Pubertal testosterone predicts mental rotation performance of young adult males

Testosterone, gender identity and gender-stereotyped personality attributes

Sex/gender differences in personality associated with gender stereotyped behavior are widely studied in psychology yet remain a subject of ongoing debate. Exposure to testosterone during developmental periods is considered to be a primary mediator of many sex/gender differences in behavior. Extensions of this research has led to both lay beliefs and initial research about individual differences in basal testosterone in adulthood relating to "masculine" personality. In this study, we explored the relationships between testosterone, gender identity, and gender stereotyped personality attributes in a sample of over 400 university students (65 % female assigned at birth). Participants provided ratings of their self-perceived masculinity and femininity, resulting in a continuous measure of gender identity, and a set of agentic and communal personality attributes. A saliva sample was also provided for assay of basal testosterone. Results showed no compelling evidence that basal testosterone correlates with gender-stereotyped personality attributes or explains the relationship between sex/gender identity and these attributes, across, within, or covarying out sex assigned at birth. Contributing to a more gender diverse approach to assessing sex/gender relationships with personality and testosterone, our continuous measure of self-perceived masculinity and femininity predicted additional variance in personality beyond binary sex and showed some preliminary but weak relationships with testosterone. Results from this study cast doubt on the activational testosterone-masculinity hypothesis for explaining sex differences in gender stereotyped traits and within-sex/gender variation in attributes associated with agency and communality.

The interaction of genetic sex and prenatal alcohol exposure on health across the lifespan

Prenatal alcohol exposure (PAE) can reprogram the development of cells and tissues, resulting in a spectrum of physical and neurobehavioral teratology. PAE immediately impacts fetal growth, but its effects carry forward post-parturition, into adolescence and adulthood, and can result in a cluster of disabilities, collectively termed Fetal Alcohol Spectrum Disorders. Emerging preclinical and clinical research investigating neurological and behavioral outcomes in exposed offspring point to genetic sex as an important modifier of the effects of PAE. In this review, we discuss the literature on sex differences following PAE, with studies spanning the fetal period through adulthood, and highlight gaps in research where sex differences are likely, but currently under-investigated. Understanding how sex and PAE interact to affect offspring health outcomes across the lifespan is critical for identifying the full complement of PAE-associated secondary conditions, and for refining targeted interventions to improve the quality of life for individuals with PAE.

The sexual brain, genes, and cognition: A machine-predicted brain sex score explains individual differences in cognitive intelligence and genetic influence in young children

Sex impacts the development of the brain and cognition differently across individuals. However, the literature on brain sex dimorphism in humans is mixed. We aim to investigate the biological underpinnings of the individual variability of sexual dimorphism in the brain and its impact on cognitive performance. To this end, we tested whether the individual difference in brain sex would be linked to that in cognitive performance that is influenced by genetic factors in prepubertal children (N = 9,658, ages 9-10 years old; the Adolescent Brain Cognitive Development study). To capture the interindividual variability of the brain, we estimated the probability of being male or female based on the brain morphometry and connectivity features using machine learning (herein called a brain sex score). The models accurately classified the biological sex with a test ROC-AUC of 93.32%. As a result, a greater brain sex score correlated significantly with greater intelligence (p_fdr  < .001, η p 2 $$ {\eta}_p^2 $$  = .011-.034; adjusted for covariates) and higher cognitive genome-wide polygenic scores (GPSs) (p_fdr  < .001, η p 2 $$ {\eta}_p^2 $$  < .005). Structural equation models revealed that the GPS-intelligence association was significantly modulated by the brain sex score, such that a brain with a higher maleness score (or a lower femaleness score) mediated a positive GPS effect on intelligence (indirect effects = .006-.009; p = .002-.022; sex-stratified analysis). The finding of the sex modulatory effect on the gene-brain-cognition relationship presents a likely biological pathway to the individual and sex differences in the brain and cognitive performance in preadolescence.

