Frequent Sexual Activity Predicts Specific Cognitive Abilities in Older Adults

Cognitive inflexibility and heightened error monitoring are related to lower sexual functioning

Sexual functioning is an important predictor of well-being and relationship satisfaction. Previous research indicates that several aspects of cognitive function are related to sex-related behaviors and functioning among individuals with sex-related disorders, neurological disorders, and in older adults; however, this has been relatively underexamined in younger populations. To examine this, the present study assessed whether behavioral and/or neurophysiological measures of cognitive function are associated with sexual functioning in a community sample of young 489 adults (64 % female) ages 18-30. Cognitive flexibility (n = 460) and inhibition (n = 466) were measured using neuropsychological assessment (D-KEFS), and conflict monitoring and error monitoring were measured by event-related potentials (conflict N2: n = 394; error-related negativity: n = 389). After separately testing relations between the different measures of cognitive function and sexual functioning, we assessed whether results (1) remained after covarying for externalizing and internalizing dimensions (PID-5; n = 489) or (2) varied by gender. Finally, we tested whether any aspects of cognitive function were unique predictors of sexual functioning. Cognitive flexibility and error monitoring (i.e., error-related negativity) were both significantly related to sexual functioning among males and females, such that poorer cognitive flexibility and heightened error monitoring were related to lower sexual functioning. No significant effects emerged for inhibition or conflict monitoring. In a multiple regression model, cognitive flexibility and error monitoring each accounted for a unique portion of variance in sexual functioning beyond other aspects of cognitive function and psychopathology-related traits. Results suggest that cognitive function is a meaningful correlate of sexual functioning in young adulthood, which should be considered further in future research.

Is Sex Good for Your Brain? A National Longitudinal Study on Sexuality and Cognitive Function among Older Adults in the United States

Using a life course approach, we examined how sexuality is related to cognitive function for partnered older adults. We utilized longitudinal data from two rounds of the National Social Life, Health, and Aging Project (NSHAP) to analyze 1,683 respondents. Cognitive function was measured using a continuous Montreal Cognitive Assessment (MoCA) score. We considered both sexual frequency and sexual quality (i.e., physical pleasure, emotional satisfaction). We estimated cross-lagged models to consider the potential reciprocal relationship between sexuality and cognitive function. Results indicated that sexuality was not related to later cognitive function in the total sample, but the pattern varied by age and gender. For adults aged 62-74, better sexual quality (i.e., feelings of physical pleasure and emotional satisfaction) was related to better cognitive functioning, while for those aged 75-90, more frequent sex was related to better cognitive functioning. Feelings of physical pleasure were related to better cognitive functioning for men but not women. There was no evidence of cognitive functioning being related to later sexuality. The findings highlight the importance of age and gender in modifying the link between sexuality and cognition in later life.

A Systematic Review on Psychological Interventions for Sexual Health in Older Age

Objectives

The present review aims to identify the existing evidence on outcome-treatment studies of psychological sexual health interventions in older age.

Methods

A systematic search was conducted for studies published until October 2022. Data search was conducted on EBSCO, MEDLINE, Web of Science, and Cochrane Central Register of Controlled Trials databases.

Results

From 30,840 screened records, 12 reports were selected. Results were grouped into four categories according to the intervention that was implemented.

Conclusions

Despite results presenting some bias concerns, this review suggests that educational and cognitive-behavioral approaches seem to be effective for promoting sexual health in older age.

Erectile Function, Sexual Satisfaction, and Cognitive Decline in Men From Midlife to Older Adulthood

BACKGROUND AND OBJECTIVES

Vascular theories of cognitive aging have focused on macrovascular changes and cognitive decline. However, according to the artery-size hypothesis, microvascular changes, such as those that underlie changes in erectile function, may also play an important role in contributing to cognitive decline. Thus, we examined associations between erectile function, sexual satisfaction, and cognition starting in middle age because this represents a transition period where declines in these areas emerge.

RESEARCH DESIGN AND METHODS

We examined 818 men from the Vietnam Era Twin Study of Aging across three waves at mean ages 56, 61, and 68. Erectile function and sexual satisfaction were measured using the International Index of Erectile Function. Cognitive performance was measured using factor scores for episodic memory, executive function, and processing speed. We tested multilevel models hierarchically, adjusting for demographics, frequency of sexual activity, and physical and mental health confounders to examine how changes in erectile function and sexual satisfaction related to changes in cognitive performance.

