Changes in affective control covary with changes in mental health difficulties following affective control training (AffeCT) in adolescents.

BACKGROUND: Everyday affective fluctuations are more extreme and more frequent in adolescence compared to any other time in development. Successful regulation of these affective experiences is important for good mental health and has been proposed to depend on affective control. The present study examined whether improving affective control through a computerised affective control training app (AffeCT) would benefit adolescent mental health. METHODS: One-hundred and ninety-nine participants (11-19 years) were assigned to complete 2 weeks of AffeCT or placebo training on an app. Affective control (i.e. affective inhibition, affective updating and affective shifting), mental health and emotion regulation were assessed at pre- and post-training. Mental health and emotion regulation were assessed again one month and one year later. RESULTS: Compared with the placebo group, the AffeCT group showed significantly greater improvements in affective control on the trained measure. AffeCT did not, relative to placebo, lead to better performance on untrained measures of affective control. Pre- to post-training change in affective control covaried with pre- to post-training change in mental health problems in the AffeCT but not the placebo group. These mental health benefits of AffeCT were only observed immediately following training and did not extend to 1 month or year post-training. CONCLUSION: In conclusion, the study provides preliminary evidence that AffeCT may confer short-term preventative benefits for adolescent mental health.

Aberrant cognitive empathy in individuals with elevated social anxiety and regulation with emotional working memory training.

Social anxiety may disrupt the empathic process, and well-regulated empathy is critical for navigating the social world. Two studies aimed to further understand empathy in the context of social anxiety. Study 1 compared individuals with elevated or normative social anxiety on a measure assessing cognitive and affective empathy for positive and negative emotions conveyed by other people ("targets"), completed under social threat. Relative to individuals with normative social anxiety, individuals with elevated social anxiety had greater cognitive empathy and no differences in affective empathy, regardless of emotion type. As greater cognitive empathy can be maladaptive, Study 2 tested whether this could be down-regulated. Individuals with elevated social anxiety underwent emotional working memory training (eWMT) for negative emotional information, or control training (CT). Effects on an empathy measure completed under social threat were assessed. Cognitive empathy for negative emotions decreased following eWMT but not CT, and this was only evident for those with higher pre-training working memory capacity. Cognitive empathy for positive emotions and affective empathy were not affected. Overall, social anxiety is associated with aberrant elevated cognitive empathy for negative and positive emotions, and the deviation in cognitive empathy for negative emotions can be regulated with eWMT for certain individuals.Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12618001196235..

Age-Related Enhancements in Positive Emotionality across The Life Span: Structural Equation Modeling of Brain and Behavior.

Aging is associated with a bias in attention and memories toward positive and away from negative emotional content. In addition, emotion regulation appears to improve with age, despite concomitant widespread cognitive decline coupled with gray matter volume loss in cortical and subcortical regions thought to subserve emotion regulation. Here, we address this emotion-aging paradox using the behavioral data of an emotion regulation task from a population-derived, male and female, human sample (CamCAN) and use structural equation modeling together with multivariate analysis of structural MRI images of the same sample to investigate brain-behavior relationships. In a series of measurement models, we show the relationship between age and emotionality is best explained by a four-factor model, compared with single and hierarchical factor models. These four latent factors are interpreted as Basal Negative Affect, Positive Reactivity, Negative Reactivity and Positive Regulation (upregulating positive emotion to negative content). Increasing age uniquely contributes to increased Basal Negative Affect, Positive Reactivity, and Positive Regulation, but not Negative Reactivity. Furthermore, we show gray matter volumes, namely in the bilateral frontal operculum, medial frontal gyrus, bilateral hippocampal complex, bilateral middle temporal gyri, and bilateral angular gyrus, are distinctly related to these four latent factors. Finally, we show that a subset of these brain-behavior relationships remain significant when accounting for age and demographic data. Our results support the notion of an age-related increase in positivity and are interpreted in the context of the socioemotional selectivity theory of improved emotion regulation in older age.SIGNIFICANCE STATEMENT Aging is associated with a paradoxical increase in well-being and improved emotion regulation despite widespread cognitive decline and gray matter volume loss in neural regions that underlie emotion regulation. Using a population-derived sample, we test the theories behind this emotion/aging paradox with an emotion regulation task and structural MRI data. We report robust age-related increases in positivity across the life span and show structural neural integrity influences this relationship with increasing age. Several brain-behavior relationships remained unaffected by age and may represent empirically derived neural markers to explore the paradox of increased well-being in old age. The results support the predictions of socioemotional selectivity theory of improved emotion regulation in older age and challenge the amygdala-focused neural predictions of the aging brain model.

