EFFECT OF OVARIAN HORMONES ON MEMORY SUPPRESSION

Abstract

Several studies suggest that memory suppression in humans occur as an active process of executive control, mediated by regions of prefrontal cortex, which is a substrate for ovarian hormones. However the effect of ovarian hormones on this process is not known. In order to address this question, we utilized the quantitative analysis of ovarian hormones in combination with the procedure of a memory control model, the think (T) /no think (NT) paradigm in a within-subject design study. We compared the rate of memory control between the follicular (low estrogen and progesterone) and mid-luteal (high estrogen and progesterone) phases of regularly cycling healthy women. Our data demonstrate that during midluteal phase, 63.6 % of subjects are able to ‘suppress’ or actively forget (significantly less % recall below the baseline) previously learned word pairs in the ‘NT condition; i.e., not to think the target word associated with the cue word’. However during the follicular phase there was no effect of ‘NT condition’ on the active forgetting of word pairs below the baseline as assessed by the memory test applied after the T/NT procedure. Thus, our results indicate that ovarian hormones are associated with the process of memory control.