Transgenerational effect of Mothers' experiences of discrimination on Black youths' hormone coupling in response to laboratory stress.

Exposure to pervasive racial discrimination of Black Americans is transgenerational in that mothers' experiences of discriminatory violence impacts their children. This study explored whether stress-related biomarkers reflect transgenerational racial stress by implementing a "dual activation" framework to probe how adrenal and gonadal hormones underlying adolescent development are co-regulated during a laboratory stressor. Data were collected from 120 Black families in the United States. Children completed the Trier Social Stress Task (TSST-C) and provided 4 saliva samples across 2 days that were assayed for cortisol (C), dehydroepiandrosterone (DHEA), and testosterone (T). Mothers reported their experiences of total discrimination and racial discrimination related to skin color/race. Thirty four percent reported experiences of discrimination and on average 46.7% reported experiences of discrimination due to their race or skin tone. Mothers' experiences of racial discrimination were associated with their child's hormonal reactivity to and recovery from the TSST-C. Youth showed stronger positive hormone coupling between C-T if their mother experienced greater discrimination. Mothers' experiences of racial discrimination influenced both C-T coupling and youths' cortisol recovery from the TSST-C. For youths with high testosterone, cortisol recovery was blunted. Results suggest that associations between racism and hormonal stress response may be transgenerational. Mothers' experiences of discrimination had a profound impact on their children's hormonal co-regulation.

Bioenergetic and vascular predictors of potential super-ager and cognitive decline trajectories-a UK Biobank Random Forest classification study.

Aging has often been characterized by progressive cognitive decline in memory and especially executive function. Yet some adults, aged 80 years or older, are "super-agers" that exhibit cognitive performance like younger adults. It is unknown if there are adults in mid-life with similar superior cognitive performance ("positive-aging") versus cognitive decline over time and if there are blood biomarkers that can distinguish between these groups. Among 1303 participants in UK Biobank, latent growth curve models classified participants into different cognitive groups based on longitudinal fluid intelligence (FI) scores over 7-9 years. Random Forest (RF) classification was then used to predict cognitive trajectory types using longitudinal predictors including demographic, vascular, bioenergetic, and immune factors. Feature ranking importance and performance metrics of the model were reported. Despite model complexity, we achieved a precision of 77% when determining who would be in the "positive-aging" group (n = 563) vs. cognitive decline group (n = 380). Among the top fifteen features, an equal number were related to either vascular health or cellular bioenergetics but not demographics like age, sex, or socioeconomic status. Sensitivity analyses showed worse model results when combining a cognitive maintainer group (n = 360) with the positive-aging or cognitive decline group. Our results suggest that optimal cognitive aging may not be related to age per se but biological factors that may be amenable to lifestyle or pharmacological changes.

Impact of hair type, hair sample weight, external hair exposures, and race on cumulative hair cortisol.

The biomarker cortisol assesses the impact of biopsychosocial stressors that activate the stress response system. Hair has emerged as a valid and non-invasive means of gauging cumulative cortisol deposited over month-long periods of time. Established protocols for the extraction of hair cortisol are being validated and refined in humans, yet methodological information about hair characteristics on cortisol remains limited. In addition to external hair exposures (e.g. dye, time spent outside), we examined hair categorization or type (e.g. kinky, straight) by extending a hair typing methodology for scientific use that is currently popular among hair care professionals. We then examined the interaction between hair type and race on cortisol levels with a hair questionnaire. Three studies were pooled to investigate how sample weight, hair type, race, heat exposures, and hair treatments impacted cumulative hair cortisol concentrations. Study 1 consisted of Adult Kenyan Medical Workers (N = 44); Study 2 Mexican and Mexican Americans (N = 106); and Study 3 American Youth (N = 107). We found significantly higher cortisol in 5 mg of hair when compared to larger sample weights, and higher cortisol in those who spent more time outdoors. Cortisol concentrations differed between racial groups and varied by hair type; moreover, there were directional differences in cumulative cortisol from straighter to curlier hair types which depended on racial group. In addition to demonstrating the impact of relatively novel control factors like hair sample weight, outdoor exposure, and hair type, the present study illustrates the importance of disentangling hair type and race to understand variability in cumulative hair cortisol. These influences should be included in future studies that measure hair cortisol.

Putting the flight in "fight-or-flight": Testosterone reactivity to skydiving is modulated by autonomic activation.

Sensation-seeking (SS) involves the tendency to pursue exciting activities, potentially including risky behaviors (e.g., substance use, risky sexual behavior). Testosterone is associated with cortisol, SS, and autonomic nervous system (ANS) functioning. Testosterone reactivity/recovery during sky-diving and its relationship to cortisol response, ANS response and SS were examined. Forty-four participants provided reactive saliva samples and autonomic activity data before, during and after sky-diving and as well as basal day saliva samples. Testosterone reactivity/recovery to skydiving was significantly greater than basal day measurements. Testosterone responsivity to skydiving was predicted by increased cortisol, increased sympathetic activity (heart rate) and reduced parasympathetic activity (RMSSD). Independent of physiological effects, increased SS predicted testosterone responsivity to skydiving. These data suggest that testosterone reactivity, and its relationship to ANS responsivity, may be associated with pleasurable responses to risky/intense situations. These data may be useful in developing novel intervention strategies for risky behaviors.