RESULTS

Lower erectile function at baseline was related to poorer performance in all cognitive domains at baseline and faster declines in processing speed over time. However, baseline sexual satisfaction was unrelated to cognitive performance. Decreases in erectile function and sexual satisfaction were both associated with memory decline.

DISCUSSION AND IMPLICATIONS

Decreasing sexual health may signal an increased risk for cognitive decline. We discuss potential mechanisms, including microvascular changes and psychological distress. Discussing and tracking sexual health in middle-aged men may help to identify those likely to face memory decline.

Sexual Activity and Related Factors of Older Women in Hunan, China: A Cross-Sectional Study

BACKGROUND

Sexuality has an important impact on people's physical and mental health, but current research on the sexual activity of older Chinese women has many limitations and more detailed studies are needed.

AIM

The objective was to determine the prevalence of sexual activity and related factors in women aged 55 to 85 years in Hunan, China.

METHODS

Based on the data from the Hunan Provincial Women Health Needs Survey in 2018, we conducted a secondary analysis of 2,401 older women aged 55 and above. The dependent variable was sexual activity, and independent variables included sociodemographic characteristics, health behaviors, reproductive and chronic medical history, and psychological characteristics. All statistical analyses were performed using SPSS 26.0. Chi-square test was used to assess the association between categorical variables, and binary logistic regression was used to examine factors related to sexual activity.

OUTCOMES

Sexual activity and related factors.

RESULTS

The prevalence of sexual activity among older women was 12.5% (301/2401) in the past month. Having a partner (OR = 1.484; 95% CI, 1.048-2.101; P = .026), jogging (OR = 2.061; 95% CI, 1.391-3.054; P < .001), dancing (OR = 1.477; 95% CI, 1.106-1.974; P = .008), vegetarian-based diet (OR = 2.197; 95% CI, 1.334-3.618; P = .002), meat-based diet (OR = 2.196; 95% CI, 1.144-4.216; P = .018) were positively associated with being sexually active. Whereas, aging (OR = 0.781; 95% CI, 0.647-0.942; P = .010), living in the urban (OR = 0.628; 95% CI, 0.488-0.808; P < .001), hypertension (OR = 0.702; 95% CI, 0.520-0.949; P = .021), and anxiety (OR = 0.680; 95% CI, 0.475-0.972; P = .034) were negatively associated with being sexually active.

CLINICAL IMPLICATIONS

Health care workers need to be aware that older women still have sexual activity and understand the needs of older women for sex education, take the initiative to discuss safe sex with them, and solve their sexual problems.

STRENGTHS AND LIMITATIONS

This is one of the largest studies to determine the prevalence of sexual activity among older women in China and its related factors. In addition, new factors such as exercise types and eating habits related to sexual activity were discovered. The limitation of this study is that it did not use a specific questionnaire to assess the sexual activity and did not consider physical tenderness other than sexual intercourse.

CONCLUSIONS

Some older women still have had sexual activity in the past month and factors such as lifestyles that can be changed and chronic diseases that can be self-managed were found to predict sexual activity. Li T, LuoY, Meng Y, et al. Sexual Activity and Related Factors of Older Women in Hunan, China: A Cross-Sectional Study. J Sex Med 2022;19:302-310.

The Health Benefits of Sexual Expression

Objective

Sexual activity is a fundamental human function with short-term and long-term emotional, social, and physical benefits. Yet within healthcare, sexuality has been marginalized and many HCPs are unaware of its beneficial implications for immediate and long-term health.

Methods

To challenge this assumption we combined the data that already had been collected by the authors with an extensive search of articles on the various health benefits of sexual activity. The results of this process are displayed according to short-term, intermediate-term, and long-term benefits with some explanation about potential causal relationships.

Results

For the time being, it cannot yet be proved that "good sex promotes good health" since good health also favors good sex.

Conclusions

Despite lacking such convincing evidence, the article concludes with recommendations for the relevant professions. The balance of research supports that sexuality anyhow deserves greater attention among HCPs and that sexuality research needs better integration within health research.

Takes Two to Tango: Cognitive Impairment and Sexual Activity in Older Individuals and Dyads

OBJECTIVES

This paper examines the association between cognitive impairment, including mild cognitive impairment (MCI) and early dementia (ED), and sexual activity in a large, longitudinal sample of community-dwelling older adults. We focus here on sexual activity, which includes both sexual activity with a partner and masturbation.

