Changes in saccadic latencies over the human menstrual cycle

The study assessed differences in sensorimotor processing as reflected in measurements of saccadic latencies at 3 different stages in the menstrual cycle (menstruation, early luteal, and premenstruation) in naturally cycling women (n = 13), and at the same time intervals in women taking an oral contraceptive (n = 6), and male controls (n = 8). Subjects (M age = 22.0 yr., SD = 2.2 yr.) were recruited by questionnaire from the student population of the University of Cambridge. Latencies were measured using a portable infrared scleral oculometer. Changes in latency across the menstrual cycle occurred only in the naturally cycling women (F(2.11) = 5.95, p < .05). Premenstrual latencies were greater (199.3 +/- 12.7 msec., M +/- SD) compared to those during menstruation (191.9 +/- 11.1 msec.) or midcycle (196.9 +/- 12.7 msec.). These findings could account for the loss of musculoskeletal coordination reported by some women prior to menstruation and suggests that administration of an oral contraceptive may alleviate this effect.