Maira Karan is a postdoctoral fellow in the department of psychiatry and behavioral sciences. Her research focuses on how positive human behaviors, such as empathy and prosociality, develop during the period of adolescence and how the adolescent brain and body mature in concert to support these positive behaviors. She has examined the development of these behaviors using experimental tasks, validated questionnaires, ecological momentary assessments, longitudinal assessments, and functional magnetic resonance imaging (fMRI). Another line of her work examines how sleep affects adolescent health and well-being with a special focus on circadian rhythms. At Stanford, she is working on merging her two lines of research to assess how sleep and circadian timing relate to prosocial behaviors. In addition to conducting research, she has a deep passion for uplifting underrepresented individuals in(to) the fields of psychology and neuroscience.
Honors & Awards
Dena Chertoff Graduate Student Service Award, UCLA (2023)
Pritzker Graduate Scholar Award, UCLA (2022)
Norma & Seymour Feshbach Doctoral Dissertation Award, UCLA (2021)
Seed Grant Award, UC Consortium on the Developmental Science of Adolescence (2019)
Honorable Mention: National Science Foundation Graduate Research Fellowship, NSF (2019)
NIH T32 Predoctoral Fellow, NICHD Training Program in Brain & Behavioral Development during Adolescence (2018-2020)
Graduate Summer Research Mentorship Fellowship, UCLA (2018, 2020)
Jamie Zeitzer, Postdoctoral Faculty Sponsor
Positive and negative emotion are associated with generalized transcriptional activation in immune cells
2023; 153: 106103
Alterations in immune system gene expression have been implicated in psychopathology, but it remains unclear whether similar associations occur for intraindividual variations in emotion. The present study examined whether positive emotion and negative emotion were related to expression of pro-inflammatory and antiviral genes in circulating leukocytes from a community sample of 90 adolescents (Mage = 16.3 years, SD = 0.7; 51.1% female). Adolescents reported their positive emotion and negative emotion and provided blood samples twice, five weeks apart. Using a multilevel analytic framework, we found that within-individual increases in positive emotion were associated with reduced expression of both pro-inflammatory and Type I interferon (IFN) response genes, even after adjusting for demographic and biological covariates, and for leukocyte subset abundance. By contrast, increases in negative emotion were related to higher expression of pro-inflammatory and Type I IFN genes. When tested in the same model, only associations with positive emotion emerged as significant, and increases in overall emotional valence were associated with both lower pro-inflammatory and antiviral gene expression. These results are distinct from the previously observed Conserved Transcriptional Response to Adversity (CTRA) gene regulation pattern characterized by reciprocal changes in pro-inflammatory and antiviral gene expression and may reflect alterations in generalized immunologic activation. These findings highlight one biological pathway by which emotion may potentially impact health and physiological function in the context of the immune system, and future studies can investigate whether fostering positive emotion may promote adolescent health through changes in the immune system.
View details for DOI 10.1016/j.psyneuen.2023.106103
View details for Web of Science ID 000982441800001
View details for PubMedID 37054596
Giving to others and neural processing during adolescence
DEVELOPMENTAL COGNITIVE NEUROSCIENCE
2022; 56: 101128
Adolescence is marked by an increased sensitivity to the social environment as youth navigate evolving relationships with family, friends, and communities. Prosocial behavior becomes more differentiated such that older adolescents increasingly give more to known others (e.g., family, friends) than to strangers. This differentiation may be linked with changes in neural processing among brain regions implicated in social decision-making. A total of 269 adolescents from 9-15 and 19-20 years of age completed a decision-making task in which they could give money to caregivers, friends, and strangers while undergoing functional magnetic resonance imaging (fMRI). Giving to caregivers and friends (at a cost to oneself) increased with age, but giving to strangers remained lower and stable across age. Brain regions implicated in cognitive control (dorsolateral and ventrolateral prefrontal cortex) showed increased blood-oxygen-level-dependent (BOLD) activation with increasing age across giving decisions to all recipients; regions associated with reward processing (ventral striatum and ventral tegmental area) showed increased activation across all ages when giving to all recipients. Brain regions associated with social cognition were either not active (dorsomedial prefrontal cortex) or showed reduced activation (temporal parietal junction and posterior superior temporal sulcus) when giving to others across all ages. Findings have implications for understanding the role of brain development in the increased complexity of social decision-making during adolescence.
