There's no breathalyzer for cannabis on the market, but the fine folks over at NORML have created My Canary, an app that measures how high you are based on a series of simple tests. While a disclaimer states it shouldn't be used to determine fitness to drive or engage in other high-risk activities, it sure is fun to test out.
The creators of My Canary "examined thousands of peer-reviewed studies on the influence of fatigue, and legal and illegal substances [...] and over 20,000 studies specifically focusing on the influence of marijuana on functioning."
Backed by that research, the app tests the following areas of cognitive and psychomotor abilities, then tells you whether you're significantly impaired. You'd better set aside at least 15 minutes if you want to do this right.
Everyone's different. "Normal" reaction time, for example, is approximately 0.75 seconds, but many people might be considerably faster or slower. Doing the test sober first establishes your norm as a point of comparison for your high self, which it can then use anytime.
Six random numbers appear, spin around, and slowly disappear: your job is to remember them. The test taps into your so-called "verbal working memory," a.k.a. the "phonological loop." It's the combination of verbal storage and a rehearsal system that your brain uses to remember the digit string. Changes in the brain that affect memory eventually affect driving ability.
You're asked to stand on one leg, raise your dominant foot a few inches off the ground, and stay steady - just like a roadside test (note: we found this tricky even while not under the influence.) It then detects any shaking or wavering that could affect skills like driving.
Reaction Time and Divided Attention
Different-colored buttons appear at random locations on the screen: you're asked to tap the correct color button as soon as it appears.
Unlike a test for normal, simple reaction time, My Canary takes into account the "perception-reaction time" - an important factor in crash-avoidance research.
Count out loud for 20 seconds, and the app tells you how close you are to the mark.
It's well-known that cannabinoids can alter your personal experience of time, making a few minutes feel like forever. Skewed time perception is a key marker of reduced overall performance.
After you're finished, My Canary scores your performance compared to your baseline. Obviously, most people know it when they're high, but after My Canary's battery of tests, you have some objective perspective on how, specifically, the stuff's treating you.
You can purchase My Canary (which isn't to be confused with the now-shuttered cannabis delivery service, Canary) for $4.99 in the Apple App Store.