Did you ever run out of icebreakers at your last cocktail-party or watch get-together? I got you covered. Besides my passion for vintage wristwatches I'm actually fascinated by and educated in understanding the inner functions of the human brain. During my day job I'm a neuroscientist working on decision-making, attention and how these are affected by the interactions of distant brain regions. This will actually be my first attempt to bring these two worlds - watches & neuroscience - together. The essay will thus be less focused on vintage watches but more on some basics of brain functioning explained for the watch nerd. And this is not as esoteric or forced as it may sound at first because the brain is intrinsically very rhythmic and cognition (i.e. thought processes) can be well understood with horological terminology.

October 18, 2024

Watches of the Brain - How Internal Clocks Shape Our Perception of the World

    Marcus Siems @siemswatches
    Collector, Author, Data Analyst

---

 

You may or may not know that besides my passion for vintage wristwatches I'm actually fascinated by and educated in understanding the inner functions of the human brain. During my day job I'm a neuroscientist working on decision-making, attention and how these are affected by the interactions of distant brain regions.

And ... drum roll please ... this will be my first attempt to bring the horological- and the neuroscience world together. I think there can be quite a lot of synergy. I will thus try to cover some basics of brain functioning explained for the watch nerd. And this is not as esoteric or forced as it may sound at first because the brain is intrinsically very rhythmic and cognition (i.e. thought processes) can be well understood with horological terminology. And frankly, let's just have a bit of fun while learning something new!

 

The brain works analoguously to a system of several clocks. How that is possible or beneficial is what I'd like to show. Picture Courtesy of Freepik.

 

1) Brain Rhythms

Similar to wristwatches the story of 'brain clocks' starts already in the early 20th Century. Almost exactly 100 years ago in 1925 the German neurologist Hans Berger pioneered the Electroencephalography (EEG) technology. The EEG is common practice in hospital as well as neuro- and psychiatric practices all around the world today. In a nutshell, EEG can measure electric potentials on the head surface that are generated by neural activity: Increased activity of neurons leads to a depolarization - and signals 'go down'.

But apart from seemingly chaotic activity Berger also observed periods of synchronous neural activity displaying depolarization and repolarization in an orchestrated fashion - the very first, thus 'alpha', rhythm was identified:

 

Figure 1. (Left) Setup of a modern EEG cap with 64 ring electrodes. (Right) The illustration of the so-called Berger effect: When the eyes are closed a prominent rhythm at about 10Hz emerges over posterior (back of the head) electrodes. Data & Photo Courtesy of the University Medical Center Hamburg Eppendorf.

 

The so-called 'Berger effect' describes a well reproducible finding that whenever someone closes their eyes you will be able to see a stable and stereotypical activity pattern - a rhythm at roundabout 10 cycles per second - strongest in electrodes over the back of your head. And from personal experience I can tell you that this is the easiest signal to find and also the most reliable one. You'd need only two electrodes and it will be directly visible in virtually every healthy and awake human: Close your eyes and the alpha rhythm is there, open them and it's gone... every single time.

In other words, large assemblies of neurons in the back of our head work together pretty much as a stable clockwork at 36,000 Vph. This is our first full-circle-moment, this is how the brain can in some instances or for periods of time be understood as small watch movements with a hairspring, a gear-train, and a balance-wheel.

 

Who would have thought that the brain's most prominent rhythm is ticking at the same rate as vintage Hi-Beat calibers of Zenith and Grand Seiko. Photo Courtesy of Phillips.

 

These rhythms aren't random or rare either. Over the last 100 years and in particular since the 1990s ([here]) brain rhythms started to play a crucial role in how we can better understand brain function, cognition and the interactions between brain regions ([here] & [here]). And we've learnt that these rhythms are everywhere, with varying frequencies, and appear to be a versatile code to route information flexibly when needed in a certain task or for a chosen behavior ([here] & [here]).

 

2) Discretizing Time - How Brain Rhythms Shape Our Perception

Before we get too deep into all sorts of different mechanisms and cognitions let us resume with our 10Hz 'alpha' rhythm. Interestingly, even though we don't see the 10Hz oscillation as prominently when the eyes are open - because it gets intermixed with other rhythms - it still plays an important role in our visual perception ([here]). And particularly these alpha oscillations appear to also structure our experienced visual world:

 

Figure 2. Schematic discretization of our visual experience through oscillatory brain activity. If two brief flashes of light are fused into one (flash 1 & 2; orange frame) or perceived as two entities (flash 3 & 4; blue & green frames) appears to depend on their timing with respect to the brain's intrinsic activity. Schematic modified from Van Rullen (2016), Trends in Cognitive Sciences.