View details for DOI 10.1016/j.dcn.2022.101128
View details for Web of Science ID 000824184000003
View details for PubMedID 35759828
View details for PubMedCentralID PMC9249997
Resting parasympathetic nervous system activity is associated with greater antiviral gene expression
BRAIN BEHAVIOR AND IMMUNITY
2021; 98: 310-316
Parasympathetic nervous system activity can downregulate inflammation, but it remains unclear how parasympathetic nervous system activity relates to antiviral activity. The present study examined associations between parasympathetic nervous system activity and cellular antiviral gene regulation in 90 adolescents (Mage = 16.28, SD = 0.73; 51.1% female) who provided blood samples and measures of cardiac respiratory sinus arrhythmia (RSA), twice, five weeks apart. Using a multilevel analytic framework, we found that higher RSA (an indicator of higher parasympathetic nervous system activity)-both at rest and during paced breathing-was associated with higher expression of Type I interferon (IFN) response genes in circulating leukocytes, even after adjusting for demographic and biological covariates. RSA was not associated with a parallel measure of inflammatory gene expression. These results identify a previously unrecognized immunoregulatory aspect of autonomic nervous system function and highlight a potential biological pathway by which parasympathetic nervous system activity may relate to health.
View details for DOI 10.1016/j.bbi.2021.08.229
View details for Web of Science ID 000706713800003
View details for PubMedID 34461235
School commute time, chronotype, and altered HPA axis functioning during adolescence
2021; 133: 105371
Hypothalamic pituitary adrenal gland (HPA) axis functioning has been linked with daily demands during adolescence. A ubiquitous, yet understudied daily demand in the lives of youth is the commute to school, which may be associated with the diurnal rhythm of cortisol as demonstrated in prior research among adults. The current study hypothesized that longer school commute times would be associated with altered HPA axis functioning as demonstrated by a heightened cortisol awakening response (CAR) and flatter diurnal slope. Additionally, given that the HPA axis follows a diurnal rhythm and adolescence is marked by changes in the circadian rhythm, adolescents with a more evening chronotype were hypothesized to evince even more altered HPA axis functioning in the face of long school commute times. A total of 269 adolescents (M = 16.38 years, SD = 0.74) provided saliva samples at wake, 15-min. post-wake, and 30-min. post-wake for the calculation of CAR and at dinnertime and bedtime for the calculation of diurnal slope, completed up to 8 nights of sleep actigraphy, and self-reported school commute time. Results suggest that more evening chronotype youth with longer school commute times evince a higher CAR, but not an altered diurnal slope. The present findings may have implications for adolescent mental health as higher CAR has been associated poor mental health and heightened stress.
View details for DOI 10.1016/j.psyneuen.2021.105371
View details for Web of Science ID 000697702200008
View details for PubMedID 34399150
View details for PubMedCentralID PMC8930079
Sleep-Wake Timings in Adolescence: Chronotype Development and Associations with Adjustment
JOURNAL OF YOUTH AND ADOLESCENCE
2021; 50 (4): 628-640
Adolescent sleep research has focused heavily on duration and quality with less work examining chronotype, defined as individual differences in sleep-wake timings driven by the circadian rhythm. This study filled a gap in the literature by utilizing actigraphy-based sleep estimates in an accelerated longitudinal design in order to better understand the developmental trajectory and individual stability of chronotype during adolescence, as well as the associations between chronotype with risky behaviors, substance use, and depressive symptoms. A total of 329 adolescents (57% female; 21% Asian American, 31% European American, 41% Latino, 7% other ethnicity) provided actigraphy-based estimates of sleep and completed questionnaires at up to three time points, two years apart, beginning at 14-17 years of age. Multilevel modeling revealed a non-linear developmental trend in chronotype whereby eveningness increased from 14 to 19 years of age followed by a trend toward morningness. Individual differences in chronotype exhibited modest stability during adolescent development. Furthermore, greater evening chronotype was associated with more risky behaviors and substance use among males, and more substance use among older adolescents, whereas depressive symptoms were not associated with chronotype. The findings from this study may have practical implications for adolescent behavioral health interventions targeted at reducing risky behaviors and substance use among youth.
