Intraindividual and interindividual variations in psychomotor task performance in spontaneously menstruating women.

OBJECTIVE To examine the variability in psychomotor task performance in women in reference to the menstrual cycle. METHODS One hundred and eighty young women with spontaneous regular menstrual period of 30 days duration and 20 young men were assessed in the Department of Pharmacology, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq during 2003. RESULTS Women had significantly lower recognition as well as motor reaction time than men with wide inter and intraindividual variations. Women also had a lower critical flicker fusion frequency threshold than men with more variation. The changes in psychomotor performance are not specific for a certain phase of the menstrual cycle. CONCLUSION Spontaneously menstruating young women are not good participants for psychomotor performance studies because of wide intra- and interindividual variations.