Hey everyone!

Apologies for last week, had a wedding and was completely tired! But amazing time nevertheless!

So in the last issue, I created a little game with my on-call bleeps to see if you might just have perfect pitch, which I highly highly recommend you attempt it before reading this issue.

Click here to play.

If you’ve already completed the game, we’re now gonna talk about the perception of music and how it relates to perfect pitch.

I’ve been reading This is Your Brain on Music by Daniel Levitin, who is a cognitive neuroscientist at McGill University, and is the Director of the Laboratory for Music Perception, Cognition, and Expertise.

I know, pretty exciting stuff he does!

In the book, he illustrates the journey to how music is being perceived.

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The Perception of Music

It starts off with a piece of music that needs to decomposed into its essential components, and it’s through a process called feature extraction.

The features of the music include the rhythm, timbre, timing, and of course the pitch.

Feature extraction is part of bottom-up processing, where the interpretation is based off the essential components to give a whole picture.

This is the lower-level processing moving up to higher-level processing.

This is where the computing of the brain kicks in, and groups these features together.

In terms of pitch, in a nutshell, it uses the unconscious knowledge of sound frequencies to determine the pitch it is exhibiting.

Once the computation is complete, the processing takes a level up to perform calculations on what it interprets the pitch to be, and it uses prior knowledge to calculate.

This is now top-down processing, where the interpretation is based off prior knowledge.

Both bottom-up and top-down processing takes place in this perception experiment, and they inform each other what the next neural action to be.

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The Illusion of Music

It sounds shocking I know, even I felt the same when I read further, but Levitin makes the point that music is a sensory illusion of how brains interpret sounds.

But that doesn’t means it’s bad, no way at all.

It’s just one step further into how brains work and what we can do when things are not what they seem to be.

Look at this image:

You can see an appearance of a white triangle covering the black one.

If you are asked how many triangles are there, you might consider at least the white triangle, and maybe the black triangle “behind” it.

But if we take a step back, we can see there are actually no triangles.

Now look at this image:

But it turns out they’re both the same length.

These two sensory illusions make a fact-check on our top-down processing, showing how easily it can misperceive, and give the wrong conclusion.

And the striking thing is that no matter how many times we see these illusions again, our brains will continue to misinform us.

But like I said, there’s nothing wrong and we shouldn’t be ashamed about falling into these illusions. It’s going to take a lot of work to prime our brains to not be misinformed.

As well as cognitive biases, it is all due to one important thing…

The brain creates structure and order.

From using the perceptual processes we just talked about, it tries to find the signal from the noise. But at times it can get misinformed.

The same thing goes with music.

With the amount of sounds coming in with different pitches, rhythms, timbres, etc, the brains imposes structure to them and finds patterns in these to make groups.

And eventually make the perception of music itself, and then comes the emotions that come out from it.

Wow, that was quite a deep topic, and from this you might be thinking from this:

“Is this the real life? Is this just fantasy?”

But I think this will turn it into more philosophy than neuroscience!

Have a great week all!

Mark x

Content

​Top-Down and Bottom-Up Processing - you might want to check out this video where I go in depth about the significance of each processing.

​How to Think Like Google - this video looks into the frameworks behind Google and how we can use it for own personal development.

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