Exploring the sex and gender correlates of cognitive sex differences

The correlates of cognitive sex differences are yet to be fully understood. Many biological and psychosocial factors modulate these cognitive abilities leading to mixed results in the scientific literature. The current study aims to explore the different parameters potentially influencing cognitive abilities acting in synergy. Sex and gender correlates of cognitive functioning were assessed in a sample of individuals ages 18 to 45 years (N = 87) from diverse sexual orientations. Sex hormones were assessed via saliva samples at four timepoints throughout the testing. Gender roles, sexual orientation and socio-demographics were measured via self-report questionnaires. Participants completed mental rotation and verbal fluency tasks. Men performed better than women at mental rotation, while no significant difference was found for verbal fluency. Significant positive associations were observed between estradiol and word fluency for the naturally cycling women compared to the women using oral contraception. While controlling for sex hormones, a significant interaction effect of sex by gender roles was identified for mental rotation among masculine women. These exploratory results suggest an effect principally driven by sex and sex hormones on cognitive performance that will need to be furthered with larger studies.

Androgen receptor polymorphism, mental rotation, and spatial visualization in men

Circulating levels of testosterone (T) have been hypothesized to influence spatial cognition in adult men, but empirical support for this idea is mixed. Many of testosterone's effects are mediated by the classic nuclear androgen receptor (AR), which contains a polymorphic glutamine repeat (CAG repeat sequence) that varies significantly across individual men and confers differences in receptor function and therefore individual responsivity to T. We genotyped the AR CAG repeat length in 146 healthy adult men who also performed cognitive tests of mental rotation and spatial visualization. Circulating T concentrations were measured in saliva. CAG repeat length was found to be a significant predictor of spatial scores on tests of visualization but not mental rotation. A weaker AR was associated with lower visualization scores. In contrast, T itself, but not CAG repeat length predicted scores on two mental rotation tests. These results support the view that T action in the brain modestly influences spatial cognition in healthy men, but suggest that T's effects on mental rotation might not be AR-dependent and instead occur through an alternative mechanism.

Psychoneuroendocrine protocol to comprehensively study sexually dimorphic cognition

Background

A large body of research provides evidence for sex differences in cognitive abilities. These sex differences stem from the interplay between biological sex (e.g., birth-assigned sex, sex hormones) and psychosocial gender (e.g., gender identity, gender-roles, sexual orientation). Literature remains rather mixed with regards to the magnitude of sex and gender effects on cognitive abilities and mental health. Growing evidence shows that sex hormone assessment combined with measures of psychosocial gender may be fundamental to comprehensively understand individual differences in sexually dimorphic cognitive abilities.

Objectives

This study protocol describes a sexually dimorphic cognitive battery to assess the influence of sex hormones on performance. In parallel, we aim to assess the inter-related effects that biological sex and psychosocial gender-based factors exert on cognition and mental health.

Methods

Our projected sample includes 180 adult participants who are at least 18 years old. Sub-groups will be recruited based on birth-assigned sex, gender identity, and sexual orientation. Biological measures will be collected via salivary samples throughout testing to include sex hormones (testosterone, estradiol and progesterone) and stress hormones (cortisol). Demographic and psychosocial variables will be measured through self-report questionnaires. Participants will be required to complete eight classic cognitive tasks that assess a variety of cognitive domains in a 2-h testing session.

Results and future directions

Results from this study provides unique insights into the correlates of cognitive sex differences and gender diversity. This will give us solid ground to further investigate these influences in clinical populations in which sex hormones and cognitive functioning are often altered.

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Cognition is modulated by multiple sex and gender factors.

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Cognitive abilities will be assessed among 180 adults representing diverse sexual orientations and gender identities.

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This protocol aims to nuance the effects of sex hormones in contrast to those of socio-cultural gender.

