My problem with the Mendi neurofeedback device

It's been a bit more than two months since I started using the Mendi neurofeedback device that I ordered via a Kickstarter campaign.

I started off enthusiastic about my Mendi, as discussed in my July 26 blog post, "I'm enjoying my Mendi neurofeedback device."

I've only been using the Mendi for a short time and need to do more exploring with it. This is my initial impression of what works best to get the ball moving upward.

My first try with the Mendi produced a pretty good score. I think this was because I simply focused on the ball and didn't try to make the ball go up.

The next few Mendi sessions didn't go so well, probably because I was trying to get a better score. From what I can tell so far -- and my experience likely is different from other Mendi users -- trying isn't the best way to train the brain.

Not trying is. 

Well, after a lot more experience with my Mendi, I'm much less enthused about the device. The main reason why was pointed to in my first blog post when I said that after I did well with the Mendi, the next few sessions didn't go so well.

For quite a while I thought the problem was with me, not the device.

But now I lean strongly to the position that the Mendi hardware, the software, or both isn't capable of reliably providing feedback on how well a user is concentrating on the single task currently available with the smart phone app: making a ball rise.

I've been meditating every day for over fifty years, often for an hour or two.

I'm a strong advocate of mindfulness, my current approach to meditation. So I'm confident that I can tell the difference between a frenzied scattered mind and a calm concentrated mind. 

Yet the scores I get with the Mendi device have little or nothing to do with my ability to focus on the ball. There's simply no evident connection between my state of mind and how much the ball moves upward, which supposedly is a reflection of oxygenated blood flow and neural activity.

The folks who designed and sell the Mendi device also seem to have a haphazard way of describing what a user is supposed to do during their sessions.

My iPhone app tells me to relax and focus on the ball. But I've also seen the advice to concentrate on trying to make the ball go upward, which is quite different from simply focusing on the ball. And other advice is to think about a mental issue you're working on, like anxiety about something.

My suspicion is that the reason there are so many different ways of describing how someone is supposed to use their Mendi device is that there's no consistent way of making the ball go up. Meaning, the device basically is giving random results, not genuine neurofeedback about someone's state of mind or ability to concentrate. 

As noted in my first blog post, I get better scores in a dark room than in the room I meditate each morning in -- which has a window facing west with a white shade that I pull down. So even though sun isn't coming through the window, even diffuse light appears to lead to a lower Mendi score.

Thus the combination of not getting results that match up with my feeling relaxed and concentrated and the sensitivity of the Mendi device to how bright a room is, possibly along with other external factors (like where on the forehead the device is worn) has caused me to stop using the device on a regular basis.

I figure that simply meditating is a better use of my time than getting scores from the device that, so far as I can tell, don't mean anything. Reportedly a software/app update is coming that might deal with my concerns, so I'll keep an open mind about the device.

I was moved to write this follow-up blog post about the Mendi device after reading a Facebook post from a user who has a similar attitude to mine. Since you have to be a member of the private Facebook group to read the posts, I'll copy in what Sami Zegnani had to say.

After several months of practice, I notice that my progress is extremely low. I have managed to make 37% increase but this is because the procedure consists of meditating during the Calibration and then I pick up the phone and inevitably my head falls and this causes an increase in blood flow in the brain. Otherwise nothing works.

 

My background is that in the middle of meditation, I reach a HRV easily exceeding 70 ms, sometimes I reach 100 ms which shows that my blood flow can be very high... On other neurofeedback devices, either on muse or on myndlift I am one of the most experienced. My scores are very good. I have thousands of hours of vipassana meditation. So I have a serious problem with this device.

 

Not only do I not progress despite regular and consistent practice, but I don't feel any well being after a session, sometimes I have a little headache! I mean I can understand that I have a low score, I started meditation 13 years ago and I had no concentration. I made 10 retreats..

