Research Roundup

Hormone in Birth Control Shot is Linked to Memory Loss

Birth control shots are a popular choice for women who don't want to remember to take a pill every day, but a study by Arizona State University graduate psychology student Blair Braden shows that the shots may impair women's memory.

A study in rats found that those who had received a certain hormone had impaired memories for several monthsIn the study, in press in Psychopharmacology, three groups of 4-month-old rats received weekly doses of medroxyprogesterone acetate (MPA), the active hormone in Depo Provera and other hormone therapies, over the course of seven months. One group of rats got the shots for four months during young adulthood, another group for three months during middle age and the last group all seven months. A control group of rats did not receive the hormone. To test the rats' memories, researchers placed them in water mazes to swim and seek out hidden platforms in the water.

At the end of the trial, researchers found that the animals that had received MPA at any point in their lives had learning and memory impairments — even after the hormone was undetectable in blood — compared with those that never had the drug. These findings suggest that MPA may not be the best birth control option for women, Braden says.

"This study is a call to women to be as informed as possible in their choices for contraceptives and hormone replacement," she says.

Depressed Hearts Recover More Slowly After Exercise

Past research has found that people with depression are twice as likely to have heart attacks, compared with those who are not depressed. Research by McGill University clinical psychology student Jennifer Gordon provides more information as to why.

In her study, 886 people — of whom 5 percent were diagnosed with major depressive disorder — took an exercise stress test. After the test, researchers recorded their heart rates and blood pressures. They found that the cardiovascular systems of people who were depressed took longer to recover from exercise than those of participants who were not depressed.

"This suggests that in depressed individuals, there's an imbalance in the autonomic nervous system, which is the biological system that's involved in the stress response," Gordon says. "This may partially explain why depressed individuals are at double the risk of cardiovascular disease."

The hope, Gordon adds, is that this study will increase awareness among health-care professionals of the need to reduce the risk of heart disease among people with mood disorders. The study was published in the November issue of Psychophysiology.

The Eyes Have Us

It's nearly impossible to avoid looking at someone's eyes, according to a study led by Kaitlin Laidlaw, a cognitive psychology doctoral student at the University of British Columbia. In the study, in press in the Journal of Experimental Psychology: Human Perception and Performance, Laidlaw and People are drawn to others’ eyes because they convey emotions, intentions and other social information, a study concludesher co-authors showed participants images of faces and asked them to look at the faces while also avoiding a particular facial feature, such as the eyes or the mouth. They found that the participants had a small but automatic predisposition to look at a person's eyes, but not their mouth. However, the participants were able to avoid the attraction of eyes in upside-down faces. This may be because — according to past research — faces need to be upright in order to effectively engage the neural mechanisms responsible for face processing, Laidlaw says.

"The eyes convey social information about intentions and emotions, and so it's natural that we'd be inclined to look there more than to other features," Laidlaw says. "There is an automatic process that is hard to override that drives us to look at eyes, and this process seems to be unique to eyes in upright faces."

Fairness Comes First in Children's Minds

Most children would rather throw away a candy bar or trinket — even one that could have gone to them — than be unfair to others, according to research led by Yale University graduate psychology student Alex Shaw.

Children appear to have an innate sense of fairness, even when it comes to sharing treats, a study suggestsIn the study, in press in the Journal of Experimental Psychology: General, researchers asked U.S. and South African children ages 6 to 8 to distribute candy bars or colorful erasers to other children who they were told had done a nice job cleaning up. They found that the children would rather throw an extra candy bar or eraser in the trash than distribute them unequally, even in cases where the children were given an option to take an extra trinket for themselves. The eraser distributors even acted fairly when the recipients didn't know how many others received.

These findings suggest that fairness may have deep, perhaps biological roots, but may not necessarily be an act of kindness, Shaw says. "Fairness is such an important part of human life, but it is still unclear why we would care about fairness, especially in cases where it conflicts with being generous to others," Shaw says. "Our results suggest that fairness is not directed toward increasing others' welfare because if this was the case, then children would give resources to others rather than wasting them."

Amy Novotney is a writer in Chicago.