Testosterone and the Brain: From Cognition to Autism

Sex and gender matter in all aspects of life. Humans exhibit sexual dimorphism in anatomy, physiology, but also pathology. Many of the differences are due to sex chromosomes and, thus, genetics, other due to endocrine factors such as sex hormones, some are of social origin. Over the past decades, huge number of scientific studies have revealed striking sex differences of the human brain with remarkable behavioral and cognitive consequences. Prenatal and postnatal testosterone influence brain structures and functions, respectively. Cognitive sex differences include especially certain spatial and language tasks, but they also affect many other aspects of the neurotypical brain. Sex differences of the brain are also relevant for the pathogenesis of neuropsychiatric disorders such as autism spectrum disorders, which are much more prevalent in the male population. Structural dimorphism in the human brain was well-described, but recent controversies now question its importance. On the other hand, solid evidence exists regarding gender differences in several brain functions. This review tries to summarize the current understanding of the complexity of the effects of testosterone on brain with special focus on their role in the known sex differences in healthy individuals and people in the autism spectrum.

Eye-movements during number comparison: Associations to sex and sex hormones

Multi-digit numbers are of a hierarchical nature with whole number magnitudes depending on digit magnitudes. Processing of multi-digit numbers can occur in a holistic or decomposed fashion. The unit-decade compatibility effect during number comparison is often used as a measure of decomposed processing. It refers to the fact that performance is reduced when the larger number contains the smaller unit digit (e.g. 73 vs. 26). It has been demonstrated that women show a larger compatibility effect than men, which is in accordance with their general tendency towards focusing on stimulus details during processing of visual hierarchical stimuli (local processing style). Such a local processing style has been related to higher progesterone and lower testosterone levels. One method to study individual processing styles is eye-tracking. The aim of the present study was to examine whether sex and sex hormones (estradiol, progesterone, testosterone) relate to eye movement behavior in the number comparison task. Unlike previous studies we found no evidence for sex differences in the behavioral compatibility effect. Nevertheless, women look more often and longer at individual digits and show a stronger compatibility effect in fixation durations compared to men, while men show more saccades between numbers than women. Estradiol and progesterone were related to fewer fixations and shorter fixation durations and more saccades between numbers in men, but not in women. Furthermore, the compatibility effect in the number of fixations and fixation durations was negatively related to testosterone in women. In summary, this is the first study to demonstrate sex differences and sex hormone influences on eye gaze behavior during number comparison.

Pubertal timing predicts adult psychosexuality: Evidence from typically developing adults and adults with isolated GnRH deficiency

Evidence suggests that psychosexuality in humans is modulated by both organizational effects of prenatal and peripubertal sex steroid hormones, and by activational effects of circulating hormones in adulthood. Experimental work in male rodents indicates that sensitivity to androgen-driven organization of sexual motivation decreases across the pubertal window, such that earlier puberty leads to greater sex-typicality. We test this hypothesis in typically developing men (n = 231) and women (n = 648), and in men (n = 72) and women (n = 32) with isolated GnRH deficiency (IGD), in whom the precise timing of peripubertal hormone exposure can be ascertained via the age at which hormone replacement therapy (HRT) was initiated. Psychosexuality was measured with the Sexual Desire Inventory-2 (SDI-2) and Sociosexual Orientation Inventory-Revised (SOI-R). In both sexes, earlier recalled absolute pubertal timing predicted higher psychosexuality in adulthood, although the magnitude of these associations varied with psychosexuality type and group (i.e., typically developing and IGD). Results were robust when controlling for circulating steroid hormones in typically developing participants. Age of initiation of HRT in men with IGD negatively predicted SOI-R. We discuss the clinical implications of our findings for conditions in which pubertal timing is medically altered.

Timing of peripubertal steroid exposure predicts visuospatial cognition in men: Evidence from three samples

