Do you think memory changes are only for aging women?  Not so, according to new research from UC Irvine.  Younger women who use birth control pills experience changes in memory as well.  The reasons for these changes are rather enlightening – and surprising.

UCI graduate researcher Shawn Nielson said, “What’s most exciting about this study is that it shows the use of hormonal contraception alters memory.  There are only a handful of studies examining the cognitive effects of the pill, and more than 100 million women use it worldwide.

If you’re wondering what is so “exciting” about alterations to your memory, Nielson stresses that the pill doesn’t damage your ability to remember. This type of contraceptive doesn’t cause a memory deficit, but a change in the type of information you recall.

The link between the pill and memory.

Birth control pills work by suppressing estrogen and progesterone to prevent pregnancy. Both hormones have already been linked to women’s strong “left brain” memory.  In this newest study, groups of women taking the pill and women going through natural hormone cycles viewed pictures of a mother, her son, and a car accident. The researchers supplied a different detailed narrative to each group. Some were told the car had hit a curb, and others were told a car had hit the boy and he was severely injured.

The following week they were given a pop test to measure their recall.  Women using birth control pills for as little as 30 days recalled more precisely the gist of the emotional traumatic event – that an accident had occurred, that the little boy had to be rushed to the hospital, and that the doctors were able to save his life and reattach his feet, for example.

Women not using the pill remembered more details, such as there was a fire hydrant beside the car. They were better able to retain specific details about the accident.

Pauline Maki, a professor of psychology and psychiatry at the University of Illinois at Chicago specializing in brain function and memory, states, “The fact that women on oral contraceptives remembered different elements of a story tells us that estrogen has an influence on how women remember emotional events.

The psychological ramifications of memory.

Nielson believes the findings of the study could help better understand why women experience PTSD more frequently than men, as well as how men recall differently than women. Most women agree that men retain the gist of things better than details.  They can’t tell you what color dress you wore to the party last month but they remember you looked nice.  That’s because they typically rely more on the right-hemisphere of the brain when it comes to encoding memory.

Women on the pill have lower levels of female hormones so they may remember emotional events similarly to men. They remember the gist of things but not the details.

The finding of this study may be surprising, but research has been underway on gender differences for decades.  These new revelations are a natural outgrowth of what has been discovered so far – that men and women remember differently.  At least we now know one reason why.