Zentrela Cognalyzer

Zentrela’s Cognalyzer – Brain Scanning Technology to Detect Cannabis Impairment

There is an issue with cannabis impairment. Enforcement agencies want to restrict cannabis from being used behind the wheel, but doing so has led medical cannabis patients into court battles to fight for their freedom. Zentrela hopes their Cognalyzer will fix false positives by scanning your brain but does their EEG-based device account for those medical cannabis patients?

Detecting cannabis on the roadside

Currently, a police officer’s ability to test a driver’s cognition and level of impairment by cannabis use is entirely subjective. Otherwise, they must rely on poor saliva and blood samples that do not analyze actual cannabis use. Zentrela’s overall goal is to implement neurotechnology in workplaces as well as during cannabis impaired driving investigations.

They plan on delivering a compliment to the Oral Fluid tests for law enforcers or even employers, rather than a replacement to their preexisting results. Basically, a cop is not going to scan anyone’s brain on the side of the road. The Zentrela’s Cognalyzer intended use for the roadside is in the station after an arrest for failing an initial oral fluid (or standard field sobriety test) to ensure no false positives.

We are basically proposing that the most objective and accurate way of determining if an employee or a driver is high is by detecting recent cannabis use with a saliva test and then comparing that result with our brainwave test. To see if that subject is still feeling the psychoactive effects, in other words, if that person is high or not.

Israel Gasperin CEO of Zentrela
Israel Gasperin, CEO and Founder of Zentrela.

Is the brainwave test within spitting distance?

The test is supposed to help differentiate between a positive saliva test based on a person’s cognition versus if the person only has a detectable amount of THC from the consumption of cannabis several hours or days ago. Zentrela published a peer-reviewed study in Advances in Therapy detailing the use of this technology. (1) However, for reasons beyond their control, they did not include chronic users (both medical and just heavier consumers) in the study. There are also a few other variables worth noting.

The efficiency of the Zentrela’s Cognalyzer and oral fluid tests vary at different cutoff levels. Justice Canada uses a 25 ng/ml limit for oral fluid to reduce the chance for false positives. At this cutoff limit, oral fluid on its own produces false positives nearly half of the time. Whereas, both tests combined produced a false-positive result 14.6% of the time four hours after cannabis use.

Zentrela’s Chief Communication Officer, Roy Agostino, did detail the commercial viability of the Cognalyzer and its preparedness for law enforcement and workplaces, noting a need for the jurisdiction’s approval.

Given optimal conditions, the study’s results are positive. To ensure those results, however, it seems that Israel hopes for jurisdictions to mesh new regulations with their technological interface.

The last laboratory-based analysis that the CRO [contract research association] used was a 2 ng/ml cutoff. This study is the first of many additional research [projects] that can let regulators or policymakers [clearly decide] on the cutoff level for saliva tests and the new cutoff level from our brain wave analysis.


The time it takes to evaluate a user’s level of impairment during a saliva test has been a sensitive topic for our resident roadside lawyer, Sarah Leamon.

I wondered if they could improve the two-and-a-half-minute collection period used in their study. Zentrela’s CSO, Dr. Dan Bosnyak chimed in for this answer.

We have been experimenting with different collection periods. Two-and-a-half minutes is something we picked arbitrarily. But, we experimented with the algorithm at shorter periods, even one minute. We need 25-second segments to [decide], but they have to be good segments …we could certainly work towards is reducing that time.

Dr. Bosnyak

An issue with ethics more than cannabis cravings

Zentrela focused on regular users in this first study, excluding one medical patient. Israel noted the reason for excluding new cannabis consumers was a problem with certain negative side effects that new users can deal with after consuming THC.

One of the reasons we weren’t looking at chronic users is because the ethics review board didn’t want us to test potential cannabis use disorder. It’s kind of silly in a way because they are going to be using cannabis anyway … So, we eliminated people that smoke too much to meet that ethical guide. 

Dr. Bosynak
Dr. Dan Bosnyak researching for cannabis impairment testing
Dr. Dan Bosnyak

Zentrela’s study required participants to refrain from using cannabis for 48 hours. When asked if any limitations could have been created from the abstinence period due to potential withdrawal symptoms, Dr. Bosnyak had a different response.

We didn’t use chronic users, more or less, deliberately.