The effect of intolerance of uncertainty on anxiety and depression, and their symptom networks, during the COVID-19 pandemic.

Individuals vary in their ability to tolerate uncertainty. High intolerance of uncertainty (the tendency to react negatively to uncertain situations) is a known risk factor for mental health problems. In the current study we examined the degree to which intolerance of uncertainty predicted depression and anxiety symptoms and their interrelations across the first year of the COVID-19 pandemic. We examined these associations across three time points (May 2020 - April 2021) in an international sample of adults (N = 2087, Mean age = 41.13) from three countries (UK, USA, Australia) with varying degrees of COVID-19 risk. We found that individuals with high and moderate levels of intolerance of uncertainty reported reductions in depression and anxiety symptoms over time. However, symptom levels remained significantly elevated compared to individuals with low intolerance of uncertainty. Individuals with low intolerance of uncertainty had low and stable levels of depression and anxiety across the course of the study. Network analyses further revealed that the relationships between depression and anxiety symptoms became stronger over time among individuals with high intolerance of uncertainty and identified that feeling afraid showed the strongest association with intolerance of uncertainty. Our findings are consistent with previous work identifying intolerance of uncertainty as an important risk factor for mental health problems, especially in times marked by actual health, economic and social uncertainty. The results highlight the need to explore ways to foster resilience among individuals who struggle to tolerate uncertainty, as ongoing and future geopolitical, climate and health threats will likely lead to continued exposure to significant uncertainty.

Social determinants of mental health during a year of the COVID-19 pandemic.

Belonging is a basic human need, with social isolation signaling a threat to biological fitness. Sensitivity to ostracism varies across individuals and the lifespan, peaking in adolescence. Government-imposed restrictions upon social interactions during COVID-19 may therefore be particularly detrimental to young people and those most sensitive to ostracism. Participants (N = 2367; 89.95% female, 11-100 years) from three countries with differing levels of government restrictions (Australia, UK, and USA) were surveyed thrice at three-month intervals (May 2020 - April 2021). Young people, and those living under the tightest government restrictions, reported the worst mental health, with these inequalities in mental health remaining constant throughout the study period. Further dissection of these results revealed that young people high on social rejection sensitivity reported the most mental health problems at the final assessment. These findings help account for the greater impact of enforced social isolation on young people's mental health, and open novel avenues for intervention.

Age-related differences in affective control and its association with mental health difficulties.

Difficulties in regulating affect are core characteristics of a wide range of mental health conditions and are associated with deficits in cognitive control, particularly in affective contexts, affective control. The current study explored how affective control relates to mental health over the course of adolescence. We developed an Affective Control Task, which was administered to young adolescents (11-14 years; n = 29); mid-adolescents (15-18 years; n = 31), and adults (22-30 years; n = 31). The task required individuals to sort cards according to continuously changing rules: color, number, or item type. There was a neutral condition in which items were shapes, and an affective condition, in which items were emotional facial expressions. Better affective control was associated with fewer mental health difficulties (p < .001, R2 = .15). Affective control partially accounted for the association between age group and mental health problems, z = 2.61, p = .009, Akaike information criterion = 484, with the association being strongest in young adolescents, r (27) = -.44, p = .018. Affective control further accounted for variance in the association between self-reported (but not experimental) emotion regulation and mental health (z = -3.44, p < .001, Akaike information criterion = 440). Poor affective control, especially in young adolescents, is associated with more mental health problems and higher levels of emotion regulation difficulties. Improving affective control therefore may constitute a promising target for prevention.

Mood and neural responses to social rejection do not seem to be altered in resilient adolescents with a history of adversity.

