In 2011, neuroscientist and best-selling author Sam Harris wrote an article titled How to Meditate in which he cites a host of research on the observed neurological benefits of mindfulness-based meditation techniques. As a life-long skeptic of anything promising enlightenment, or being associated with incense, I've never considered meditation to be a truly constructive way to spend one's time. However, I recall being fairly compelled by Sam's article. Sam dispassionately describes a variety of scientifically demonstrable benefits of meditation. Such as mitigating anxiety and depression, improving cognitive function, and even producing changes in gray matter density in regions of the brain related to learning and memory, emotional regulation, and self awareness. And he does this without giving praise to any cult iconography or incantations. Just science.

About 8 months ago, he wrote a brief follow-up article including two guided meditations, one 9 minutes long and one 26 minutes long. Here's a snippet from the text:

There is nothing spooky or irrational about mindfulness, and the literature on its psychological benefits is now substantial. Mindfulness is simply a state of clear, nonjudgmental, and nondiscursive attention to the contents of consciousness, whether pleasant or unpleasant. [link]

Stumbling across this recently, I decided to give this topic a little more attention. However, being borderline obsessed with data collection/visualization/processing, I couldn't just try it out. I had to figure out a means of quantifying my body's response. So I did what any rational person would do and built a small EKG with Matlab. Recording my heart rate would be an easy way to at least superficially gauge my relaxation level without having to embark on a journey of learning more complex biosignal processing interpretation. The end result of my 9 minute meditation session was this graph. The green plot is the audio from Harris' 9 minute guided meditation, and the red plot is my heart rate as I listened to the audio.