 

Our conscious experience might hereby work analogous to a movie-roll. If two images are shown in short succession we sometimes fuse them together and perceive it as one (like flash 1&2; orange frame) and sometimes we would perceive the two after one another (flash 3&4; blue & green frames)([here] & [here]). Importantly, whether one or the other scenario is experienced appears to depend on where the two flashes occur within the oscillation - in the same (fused) or different cycles (separate). One oscillation can thus be understood like one frame within a movie*.

 

2a) Discretized Time through Hand Motion

Now let's rephrase this with horological terms. An oscillation is pretty much a pendulum swing... and there is a pendulum within each mechanical watch, namely the balance wheel. The spring within the balance wheel is constantly elongated and constricted - back and forth. Even though the balance wheel is in perpetual motion, due to the lever escapement we only perceive motion of the hands at discrete points in time. Discretizing brain oscillations is thus (in spirit) the same as adding the lever escapement to the balance wheel!

 

Figure 3. Schematic discretization of our visual experience analogous to the inner workings of a watch movement. If two brief flashes of light are fused into one (flash 1&2; orange dial) or perceived as two entities (flash 3&4; blue & green dials) hereby depends on their timing with respect to the hand motion**.

 

Thus, just like in the brain, a watch movement digitalizes a constant stream of energy into discrete units. To come back to our two-flash example they would thus be fused into one flash (1&2) or perceived as two (3&4) depending on whether 'the hand moved' in between flashes.

 

3) Adaptive Timing - Brain Rhythms Adjusting to the Environment

However, there is one important difference between watches and brains: The rate/frequency is stable a watch caliber but adaptive for the biological system... For example brain rhythms can be rapidly modulated, interrupted and restarted - 'reset' - by internal thought processes ([here]) as well as brief changes in our environment ([here]):

 

Figure 4. Schematic of an eternal 'reset' of the neuronal oscillation as a response to changes in the environment. The 'reset' describes that however the activity (colored lines) was before the stimulus (light bulb & vertical dashed line) it switches into a stereotypical mode afterwards. Adapted and modified from Landau et al., 2015, Current Biology.

 

However, more subtly oscillations can also align with environmental conditions. For example the frequency adapts when a task is easy or very difficult. During a hard task you might need to sample information over more 'discrete units' so the frequency increases ([here]). This is compatible to changing the rate of your chronograph to be able to measure the time in smaller and smaller units gaining precision. On the other hand, when you would need to be very sure that a certain event occured the brain would integrate information over longer periods so the oscillation cycle length increases (thus, frequency decreases) ([here]). Similarly, the frequency of the rhythm adapts in predictable environments ([here]).

 

4) What to Make of All of This?

This is  very good question... Well, I hope that for your next cocktail party or watch get-together you can drop some random icebreakers on how the brain is like a more adaptive, more flexible, more biological watch movement. The tick-tick-tick of each hand motion is the perceivable output of energy constantly transmitting from the mainspring to the escapement. In the same way the constant stream of information from our environment is parsed into digestible segments in our brain and ultimately our conscious experience of the world.

 

'Watch in the Head' - an AI generated image. Courtesy DeepAI.

 

But beside those information - and I'm saying this with a broad smile - I'm really not sure what my target audience for this particular piece is***. I very much enjoyed writing it! ... But as nerdy as all of this appears, it is very much pure entertainment for probably 99.99999% of the potential readers out there. It is my 'look how cool all of this is' moment. And I'm very glad about this.

However, if there is an interested reader out there who gets something out of this beyond amassing superfluous knowledge I'm always more than happy to dive deeper into the issue. Until then: You can be proud of yourself because you've reached the END!

 

 

* Interestingly, this is also exactly how movies work: Frames - like the light bulbs 1&2 - come and go too quickly for our brain to perceive the transitions and the pictures become a smooth experience - a movie.

** I have to admit: to keep the illustration simple I changed the timing between escapement motion and oscillation. In watches the escapement moves twice per full oscillation, namely when the spring is relaxed (thus neither constricted nor elongated).

*** To my memoir ghostwriter: This may have been the exact moment I lost it...

 

  

Glossary

Cognition: General term for all higher/internal thought processes beyond early sensory input.

Frequency: How many oscillations you can fit into one second, displayed in Hertz (Hz = 1 / second). Multiply by 3,600 and you get to the horological unit of frequency Vph (vibrations per hour).

Neuron: A pyramid-shaped brain cell that is critical for the direct electro-chemical information transfer within the brain. They are the foundation of brain function.

Oscillation: One complete cycle of a up-down potential fluctuation. Analogously, you can think of a full pendulum swing from left to right to left.

Rhythm: Ongoing oscillatory activity at a relatively stable frequency.

 

All rights on text and graphics reserved to the Author.