Way back in the 1970s there was an EEG device called the Mind Mirror, which was a spectral display of the brain activity of the two sides of the user’s brain. This was in a world without desktop computers and smartphones, no DSP, and used analogue electronics to get the display of 14 frequency sub-bands in rows of 16 LEDs. Designed by Geoff Blundell in association with Max Cade, this was used to look at the brainwaves of people in meditative states.
If you’re a materialist rationalist, you may as well stop reading now because there’s a fair amount of woo-woo in this. I personally like the combination of tech and woo-woo, but each to their own 🙂 The area of biofeedback has a lot of fantastic claims, but ranges from the sinple use of relaxation tapes through all sorts of werd and wonderful ideas of changing consciousness by feeding back signals from the body.
Although the development of the Mind Mirror was largely empirical, the studies leading to it’s development did at least use many subjects and try and control many of the variables.
In the 1970s Max Cade was studying biofeedback using skin resistance, then in 1973 using a single channel EEG, with a single channel display where the filters were switchable to present a choice of frequency bands, one at a time. He ran this with a bunch of people chosen for experience with meditation, the long-form description is in the book “The Awakened Mind” by Nona Coxhead. Basically they observed similarities in the mix of brain activity between different people in similar states of consciousness.
The trouble with using an EEG is that it’s like trying to get information about a crowd by recording the amplitude of the sound picked up a distance away, but since there’s no mind-jack in the side of people’s heads it’s the best to be had. Nowadays you can get spatial detail of what’s going on in the brain using fMRI but this is still a macro observation, in that case of changes in blood flow as a result of brain activity. The EEG is picking up the electrical signals from the brain, but averaged over many neurons.
There was also a more specific book on the Mind Mirror called The Meaning of EEG by Geoff Blundell which I gather was the instruction manual, but there’s not much on that to be found, apart from a cover picture.
Why the Mind Mirror – forty years of better tech has overtaken it surely?
Getting an EEG is a lot easier now. Get yourself onto OpenBCI and you’ll have no end of fascinating stuff to play with, or review some more approaches here. Looks to me like the tech has been sorted.
But at the end of the day, it’s all just sensor data. We are taking the faint signals averaged across a load of wetware and insulating material and displaying them on the screen. Woo-hoo, but so what? It’s all just numbers on a screen, there is no meaning to it. What Cade and Blundell did was actually trial their machine on real people –
Maxwell Cade and Geoff Blundell calibrated the first prototype Mind Mirrors on people with known advanced training in mind states and were able to bridge the gap between internal descriptions and measurable EEG states on the brain.
The limitations of their hardware led them to focus on two channels, near the occipital lobe, and they experimented to try and get some reproducibility and correlation with different states of consciousness/relaxation/meditation. It’s this part of the puzzle that’s missing from the geeky big data stuff out there, and without that it’s just data, not information. As lifehacker says
Of course, self-awareness is a big part of both therapy and philosophy. It’s also the basis of the quantified self movement , which assumes that if you collect data about yourself you can make improvements based on that data.
The trouble with quantification is that data is not knowledge and knowledge is not wisdom. Where Cade and Blundell scored versus a lot of quantified self data is they looked at the quantified data across many people, trying to correlate it with characteristics of self-awareness, or at least chilled-outness.
The advantages of the Mind Mirror is partly due to the simplicity of the rig, picking up signals from two channels and displaying them. It meant that the machine was portable, but it also makes correlation of the display with other people’s states of mind a lot easier than trying to parse the welter of data from, say, a 16 channel EEG display. The value of the Mind Mirror to my eyes is the combination of work of Cade and his successors with this particular methodology and filter bank, and the fact that it isn’t limited to a particular place.
Reverse engineering the Mind Mirror
There’s a lot of good information about the machine on Mind Mirror EEG.
Mind Mirror EEG are good enough to give us the filter frequency specifications indirectly, and more directly here.
I converted these to a staggered tuned second order bandpass filter and simulated this.
And you can immediately see that they adjusted the centre frequencies unevenly, presumably to get more resolution in the alpha and beta wave regions. This is a log frequency display, and the obvious way is to spread the channels evenly keeping a constant fractional bandwidth.
Now the obvious way to do this nowadays is with a PC and a FFT, and you can buy a Mind Mirror from Vilistius that’s probably how the latest incarnation of this works. But it is £1.5k, and it uses a computer for the display, which is not a thing of beauty.
I don’t find computers and smartphones conducive to relaxation and meditation. They are good at what they do, but relaxation not one of them. Whereas the original Mind Mirror was self-contained and used LEDs for a display.
In the next part I will look at what can be gleaned about the Mind Mirror hardware.
Hello,
I was a close friend of Geoff’s and worked alongside him for many years inheriting a number of his biofeedback machines and a couple of therapeutic strobes. I have continued our work using some biofeedback instruments in my own work.
Thank you for your blog . It’s wonderful seeing this work discussed.
That’s fascinating, can you tell me any more about the status of this work?
Dear Richard,
I can tell you, that your take on the subject is that of Geoffs, I have the green book above , which does give more insight into Geoffs design and purpose for EEG biofeedback research. More a self modulating device and no , not much ..woo-woo
Naturally. Having said this, it is based on subjects monitored of which there were many hundreds by the 1980’s , a part of medical enquiry. The information which could be seen as two Hemispheres for the first time with the mind mirror, made clear that something is happening with our brains when we attempt to meditate or in some research heal. A very striking discovery was that healers and those being healed , when monitored simultaneously showed the same brain patterns.. they literally were mind mirroring.
