Cyclical variation in digit-span and visual-search performance in women differing in the severity of their premenstrual symptoms.

Groups of women differing in the severity of reported premenstrual symptoms were compared over two menstrual cycles on a digit-span task, a visual-search task, and a combination of the two. Neither group exhibited large performance changes during the premenstrual phase of the cycle. High-symptom women differed somewhat from low-symptom women in the effect of menstrual phase on digit-span performance, recalling slightly fewer series correctly during the premenstrual phase. The response latency of high-symptom women on the visual-search task was substantially longer than that of the low-symptom women regardless of menstrual phase. These results suggest that there may be stable differences between high-symptom and low-symptom subjects that are greater than the cyclical fluctuation within either group.