METHODS

We analyzed 3777 older individuals and members of 955 intimate dyads using the National Social Life, Health and Aging Project (2010 and 2015). We used ordered-probit regression, cross-lagged panels models, and probit regression.

RESULTS

We find that older adults with cognitive limitations, either MCI or early dementia, are about as likely to be sexually active with a partner as those with normal cognitive function. This is the case both in the cross section and longitudinally. Both men and women with early dementia are less likely to have masturbated, however. Among married and cohabiting couples, we find no association between cognitive impairment in either the husband, the wife, or in both partners and their joint sexual activity. Women whose measured cognitive function is lower than their husband's are less likely to report any masturbation.

DISCUSSION

Sex with a partner, a fundamentally social activity, seems to be conserved in the face of cognitive limitation but masturbation, a solitary activity, does not. We argue that the intimate dyad plays an important role in conserving partnered sexual activity. Results can inform strategies to maintain sexual well-being of older adults with cognitive impairment and their partners as part of overall strategies to improve quality of life.

Is Ejaculation Frequency in Men Related to General and Mental Health? Looking Back and Looking Forward

Despite its relevance for human sexuality, literature on potential effects of ejaculation frequency and masturbation on general and mental health outcomes is sparse. Reasons for this knowledge gap include a general lack of interest, but also methodological challenges and still existing superstition. This paper reconciles literature from various fields to extract relevant information on how ejaculation frequency effects general and mental health outcomes. Culture-bound syndromes have been reported in countries still strictly tabooing or condemning masturbation. Masturbatory guilt describes a phenomenon in individuals experiencing a discrepancy between moral standards and own behavior with respect to masturbation. Abstinence is one aspect under study in the area of fertility treatment. Specific time frames and their respective implications on quality of sperm remain inconclusive. Limited temporal resolution capacities hamper the precise study of brain structures directly activated during ejaculation. The relation between ejaculation frequency and hormonal influences remains poorly understood. Future research that specifically addresses ejaculation frequency and potential mental and general health outcomes is needed. In contrast to extracting knowledge as a byproduct from other studies with a different focus, this enables sound study designs and could provide evidence-based results which could then be further discussed and interpreted.

Associations of Future Cognitive Decline with Sexual Satisfaction among Married Older Adults

Objectives: This study sought to explore changes in longitudinal cognitive status in relation to baseline measures of intimacy and sexuality in cognitively intact, married older adults.Methods: Baseline intimacy and sexuality survey data from 155, cognitively intact, married, older adults were collected using a novel survey instrument that explored the domains of: 1) romance with one's partner, 2) sexual satisfaction, 3) beliefs about sexuality, and 4) social support and emotional intimacy. These data were analyzed in relation to change in cognitive status over a 10-year follow-up period using binary logistic regression modeling. Exploratory factor analysis was used to assess the shared variance of survey items attributable to intimacy and sexuality without specification of an a priori hypothesis regarding the association of intimacy and sexuality with future change in cognitive status.Results: Over the 10-year study period, 33.5% (n = 52) of individuals developed cognitive impairment. Participants with greater sexual satisfaction scores at baseline were statistically less likely to convert from cognitively intact to mild cognitive impairment or dementia in the future (p = .01). The domains of romance with one's partner, beliefs about sexuality, and social support/emotional intimacy were not predictive of future longitudinal changes in cognitive status.Conclusions: Sexual satisfaction is associated with longitudinal cognitive outcomes in cognitively intact, married, older adults.Clinical implications: Clinicians should routinely assess for sexual satisfaction among older adults and refer to appropriate providers, such as couples or sex therapists, when appropriate.

Sexual Health Implications of COVID-19 Pandemic

INTRODUCTION

A novel coronavirus (COVID-19) reached pandemic levels by March 11th, 2020, with a destructive impact across socioeconomic domains and all facets of global health, but little is known of its impact on sexual health.

OBJECTIVE

To review current knowledge on sexual health-related containment measures during pandemics, specifically COVID-19, and focus on 2 main areas: intimacy and relational dynamics and clinical effects on sexual health.

METHODS

We carried out a literature search encompassing sexual health and pandemic issues using Entrez-PubMed and Google Scholar. We reviewed the implications of the COVID-19 pandemic on sexual health regarding transmission and safe sex practices, pregnancy, dating and intimacy amid the pandemic, benefits of sex, and impact on sexual dysfunctions.