View details for DOI 10.1007/s10964-021-01407-1
View details for Web of Science ID 000619709900001
View details for PubMedID 33606125
View details for PubMedCentralID PMC7993411
A daily diary study of sleep chronotype among Mexican-origin adolescents and parents: Implications for adolescent behavioral health
DEVELOPMENT AND PSYCHOPATHOLOGY
2021; 33 (1): 313-322
The current study used daily assessments of sleep to examine stability and change in sleep chronotype in adolescents and their parents. The study assessed adolescent sleep chronotype according to age, gender, and parent chronotype, and evaluated its associations with emotional and behavioral problems in youth. Participants included of 417 Mexican American adolescents (Mage = 16.0 years, Range = 13.9-20.0) and 403 caregivers, who reported bed and wake times daily for 2 consecutive weeks at two time points spaced 1 year apart. In addition, adolescents completed established self-report questionnaires of emotional and behavioral problems. Chronotype was computed as the midsleep point from bed to wake time on free days, correcting for sleep debt accumulated across scheduled days. Multilevel modeling showed a curvilinear association between adolescent age and chronotype, with a peak eveningness observed between ages 16 to 17. Adolescent and parent chronotypes were contemporaneously correlated, but each was only moderately stable over the 1-year period. Later adolescent chronotype was contemporaneously associated with more substance use in all adolescents. Individual development and the family context shape sleep chronotype in adolescents and parents. Sleep chronotype is implicated in adolescent behavioral health.
View details for DOI 10.1017/S0954579419001780
View details for Web of Science ID 000620257700025
View details for PubMedID 32308171
Evidence from a Randomized Controlled Trial that Altruism Moderates the Effect of Prosocial Acts on Adolescent Well-being
JOURNAL OF YOUTH AND ADOLESCENCE
2021; 50 (1): 29-43
Despite growing public and scientific interest in the positive benefits of prosociality, there has been little research on the causal effects of performing kind acts for others on psychological well-being during adolescence. Developmental changes during adolescence, such as greater perspective taking, can promote prosociality. It was hypothesized that performing kind acts for others would improve adolescent well-being (positive and negative affect, perceived stress) and increase prosocial giving. As part of a randomized controlled trial, 97 adolescents (Mage = 16.224, SD = 0.816, range 14-17; 53.608% female) were assigned to either perform kind acts for others (Kindness to Others, N = 33), perform kind acts for themselves (Kindness to Self, N = 34), or report on daily activities (Daily Report, N = 30) three times per week for four weeks. Well-being factors were measured weekly and giving was tested post-intervention. Overall, changes over time in well-being did not differ across conditions. However, altruism emerged as a significant moderator such that altruistic adolescents in the Kindness to Others condition showed increased positive affect, decreased negative affect, and decreased stress. Increased positive affect was also linked to greater prosocial giving for Kindness to Others adolescents. These findings identify individual differences that may shape the effects of doing kind acts for others on well-being during adolescence.
View details for DOI 10.1007/s10964-020-01362-3
View details for Web of Science ID 000599026600001
View details for PubMedID 33278014
View details for PubMedCentralID PMC8039084
Sleep quality and cultural orientation among Chinese and Korean undergraduates in the United States
JOURNAL OF AMERICAN COLLEGE HEALTH
2022; 70 (3): 660-664
ObjectiveThe present study examined the relationship between cultural orientation styles and sleep quality among Chinese and Korean undergraduates in the United States. Method: A total of 266 participants (Mage = 20.55 years, SD = 1.93; 49% Chinese, 51% Korean) completed an online survey. Ethnic identity and American identity measures were used to categorize participants into one of four cultural orientations: bicultural, Asian, American, and marginal. Sleep quality was assessed using the well-validated Pittsburgh Sleep Quality Index. Results: Seventy percent of participants were poor-quality-sleepers. Regression models showed that marginal orientation was associated with worse sleep quality as compared to bicultural orientation and Asian orientation. Conclusions: Poor sleep is prevalent among Asian undergraduates in the U.S. and may be further heightened for those who are disconnected from both their ethnic and American cultures. Promoting a sense of cultural connectedness may help to increase their sleep quality.
View details for DOI 10.1080/07448481.2020.1763368
View details for Web of Science ID 000537890800001
View details for PubMedID 32432975