Does the nature of nervous impulses give us a finite number of things we can perceive?

Question

This is a subject that is very disturbing to me and one that I've been obsessing over for years. I warn you now that this is probably not the sort of thing you get asked on this website and I'm not even sure if I'm explaining it very well but please bear with me.

I have, or at least used to have, a great passion for art and have always been a very creative person. But years ago I began obsessing over the idea there are only a finite number of possible images that we can perceive. And therefore everything I have ever created or will ever create is part of a predetermined, limited set of possibilities.

The amount of knowledge I have about how perception works is that when light hits a photoreceptor in the eye it fires electricity into its connecting nerve cell, this triggers the nerve cell to zap the next one and so on until it reaches the brain. The brain has a memory of where each chain of nerves is connected to and so it identifies that otherwise indistinguishable zap as coming from a particular photoreceptor in the eye. That each chain of nerve cells simply transmits it is on or off and nothing else. I worried that meant our perception works exactly like am LED screen, meaning that when light shines on the grid of photoreceptors, the image that gets sent to the brain is made of dots of exactly one solid colour and the only reason we don't notice it because the brain smooths the edges. This would mean that, if eyesight works like a digital camera there is a finite limit of things that we can possibly see because there is a finite number of images you can possibly create with a digital camera. I even found an article on the Internet that claim that's exactly how it works, they even have a diagram:

Eventually I found a way around it when it turned out that the eye is constantly making microscopic movements even when holding still.

But what about hearing? I know we have sensors in the form of hairs that trigger a nervous impulse to the brain when they are stimulated. But as I understand it, each one can only send that on/off binary signal when they are triggered by a very specific level of sound. What happens if there is a sound that is in between two hairs? Do you simply not here it? Is the same true for all the sensors we have?

I know that the brain processes a lot of what is sent. I know that there are things outside our range of perception such as ultrasonic and UV light. And I know we all have our personal reactions and even perceptions. But none of that matters to me.

What I want to know is, can our senses cover a continuous spectrum? Or, is everything we perceive a number of discrete and finite possibilities made up of digital, pixelated, quantised information? Can we only perceive image A and image B with nothing in between, or can we perceive image A.012744 and A.064212454 And A.24545157845?

Answer 1

I know we have sensors in the form of hairs that trigger a nervous impulse to the brain when they are stimulated. But as I understand it, each one can only send that on/off binary signal when they are triggered by a very specific level of sound.

Your overall question borders on philosophy and the biology of consciousness which is hardly understood at all. However, your picture of sensory input is a huge oversimplification. That's not really your fault, it's the sort of thing you are likely to pick up from pop science descriptions, which in turn are faulty because this is not a dead field where everything is understood to a T. Even the question of which parts of perception "are" digital and which "are" analog is still under investigation. However it makes your question hard to answer because it's sort of ill-posed since is assumes a purely digital model.

To address one oversimplification, our perceptions of the outside world are not necessarily binary on off bits. It is hypothesized that some neurons signal by changing the rate at which they fire. Is the rate continuously variable? It's not clear, but it certainly provides a much larger range of encodings than 1 and 0.

Can we only perceive image A and image B with nothing in between, or can we perceive image A.012744 and A.064212454 And A.24545157845?

I don't know how this meshes with your statement that 'And I know we all have our personal reactions and even perceptions'. If you've ever looked into color blindness then you already know that some of your fellow humans can't distinguish between A.012744 and A.064212454, even if you can. It's not that they can't see them, they just can't tell that they are different.