Contrary to previous studies, new research has suggested that meditation does not have the power to spark structural brain change within just a matter of weeks.

In the new study, published in the journal Science Advances, researchers from the University of Wisconsin-Madison tested the idea of whether an eight-week mindfulness course could induce physical changes in the brain.

Previous research has indicated that even some relatively straightforward mediation practices can help to rewire the brain by improving connectivity and even changing the volume of your prefrontal cortex, the part of your brain involved in complex cognitive behavior, personality expression, and moderating social behavior. 

However, this latest study – one of the largest and most rigorously controlled to date – failed to repeat those findings. 

The team gathered 200 healthy people with no meditation experience or mental health concerns and asked them to undergo an MRI brain scan. The participants were then divided into three groups: some underwent an eight-week Mindfulness-Based Stress Reduction course, while others received a non-mindfulness-based well-being intervention, and the final group didn't receive any type of training.

After the eight weeks were up, the participants underwent another brain scan to see whether their brains had gone under any noticeable changes. Although most people who received an intervention reported feeling increased mindfulness after the eight weeks, they found no evidence of structural brain changes among any of the participants.

The researchers are not totally sure why their experiments reached different findings from previous work, but they suspect it might have something to do with previous research studying participants had enrolled themselves in the mindfulness classes. Their experiments also involve significantly more people than previous pieces of research, giving more weight to their findings. 

“The simple act of choosing to enroll in MBSR [Mindfulness-Based Stress Reduction] may be associated with increased benefit,” the study reads.

“It is notable that the current study also had sample sizes over three times that of prior work,” it adds. “Given the low sample sizes of prior work and the larger samples and lack of replication in the current study, there is a possibility that prior results suffered from inflated effect sizes and low positive predictive value.”

None of this is to suggest that mindfulness and meditation are without their benefits for mental health, cognitive sharpness, and well-being. Above all, the researchers concede that participants only practiced mindfulness for just eight weeks. Perhaps, they argue, people need to have practiced for longer to see profound changes in the brain. 

"We are still in the early stages of research on the effects of meditation training on the brain and there is much to be discovered," lead study author Richard J. Davidson, a professor of psychology and psychiatry at the University of Wisconsin-Madison, said.