Feedback-Related Negativity and Frontal Midline Theta Reflect Dissociable Processing of Reinforcement.

Prediction errors (PEs) encode representations of rewarding and aversive experiences and are critical to reinforcement processing. The feedback-related negativity (FRN), a component of the event-related potential (ERP) that is sensitive to valenced feedback, is believed to reflect PE signals. Reinforcement is also studied using frontal midline theta (FMΘ) activity, which peaks around the same time as the FRN and increases in response to unexpected events compared to expected events. We recorded EEG while participants completed a monetary incentive delay (MID) task that included positive reinforcement and negative reinforcement conditions with multiple levels of the outcome, as well as control conditions that had no reinforcement value. Despite the overlap of FRN and FMΘ, these measures indexed dissociable cognitive processing. The FRN was sensitive to errors in both positive and negative reinforcement but not in control conditions, while frontal theta instead was sensitive to outcomes in positive reinforcement and control conditions, but not in negative reinforcement conditions. The FRN was sensitive to the point level of feedback in both positive and negative reinforcement, while FMΘ was not influenced by the feedback point level. Results are consistent with recent results indicating that the FRN is influenced by unsigned PEs (i.e., a salience signal). In contrast, we suggest that our findings for frontal theta are consistent with hypotheses suggesting that the neural generators of FMΘ are sensitive to both negative cues and the need for control.

Assay validation of hair androgens across the menstrual cycle.

INTRODUCTION: Saliva is a common noninvasive biofluid for measuring stress and sex hormones, yet one pressing limitation is that salivary hormones fluctuate momentarily, daily, and (for girls) across the menstrual cycle. Hair steroid assays are thought to provide a cumulative index which collapses across hormonal variability, potentially eliminating the confound of daily and menstrual cyclicity and thereby reflecting individual differences in average hormone levels. Here we seek to validate a hair bioassay methodology and test whether hair androgens accurately measure long-term, stable androgen levels in emerging adult women across two menstrual cycles. METHODS: Hair samples were collected at the end of each menstrual cycle for two cycles, and saliva samples were collected in the morning once per week across two menstrual cycles (N = 11 women). Hair samples were segmented by 1 cm for the first 4 cm to reflect the hormone levels of the past four serial months. Hair samples were assayed using commercially-available enzyme-immuno-assays for testosterone and DHEA. RESULTS: Hair androgen concentrations were significantly correlated with averaged saliva hormone levels (DHEA: r = .75, p < .05; Testosterone: r = .67, p < .05). With respect to hair hormone stability, there were significant correlations for almost all the pairs of two 1 cm hair segments collected in two months that corresponded to the same time period. Hair androgens in one segment were significantly correlated with those in next segment. Regarding salivary androgen stability, the intra-class correlation across the weekly saliva samples indicated that for DHEA 59% of the total variance was within person and 41% was between person; and for testosterone 91% of the total variance was between person, and only 9% within person. DISCUSSION: Results suggest that a one-time measure of hair provides a valid and reliable estimate of average steroid levels across two months. Moreover, whereas saliva measures of androgen levels capture week-to-week fluctuations in steroids, hair samples provide information on individual differences in average exposure to steroids, across long periods of time, such as months. Results are encouraging that hair DHEA and testosterone reflects the cumulative hormonal concentration and can be used as a stable hormonal index. Results also indicate that it is feasible to collect the first 3-4 centimeters of hair for studies of stable hormone levels.

Neural mechanisms underlying the link between effortful control and aggression: An ERP study.

Aggression and violence are social behaviors that exact a significant toll on human societies. Individuals with aggressive tendencies display deficits in effortful control, particularly in affectively charged situations. However, not all individuals with poor effortful control are aggressive. This study uses event-related potentials (ERPs) recorded from a large sample (n = 75 undergraduates) to decompose the chronology of neural mechanisms underlying the ability to effortfully-control behavior, and then explores whether deficits in these cognitive functions might then lead to aggressive behavior. This study investigated which ERPs moderate the effortful control - aggression association. We examined three successive ERP components, the P2, N2, and P3, which have been associated with attentional orienting, response conflict, and working memory updating, for stimuli that required effortful control. N2 amplitudes were larger for trials requiring a switch from a preplanned action strategy than trials where a preplanned action strategy was followed. Furthermore, results indicated that N2 activation, but not P2 or P3 activation, moderated the relationship between effortful control and aggression. Our results suggest that small (less negative) N2s moderate the association between effortful control and aggression. These effects were present only in negative contexts, and only for high-conflict trials. Results suggest that individual differences in neural processing efficiency contributes to the execution of effortfully controlled behavior and avoidance of aggression.