively simplistic preliminary analyses which replicate and provide an initial step in combining functional brain activity and smartphone usage patterns to better understand issues related to mental health. Smartphones are a prevalent part of modern life and the usage of mobile sensing data from smartphones promises to be an important tool for mental health diagnostics and neuroscience research.

Reducing reward responsivity and daily food desires in female dieters through domain-specific training.

According to the strength model, self-regulation relies on a domain-general capacity that may be strengthened by training. From this perspective, training self-regulation in one domain may transfer to other domains. Here we used two inhibitory training paradigms, a domain-general and domain-specific stop-signal training task and compared their effects on brain reward activity as well as daily food desires in female dieters. Before and after the training, functional magnetic resonance imaging was used to assess food cue-reactivity, coupled with one week of smart-phone ecological momentary assessments to examine eating urges. Whereas the food-specific inhibitory training was successful in reducing both food cue-reactivity and food desires, the domain-general (sound-cue) training showed no transfer effects. These findings suggest that domain-specific training may be a more effective method for supporting self-regulation than domain-general approaches aimed at strengthening self-regulation across domains.

Reward-related regions form a preferentially coupled system at rest.

Neuroimaging studies have implicated a set of striatal and orbitofrontal cortex (OFC) regions that are commonly activated during reward processing tasks. Resting-state functional connectivity (RSFC) studies have demonstrated that the human brain is organized into several functional systems that show strong temporal coherence in the absence of goal-directed tasks. Here we use seed-based and graph-theory RSFC approaches to characterize the systems-level organization of putative reward regions of at rest. Peaks of connectivity from seed-based RSFC patterns for the nucleus accumbens (NAcc) and orbitofrontal cortex (OFC) were used to identify candidate reward regions which were merged with a previously used set of regions (Power et al., 2011). Graph-theory was then used to determine system-level membership for all regions. Several regions previously implicated in reward-processing (NAcc, lateral and medial OFC, and ventromedial prefrontal cortex) comprised a distinct, preferentially coupled system. This RSFC system is stable across a range of connectivity thresholds and shares strong overlap with meta-analyses of task-based reward studies. This reward system shares between-system connectivity with systems implicated in cognitive control and self-regulation, including the fronto-parietal, cingulo-opercular, and default systems. Differences may exist in the pathways through which control systems interact with reward system components. Whereas NAcc is functionally connected to cingulo-opercular and default systems, OFC regions show stronger connectivity with the fronto-parietal system. We propose that future work may be able to interrogate group or individual differences in connectivity profiles using the regions delineated in this work to explore potential relationships to appetitive behaviors, self-regulation failure, and addiction.

An fMRI investigation of the neural correlates underlying the autonomous sensory meridian response (ASMR).

Introduction : The "autonomous sensory meridian response" (ASMR) is a neologism used to describe an internal sensation of deep relaxation and pleasant head tingling which is often stimulated by gentle sounds, light touch, and personal attention. Methods : An fMRI-based methodology was employed to examine the brain activation of subjects prescreened for ASMR-receptivity (n=10) as they watched ASMR videos and identified specific moments of relaxation and tingling. Results : Subjects who experienced ASMR showed significant activation in regions associated with both reward (NAcc) and emotional arousal (dACC and Insula/IFG). Brain activation during ASMR showed similarities to patterns previously observed in musical frisson as well as affiliative behaviors. Conclusion : This is the first study to measure the activation of various brain regions during ASMR and these results may help to reveal the mechanistic underpinnings of this sensation.

Reward System Activation in Response to Alcohol Advertisements Predicts College Drinking.

OBJECTIVE: In this study, we assess whether activation of the brain's reward system in response to alcohol advertisements is associated with college drinking. Previous research has established a relationship between exposure to alcohol marketing and underage drinking. Within other appetitive domains, the relationship between cue exposure and behavioral enactment is known to rely on activation of the brain's reward system. However, the relationship between neural activation to alcohol advertisements and alcohol consumption has not been studied in a nondisordered population. METHOD: In this cross-sectional study, 53 college students (32 women) completed a functional magnetic resonance imaging scan while viewing alcohol, food, and control (car and technology) advertisements. Afterward, they completed a survey about their alcohol consumption (including frequency of drinking, typical number of drinks consumed, and frequency of binge drinking) over the previous month. RESULTS: In 43 participants (24 women) meeting inclusion criteria, viewing alcohol advertisements elicited activation in the left orbitofrontal cortex and bilateral ventral striatum-regions of the reward system that typically activate to other appetitive rewards and relate to consumption behaviors. Moreover, the level of self-reported drinking correlated with the magnitude of activation in the left orbitofrontal cortex. CONCLUSIONS: Results suggest that alcohol cues are processed within the reward system in a way that may motivate drinking behavior.

