Dear Daniela, 

just to make sure: we didn't do an intensive training, just a short introduction, without even mentioning mindfulness... So I think our study is not really a good example for studies on mindfulness training.

Here are some studies that investigate mindfulness training with a control group:

http://www.ncbi.nlm.nih.gov/pubmed/23125828

http://www.ncbi.nlm.nih.gov/pubmed/23115195

http://www.ncbi.nlm.nih.gov/pubmed/22689216

http://www.ncbi.nlm.nih.gov/pubmed/22586252

http://www.ncbi.nlm.nih.gov/pubmed/21071182

http://www.ncbi.nlm.nih.gov/pubmed/21334442

Thank you I appreciate your answer! I will look into these studies right away.

To search on PUBMED, can do "mindfulness and imaging" and/or "meditation and imaging". There should be quite a few of them. Hope this helps.

Thank you!