Elteto, N. 1 , Janacsek, K. 1, 2 & Nemeth, D. 1, 2
1 Institute of Psychology, Eötvös Loránd University, Budapest, Hungary
2 MTA-ELTE NAP B Brain, Memory and Language Lab, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
Evidence suggests that estrogen might differentially affect various cognitive functions. However, only a few studies investigated procedural learning. Here we investigated the effects of both oral contraceptive (OC) related and menstrual-cycle-related hormonal changes. In a group of 121 healthy women we administered the Alternating Serial Reaction Time task, which allows to separately measure pure statistical learning and higher-order sequence learning in one paradigm. The two learning performances were inversely related to OC use. OC users showed significantly better statistical learning, while OC non-users showed significantly better higher-order sequence learning. In a second analysis we investigated the effect of ovarian estrogen in a subgroup of 69 regularly menstruating women with no OC use. Quadratic models accounted for the change in both statistical learning (inverted U-shaped curve) and higher-order sequence learning (U-shaped curve) across the menstrual cycle. Indeed, participants were significantly less sensitive to local statistical structures and more efficient at filtering out long-range correlations in the periovulatory phase, when estrogen concentration is the highest during the menstrual cycle. Our results provide insight into the relation of female sex hormones and different learning mechanisms.