Experiments in male rodents demonstrate that sensitivity to the organizational effects of steroid hormones decreases across the pubertal window, with earlier androgen exposure leading to greater masculinization of the brain and behavior. Similarly, some research suggests the timing of peripubertal exposure to sex steroids influences aspects of human psychology, including visuospatial cognition. However, prior studies have been limited by small samples and/or imprecise measures of pubertal timing. We conducted 4 studies to clarify whether the timing of peripubertal hormone exposure predicts performance on male-typed tests of spatial cognition in adulthood. In Studies 1 (n = 1095) and 2 (n = 173), we investigated associations between recalled pubertal age and spatial cognition in typically developing men, controlling for current testosterone levels in Study 2. In Study 3 (n = 51), we examined the relationship between spatial performance and the age at which peripubertal hormone replacement therapy was initiated in a sample of men with Isolated GnRH Deficiency. Across Studies 1-3, effect size estimates for the relationship between spatial performance and pubertal timing ranged from. -0.04 and -0.27, and spatial performance was unrelated to salivary testosterone in Study 2. In Study 4, we conducted two meta-analyses of Studies 1-3 and four previously published studies. The first meta-analysis was conducted on correlations between spatial performance and measures of the absolute age of pubertal timing, and the second replaced those correlations with correlations between spatial performance and measures of relative pubertal timing where available. Point estimates for correlations between pubertal timing and spatial cognition were -0.15 and -0.12 (both p < 0.001) in the first and second meta-analyses, respectively. These associations were robust to the exclusion of any individual study. Our results suggest that, for some aspects of neural development, sensitivity to gonadal hormones declines across puberty, with earlier pubertal hormone exposure predicting greater sex-typicality in psychological phenotypes in adulthood. These results shed light on the processes of behavioral and brain organization and have implications for the treatment of IGD and other conditions wherein pubertal timing is pharmacologically manipulated.

Sex Hormones as Cognitive Enhancers?

Understanding the differences in the way women and men think has made headway thanks to experiments showing how sex hormones influence cognitive capacities. Masculine and feminine sex hormones (androgens and estrogens, respectively) affect cognition in different ways and may account for some of the gender differences in cognitive abilities, allowing men and women to perform better in certain cognitive tests. In this opinion article, we discuss studies addressing differences in cognitive functions between males and females and the underlying neural substrates, as well as the effects of sex hormone supplementation. Even though some studies on patients receiving exogenous sex hormones showed gender differences that emerge at group levels on a few cognitive tasks, it is not yet clear whether these differences can be partially attributed to hormonal causes. Supplementation of female estrogen can enhance verbal skills, whereas masculine androgen can increase performance in mathematical and visuospatial tasks. Studies of the administration of exogenous sex hormones have allowed further insight into the use of sex hormones as possible cognitive enhancers.

Socioeconomic disparities and sexual dimorphism in neurotoxic effects of ambient fine particles on youth IQ: A longitudinal analysis

Mounting evidence indicates that early-life exposure to particulate air pollutants pose threats to children's cognitive development, but studies about the neurotoxic effects associated with exposures during adolescence remain unclear. We examined whether exposure to ambient fine particles (PM2.5) at residential locations affects intelligence quotient (IQ) during pre-/early- adolescence (ages 9-11) and emerging adulthood (ages 18-20) in a demographically-diverse population (N = 1,360) residing in Southern California. Increased ambient PM2.5 levels were associated with decreased IQ scores. This association was more evident for Performance IQ (PIQ), but less for Verbal IQ, assessed by the Wechsler Abbreviated Scale of Intelligence. For each inter-quartile (7.73 μg/m3) increase in one-year PM2.5 preceding each assessment, the average PIQ score decreased by 3.08 points (95% confidence interval = [-6.04, -0.12]) accounting for within-family/within-individual correlations, demographic characteristics, family socioeconomic status (SES), parents' cognitive abilities, neighborhood characteristics, and other spatial confounders. The adverse effect was 150% greater in low SES families and 89% stronger in males, compared to their counterparts. Better understanding of the social disparities and sexual dimorphism in the adverse PM2.5-IQ effects may help elucidate the underlying mechanisms and shed light on prevention strategies.

