Frequency of Penile–Vaginal Intercourse is Associated with Verbal Recognition Performance in Adult Women

Abstract

Previous studies have identified a number of factors that contribute to improved cognitive function, and to memory function specifically, in cognitively normal individuals. One such factor, frequency of penile–vaginal intercourse (PVI), has been reported in a number of animal studies to be advantageous to memory for previously presented objects by increasing neurogenesis in the dentate gyrus of the hippocampus. However, studies investigating the potential benefits of frequent PVI on memory function in young women are to the best of our knowledge absent from the literature. The current study thus investigated whether the self-reported frequency of sexual intercourse was related to memory function in healthy female college students. To determine whether variation in PVI would be associated with memory performance, we asked 78 heterosexual women aged 18–29 years to complete a computerized memory paradigm consisting of abstract words and neutral faces. Results showed that frequency of PVI was positively associated with memory scores for abstract words, but not faces. Because memory for words depends to a large extent on the hippocampus, whereas memory for faces may rely to a greater extent on surrounding extra-hippocampal structures, our results appear to be specific for memory believed to rely on hippocampal function. This may suggest that neurogenesis in the hippocampus is higher in those women with a higher frequency of PVI, in line with previous animal research. Taken together, these results suggest that PVI may indeed have beneficial effects on memory function in healthy young women.

Appendix

Select Experience of Intimacy Questionnaire Items

Sexual Intimacy Items

Do you engage in sexual intercourse? Yes ____, No ____

If yes, how often do you engage in sexual intercourse?

• 1. more than once per day ___

• 2. once per day ___

• 3. once per week to six times per week ___

• 4. once every two–three weeks ___

• 5. once per month ___

• 6. less than once per month ___

If yes, does your partner ejaculate inside your vagina, without a condom? Yes___, No___

How often does your partner ejaculate inside of you, without a condom, when you engage in sexual intercourse (approximately)?

• 1. 100 % of the time___

• 2. 75 % of the time___

• 3. 50 % of the time___

• 4. 25 % of the time___

• 5. n/a___

If you engage in sexual intercourse, how often do you achieve orgasm (approximately)?

• 1. 100 % of the time___

• 2. 75 % of the time___

• 3. 50 % of the time___

• 4. 25 % of the time___

• 5. less than 25 % of the time___

• 6. I do not orgasm during sexual intercourse___

How often do you engage in sexual activity other than sexual intercourse? (Including, but not limited to, such activity as oral sex, genito-genital rubbing, genital petting, and mutual masturbation, but excluding kissing.)

• 1. more than once per day ___

• 2. once per day ___

• 3. once per week to six times per week___

• 4. once every two–three weeks ___

• 5. once per month ___

• 6. less than once per month ___

• 7. I do not engage in sexual activity of any kind ___

Do you masturbate (Yes___, No___), and if so, how many times per week? _________

If you masturbate, how often do you achieve orgasm (approximately)?

• 1. 100 % of the time___

• 2. 75 % of the time___

• 3. 50 % of the time___

• 4. 25 % of the time___

• 5. I do not orgasm from masturbation___

Rubin’s Measurement of Romantic Love Scale

If you are in a monogamous relationship or are seeing a partner on a regular basis (i.e., through casually dating or through a semi-monogamous relationship), please indicate the degree of liking and loving you feel toward this partner (referred to below as “X”) by answering the following questions:

Using the 9-point scale below, please indicate the extent to which you agree or disagree by writing the appropriate number in the space corresponding to each item.

1 Not at all true; disagree completely

2

3

4

5

6

7

8

9 Definitely true; agree completely

Experience of Loving

• 1. ___ If X were feeling badly, my first duty would be to cheer him up.

• 2. ___ I feel that I can confide in X about virtually everything.

• 3. ___ I find it easy to ignore X’s faults.

• 4. ___ I would do almost anything for X.

• 5. ___ I feel very possessive toward X.

• 6. ___ If I could never be with X, I would feel miserable.

• 7. ___ If I were lonely, my first thought would be to seek X out.

• 8. ___ One of my primary concerns is X’s welfare.

• 9. ___ I would forgive X for practically anything.

• 10. ___ I feel responsible for X’s well-being.

• 11. ___ When I am with X, I spend a good deal of time just looking at him.

• 12. ___ I would greatly enjoy being confided in by X.

• 13. ___ It would be hard for me to get along without X.