Childhood adversity (CA) increases the risk of subsequent mental health problems. Adolescent social support (from family and/or friends) reduces the risk of mental health problems after CA. However, the mechanisms of this effect remain unclear, and we speculate that they are manifested on neurodevelopmental levels. Therefore, we investigated whether family and/or friendship support at ages 14 and 17 function as intermediate variables for the relationship between CA before age 11 and affective or neural responses to social rejection feedback at age 18. We studied 55 adolescents with normative mental health at age 18 (26 with CA and therefore considered "resilient"), from a longitudinal cohort. Participants underwent a Social Feedback Task in the magnetic resonance imaging scanner. Social rejection feedback activated the dorsal anterior cingulate cortex and the left anterior insula. CA did not predict affective or neural responses to social rejection at age 18. Yet, CA predicted better friendships at age 14 and age 18, when adolescents with and without CA had comparable mood levels. Thus, adolescents with CA and normative mood levels have more adolescent friendship support and seem to have normal mood and neural responses to social rejection.

Accurate determination of brain metabolite concentrations using ERETIC as external reference.

Magnetic Resonance Spectroscopy (MRS) can provide in vivo metabolite concentrations in standard concentration units if a reliable reference signal is available. For 1 H MRS in the human brain, typically the signal from the tissue water is used as the (internal) reference signal. However, a concentration determination based on the tissue water signal most often requires a reliable estimate of the water concentration present in the investigated tissue. Especially in clinically interesting cases, this estimation might be difficult. To avoid assumptions about the water in the investigated tissue, the Electric REference To access In vivo Concentrations (ERETIC) method has been proposed. In this approach, the metabolite signal is compared with a reference signal acquired in a phantom and potential coil-loading differences are corrected using a synthetic reference signal. The aim of this study, conducted with a transceiver quadrature head coil, was to increase the accuracy of the ERETIC method by correcting the influence of spatial B1 inhomogeneities and to simplify the quantification with ERETIC by incorporating an automatic phase correction for the ERETIC signal. Transmit field ( B1+) differences are minimized with a volume-selective power optimization, whereas reception sensitivity changes are corrected using contrast-minimized images of the brain and by adapting the voxel location in the phantom measurement closely to the position measured in vivo. By applying the proposed B1 correction scheme, the mean metabolite concentrations determined with ERETIC in 21 healthy subjects at three different positions agree with concentrations derived with the tissue water signal as reference. In addition, brain water concentrations determined with ERETIC were in agreement with estimations derived using tissue segmentation and literature values for relative water densities. Based on the results, the ERETIC method presented here is a valid tool to derive in vivo metabolite concentration, with potential advantages compared with internal water referencing in diseased tissue.

Training the emotional brain: improving affective control through emotional working memory training.

Affective cognitive control capacity (e.g., the ability to regulate emotions or manipulate emotional material in the service of task goals) is associated with professional and interpersonal success. Impoverished affective control, by contrast, characterizes many neuropsychiatric disorders. Insights from neuroscience indicate that affective cognitive control relies on the same frontoparietal neural circuitry as working memory (WM) tasks, which suggests that systematic WM training, performed in an emotional context, has the potential to augment affective control. Here we show, using behavioral and fMRI measures, that 20 d of training on a novel emotional WM protocol successfully enhanced the efficiency of this frontoparietal demand network. Critically, compared with placebo training, emotional WM training also accrued transfer benefits to a "gold standard" measure of affective cognitive control-emotion regulation. These emotion regulation gains were associated with greater activity in the targeted frontoparietal demand network along with other brain regions implicated in affective control, notably the subgenual anterior cingulate cortex. The results have important implications for the utility of WM training in clinical, prevention, and occupational settings.

Can Emotional Working Memory Training Improve Cognitive Behavioral Therapy Outcomes for Social Anxiety Disorder: A Pilot Study.

Social anxiety disorder (SAD) models highlight maladaptive attention as a maintaining factor of SAD, potentially negatively impacting how individuals with SAD engage with cognitive behavioral therapy (CBT) content in a therapist's presence. Emotional working memory training (eWMT) has been shown to improve affective attentional control. This pilot study assessed the proposed methodology for a randomized controlled trial (RCT) to determine whether eWMT, by improving attentional control prior to internet-based CBT (iCBT), results in better CBT outcomes. The RCT would be considered feasible if the pilot study achieved rates ≥80% for eligible participants recruited, study measures completion, intervention completion, and participant retention. Results from 10 randomized participants showed rates ≥80% for recruitment of eligible participants and iCBT intervention completion. Completion of study measures, eWMT and Placebo training interventions, and participant retention were <80%. Results highlight the need to consider strategies to improve the methodology prior to the RCT.

