Sex Differences, Physiological Response, and Emotion

Abstract

Females have a higher prevalence for PTSD and other anxiety disorders than males, thus fluctuating sex hormones, such as estrogen, are considered to play a role. Research suggests that during predictable cue tasks, high estrogen females had greater startle response toward predictable tasks compared to unpredictable and control tasks. The current study used physiological responses and self-reported measures to investigate fear response during the oddball task within naturally and unnaturally cycling females. The oddball task consisted of five time points, consistent with control, unpredictable, predictable, extinction, and control blocks. Participants viewed a randomized slide show of three visual stimuli consisting of natural and control images. Participants (n = 26) were split into high or low estrogen groups and were placed in a separate group if using a hormonal contraceptive. Results found that, overall, participants had a greater positive affect at time two than at time five, F(4,80) = 3.832, p = .007. Given the small sample size, a second set of analyses assessed high estrogen level females and those using hormonal contraceptive (lower estrogen) after time the first control (time two) and after the unpredictable and predictable block (time three). Results found between group differences in state anxiety, such that HC females had greater state anxiety than the high estrogen group, F(1,12) = 4.880 , p = .047. These results were opposite for our hypotheses that overall, females with high estrogen levels will have greater self-reported mood, anxiety, and physiological response across the study. Results also opposed our hypothesis such that a group by time interaction revealed participants in the HC group had significantly higher positive affect at time two which decreased at time three, F(1,12) = 4.931, p = .046; This significant difference between time points occurred only in participants using HC.