 

But what I do know is that in just a few short weeks, the progress in meditation has been felt. I have no problem with having to learn. I recently started Wim Hof and I saw the benefits even though I was a novice. But with mendi, nothing, nothing nothing.

 

I wanted to wait before saying anything but now that several weeks have passed, I have a huge doubt about the device and its measurement. I'm really sorry to have to say this because I would have liked to say something good about this device. If this post can reassure people who are practicing and who think that maybe they are the problem. No, it's not necessarily you.

Comments

[David Tenser]

Hi Brian,

This is David from Team Mendi. First of all, I want to thank you for being a Mendi user and for taking the time to share your experiences and thoughts about the device.

I can assure you that Mendi’s measurement of your blood oxygenation in your PFC isn’t random. Our device has been validated by researchers to outperform hardware devices costing $20K+. Mendi is bringing this advanced technology into a consumer-grade hardware device for the first time and we have made significant improvements to the overall design to accommodate this.

You are right in that, just like with fNIRS-based lab equipment, Mendi is sensitive to external light sources. During research and in neurofeedback clinics, they often put layers of “bandage” around their headsets to shield it from external light.

We currently recommend users to practice in a dimly lit or dark room to increase the ability for the device to read your blood flow correctly, simply because this will make it easier for you to learn how to control the movement of the ball. It’s also important not to move around too much, particularly your eyebrows, which are very close to the Mendi device and can therefore accidentally move the device and confuse it.

The good news is that we are hard at work to fix this, and I’m extremely excited about the new signal processing algorithm that the team has been developing. The next release that we’re scheduling in the next month has a 40% quicker response from detected PFC activity to the movement of the ball on the screen, as well as making it work well with a wider range of bright conditions (including certain LED lights) that can otherwise interfere with the signal.

And that’s just the starting point. Over the next several months, we’ll be rolling out a number of important enhancements to further strengthen the environmental resilience of Mendi, as in, its ability to handle scenarios that have traditionally been well outside of scope for high-tech fNIRS-based neurofeedback training, such as the ability to use it in a brightly lit room, outdoors, or even when moving around.

We’re very humbled by the fact that users are reporting life-changing results from consistent training with Mendi - but we are not surprised, because we know from existing science that the brain is becoming healthier with each session as your neural pathways are strengthened.

We’re also excited to release the next phase of Mendi, which will combine goal-based neurofeedback brain training with behavioural science. This is what we call the Mendi Brain Health model, which is rooted in the most recent neuroscience as a product of our collaboration with top scientists. It’s something that has never been done before.

At the same time, this doesn’t distract us from the important work to ship the best neurofeedback-based brain training product on the market, including all the improvements I mentioned above - but we believe that the introduction of Mendi’s full brain health model will shift the focus a little bit from the in-game session scores to the long-term improvements we’re making on your brain health.

Again, thank you for being a Mendi user and for your candid feedback about your journey with it so far!

[Brooks Barton]

Hello - Hoping someone can give me some insight into the implications of the article to which I have attached a link below. My question is simply this: can the Mendi device make anxiety worse? It seems in some cases it’s an overactivity of the prefrontal cortex that causes certain anxiety orders, at least in part, whereas in other anxiety disorders it could be an under activity of the prefrontal cortex. Is it more accurate to say Mendi balances out the prefrontal cortex or does it always stimulate it?

https://pubmed.ncbi.nlm.nih.gov/18019606/

[Anonymous]

I am feeling nothing and nothing and nothing with mendi so farm I used my lift and felt so much better I don't associate myself to myndliftm mendinhas been very disappointing I don't see a clear instruction on how t use it. The comments and review from you and the member from Facebook iare similar with my experience. I feel very frustrated with mensibright now

[Zoey]

I honestly think mendi needs to provide us more connections to understand how we can empower ourselves to increase the score. Like a game, it would be pointless if we didn't understand the mechanics of the game controls and rules. Mendi just tells us the rules. Yet the game's measurement is odd to me. What do the stars mean( is that blood flow?) Is the rise and fall loss of concentration? Cause I can get it to rise without stars) if the users don't understand inner correlation to the game its just not as powerful as I would've hoped.

