One group of participants was told to fix their minds only on breathing. Another group was told to think about anything that came to mind.
Those who thought in a conscious way came up with false memories. This was not true with the mind-wandering group.
Brent MW, Laura M, Stephanie S, Matthew E, and Edmund F (2015). Increased False-Memory Susceptibility After Mindfulness Meditation. Journal of Psychological Science, Vol 26, Issue 10, 2015