For the past several months I have been testing the CNS Tap Test, a mobile phone adaptation of the Finger Tap test often used by neuropsychologists and fitness professionals to measure the status of the central nervous system. The objective of this measurement experiment was to see if I could use this app to measure more objectively my physical and psychological health (I currently use subjective scales). The results were interesting but not sufficiently conclusive to include this test in my self-tracking inventory.
I have been performing the test thrice a day for nearly 3 months, accumulating over nearly 300 records. Those of you who are familiar with my Measured Me experiment know that I currently measure my well-being three times a day using the following nine indicators (the daily averages are posted on my Lifestream dashboard):
- physical health (presence and severity of symptoms or health conditions)
- physical energy (subjective measure of how energetic I felt during the morning/afternoon/evening)
- stress (subjective measure of how stressed I felt on average that morning/afternoon/evening)
- positivity and intensity of emotions (subjective 10-point scales)
- mental alertness (measured using Mind Metrics) app, mobile adaptation of psychomotor vigilance test)
- cognitive functioning (measured using Stroop Effect) app, adaptation of Stroop test)
- happiness (subjective measure of how happy I felt on average that morning/afternoon/evening)
- life satisfaction (subjective measure of how content I was with 6 aspects of my life that morning/afternoon/evening)
The measurement experiment consisted of performing a finger tap, alertness and cognitive functioning tests at a random moment in the morning, afternoon or evening, and then at the end of that morning/afternoon/evening assessing the last 3-6 hours with regard to other indicators of well-being. The app suggests taking measurements for both left and right hand, but for the sake of saving time, I used only right hand when taking the tests. After three months of collecting data, I looked at some statistical patterns.
First, I checked if tap scores differed across mornings, afternoons and evenings. As you can see, the average score were pretty much the same, and there were no statistically significant differences:
In other words, the tap test did not capture circadian rhythms throughout the day.
I then looked at the correlations between the tap score and nine well-being indicators (I used Spearman’s rho). Out of nine correlations, only three were statistically significant and meaningful (albeit puzzling):
According to the sources cited by the app developers, lower test scores are associated with fatigue, impending sickness, injury or overtraining, whereas elevated scores are associated with the optimal state of the central neural system. However, in my case there was no correlation with the physical energy whatsoever, and the correlation with the health score was negative, suggesting that for me, higher tap test scores are associated with sickness. The correlation with stress (higher tap test scores are associated with higher stress levels) is not necessarily contradictory, as stress is often associated with optimal performance (eustress). The tap scores, however, were positively associated with cognitive functioning (which I measured using Stroop tests).
Unfortunately, I am not a professional sportsman and do not have any data on sports performance; as for the productivity and creativity, there were not statistically significant associations.
Considering the negligible size and contradictory directionality of the correlations, I concluded that the finger tap test is not really suitable for the purposes of my Measured Me project.