Dual N-Back, Learning and Heart Rate Variability

Following my Heart Rate Variability, Learning and Flow study I took the recommendations from fellow quantified selfers and ran another round of sessions using a Dual N-Back game produced by the Brain Workshop.

What I did:

  • played a Dual 2-Back brain game on my Mac once or twice sitting at the same location in the morning each day for 8 days,
  • set the game for 90 trials that lasted anywhere from 273 to 282 seconds per session resulting in a measured success score that was expressed in terms of % correct,
  • measured the total heart rate coherence accumulated points score as given by Heartmath Pro over the total session,
  • divided the total accumulated points per session by the number of minutes to derive a “points per minute” score per session,
  • after entering that data into excel graphed the resulting points per session over the learning cycle.

How I did it:

Everything for this study was executed on the Mac. Heartmath Pro, the DualNBack game and excel were all windows on the Mac screen. Because I had set a disciplined approach to the first brain game I simply rotated the method in here.

As before I started the Heartmath Pro and waited until 30 seconds had elapsed so I was getting an HRV based cardiac coherence reading. After the coherence reading began I would start the Dual 2-Back game. The game was approximately 4.5 minutes to play. Here is a short YouTube video showing the mechanic of a Dual N-Back game.

Playing Dual 2-Back meant I was remembering the letter and location shown two iterations prior to the one being show on the screen currently.

What I Learned:

My correct answer percentage per session increased linearly the more I played. When I started I played using instinct then begin using a simple strategy to track the different elements around session 9. From there the learning continued but it was still linear. The strategy alone did not take the scores immediately higher, but it did enable continued improvement.

Slide1My Heart Rate Variability (HRV) also steadily increased the more I played. The points/minute proxy for HRV started at a low of 10 when I started playing and was in the 25 to 30 range at the 15 through 17th session. My subjective experience was of stress and concentration in the early session then more relaxed in the later sessions, mostly because I had worked out a strategy and attributed different scores to my having implemented the strategy well or not. Specifically, my mindset went from “I don’t know how to improve” in sessions 1 through 8 to “I need to implement a known strategy better” in 9 through 17. Here are the points/minute results over the sessions:

Slide2

Dual N-back demands constant attention, unlike the nearly autonomous reactions the category brain game allowed after repeated play. My experience with Dual N-back was consistent low level stress where the category game was more like “zoning out” and watching my fingers hit the screen. In comparison to the range of 10 to 30 points/minute in the Dual N-back game the category game points/minute were routinely between 30 and 50 as shown here:

Slide3

One insight I gleaned was that there is no “know it” or “don’t know it” binary state with respect to mastering a task. Knowledge and capability steadily increase as reflected in the quality of the output. Physiological stress decreases steadily as reflected in the increase in HRV. So my own tendency to think of mastery as binary is incorrect. Mastery at the capability and physiological level is a continuum and we move linearly along it. And movement along that continuum is as much about belief in the ability to improve as it is about underlying capability.

Sign up for the QuantXLaFont Newsletter
Get our lifestyle tips and studies delivered to your inbox.
Thank you! We don't spam :)

2 thoughts on “Dual N-Back, Learning and Heart Rate Variability

  1. > One insight I gleaned was that there is no “know it” or “don’t know it” binary state with respect to mastering a task. Knowledge and capability steadily increase as reflected in the quality of the output. Physiological stress decreases steadily as reflected in the increase in HRV.

    Which is why you had set it to 2-back, right? If you had on the regular adaptive settings, I think when you began hitting 90%s you’d get bumped up to 3-back and then your HRV scores *should* fall considerably as you’re suddenly under considerably more stress. Which raises a new question for me: could you use HRV to tune the adaptivity? In the category game, it looks like you hit the ceiling and your HRV became ~39pt/min; in the 2-back graph, it’s a bit hard to tell because the graph is wiggly, but it looks like the endpoint of the trendline is still 30-35. So you might want to increase to 3-back soonish.

    1. I have continued on and am now doing 3-Back though only four sessions in. As you suspected HRV fell back to bottom of range. I am going to track 3-Back across 20 sessions and compare performance and HRV so we can see if the progression is similar to the 2-Back. 3-Back is far less fun for reasons you point out in the Dual N-Back FAQ on your blog.

Leave a Reply

Your email address will not be published. Required fields are marked *