Deemed by many as an activity for hippies, meditation has been practiced by humans for thousands of years, and for good reason: It’s been shown to reduce stress, boost our memory, heighten mood and increase self-awareness. And it’s becoming increasingly evident that these beneficial effects are not short-lived and simply the result of relaxation.

Studies have shown that just eight weeks of meditation can result in significant changes in brain regions associated with attention and emotional integration. But interestingly, it seems that the practice affects the brains of men and women differently. According to a new study, male and female meditators display changes in different regions of a brain structure involved in learning, memory and emotion: the hippocampus.

To come to this conclusion, scientists from the University of California, Los Angeles (UCLA), enrolled 60 male and female participants into a study, half of whom were meditators and the other half closely-matched controls. Within the meditation group, volunteers had engaged in the practice for between five and 46 years, with an average duration of 20 years, but this did not differ significantly between males and females.

The researchers were particularly interested in the hippocampus because earlier work has suggested that meditation can measurably alter this area, for example by increasing its dimensions and volume, or enhancing the amount of tissue, or grey matter, present. Since a significant amount of evidence points to the existence of sex differences in the hippocampus, the researchers wanted to know whether the effects of meditation manifest differently in the hippocampi of men and women.

The team therefore used magnetic resonance imaging (MRI) to scan the brains of both groups and analyze their hippocampal anatomy. Even though the researchers found no significant differences in total brain volume between the meditators and their controls, they did find that those who meditated displayed significant changes in their hippocampi, including a larger volume and a higher density of grey matter.

More importantly, the researchers also observed that the changes differed between males and females. For example, while differences were apparent across both hippocampal hemispheres of males, the effects were more pronounced on the left side. Females, on the other hand, demonstrated differences almost exclusively in the right hippocampus. This is the first study to highlight the existence of such sex-specific differences. The findings have been published in Frontiers in Psychology.

While the researchers were specifically investigating meditators vs non-meditators, it is impossible to assert that meditation is driving these changes, or whether they are due to genetic differences between males and females. However, the team points out that the results could suggest that the hippocampi of males and females are differently receptive to mindfulness practices such as meditation.

A more robust way to study changes associated with meditation would be to follow participants over time, starting before they adopt the practice and then comparing their brains with control groups for many years. Furthermore, the authors write that it would be interesting to further extend this study by examining other brain structures, rather than specifically honing in on one.

[H/T: PsyPost]