Here is recent research on the biofeedback technique used on this website. The website’s technique is called heart rate variability [HRV] biofeedback in the literature. I will share links to articles ( some with their abstracts on the journal pages). Also, I have taught clinical biofeedback to staff from The U of MN Medical Center and elsewhere for staff trainings (including CEUs to psychiatric staff from The State of MN (here is my clinical site- www.minnesotabiofeedback.com).
If you would like to search for research on the web, I recommend using Google Scholar. You can search for “heart rate variability biofeedback” and then add in a description of what you want to use it for like “performance” or “anxiety”. You can click here to open Google Scholar in a new tab or window. Below is a list of research found on Google Scholar for performance, anxiety, attention, and behavior in adults, art performers, students, and others. It also covers EEG and vagal nerve regulation, proving that this has an affect of cognitive health and attention and focus.
An article for HRV biofeedback and anxiety in college students: http://link.springer.com/article/10.1007/s10484-011-9151-4
An article for HRV biofeedback for “competitive anxiety”: http://www.drleahlagos.com/docs/biof_heart_rate-1-Dr.%20Lagos.pdf
An article showing HRV as effective for clinical depression, and that relating to vagal nerve function: https://link.springer.com/article/10.1007/s10484-006-9029-z
Heart rate variability biofeedback for heart health and vagal nerve function (i.e. the vagal nerve functions are known for their correlations with attention, I posted another article below for that) SMRhttp://www.sciencedirect.com/science/article/pii/S0002870305002826
Here is an article showing the connection between HRV biofeedback training, and increases in the SMR EEG rhythm that is the longest established neurotherapy treatment (originally researched for ADHD). The vagal nerve functions and SMR are also helped (if we connect the articles). http://www.tandfonline.com/doi/abs/10.1080/10874208.2013.759020
This one shows how HRV may be used with Acceptance and Commitment Therapy with good results:http://www.tandfonline.com/doi/abs/10.1080/10874208.2011.570695
This one shows how HRV helps cognitive functions during performance stress in students and helps anxiety in a controlled research at The University of Pennsylvania: http://onlinelibrary.wiley.com/doi/10.1002/acp.1750/full
I have read one article that proves the same thing that other literature says, that the connection, and mindfulness teaching from a clinician is more effective without biofeedback equipment than just biofeedback equipment for the client doing it alone…nothing replaces a human.
Thank You For Your Time, Peter