Psychoneuroendocrinology (2015) 51, 1—10 Available online at www.sciencedirect.com ScienceDirect j ourna l h om epa ge : www.elsevier.com/locate/psyneuen Progesterone and mental imagery interactively predict emotional memories Jacinta Wassell a , Sebastian Rogers a , Kim L. Felmingam b , Joel Pearson a , Richard A. Bryant a,* a School of Psychology, University of New South Wales, Sydney, Australia b School of Psychology, University of Tasmania, Hobart, Australia Received 23 November 2013; received in revised form 1 September 2014; accepted 6 September 2014 KEYWORDS Emotional memory; Progesterone; Imagery; Sex differences Summary Different lines of research suggest that the consolidation of emotional memories is influenced by (a) endogenous levels of sex hormones, and (b) individual differences in the capacity to use vivid mental imagery. No studies to date have investigated how these factors may interact to influence declarative emotional memories. This study examined the interacting influence of progesterone and mental imagery strength on emotional memory consolidation. Twenty-four men, 20 women from the low progesterone (follicular) menstrual phase, and 20 women from the high progesterone (mid-luteal) phase of the cycle were assessed using an objective performance-based measure of mental imagery strength, and then shown a series of aversive and neutral images. Half of the images were accompanied by instructions to pro- cess sensory features, and the remaining half to process the conceptual characteristics of the images. Two days later, all participants returned for a surprise free recall memory test. The interaction of progesterone and mental imagery strength significantly predicted recall of visually processed, but not verbally processed, negative images. These data suggest that men- tal imagery strength may be one mechanism underlying the documented association between endogenous progesterone and enhanced emotional memory performance in the literature. © 2014 Elsevier Ltd. All rights reserved. It is widely acknowledged that emotional arousal has an enhancing effect on lasting, declarative memory (Cahill and McGaugh, 1995, 1998; Anderson et al., 2006). A significant ∗ Corresponding author at: School of Psychology, University of New South Wales, NSW 2052, Australia. Tel.: +61 2 9385 3640; fax: +61 2 9385 3641. E-mail address: r.bryant@unsw.edu.au (R.A. Bryant). body of literature from both animal and human studies suggests that emotional arousal triggers the release of nora- drenergic and glucocorticoid stress hormones, that promote the preferential encoding of arousing over neutral informa- tion (McGaugh, 2004). These adrenal hormones are thought to interact in the amygdala of the brain to facilitate mem- ory formation via afferent projections to the hippocampus and related cortical areas (McGaugh and Roozendaal, 2002). Further, cognitive researchers have proposed that the high http://dx.doi.org/10.1016/j.psyneuen.2014.09.005 0306-4530/© 2014 Elsevier Ltd. All rights reserved.