Lastly many of the points you raised re.. data, numbers, computers being non conducive to relaxation are why we began working in other areas to find ways of creating a fuller self awareness focussing less on the individual but self awareness within group settings.
The research has led onto gamma measurements, contributing to MRI improvements in brain research. Treatment research based on biofeedback for PTSD amongst other conditions. Even used for military training by the Americans. Importantly Geoff was a one of kind person, who’s few and far between ( mentally and geographically) peers shared their interest in research at the very edge of the horizon. He was as likely to hire a poet at his company Audio Ltd as he knew the person s creativity could be guided, as an engineer, and never lost sight of wages or bills. He was a great friend, and I am told I knew him better than anyone by those who were close to him. It was a privilege to know and work with him and to inherit from him.
I continue to find ways to take our work forward, via the scientific and medical network, a project currently receiving funding from the George Blaker education trust called Wider Horizons and in my own personal work. I have a special interest in biofeedback research and Dr Iain McGilchrists writings and research. It appears that it can take a while for experimental electrical engineering to find its way into the mainstream
consciousness.
Athena Constantine Constantinou
( I note you are in Suffolk, I myself was a resident in Melton Woodbridge for 6-7yrs , wonderful part of England )
Dear Athena
Where/how can I learn more about your ongoing applied research?
Much love and gratitude to you both for taking this forward!
Has this project got any further? I was one of Max Cade’s subjects, working with him in biofeedback classes in the Franklin School. Now that I have retired and can afford a Mind Mirror (but not the Vilistus(?) one!), I’d like to work on his methods again.
It was somewhat kiboshed when I acquired an early Mind Mirror which I repaired. Having said that I haven’t taken it further than the engineering repair because the electrode stuff is still messy 😉
I attended one of Vilistus’ free seminars in Birmingham (UK) and their device seemed to work fine. A cheaper option is OpenEEG which you can buy from Olimex, and run that. It’s referenced in this post. Although I groused about the Olimex filter it’s probably OK if you don’t have too much mains pickup.
EEGMir does have a mind mirror mode that mimics the analogue filters of the Mind Mirror (rather than using a FFT, which is sub-optimal according to the Mind Mirror designers. They could be talking their book, though I find the comments on the weakness of the FFT for replicating Cade’s work reasonably coherent from an engineering viewpoint. I did manage to make EEGMir run on a Raspberry Pi
If you’re in the US, Judith Pennington runs a lot of stuff based on the Mind Mirror and the legacy of Max Cade’s work. I am intrigued by your experience of working with Max Cade. A lot of the modern quantified self stuff is pretty sterile IMO – Max Cade’s edge was in collecting results from people who were demonstrably good at meditation and altered states and it appears helping normal people go in that direction using biofeedback.
I find Cade’s approach more to my taste but so much of the information from that work seems to have been lost.
Hi
I have both an original MM (not working) and the Vilistus equipment, I’m also a Neurophysiologist so have significant knowledge of the EEG.
Any discussion would be welcome.
I have the villistus system – and have studied Max’s work, I’d love to hear more of your experineces
Hi
I have both an original MM (not working) and the Vilistus equipment, I’m also a Neurophysiologist so have significant knowledge of the EEG.
Any discussion would be welcome.
I don’t recall more than fragmentary memories of my time in Max’s biofeedback classes at the Franklin School. A. Most of the EEG work we did was with single channel EEG machines (made, I believe, somewhere near Ravenscourt Park tube station, as I went there to pick mine up … which I stupidly threw away some years later, when it stopped working). B. In some of the “advanced” classes, where everyone in the group was able to maintain high-amplitude theta states, Max would read a haiku at the end of the class and ask us to come back the following week with something we had created, triggered by the poem. (I still have some of the drawings and paintings that I did.) We were able to walk around the room, carrying our EEGs, maintaining the high-theta state. C. I remember in one class, Max had a visitor who had asked to check our auras while we were sitting; she would put her hands under our feet to do this. I had been going to a ritual magic class in the School, and asked if I could try an experiment; I carried out the Middle Pillar exercise, which involves flows going in different directions around the body … she could feel each change, and its direction. C. I don’t remember much about using the Mind Mirrors, although I do remember them being demonstrated. D. With regard to temperature control (Max did use skin resistance meters and electronic thermometers in the classes), I only found out recently a little more about what he had been doing: in “The Awakening Mind” (1996 paperback reprint, paragraph 2, page 149), the authors mention a subject that’s almost certainly me, “Peter Y”, as being involved in a supposed telepathy and temperature modification experiment. D. In the first or second “Mind, Body and Spirit” exhibition (I think it was at Earl’s Court), there was a presentation about Max’s work, including a video of one of his Franklin School classes … I’m there! E. I remember Isabel being at most of the classes; a very comfortable lady.
I’ve always regretted that the Franklin School closed after about three years. I’d have loved to continue my classes there. Why, on earth, does the mind-work of those times seem to have died out? Only recently I went to a presentation of sound and strobing lights which seem to have been presented as a wonderful new thing, which simply replicates in an arena setting what the Mind Lab of the seventies did for an individual (I’ve just dug my Mind Lab out of storage and am going to see if it’s still working … they’re not available nowadays, either, like the original Mind Mirror.)