My world is not your world

| February 8, 2020

We all feel that we know a lot about our immediate environment – what we hear, smell, feel and touch. We see the colours around us; or do we? So it is rather unsettling to discover this might all be a fabrication. Some researchers even contend that the live-stream movie in my head bears no resemblance whatsoever to reality.

We are aware that we can’t see ultraviolet light; we can’t sense the Earth’s magnetic field unlike turtles, worms and wolves: we are deaf to high and low pitch noises that other animals can hear; and have a relatively weak sense of smell.

On top of this, our brain presents us with only a snapshot. If our senses took in every detail, we would be overwhelmed. Did you notice the last time you blinked, or that fleshy protuberance called your nose that is always in your peripheral vision? Or the hole in your vision caused by the eye’s nerve fibres which take the data to your brain?

No, because your brain edits them out. A lot of what our senses are doing is something like data compression: simplifying, in order to be able to function.

In fact, most of what we “see” is an illusion. Our eyes aren’t all-seeing, but capture fleeting glimpses of the outside world between rapid movements called saccades. During these, we are effectively blind because the brain doesn’t process the information that comes in when they happen. If you doubt this, stare into your own eyes in a mirror, then rapidly flick your gaze from one side to the other and back again. Did you see your eyes move?

This is only the start of it. The brain, after all, is sealed in darkness and silence within the solid casing of the skull. It has no direct access to the outside world, and so relies on the information that reaches it via a few electrical cables from our sensory organs.

Our eyes pick up information about wavelengths of electromagnetic radiation, our ears detect vibrations of air particles and our noses and mouths detect volatile molecules that we experience as smells and flavours. Through complex processes we only partly understand, the brain integrates these independent inputs into a unified conscious awareness.

The question is, how well does this subjective internal picture represent objective reality?

The ear is quite a complex device. Sound waves are transmitted through the auditory meatus, causing the eardrum (tympanic membrane) to vibrate. These vibrations are transmitted through the three small bones (ossicles) of the middle ear to the inner ear. A duct connects the middle ear to the back of the throat, enabling the release of pressure that builds up in the middle ear.

The cochlea (a spiral organ of the inner ear- contains special cells that convert the sound vibrations into nerve, or electrical impulses which are transmitted to the hearing centres of the brain via the cochlear nerve.

Before the cochlear implant was created, a lot of research was carried out on the ear and hearing.  One of the experiments involved taking the electric signal generated by one patient’s ear and feeding it directly into the same area of a second patient. The result was garbage. The second patient’s brain could not interpret the signal. It soon became clear that an individual’s brain had to learn to adjust to our particular ears before it can interpret the signal correctly.

When we are born, our brain is overwhelmed with data from all our sense organs and has to learn to interpret the signals in a logical and meaningful way. I feel we can logically extrapolate this to our other sense organs, especially the eye, which is far more complex.

If we accept this hypothesis, then we have to assume that the world we sense is not the same as other people’s – my ‘red’ is not the same as yours; my interpretation of a scene is also different. This could explain why some people shudder when they see me in my quite acceptable shirt and tie (my wife being one).

To me, they form a pleasant colour combination. It could also explain why some artists can produce such wonderful pieces with such little effort. They simply sense the world differently to the rest of us.