A balance of activity in brain control and reward systems predicts self-regulatory outcomes.

Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily life. Sixty-nine chronic dieters, a population known for frequent lapses in self-control, completed a food cue-reactivity task during an fMRI scanning session, followed by a weeklong sampling of daily eating behaviors via ecological momentary assessment. We related participants' food cue activity in brain systems associated with executive control and reward to real-world eating patterns. Specifically, a balance score representing the amount of activity in brain regions associated with self-regulatory control, relative to automatic reward-related activity, predicted dieters' control over their eating behavior during the following week. This balance measure may reflect individual self-control capacity and be useful for examining self-regulation success in other domains and populations.

Genetic risk for obesity predicts nucleus accumbens size and responsivity to real-world food cues.

Obesity is a major public health concern that involves an interaction between genetic susceptibility and exposure to environmental cues (e.g., food marketing); however, the mechanisms that link these factors and contribute to unhealthy eating are unclear. Using a well-known obesity risk polymorphism (FTO rs9939609) in a sample of 78 children (ages 9-12 y), we observed that children at risk for obesity exhibited stronger responses to food commercials in the nucleus accumbens (NAcc) than children not at risk. Similarly, children at a higher genetic risk for obesity demonstrated larger NAcc volumes. Although a recessive model of this polymorphism best predicted body mass and adiposity, a dominant model was most predictive of NAcc size and responsivity to food cues. These findings suggest that children genetically at risk for obesity are predisposed to represent reward signals more strongly, which, in turn, may contribute to unhealthy eating behaviors later in life.

The Dorsal Medial Prefrontal Cortex Responds Preferentially to Social Interactions during Natural Viewing.

UNLABELLED: Humans display a strong tendency to make spontaneous inferences concerning the thoughts and intentions of others. Although this ability relies upon the concerted effort of multiple brain regions, the dorsal medial prefrontal cortex (DMPFC) is most closely associated with the ability to reason about other people's mental states and form impressions of their character. Here, we investigated this region's putative social category preference using fMRI as 34 participants engaged in uninstructed viewing of a complex naturalistic stimulus. Using a data-driven "reverse correlation" approach, we characterize the DMPFC's stimulus response profile from ongoing neural responses to a dynamic movie stimulus. Results of this analysis demonstrate that the DMPFC's response profile is dominated by the presence of scenes involving social interactions between characters. Subsequent content analysis of video clips created from this response profile confirmed this finding. In contrast, regions of the inferotemporal and parietal cortex were selectively tuned to faces and actions, both features that often covary with social interaction but may be difficult to disentangle using standard event-related approaches. Together, these findings suggest that the DMPFC is finely tuned for processing social interaction above other categories and that this preference is maintained during unrestricted viewing of complex natural stimuli such as movies. SIGNIFICANCE STATEMENT: Recently, studies have brought into question whether the dorsal medial prefrontal cortex (DMPFC), a region long associated with social cognition, is specialized for the processing of social information. We examine the response profile of this region during natural viewing of a reasonably naturalistic stimulus (i.e., a Hollywood movie) using a data-driven reverse correlation technique. Our findings demonstrate that, during natural viewing, the DMPFC is strongly tuned to the social features of the stimulus above other categories. Moreover, this response differs from other areas with previously well characterized response profiles such as the lateral and medial fusiform gyrus. These findings suggest that this region's dominant function in everyday situations is to support reasoning about the thoughts and intentions of conspecifics.

Striatal Associative Learning Signals Are Tuned to In-groups.

An important feature of adaptive social behavior is the ability to flexibly modify future actions based on the successes or failures of past experiences. The ventral striatum (VS) occupies a central role in shaping behavior by using feedback to evaluate actions and guide learning. The current studies tested whether feedback indicating the need to update social knowledge would engage the VS, thereby facilitating subsequent learning. We also examined the sensitivity of these striatal signals to the value associated with social group membership. Across two fMRI studies, participants answered questions testing their knowledge about the preferences of personally relevant social groups who were high (in-group) or low (out-group) in social value. Participants received feedback indicating whether their responses were correct or incorrect on a trial-by-trial basis. After scanning, participants were given a surprise memory test examining memory for the different types of feedback. VS activity in response to social feedback correlated with subsequent memory, specifying a role for the VS in encoding and updating social knowledge. This effect was more robust in response to in-group than out-group feedback, indicating that the VS tracks variations in social value. These results provide novel evidence of a neurobiological mechanism adaptively tuned to the motivational relevance of the surrounding social environment that focuses learning efforts on the most valuable social outcomes and triggers adjustments in behavior when necessary.

Generation and Evaluation of a Cortical Area Parcellation from Resting-State Correlations.