The relationship between cognitive and affective control and adolescent mental health.

Background: Cognitive control problems have been implicated in the etiology and maintenance of mental health problems, including depression, in adults. Studies in adolescents have been more equivocal, with some showing changes in cognitive control in adolescents with mental health problems, whereas others fail to show an association. This study examines whether adolescent mental health is associated with affective control, the application of cognitive control in affective contexts, which shows more protracted development than cognitive control. Methods: The present study investigated the association of cognitive and affective control with depressive symptomatology and self-reported diagnostic history of mental health problems in adolescents. The study included 1929 participants (M age = 13.89) from the Future Proofing Study (N = 6,388, 11-16 years), who completed affective (incl., affective stimuli) and/or cognitive (incl., neutral stimuli) versions of a working memory (backward digit-span) and/or shifting (card-sorting) task at least once within 3 weeks of assessing mental health. Results: Poorer working memory was associated with greater depressive symptomatology in adolescents (ß = -0.06, p = .004), similarly across cognitive and affective control conditions (ß = -0.02, p = .269). Adolescents with self-reported diagnostic history of mental health problems had significantly poorer shifting ability in affective compared to cognitive control conditions (b = 0.05, p = .010), whereas for adolescents with no self-reported diagnoses, shifting ability did not differ between conditions (b = -0.00, p = .649). Conclusions: The present analyses suggest that working memory difficulties, in particular, may be associated with the experience of current depressed mood in adolescents. Problems with affective shifting may be implicated in a range of mental health problems in adolescents. Given the ubiquitous need for efficient cognitive functioning in daily life, enhancing cognitive and affective control in adolescents may be a promising means of improving functioning across a range of domains, including affective functioning, and by extension, adolescent mental health.

Affect and mental health across the lifespan during a year of the COVID-19 pandemic: The role of emotion regulation strategies and mental flexibility.

During the COVID-19 pandemic, there has been a rise in common mental health problems compared to prepandemic levels, especially in young people. Understanding the factors that place young people at risk is critical to guide the response to increased mental health problems. Here we examine whether age-related differences in mental flexibility and frequency of use of emotion regulation strategies partially account for the poorer affect and increased mental health problems reported by younger people during the pandemic. Participants (N = 2,367; 11-100 years) from Australia, the UK, and US were surveyed thrice at 3-month intervals between May 2020 and April 2021. Participants completed measures of emotion regulation, mental flexibility, affect, and mental health. Younger age was associated with less positive (b = 0.008, p < .001) and more negative (b = -0.015, p < .001) affect across the first year of the pandemic. Maladaptive emotion regulation partially accounted for age-related variance in negative affect (ß = -0.013, p = .020), whereby younger age was associated with more frequent use of maladaptive emotion regulation strategies, which, in turn, was associated with more negative affect at our third assessment point. More frequent use of adaptive emotion regulation strategies, and in turn, changes in negative affect from our first to our third assessment, partially accounted for age-related variance in mental health problems (ß = 0.007, p = .023). Our findings add to the growing literature demonstrating the vulnerability of younger people during the COVID-19 pandemic and suggest that emotion regulation may be a promising target for intervention. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Trauma Memory Characteristics and Neurocognitive Performance in Youth Exposed to Single-Event Trauma.

Cognitive models of posttraumatic stress disorder (PTSD) highlight characteristics of trauma memories, such as disorganisation, as key mechanisms in the aetiology of the disorder. However, studies investigating trauma memory in youth have provided inconsistent findings. Research has highlighted that PTSD in youth may be accompanied by difficulties in neurocognitive functioning, potentially impacting ability to recall the trauma memory. The present study sought to investigate both trauma memory characteristics and neurocognitive functioning in youth aged 8-17 years. Youths exposed to single-event trauma, with (N = 29, Mage = 13.6, 21 female) and without (N = 40, Mage = 13.3, 21 female) a diagnosis of PTSD, completed self-report measures of trauma memory, a narrative memory task and a set of neurocognitive tests two to six months post-trauma. A group of non trauma-exposed youths (N = 36, Mage = 13.9, 27 female) were compared on narrative and neurocognitive tasks. Results indicated that trauma memories in youth with, versus without, PTSD were more sensory-laden, temporally disrupted, difficult to verbally access, and formed a more 'central' part of their identity. Greater differences were observed for self-reported memory characteristics compared to narrative characteristics. No between group differences in neurocognitive function were observed. Self-reported trauma memory characteristics highlight an important factor in the aetiology of PTSD. The observed lack of significant differences in neurocognitive ability potentially suggests that cognitive factors represent a more relevant treatment target than neurocognitive factors in single-event PTSD. Further research to understand the cognitive factors represented by self-reported trauma memory characteristics is recommended.