RESULTS

Coronavirus transmission occurs via inhalation and touching infected surfaces. Currently, there is no evidence it is sexually transmitted, but there are sexual behaviors that pose a higher risk of infectivity due to asymptomatic carriers. Nonmonogamy plays a key role in transmission hubs. New dating possibilities and intimacy issues are highlighted. Sexual activity has a positive impact on the immune response, psychological health, and cognitive function and could mitigate psychosocial stressors. COVID-19 pandemic affects indirectly the sexual function with implications on overall health.

CONCLUSION

Increased awareness of health-care providers on sexual health implications related to the COVID-19 pandemic is needed. Telemedicine has an imperative role in allowing continued support at times of lockdown and preventing worsening of the sexual, mental, and physical health after the pandemic. This is a broad overview addressing sexual issues related to the COVID-19 pandemic. As this is an unprecedented global situation, little is known on sexuality related to pandemics. Original research is needed on the topic to increase the understanding of the impact the current pandemic may have on sexual health and function. Pennanen-Iire C, Prereira-Lourenço M, Padoa A, et al. Sexual Health Implications of COVID-19 Pandemic. Sex Med Rev 2021;9:3-14.

Sexual Expression and Cognitive Function: Gender-Divergent Associations in Older Adults

Prior research demonstrates a positive association between sexual activity and cognitive function in later life. However, the relationship between the type of sexual activity and cognitive function in older adulthood remains unclear. This study explored the associations between the frequency of engaging in different types of sexual activities (intercourse, masturbation, and kissing/petting/fondling) and cognitive function in older women and men. Using data from Wave 6 of the English Longitudinal Study of Aging (ELSA), 1915 women and 2195 men (age range 50-89 years; n = 4110) reporting any type of sexual activity over the past 12 months were included in the study. Multiple regression controlling for age, education, satisfaction with sex life, cohabiting, wealth, general health, physical activity, depression, and loneliness was used to explore the associations between the frequency of engagement in intercourse, masturbation, and kissing/petting/fondling, and two measures of cognitive function: word recall and number sequencing. For women, masturbation was linked to better word recall (p = .008), while for men, kissing/petting/fondling was associated with better number sequencing (p = .035). In women (p = .016) and men (p = .018), dissatisfaction with sex life was associated with better number sequencing. The results point to gendered links between sexual activity and cognitive function. These gender-related divergences may reflect differences in biological/neurological mechanisms, or in cognitive lifestyle factors that could influence cognitive reserve in later life. This novel study underscores the need to delineate the underlying mechanisms of the association between sex and cognition in men and women.

Regulation of adult hippocampal neurogenesis exerted by sexual, cognitive and physical activity: An update

In 1962, Joseph Altman described that the brain generates neurons after the postnatal period, and this continues throughout your life (Altman, 1962). This was a breakthrough in the neuroscience field because before this the accepted paradigm was that the brain only generated neurons during the embryonal development. This discovery has been controversial ever since, especially since one of the areas of the brain with neurogenic properties is the hippocampus, which is the area involved in memory storage and neurodegenerative processes. The adult hippocampal neurogenesis modulates in response to different environmental factors. In this article, we review how exercise and cognitive and sexual activity can regulate the generation of new neurons in the hippocampal in an adult brain and the impact of these new neurons in the brain circuitry.

Characterization of the Effects of a Six-Month Dancing as Approach for Successful Aging

Aging is accompanied by a decline in multiple domains. Positive effects of dance practice on several health issues have been evaluated in young adults, while the effects of regular social dance practice on physical fitness, sexual health, and cognitive functions have not been studied yet in older experienced dancers. Thus, the aim of this study has been to investigate whether a 6-month social dance practice might influence fitness performance, sexual health, and specific cognitive functions and/or mood characteristics in older experienced dancers. Thirty experienced dancers (age: 71.2±5.1 years, 18 females/12 males) were enrolled from the dance school "NonSoloLiscio" of Catanzaro. Body composition, physical fitness, sexual health, and cognitive functions were assessed before (T0) and after (T6) intervention. After 6 months of dance practice, percent of fat mass (%FM) significantly decreased (p<0.01), while fat-free mass (FFM) significantly increased (p<0.01) in both genders. Moreover, significant main effects of time on physical fitness tests, such as chair stand test (CST) (p<0.01), gait speed (p<0.05), and timed up and go (p<0.05), were found. Sexual health was significantly higher in males than in females at T0 and no significant effects of dance on subjects' sexual health were found. Interestingly, trait of anxiety significant decreased (p<0.05) and perception of retrospective memory significantly increased (p=0.05) after training independently of gender. Our preliminary results suggest that, even in older intermediate-level dancer, the practice of social dance might positively influence body composition and also increase fitness performance, memory functions, and anxiety. In contrast, no effects on sexual health were observed after 6 months of dancing.