The cortical surface is organized into a large number of cortical areas; however, these areas have not been comprehensively mapped in the human. Abrupt transitions in resting-state functional connectivity (RSFC) patterns can noninvasively identify locations of putative borders between cortical areas (RSFC-boundary mapping; Cohen et al. 2008). Here we describe a technique for using RSFC-boundary maps to define parcels that represent putative cortical areas. These parcels had highly homogenous RSFC patterns, indicating that they contained one unique RSFC signal; furthermore, the parcels were much more homogenous than a null model matched for parcel size when tested in two separate datasets. Several alternative parcellation schemes were tested this way, and no other parcellation was as homogenous as or had as large a difference compared with its null model. The boundary map-derived parcellation contained parcels that overlapped with architectonic mapping of areas 17, 2, 3, and 4. These parcels had a network structure similar to the known network structure of the brain, and their connectivity patterns were reliable across individual subjects. These observations suggest that RSFC-boundary map-derived parcels provide information about the location and extent of human cortical areas. A parcellation generated using this method is available at http://www.nil.wustl.edu/labs/petersen/Resources.html.

Individual Differences in Reward and Somatosensory-Motor Brain Regions Correlate with Adiposity in Adolescents.

The prevalence of adolescent obesity has increased dramatically over the past three decades, and research has documented that the number of television shows viewed during childhood is associated with greater risk for obesity. In particular, considerable evidence suggests that exposure to food marketing promotes eating habits that contribute to obesity. The present study examines neural responses to dynamic food commercials in overweight and healthy-weight adolescents using functional magnetic resonance imaging (fMRI). Compared with non-food commercials, food commercials more strongly engaged regions involved in attention and saliency detection (occipital lobe, precuneus, superior temporal gyri, and right insula) and in processing rewards [left and right nucleus accumbens (NAcc) and left orbitofrontal cortex (OFC)]. Activity in the left OFC and right insula further correlated with subjects' percent body fat at the time of the scan. Interestingly, this reward-related activity to food commercials was accompanied by the additional recruitment of mouth-specific somatosensory-motor cortices-a finding that suggests the intriguing possibility that higher-adiposity adolescents mentally simulate eating behaviors and offers a potential neural mechanism for the formation and reinforcement of unhealthy eating habits that may hamper an individual's ability lose weight later in life.

ACTIVITY IN CORTICAL MIDLINE STRUCTURES IS MODULATED BY SELF-CONSTRUAL CHANGES DURING ACCULTURATION.

Recent immigrants to another culture generally experience a period of acculturation during which they show self-construal changes. Here, we examine how this acculturation period alters brain activity associated with self-referential cognition. Twenty-seven native Chinese-speaking recent immigrants completed a trait-judgment task in which they judged whether a series of psychological traits applied to themselves and, separately, whether these traits applied to their mothers. Participants were scanned at two intervals: within the first two months of their arrival in the United States (Time 1), and also six months after the initial scan (Time 2). Results already revealed a significant self-vs.-mother differentiation at Time 1 in the medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC). However, at time 2, this pattern diverged depending on whether immigrants became more or less like their original culture. That is to say, for immigrants who became less like Easterners, the self vs. mother difference remained, whereas for participants who became even more like Easterners, the self vs. mother difference in cortical midline structures disappeared. These findings support the notion that self-construal changes during the process of acculturation are reflected in the relative engagement of brain structures implicated in self-referential processing (i.e., MPFC and PCC) when judging traits with reference to oneself or a close other.

In search of a human self-regulation system.

The capacity for self-regulation allows people to control their thoughts, behaviors, emotions, and desires. In spite of this impressive ability, failures of self-regulation are common and contribute to numerous societal problems, from obesity to drug addiction. Such failures frequently occur following exposure to highly tempting cues, during negative moods, or after self-regulatory resources have been depleted. Here we review the available neuroscientific evidence regarding self-regulation and its failures. At its core, self-regulation involves a critical balance between the strength of an impulse and an individual's ability to inhibit the desired behavior. Although neuroimaging and patient studies provide consistent evidence regarding the reward aspects of impulses and desires, the neural mechanisms that underlie the capacity for control have eluded consensus, with various executive control regions implicated in different studies. We outline the necessary properties for a self-regulation control system and suggest that the use of resting-state functional connectivity analyses may be useful for understanding how people regulate their behavior and why they sometimes fail in their attempts.

To apply yourself is human, to reapply divine.

Prefrontal cortex is involved in adapting our emotional response to setbacks. While we feel that some setbacks are controllable, others are not. Here, Bhanji and Delgado (2014) reveal the neural substrates of persistence in the face of controllable and uncontrollable setbacks.

Neural predictors of giving in to temptation in daily life.

