Implicit memory varies across the menstrual cycle: estrogen effects in young women

Abstract

Evidence that ovarian steroid hormones such as estrogen and progesterone affect cognition comes from studies of memory in older women receiving estrogen replacement therapy and studies of sexually dimorphic skills in young women across the menstrual cycle. Sixteen women (ages 18-28) completed tests of memory (implicit category exemplar generation, category-cued recall, implicit fragmented object identification) and sexually dimorphic skills (fine motor coordination, verbal fluency, mental rotations) at the early follicular (low estrogen and progesterone) and midluteal (high estrogen and progesterone) phases of the menstrual cycle. Performance on category exemplar generation, a test of conceptual implicit memory, was better at the midluteal than the follicular phase. In contrast, performance on a test of explicit memory, category-cued recall, did not vary across the menstrual cycle. At Session 1, women in the follicular phase performed better on the fragmented object identification task than did those in the midluteal phase. This unexpected finding suggests that high levels of ovarian hormones might inhibit perceptual object priming. Results confirmed previous reports of decreased mental rotations and improved motor skills and fluency in the midluteal phase. Estradiol levels correlated positively with verbal fluency and negatively with mental rotations and perceptual priming, which suggest that estrogen, and not progesterone, was responsible for the observed changes in cognition. Mood did not vary across the cycle phases. Overall, the findings suggest that estrogen may facilitate the automatic activation of verbal representations in memory.

Motor-learning Impairment by Amantadine in Healthy Volunteers

“…Although our study sample size does not permit to draw firm conclusions about the role of gender in this type of motor learning, women appeared to perform significantly worser than men in our motor-adaptation task, in accordance with the findings of Sawaki et al (2003), who reported gender differences on a simple motor-learning paradigm using flexion-extension thumb movements. Also, it lends support to the hypothesis that female hormones may modulate neural plasticity and motor-skill learning (Maki et al, 2002;Smith et al, 1999). In our study, however, while gender may have modulated motor learning differently, it cannot explain the significant differences between amantadine low-performance and placebo low-performance subgroups, which are matched for sex distribution.…”

Hippocampal volume and functional connectivity changes during the female menstrual cycle

“…Some studies observed performance differences over the menstrual cycle in tasks measuring spatial and verbal abilities as well as memory (Hampson, 1990;Hausmann et al, 2000;Maki et al, 2002;Rosenberg and Park, 2002), domains that are known to be related to hippocampal function (Kühn and Gallinat, 2014). However, some studies report no cyclerelated variations in performance on verbal and visuospatial tests (e.g., Epting and Overman, 1998;Gordon and Lee, 1993).…”

The effect of sex and menstrual phase on memory formation during a nap

“…Studies have shown cognitive differences between women in the early follicular phase when hormones are low (i.e., menses) compared with other phases of the menstrual cycle , Maki et al, 2002. For example, one study found that spatial abilities were increased in women during the early follicular phase, whereas fine motor skills and verbal fluency were enhanced during the mid-luteal phase .…”