Media multitasking is associated with higher risk for obesity and increased responsiveness to rewarding food stimuli.

Obesity among children and adolescents has dramatically increased over the past two to three decades and is now a major public health issue. During this same period, youth exposure to media devices also became increasingly prevalent. Here, we present the novel hypothesis that media multitasking (MMT)-the simultaneous use of and switching between unrelated forms of digital media-is associated with an imbalance between regulatory processes and reward-related responses to appetitive food stimuli, resulting in a greater sensitivity to external food cues among high media multitaskers. This, in turn, may contribute to overeating and weight gain over time. To test this hypothesis, we conducted two studies examining research participants who grew up during the recent period of escalating multitasking and obesity-and among whom 37% are overweight or obese. In Study 1, participants' propensity to engage in MMT behaviors was associated with a higher risk for obesity (as indicated by higher body mass index and body fat percentage). Next, in Study 2, a subset of participants from Study 1 were exposed to appetitive food cues while undergoing functional neuroimaging and then, using passive mobile sensing, the time participants spent in various food points-of-sale over an academic term was inferred from GPS coordinates of their mobile device. Study 2 revealed that MMT was associated with an altered pattern of brain activity in response to appetizing food cues, specifically an imbalance favoring reward-related activity in ventral striatum and orbitofrontal cortex-relative to recruitment of the frontoparietal control network. This relationship was further tested in a mediation model, whereby increased MMT, via a brain imbalance favoring reward over control, was associated with greater time spent in campus eateries. Taken together, findings from both studies suggest the possibility that media multitasking may be implicated in the recent obesity epidemic.

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.

Media multitasking is associated with altered processing of incidental, irrelevant cues during person perception.

BACKGROUND: Media multitasking (MMT)-using and switching between unrelated forms of media-has been implicated in altered processing of extraneous stimuli, resulting in performance deficits. Here, we sought to extend our prior work to test the hypothesis that MMT might be associated with enhanced processing of incidental environmental cues during person perception. METHOD: We tested the relationship between individual differences in MMT and person perception, by experimentally manipulating the relevance of environmental cues that participants could use to make trait and personality judgements of an unfamiliar social target. Relevant environmental cues consisted of neat or messy arrangements of the target's belongings, whereas irrelevant cues consisted of similarly neat or messy arrangements of the testing room in which participants viewed a video of the target. RESULTS: In general, relevant cues affected ratings of the target's conscientiousness. Additionally, and consistent with our hypothesis, there was a significant interaction between irrelevant cue condition and MMT, such that high media multitaskers more readily incorporated irrelevant environmental cues into their evaluations of the target's conscientiousness. CONCLUSIONS: These results suggest that high media multitaskers are more responsive to irrelevant environmental cues, which in turn can lead them to form inaccurate impressions of others.

Minding One's Reach (To Eat): The Promise of Computer Mouse-Tracking to Study Self-Regulation of Eating.

In this review, we present the case for using computer mouse-tracking techniques to examine psychological processes that support (and hinder) self-regulation of eating. We first argue that computer mouse-tracking is suitable for studying the simultaneous engagement of-and dynamic interactions between-multiple perceptual and cognitive processes as they unfold and interact over a fine temporal scale (i.e., hundreds of milliseconds). Next, we review recent work that implemented mouse-tracking techniques by measuring mouse movements as participants chose between various food items (of varying nutritional content). Lastly, we propose next steps for future investigations to link behavioral features from mouse-tracking paradigms, corresponding neural correlates, and downstream eating behaviors.

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.

Distracting tracking: Interactions between negative emotion and attentional load in multiple-object tracking.

Stimuli that attract exogenous attention have been shown to interfere with behavioral performance on various tasks. In the present study, participants performed multiple-object tracking (MOT) in conditions where either neutral or negatively valenced images were flashed at fixation. Results reveal a significant impairment of tracking accuracy in the emotional MOT conditions compared to the neutral conditions specifically at the highest level of task difficulty. These findings suggest that emotional distraction is most detrimental when maximal endogenous attentional engagement is required. This interaction between emotional distraction and attentional load is inconsistent with existing models of emotional distraction. (PsycINFO Database Record

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.

Structural integrity of frontostriatal connections predicts longitudinal changes in self-esteem.