The ability to control desires, whether for food, sex, or drugs, enables people to function successfully within society. Yet, in tempting situations, strong impulses often result in self-control failure. Although many triggers of self-control failure have been identified, the question remains as to why some individuals are more likely than others to give in to temptation. In this study, we combined functional neuroimaging and experience sampling to determine if there are brain markers that predict whether people act on their food desires in daily life. We examined food-cue-related activity in the nucleus accumbens (NAcc), as well as activity associated with response inhibition in the inferior frontal gyrus (IFG). Greater NAcc activity was associated with greater likelihood of self-control failures, whereas IFG activity supported successful resistance to temptations. These findings demonstrate an important role for the neural mechanisms underlying desire and self-control in people's real-world experiences of temptations.

Self-regulatory depletion enhances neural responses to rewards and impairs top-down control.

To be successful at self-regulation, individuals must be able to resist impulses and desires. The strength model of self-regulation suggests that when self-regulatory capacity is depleted, self-control deficits result from a failure to engage top-down control mechanisms. Using functional neuroimaging, we examined changes in brain activity in response to viewing desirable foods among 31 chronic dieters, half of whom completed a task known to result in self-regulatory depletion. Compared with nondepleted dieters, depleted dieters exhibited greater food-cue-related activity in the orbitofrontal cortex, a brain area associated with coding the reward value and liking aspects of desirable foods; they also showed decreased functional connectivity between this area and the inferior frontal gyrus, a region commonly implicated in self-control. These findings suggest that self-regulatory depletion provokes self-control failure by reducing connectivity between brain regions that are involved in cognitive control and those that represent rewards, thereby decreasing the capacity to resist temptations.

Rejection sensitivity polarizes striatal-medial prefrontal activity when anticipating social feedback.

As a social species, humans are acutely aware of cues that signal inclusionary status. This study characterizes behavioral and neural responses when individuals anticipate social feedback. Across two fMRI studies, participants (n = 42) made social judgments about supposed peers and then received feedback from those individuals. Of particular interest was the neural activity occurring when participants were awaiting social feedback. During this anticipatory period, increased neural activity was observed in the ventral striatum, a central component of the brain's reward circuitry, and dorsomedial pFC, a brain region implicated in mentalizing about others. Individuals high in rejection sensitivity exhibited greater responses in both the ventral striatum and dorsomedial pFC when anticipating positive feedback. These findings provide initial insight into the neural mechanisms involved in anticipating social evaluations as well as the cognitive processes that underlie rejection sensitivity.

What Can the Organization of the Brain's Default Mode Network Tell us About Self-Knowledge?

Understanding ourselves has been a fundamental topic for psychologists and philosophers alike. In this paper we review the evidence linking specific brain structures to self-reflection. The brain regions most associated with self-reflection are the posterior cingulate and medial prefrontal (mPFC) cortices, together known as the cortical midline structures (CMSs). We review evidence arguing that self-reflection is special in memory, while noting that these brain regions are often engaged when we think about others in our social worlds. Based on the CMSs' patterns of connectivity and activity, we speculate about three possible interpretations of their role in supporting self-reflection that are somewhat overlapping, and not intended to be mutually exclusive. First, self may be a powerful, but ordinary case for a cognitive system specialized for thinking about people. Second, mPFC may serve as a processing "hub," binding together information from all sensory modalities with internally generated information. Third, mPFC may serve as a cortical director of thought, helping to guide moment-by-moment conscious processing. Suggestions are made for future research avenues aimed at testing such possibilities.

Neural responses to ambiguity involve domain-general and domain-specific emotion processing systems.

Extant research has examined the process of decision making under uncertainty, specifically in situations of ambiguity. However, much of this work has been conducted in the context of semantic and low-level visual processing. An open question is whether ambiguity in social signals (e.g., emotional facial expressions) is processed similarly or whether a unique set of processors come on-line to resolve ambiguity in a social context. Our work has examined ambiguity using surprised facial expressions, as they have predicted both positive and negative outcomes in the past. Specifically, whereas some people tended to interpret surprise as negatively valenced, others tended toward a more positive interpretation. Here, we examined neural responses to social ambiguity using faces (surprise) and nonface emotional scenes (International Affective Picture System). Moreover, we examined whether these effects are specific to ambiguity resolution (i.e., judgments about the ambiguity) or whether similar effects would be demonstrated for incidental judgments (e.g., nonvalence judgments about ambiguously valenced stimuli). We found that a distinct task control (i.e., cingulo-opercular) network was more active when resolving ambiguity. We also found that activity in the ventral amygdala was greater to faces and scenes that were rated explicitly along the dimension of valence, consistent with findings that the ventral amygdala tracks valence. Taken together, there is a complex neural architecture that supports decision making in the presence of ambiguity: (a) a core set of cortical structures engaged for explicit ambiguity processing across stimulus boundaries and (b) other dedicated circuits for biologically relevant learning situations involving faces.