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Oral contraceptive pills (OCs), which are used to prevent pregnancy by the majority of women in the United States, contain steroid hormones that may affect the brain's structure and function. In this investigation, we tested the hypothesis that OC use is associated with differences in brain structure using a hypothesis-driven, surface-based approach. In 90 women, (44 OC users, 46 naturally-cycling women), we compared the cortical thickness of brain regions that participate in the salience network and the default mode network, as well as the volume of subcortical regions in these networks. We found that OC use was associated with significantly lower cortical thickness measurements in the lateral orbitofrontal cortex and the posterior cingulate cortex. These regions are believed to be important for responding to rewards and evaluating internal states/incoming stimuli, respectively. Further investigations are needed to determine if cortical thinning in these regions are associated with behavioral changes, and also to identify whether OC use is causally or only indirectly related to these changes in brain morphology.

Significant sex differences in the well-documented relationship between stress hormones and memory have emerged in recent studies. The potentiating effects of glucocorticoids on memory vary across the menstrual cycle, suggesting a potential interaction between these stress hormones and endogenously cycling sex hormones. Here, we show that memory for emotional materials changes significantly in accordance with hormonal changes across the menstrual cycle, suggesting that ovarian sex hormones influence the modulation of emotional memories. Sixty healthy, naturally cycling women rated 120 images on arousal and valence. One week later they completed free recall and recognition memory tests. Their menstrual cycle phases were estimated by self-report and confirmed by salivary assay of 17[beta]-estradiol and progesterone. Memory for emotional items only was significantly better in the high hormone (luteal) phase compared with the low hormone (follicular) phase on the free recall test; on both tests memory correlated positively with progesterone collected at the time of encoding. These findings suggest that emotional memory performance changes across the menstrual cycle, and that this change is in part mediated by endogenous progesterone cycling.

In essentially every domain of neuroscience, the generally implicit assumption that few, if any, meaningful differences exist between male and female brain function is being challenged. Here we address how this development is influencing studies of the neurobiology of learning and memory. While it has been commonly held that males show an advantage on spatial tasks, and females on verbal tasks, there is increasing evidence that sex differences are more widespread than previously supposed. Differing performance between the sexes have been observed on a number of common learning tasks in both the human and animal literature, many neither purely spatial nor verbal. We review sex differences reported in various areas to date, while attempting to identify common features of sexually dimorphic tasks, and to place these differences in a neurobiological context. This discussion focuses on studies of four classes of memory tasks for which sex differences have been frequently reported: spatial, verbal, autobiographical, and emotional memory. We conclude that the female verbal advantage extends into numerous tasks, including tests of spatial and autobiographical abilities, but that a small but significant advantage may exist for general episodic memory. We further suggest that for some tasks, stress evokes sex differences, which are not normally observed, and that these differences are mediated largely by interactions between stress and sex hormones. (Contains 4 tables.)

Background: Identifying factors that confer resilience to developing delirium is critical given the negative impact of delirium on clinical care and risk for mortality. Here, we investigated a cohort of cognitively normal older adults undergoing elective surgery and examined the role of pre‐operative memory function and cortical thickness in the incidence and severity of post‐operative delirium (POD). We hypothesized that 1) those older adults with episodic memory function comparable to that of young adults ("SuperAgers" or SA) would show reduced incidence of POD compared with typically‐aging older adults (TOA) and 2) cortical thickness in the anterior mid‐cingulate cortex (aMCC), the integrity of which has been consistently associated with SuperAging, would predict reduced incidence and severity of POD. Method: 19 SA and 74 TOA (mean age 75.8 +/‐ 4.1; 57F/36M) completed neuropsychological testing and underwent structural brain MRI pre‐operatively as part of the Successful AGing after Elective Surgery (SAGES) Study. SA were identified based on neuropsychological criteria defined in previous studies. Delirium incidence and severity were assessed using the Confusion Assessment Method (CAM) daily throughout hospitalization. A general linear model analysis was performed to identify regions of the cerebral cortex whose thickness was associated with CAM scores. Results: No differences were found in age or education between SA and TOA. Remarkably, no SA developed POD; POD occurred only in the TOA group (D‐TOA = 15). Severity of POD was negatively associated with cortical thickness of bilateral aMCC. A one‐way ANOVA comparing mean aMCC thickness across subgroups revealed a significant effect (F(2,89) = 3.09, p ≤.05), with thickness greatest in SA compared with D‐TOA (t(31) = 2.47, p ≤.019, Cohen's d = 0.89), but comparable compared to thickness seen in non‐delirious (ND) TOA (t(76) = 0.72, p ≤.72, d = 0.10). Greater aMCC thickness was also observed for ND‐TOAs compared with D‐TOAs (t(71) = 2.26, p ≤.03 d = 0.72). Conclusion: These findings suggest that superior memory function and greater structural integrity of the aMCC may be important indices of resilience to delirium in older adults that can serve as a target of preventive or therapeutic interventions. [ABSTRACT FROM AUTHOR]

The resting connectivity of the brain’s salience network, particularly the ventral subsystem of the salience network, has been previously associated with various measures of affective reactivity. Numerous studies have demonstrated that increased affective arousal leads to enhanced consolidation of memory. This suggests that individuals with greater ventral salience network connectivity will exhibit greater responses to affective experience, leading to a greater enhancement of memory by affect. To test this hypothesis, resting ventral salience connectivity was measured in 41 young adults, who were then exposed to neutral and negative affect inductions during a paired associate memory test. Memory performance for material learned under both negative and neutral induction was tested for correlation with resting connectivity between major ventral salience nodes. The results showed a significant interaction between mood induction (negative vs neutral) and connectivity between ventral anterior insula and pregenual anterior cingulate cortex, indicating that salience node connectivity predicted memory for material encoded under negative, but not neutral induction. These findings suggest that the network state of the perceiver, measured prior to affective experience, meaningfully influences the extent to which affect modulates memory. Implications of these findings for individuals with affective disorder, who show alterations in both connectivity and memory, are considered.