How is resilience being measured? Brain activity? How is thay reflected in the game?

I mean otherwise I rather just Meditate and exercise than to Stare at a screen for 10-15 minutes.

[Jim Nowak]

Hi. I'd like to jump into this conversation about the Mendi as I find it a fascinating subject; there are many things I like about the experience, including such things as the packaging, the design, and the simplicity. Also the helpfulness of the company is much appreciated. As for results, I would characterize them as somewhat sporadic (after about two months of twice-daily ten minutes sessions) One complication I have with using the Mendi is that I generally become drowsy and find myself fighting to stay awake. I don't think of this as being focused, though the relaxation is helpful. There are times - with eyes closed - where I can zone into the sound of the bell, at the same time passively concentrating on my abdominal area. This odd combination produces a wonderful meditative feeling. Over time, I think training to focus on creating this feeling would be very beneficial. It also can then be done with eyes open but slightly unfocused, in a sort of sahaja samadhi ope-eyed meditation. Lastly, I would tend to agree with others who question the accuracy of the measurements, as the feedback that I get from the markers used seem capricious and might even distract from the actual benefit that I see possible from the use of a Mendi. I hope that others might find some of these ramblings helpful in some way - in general I think we are all on an upward trajectory. I wish everyone the best of luck.

[Dee]

Wow - thank you for sharing this.

I almost bought this device to save money on expensive neurofeedback in-office treatments with IASIS MCN, but would rather not waste my money or time on Mendi and would prefer to use something that actually works for anxiety, adhd, depression and other symptoms.

[D]

Bull crap this a scam

[Jim]

Over this amount of time with this Mendi devices having sold 10’s of thousands.
As a potential buyer I would of thought I would have seen a lot more negative or responses in general on this blog. I’m still not sold on ordering but I’m not thinking it’s a total scam either. Adding improvements to the Mendi without labeling it an upgrade makes me feel like no improvements were ever made.
At least give 3 or more games for the entertainment value!

[Ami Richardson]

After owning the Mendi for over a year, I tend to agree with you. Simply put, in my experience, the Mendi device and brain training game/program is a disappointing product set with such limited value (if any) that it is no better than snake oil. I notice a company rep responded to this post almost two years ago, and in that time, little has changed about the way the device or OS operates. They do seem to have recruited a popular YouTube “doctor” to give them glowing reviews and robustly refute any dissenters. I must admit, his videos are what convinced me to give the headband a try, and I’m now disappointed as you were.

Like you, I much prefer the Muse device for meditation and breathing exercises, and while I did try Myndlift for 8 months to limited results, TMS has been the only treatment that I’ve found to truly treat my anxiety, depression and PTSD with any degree of efficacy, such that my ADHD medication (along with 15mg methyfolate, SAM-E, high doses of EPA, and NAC Ethyl Ester, for full transparency) is now working robustly and I no longer feel my brain is working against me.

Good luck to everyone out there looking for solutions. Maybe Mendi will work for you, but I highly doubt it. There are so many better solutions out there, so I’d encourage you not to settle for this one.

[Miguel Marcos Martinez]

I’m curious what the consensus is with Mendi at this point in time. The device has proven resilient in the market. Cody Rall reviews recent research that supports positive results with Mendi in this video from March 2024. Rall notes that the biggest improvements are to be seen from people who have diagnosed issues. This makes sense to me. I meditate as well and I would not expect a great improvement to my years of meditation from this or any other device or drug. I also want my meditation practice itself to be the source of greater self-awareness and compassion. I am more interested in seeing how it assists in greater concentration and focus. I wonder if anyone has observations on this.

Here’s Rall’s video: https://youtu.be/JJCoinnzbgc