Pubertal onset as a critical transition for neural development and cognition

Adolescence, broadly defined as the period between childhood and adulthood, is characterized by a variety of neuroanatomical and behavioral changes. In human adolescents, the cerebral cortex, especially the prefrontal cortex, decreases in size while the cortical white matter increases. Puberty appears to be an important factor in both of these changes. However, the white matter continues to grow beyond what is thought to be adolescence, while the gray matter of the cortex stabilizes by young adulthood. The size changes that are the manifestation of cortical reorganization during human adolescence are also seen in cellular reorganization in the rat cortex. The prefrontal cortex loses neurons, dendrites and synapses while myelination in the white matter continues to increase. All of this reorganization is more marked in female rats, and there is evidence both from pubertal timing and from removal of the ovaries that puberty plays an important role in initiating these changes in females. The maturation of behavioral functions of the prefrontal cortex, such as inhibitory control, occurs in both humans and rats across adolescence. There is also evidence for puberty as a major factor in decreasing perseveration in rats, but few studies have been done using pubertal status as an experimental variable, and the role of the gonadal steroids in modulating behavior throughout life makes clear effects more difficult to document. In all, puberty appears to be so essential to the changes occurring during adolescence that it should be recorded when possible, especially given the sex difference in pubertal timing. This article is part of a Special Issue entitled SI: Adolescent plasticity.

Psychological effects of androgen-deprivation therapy on men with prostate cancer and their partners

The clinical benefits of androgen-deprivation therapy (ADT) for men with prostate cancer (PC) have been well documented and include living free from the symptoms of metastases for longer periods and improved quality of life. However, ADT comes with a host of its own serious side effects. There is considerable evidence of the adverse cardiovascular, metabolic, and musculoskeletal effects of ADT. Far less has been written about the psychological effects of ADT. This review highlights several adverse psychological effects of ADT. The authors provide evidence for the effect of ADT on men's sexual function, their partner, and their sexual relationship. Evidence of increased emotional lability and depressed mood in men who receive ADT is also presented, and the risk of depression in the patient's partner is discussed. The evidence for adverse cognitive effects with ADT is still emerging but suggests that ADT is associated with impairment in multiple cognitive domains. Finally, the available literature is reviewed on interventions to mitigate the psychological effects of ADT. Across the array of adverse effects, physical exercise appears to have the greatest potential to address the psychological effects of ADT both in men who are receiving ADT and in their partners.

On the effects of testosterone on brain behavioral functions

Testosterone influences the brain via organizational and activational effects. Numerous relevant studies on rodents and a few on humans focusing on specific behavioral and cognitive parameters have been published. The results are, unfortunately, controversial and puzzling. Dosing, timing, even the application route seem to considerably affect the outcomes. In addition, the methods used for the assessment of psychometric parameters are a bit less than ideal regarding their validity and reproducibility. Metabolism of testosterone contributes to the complexity of its actions. Reduction to dihydrotestosterone by 5-alpha reductase increases the androgen activity; conversion to estradiol by aromatase converts the androgen to estrogen activity. Recently, the non-genomic effects of testosterone on behavior bypassing the nuclear receptors have attracted the interest of researchers. This review tries to summarize the current understanding of the complexity of the effects of testosterone on brain with special focus on their role in the known sex differences.

Why women see differently from the way men see? A review of sex differences in cognition and sports

The differences of learning and memory between males and females have been well documented and confirmed by both human and animal studies. The sex differences in cognition started from early stage of neuronal development and last through entire life span. The major biological basis of the gender-dependent cognitive activity includes two major components: sex hormone and sex-related characteristics, such as sex-determining region of the Y chromosome (SRY) protein. However, the knowledge of how much biology of sex contributes to normal cognitive function and elite athletes in various sports are still pretty limited. In this review, we will be focusing on sex differences in spatial learning and memory - especially the role of male- and female-type cognitive behaviors in sports.

Sex differences in cognitive impairment and Alzheimer's disease

Studies have shown differences in specific cognitive ability domains and risk of Alzheimer's disease between the men and women at later age. However it is important to know that sex differences in cognitive function during adulthood may have their basis in both organizational effects, i.e., occurring as early as during the neuronal development period, as well as in activational effects, where the influence of the sex steroids influence brain function in adulthood. Further, the rate of cognitive decline with aging is also different between the sexes. Understanding the biology of sex differences in cognitive function will not only provide insight into Alzheimer's disease prevention, but also is integral to the development of personalized, gender-specific medicine. This review draws on epidemiological, translational, clinical, and basic science studies to assess the impact of sex differences in cognitive function from young to old, and examines the effects of sex hormone treatments on Alzheimer's disease in men and women.