Gender difference and correlation between sexuality, thyroid hormones, cognitive, and physical functions in elderly fit

PURPOSE

Sexuality in the elderly is related to psycho-physical well-being. Aim of this study was to analyze the correlation between sexual health, thyroid hormones, cognitive functions, and physical fitness in elderly population.

METHODS

Fifty-one fit adults were recruited (age: 71.9 ± 5.3 years, 26 females and 25 males). Sexuality was evaluated using the Changes in Sexual Functioning Questionnaire-short form (CSFQ-14) and the Sexual Attitude Scale (SAS). Thyroid function was assessed by measuring serum TSH, FT3, and FT4. Cognitive functions and depressive symptoms were evaluated by the Mini Mental State Examination (MMSE) test and Geriatric Depression Scale (GDS) scores. Subjects' physical fitness was evaluated using the following tests: Short Physical Performance Battery (SPPB), Handgrip test (HG), Timed Up and Go test (TUG), and 2-Minute step test (ST).

RESULTS

CSFQ-14 positively correlated with MMSE (p < 0.05) and negatively with GDS (p < 0.05), while thyroid function was not correlated with sexuality, in both genders. A negative relationship between FT4 vs. weight, FT3 vs. HG and FT3/FT4 ratio vs. ST were found (p = 0.05) in females, while in males, it occurred for TSH vs. TUG (p < 0.05); a positive relationship existed in females between FT4 vs. ST (p < 0.05). Finally, CSFQ-14 was significantly correlated with SPPB (p < 0.05), CST, TUG, and ST (p < 0.01), in both genders.

CONCLUSION

We demonstrated a strict relationship between active sexuality, preserved cognitive function and appropriate physical fitness in elderly subjects, independently from gender. Our preliminary data suggest that in elderly fit population, peripheral thyroxin deiodination may be a useful predictor of better physical performance and more successful aging.

Cognitive function, depression, and anxiety in patients undergoing radical prostatectomy with and without adjuvant treatment

BACKGROUND

Prostate cancer (PC) is one of the most common malignant tumors in developed countries. Both PC and treatment for PC have an adverse impact on physical and mental well-being, and are associated with decreased quality of life. The aim of the present study was to examine the relationship between neuropsychological symptoms and clinical course in PC patients undergoing radical prostatectomy with or without adjunct therapy.

METHODS

The cohort comprised 100 patients aged 50-77 years who underwent radical, laparoscopic prostatectomy for PC. Twenty-three patients with a more advanced clinical stage also received adjuvant therapy (radiotherapy and hormonotherapy). Clinical evaluation included self-report assessment, physical examination, and biochemical tests (testosterone and prostate-specific antigen). In addition, the presence and intensity of sexual dysfunction, urinary dysfunction, anxiety-depressive symptoms, and cognitive dysfunction were assessed.

RESULTS

The group of patients undergoing complex therapy was characterized by a significantly worse result of deferred memory (p=0.04). A significant correlation was found between post-surgery erectile function and scores for the visual working memory test (correct answers; VWMT-C; p=0.006) and Hospital Anxiety and Depression Scale depression (p=0.045) and anxiety scores (p=0.02). A trend toward significance was also observed for simple reaction time (correct answers; p=0.09). A significant correlation was found between results for the delayed verbal memory test and all physical symptoms (International Consultation on Incontinence Questionnaire-total, p=0.02; International Index of Erectile Function-5, p=0.006). Similarly, a significant correlation was found between the VWMT-C and score for sexual dysfunction (p=0.003).

CONCLUSION

Patients undergoing both surgical and adjunct therapy for PC are at risk for psychological burden and cognitive disorders. In the present cohort, physical complications of therapy were associated with depression, anxiety, and delayed memory dysfunction. Furthermore, this study has proven that fewer complications after surgery are associated with better psychological and cognitive functioning. Appropriate neuropsychological and psychiatric care can improve compliance and quality of life among patients after prostatectomy.