Social rejection sensitivity and its role in adolescent emotional disorder symptomatology.

BACKGROUND: Most emotional disorders first emerge during adolescence, a time characterized by heightened sensitivity to social information, especially social rejection. Social rejection sensitivity (SRS), then, may be a promising intervention target. METHODS: To explore this, 357 participants (M (SD) age = 19.40 (4.18), 63% female) completed self-report measures of SRS, its proposed antecedent, perceived parenting style, its proposed behavioral correlate, negative interpretation bias, and its proposed  clinical correlate, emotional disorder symptoms. Participants additionally completed a single session of a social interpretation bias modification task, the ambiguous social scenarios task (ASST). RESULTS: SRS was associated with perceived parental rejection, while controlling for other types of maladaptive parenting. SRS partially accounted for variance in the relationship between perceived parental rejection and emotional disorder symptomatology, as well as the relationship between negative interpretation bias and emotional disorder symptoms. Learning rates (i.e., change in reaction time across the task) on the ASST differed as a function of age and SRS, such that younger participants with higher SRS showed the slowest rate of learning. Moreover, individual differences in SRS accounted for the magnitude of change in negative interpretation bias before and after the ASST. Individuals with greater SRS showed less change in interpretation bias. CONCLUSIONS: SRS appears strongly associated with emotional disorder symptoms in adolescents. Importantly, SRS was associated with the malleability of negative interpretation bias, which may help account for the mixed findings on the effectiveness of interpretation-bias-modification-paradigms in adolescents.

Association of Antenatal COVID-19-Related Stress With Postpartum Maternal Mental Health and Negative Affectivity in Infants.

Importance: Antenatal stress is a significant risk factor for poor postpartum mental health. The association of pandemic-related stress with postpartum outcomes among mothers and infants is, however, less well understood. Objective: To examine the association of antenatal COVID-19-related stress with postpartum maternal mental health and infant outcomes. Design, Setting, and Participants: This cohort study was conducted among 318 participants in the COVID-19 Risks Across the Lifespan study, which took place in Australia, the UK, and the US. Eligible participants reported being pregnant at the first assessment wave between May 5 and September 30, 2020, and completed a follow-up assessment between October 28, 2021, and April 24, 2022. Main Outcomes and Measures: COVID-19-related stress was assessed with the Pandemic Anxiety Scale (score range, 0-4, with higher scores indicating greater COVID-19-related stress). The 8-item Patient Health Questionnaire (score range, 0-3, with higher scores indicating more frequent symptoms of depression) was used to measure maternal depression at each time point, and the 7-item General Anxiety Disorder scale (score range, 0-3, with higher scores indicating more frequent symptoms of anxiety) was used to measure generalized anxiety at each time point. At follow-up, postpartum distress was assessed with the 10-item Postpartum Distress Measure (score range, 0-3, with higher scores indicating greater postpartum distress), and infant outcomes (negative and positive affectivity and orienting behavior) were captured with the Infant Behavior Questionnaire (score range, 1-7, with higher scores indicating that the infant exhibited that affect/behavior more frequently). Results: The study included 318 women (mean [SD] age, 32.0 [4.6] years) from Australia (88 [28%]), the US (94 [30%]), and the UK (136 [43%]). Antenatal COVID-19-related stress was significantly associated with maternal postpartum distress (ß = 0.40 [95% CI, 0.28-0.53]), depression (ß = 0.32 [95% CI, 0.23-0.41]), and generalized anxiety (ß = 0.35 [95% CI, 0.26-0.44]), as well as infant negative affectivity (ß = 0.45 [95% CI, 0.14-0.76]). The findings remained consistent across a range of sensitivity analyses. Conclusions and Relevance: The findings of this cohort study suggest that targeting pandemic-related stressors in the antenatal period may improve maternal and infant outcomes. Pregnant individuals should be classified as a vulnerable group during pandemics and should be considered a public health priority, not only in terms of physical health but also mental health.