Switching between forest and trees: opposite relationship of progesterone and testosterone to global-local processing

Sex differences in attentional selection of global and local components of stimuli have been hypothesized to underlie sex differences in cognitive strategy choice. A Navon figure paradigm was employed in 32 men, 41 naturally cycling women (22 follicular, 19 luteal) and 19 users of oral contraceptives (OCs) containing first to third generation progestins in their active pill phase. Participants were first asked to detect targets at any level (divided attention) and then at either the global or the local level only (focused attention). In the focused attention condition, luteal women showed reduced global advantage (i.e. faster responses to global vs. local targets) compared to men, follicular women and OC users. Accordingly, global advantage during the focused attention condition related significantly positively to testosterone levels and significantly negatively to progesterone, but not estradiol levels in a multiple regression model including all naturally cycling women and men. Interference (i.e. delayed rejection of stimuli displaying targets at the non-attended level) was significantly enhanced in OC users as compared to naturally cycling women and related positively to testosterone levels in all naturally cycling women and men. Remarkably, when analyzed separately for each group, the relationship of testosterone to global advantage and interference was reversed in women during their luteal phase as opposed to men and women during their follicular phase. As global processing is lateralized to the right and local processing to the left hemisphere, we speculate that these effects stem from a testosterone-mediated enhancement of right-hemisphere functioning as well as progesterone-mediated inter-hemispheric decoupling.

Childhood verbal development and drinking behaviors from adolescence to young adulthood: a discordant twin-pair analysis

BACKGROUND

Studies suggest that better cognitive and verbal abilities in childhood predict earlier experimentation with alcohol and higher levels of drinking in adolescence, whereas poorer ability is related to a higher likelihood of remaining abstinent. Whether individual differences in language development in childhood predict differences in adolescent drinking behaviors has not been studied.

METHODS

To address that question, we compared co-twins from twin pairs discordant for their childhood language development and studied associations of parental reports of within-pair differences in age at speaking words, age at learning to read, and expressive language skills during school age with self-reported within-pair differences in drinking, intoxication, and alcohol-related problems across adolescence and young adulthood. Data from 2 longitudinal population-based samples of twin families were used, with verbal developmental differences in childhood reported by the parents when the twins were 12 and 16 years of age, respectively.

RESULTS

Conditional logistic regression analyses and within-pair correlation analyses suggested positive associations between verbal development and drinking behaviors in both data sets. In analyses adjusted for birth order and birth weight, the co-twin reported to be verbally more advanced in childhood tended to report more frequent drinking and intoxication in adolescence in both samples. Better verbal development also was associated with the likelihood of having friends who drink in adolescence.

CONCLUSIONS

These findings suggest that, adjusting for familial and other factors shared by co-twins, better verbal development in childhood predicts more frequent drinking and intoxication in adolescence and young adulthood, possibly due, in part, to peer associations.

Sex hormones and mental rotation: an intensive longitudinal investigation

The present study used an intensive longitudinal design to examine whether mental rotation performance varies according to a monthly cycle in both males and females and whether these variations are related to variations in progesterone, estradiol, and testosterone levels. We collected reaction time and accuracy data for 10 males and seven females each workday over eight weeks using 136 pairs of mental rotation stimuli/day, and measured sexual hormones concentrations in the saliva twice a week. A mixed linear model statistical analysis revealed that all females and seven males showed significant cycle effects in mental rotation performance. The female cycle showed an amplitude that was twice as large compared with the amplitude found in males. For males and females, estradiol and testosterone were significantly linearly and quadratically related to interindividual variation in performance at the beginning of the study (progesterone was linearly related to performance for females). The association between testosterone and performance differed across sexes: for males, it had an inverse U-shape, for females it was U-shaped. Towards the end of the study, none of the hormones were significantly related to performance anymore. Thus, the relationship between hormones and mental rotation performance disappeared with repeated testing. Only estradiol levels were significantly elevated at the lowest point of the cycle in mental rotation performance in females. In conclusion, in this intensive longitudinal study spanning two months, a monthly cycle in mental rotation performance was found among both males and females, with a larger cycle's amplitude for females.