Cognitive Impairment, Sexual Activity and Physical Tenderness in Community-Dwelling Older Adults: A Cross-Sectional Exploration

BACKGROUND

The ability to engage in sexual activity and better cognitive functioning are both associated with better health. However, the association between cognitive functioning and sexual activity is understudied.

OBJECTIVE

To examine the association between cognitive functioning with sexual activity and physical tenderness among community-dwelling older adults.

METHODS

From the Rotterdam Study, cognitive impairment and sexual activity were assessed in 4,201 community-dwelling, 60+ year olds between 2008 and 2014 in the Netherlands. Mild cognitive impairment (MCI) was based upon subjective complaints related to age and education-adjusted test scores. Mini-Mental State Examination (MMSE) impairment was defined by a score of < 26. Sexual activity and physical tenderness (e.g., fondling or kissing) in the last 6 months were assessed at an interview. Analyses were stratified by gender and partner status, with prevalence rates for the "no impairment" categories weighted based on age from the cognitive impairment categories. Inter-rater reliability was examined utilising 74 cohabiting couples of opposite gender.

RESULTS

It was found that 14% were categorised as having cognitive impairment, and < 1% as dementia (excluded from subsequent analyses). There was strong evidence that the odds of engaging in physical tenderness (observed through MMSE < 26, OR 2.14, 95% CI 1.32-3.48, p = 0.002) and sexual activity (MCI, OR 2.36, 95% CI 1.35-4.12, p = 0.003) among partnered females with no impairment was twice that observed among cognitively impaired partnered females. There was weak evidence that the odds of engaging in physical tenderness (MMSE < 26, OR 1.59, 95% CI 1.04-2.42, p = 0.03) and sexual activity (MMSE < 26, OR 1.51, 95% CI 1.02-2.24, p = 0.04) among partnered males with no impairment was 50% greater than observed among cognitively impaired partnered males. The associations between cognitive functioning and physical tenderness continued to remain after adjustment for physical function, diabetes, cardiovascular disease and cancer. There was no clear evidence of a difference between amnestic and non-amnestic MCI for sexual behaviour. There was moderate to substantial agreement among the coupled adults who had 1 partner categorised with MCI.

CONCLUSION

Having no cognitive impairment was associated with more engagement in sexual activity and physical tenderness among community-dwelling older adults. Sexuality is an important aspect of active aging and our findings illustrate a potential barrier to maintaining or instigating intimate relationships as we age. Longitudinal analyses are required to explore the direction of effect.

Sexual Activity and Cognitive Decline in Older Adults

This prospective study tested whether sexual activity and emotional closeness during partnered sexual activity relate to cognitive decline (episodic memory performance) in older adulthood. In total, 6016 adults aged 50 and over (2672 men, 3344 women; M age = 66.0 ± 8.8 years) completed an episodic memory task and self-report questions related to health, sexual activity, and emotional closeness. Two years later, participants again completed the episodic memory task. After controlling for demographic and health-related lifestyle factors, more frequent sexual activity and greater emotional closeness during partnered sexual activity were associated with better memory performance. The association between sexual activity and memory performance was stronger among older participants in the sample. Memory performance worsened over 2 years, but change in memory performance was unrelated to sexual activity or emotional closeness during partnered sexual activity. These findings build on experimental research that has found sexual activity enhances episodic memory in non-human animals. Further research using longer timeframes and alternative measures of cognitive decline is recommended.

Slow-Wave Activity Enhancement to Improve Cognition

Slow-wave activity (SWA), and its coupling with other sleep features, reorganizes cortical circuitry, supporting cognition. This raises the question: can cognition be improved through SWA enhancement? SWA enhancement techniques range from behavioral interventions (such as exercise), which have high feasibility but low specificity, to laboratory-based techniques (such as transcranial stimulation), which have high specificity but are less feasible for widespread use. In this review we describe the pathways through which SWA is enhanced. Pathways encompass enhanced neural activity, increased energy metabolism, and endocrine signaling during wakefulness; also direct enhancement during sleep. We evaluate the robustness and practicality of SWA-enhancement techniques, discuss approaches for determining a causal role of SWA on cognition, and present questions to clarify the mechanisms of SWA-dependent cognitive improvements.