Dr. Bosnyak

Chronic use and the cerebellum — the Cognalyzer’s biggest hurdle

Consistent cannabis use can cause the brain and the endocannabinoid system to adapt to larger doses of cannabinoids, especially THC. Chronic cannabis users and medical patients will become used to THC over time, experiencing less loss of equilibrium than occasional consumers. (2)

But, do these temporary changes cause a problem with the brain scan?

We don’t have an answer — yet. Zentrela works with chronic users for our model of measuring psychoactive effects in the lab. We actually have a calibration procedure that allows us to take the known unimpaired user and then calculate the algorithm according to that. That obviously doesn’t work for law enforcement procedures where you have a pre-cannabis consumption standard.

It’s probably the case that we could create a classifier that essentially detects if a person is a chronic user or not. And then, apply a different algorithm if they appear to fit a different pattern of chronic users. I think that would be a good direction.

But, you’re quite correct that chronic users are the significant issue in driving impairment.

Dr. Bosnyak

Are two tests better than one?

I wanted to know if certain people can be naturally high. Dr. Bosnyak agreed that it is possible and another reason why their brainwave test relies on complimenting a serological sample. On its own, the EEG is less reliable.

Our test is not defintive because it still does produce 15 percent false positives. There’s definitely people in the absence of any recent cannabis use that test positive.

For whatever reason, the results of our test are significantly [more] independent than the results of the saliva test — to some extent at least. By combing the two together in conjunction, you decrease the likelihood of a false positive significantly. That is what we showed in our publication.

Dr. Bosynak
brain scan cannabis impairment

Are they ready to scan your brain?

So, it appears Zentrela’s Cognalyzer will work well for situations that require zero tolerance cut-offs and to ensure false positives do not occur. For example, recently an employee in New Jersey was fired after being forced to commit to a serological drug test, which inevitably showed THC in his system from use during his personal time. (3) Meanwhile, Amazon announced that it will stop testing US employees for cannabis use. (4)

Beyond workplaces, neurotechnology interfaces might find better roles with research than the roadside. Perhaps, one day we can prove cannabis impairment is no more severe than stress, and we can do away with impairment detection at the roadside given good scientific evidence. (5, 6)

A headset for cannabis research

Different strains of cannabis produce different effects, and different terpenes produce a hypothetical entourage effect. But, this effect is just a theory and not based on objective data for the consumer. Zentrela hopes their neurotechnology technology can add data to help consumers learn what type of psychoactive effects each cannabis product can create for them.

Israel suspects that Health Canada hasn’t been allowing compliance attributes due to limited scientific and clinical data on different cannabis products.

It is well known that nano-emulsification technology used in THC beverages or edibles may impact the potency … It is a bit inaccurate and misleading for consumers to select a cannabis product based on THC potency.


End of phone call.

Let us know in the comments if you feel brain scans are more or less invasive than blood tests. Do you think cannabis impairment detection by Zentrela’s cognalyzer is viable or is stress a far worse outcome on the roadside?


  1. McDonald, A.C., Gasperin Haaz, I., Qi, W. et al. Sensitivity, Specificity and Accuracy of a Novel EEG-Based Objective Test, the Cognalyzer®, in Detecting Cannabis Psychoactive Effects. Adv Ther 38, 2513–2531 (2021). https://doi.org/10.1007/s12325-021-01718-6
  2. Stella N. (2013). Chronic THC intake modifies fundamental cerebellar functions. The Journal of clinical investigation123(8), 3208–3210. https://doi.org/10.1172/JCI70226
  3. Amanada Hoover. June, 2021. N.J. medical marijuana patient fired for using cannabis in his free time, lawsuit claims. NJ.
  4. Dave Clark. June 2021. Update on our vision to be Earth’s Best Employer and Earth’s Safest Place to Work. Amazon.
  5. Hostiuc, S., Moldoveanu, A., Negoi, I., & Drima, E. (2018). The Association of Unfavorable Traffic Events and Cannabis Usage: A Meta-Analysis. Frontiers in pharmacology9, 99. https://doi.org/10.3389/fphar.2018.00099
  6. Hostiuc, S., Moldoveanu, A., Negoi, I., & Drima, E. (2018). The Association of Unfavorable Traffic Events and Cannabis Usage: A Meta-Analysis. Frontiers in pharmacology9, 99. https://doi.org/10.3389/fphar.2018.00099