Diverse neurological and psychiatric conditions are marked by a diminished sense of positive self-regard, and reductions in self-esteem are associated with risk for these disorders. Recent evidence has shown that the connectivity of frontostriatal circuitry reflects individual differences in self-esteem. However, it remains an open question as to whether the integrity of these connections can predict self-esteem changes over larger timescales. Using diffusion magnetic resonance imaging and probabilistic tractography, we demonstrate that the integrity of white matter pathways linking the medial prefrontal cortex to the ventral striatum predicts changes in self-esteem 8 months after initial scanning in a sample of 30 young adults. Individuals with greater integrity of this pathway during the scanning session at Time 1 showed increased levels of self-esteem at follow-up, whereas individuals with lower integrity showed stifled or decreased levels of self-esteem. These results provide evidence that frontostriatal white matter integrity predicts the trajectory of self-esteem development in early adulthood, which may contribute to blunted levels of positive self-regard seen in multiple psychiatric conditions, including depression and anxiety.

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.

Neural Population Decoding Reveals the Intrinsic Positivity of the Self.

People are motivated to hold favorable views of themselves, which manifests as a positivity bias when evaluating their own performance and abilities. However, it remains an open question whether positive affect is an essential component of people's self-concept. Prior functional neuroimaging research demonstrated that similar regions of the brain support positive affect and self-referential processing, although a direct test of their shared representation has yet to be examined. Here we use functional magnetic resonance imaging in conjunction with multivariate pattern analysis in a cross-domain neural population decoding paradigm. We found that a multivariate pattern classifier model trained to dissociate neural responses to viewing positively and negatively valenced images can dissociate thinking about oneself from a close friend during a lexical trait-judgment task commonly used in the study of self-referential processing. Cross-domain classification accuracy was found to be highest in the ventral medial prefrontal cortex (vMPFC), a region previously implicated in both self-referential processing and positive affect. These results show that brain responses during self-referential processing can be decoded from multi-voxel activation patterns in the vMPFC when viewing positively valenced material, thereby providing evidence that positive affect may be a central component of the mental representation of the self.

Structural integrity between executive control and reward regions of the brain predicts body fat percentage in chronic dieters.

Failure to maintain a healthy body weight may reflect a long-term imbalance between the executive control and reward systems of the brain. The current study examined whether the anatomical connectivity between these two systems predicted individual variability in achieving a healthy body weight, particularly in chronic dieters. Thirty-six female chronic dieters completed a food-cue reactivity task in the scanner. Two regions-of-interest (ROIs) were defined from the reactivity task: the inferior frontal gyrus (IFG), which engages cognitive control and the orbitofrontal cortex (OFC), which represents reward value. A white matter tract connecting these two ROIs was identified across participants using diffusion tensor imaging (DTI) and probabilistic tractography. Results showed a negative relationship between body fat percentage and white matter integrity within the identified tract. This suggests that reduced structural integrity between the OFC and IFG may be related to self-regulatory problems for those who chronically diet to control body weight.

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.

Motivational and neural correlates of self-control of eating: A combined neuroimaging and experience sampling study in dieting female college students.

Self-regulation is a critical ability for maintaining a wide range of health behaviors, especially in preventing overeating and weight gain. Previous work has identified various threats to self-control in the eating domain, chief among which are desire strength and negative affect. In the present study, we examined individual differences in college-aged dieters' experiences of these threats as they encountered temptations to eat in their daily lives, and tested whether these differences characterized sub-groups of dieters with divergent self-control outcomes. Specifically, 75 dieting females (age range: 18-23) participated in a combined functional magnetic resonance imaging (fMRI) and experience sampling study. Participants passively viewed food cues during a fMRI session, and then reported their daily eating behaviors for one week via ecological momentary assessment. We examined the characteristics of dieters who exhibited the most favorable combination of the aforementioned factors (i.e., low desire strength and positive mood) and who were thus most successful at regulating their eating. These dieters endorsed more autonomous reasons for their self-regulatory goals, and during the food cue reactivity task more readily recruited the inferior frontal gyrus, a brain region associated with inhibitory control. We suggest that these motivational and neural correlates may also be implicated in self-regulation of other important health behaviors.

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.

Individual differences in response of dorsomedial prefrontal cortex predict daily social behavior.

The capacity to accurately infer the thoughts and intentions of other people is critical for effective social interaction, and neural activity in dorsomedial prefrontal cortex (dmPFC) has long been linked with the extent to which people engage in mental state attribution. In this study, we combined functional neuroimaging and experience sampling methodologies to test the predictive value of this neural response for daily social behaviors. We found that individuals who displayed greater activity in dmPFC when viewing social scenes spent more time around other people on a daily basis. These findings suggest a specific role for the neural mechanisms that support the capacity to mentalize in guiding individuals toward situations containing valuable social outcomes.

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.