Reappraisal capacity is unrelated to depressive and anxiety symptoms.

Research suggests affective symptoms are associated with reduced habitual use of reappraisal as an emotion regulation strategy in individuals with mental health problems. Less is known, however, about whether mental health problems are related to reduced reappraisal capacity per se. The current study investigates this question using a film-based emotion regulation task that required participants to use reappraisal to downregulate their emotional response to highly evocative real-life film footage. We pooled data (N = 512, age: 18-89 years, 54% female) from 6 independent studies using this task. In contrast to our predictions, symptoms of depression and anxiety were unrelated to self-reported negative affect after reappraisal or to emotional reactivity to negative films. Implications for the measurement of reappraisal as well as future directions for research in the field of emotion regulation are discussed.

Uncertainty as a driver of the youth mental health crisis.

Mental health problems in young people have been on the rise for over a decade, with that trend accelerating during the pandemic. This review proposes that the catalyst effect of the pandemic offers insights into a key driver of increases in youth depression and anxiety: greater uncertainty. Uncertainty about many aspects of everyday life, including social connections, education, job security and health, increased during the pandemic, and this coincided with increasing rates of depression and anxiety. Lab-based developmental cognitive and clinical neuroscience research on tolerance of uncertainty and adolescent mental health shows that when adolescents fail to show age-typical tolerance of uncertainty, they are at greater risk of mental health problems. Avenues for future research to understand and promote tolerance of uncertainty in adolescents are proposed.

Cognitive and affective control for adolescents in care versus their peers: implications for mental health.

BACKGROUND: Many adolescents who have been removed from the care of their biological parent(s) and placed in State or Local Authority care have experienced significant adversity, including high rates of maltreatment and other trauma(s). As a group, these young people experience far higher rates of mental health difficulties compared to their peers. While their mental health outcomes are well-documented, little is known about mechanisms that may drive this. One potential mechanism, linked to both trauma and adversity exposure and mental health, is affective control (the application of cognitive control in affective contexts). METHODS: We compared cognitive and affective control in 71 adolescents (65% girls) in care aged 11-18 (M = 14.82, SD = 2.10) and 71 age and gender-matched peers aged 11-19 years (M = 14.75, SD = 1.95). We measured cognitive and affective control using standard experimental tasks, and for those in care, we also examined associations with self-reported emotion regulation, mental health, and school well-being. RESULTS: After controlling for IQ, there was a significant group difference in affective control performance, with those in care on average performing worse across all tasks. However, further analyses showed this was driven by deficits in overall cognitive control ability, and was not specific to, or worsened by, affective stimuli. Further, we found no evidence that either cognitive or affective control was associated with emotion regulation abilities or the mental health and well-being of young people in care. CONCLUSIONS: Results suggest that cognitive and affective control may not underlie mental health for young people in care, though limitations should be considered. We discuss implications for theory and intervention development, and avenues for further research. TRIAL REGISTRATION: https://doi.org/10.17605/OSF.IO/QJVDA.

Affective working memory in depression.

Depressed individuals show a wide range of difficulties in executive functioning (including working memory), which can be a significant burden on everyday mental processes. Theoretical models of depression have proposed these difficulties to be especially pronounced in affective contexts. However, evidence investigating affective working memory (WM) capacity in depressed individuals has shown mixed results. The preregistered study used a complex span task, which has been shown to be sensitive to difficulties with WM capacity in affective relative to neutral contexts in other clinical groups, to explore affective WM capacity in clinical depression. Affective WM capacity was compared between individuals with current depression (n = 24), individuals in remission from depression (n = 25), and healthy controls (n = 30). The results showed that, overall, WM capacity was more impaired in the context of negative distractor images, relative to neutral images. Furthermore, those with a lifetime history of depression (individuals with current depression and individuals remitted from depression), performed worse on the task, compared to healthy controls. However, there was no support for the greater disruption of WM capacity in affective compared to neutral contexts in those with a lifetime history of depression. These findings' implications for current models of depression are discussed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).