‘The task is not so much to see what no
one has yet seen; but to think what nobody has yet thought, about which
everybody has seen.
ERWIN SCHRODINGER
Let me start with colour of a rose because that is where this whole
thought process started.
It is now clear that colour of a rose, or for that matter any
object, is an experience created in our minds. Objects don’t have colour. The
proverbial red rose is colourless. Let us see why.
When we look at a non-luminous object, electromagnetic waves (EM)
reflect from its outer surface and gets into our eyes, falling on our retinas.
From the retinas, electrical impulses shoot through our optic nerves and
reaches the occipital lobes of our brains where the experience of vision is
created. Exactly how our brain creates the experience of vision is still not
clear, though neuroscience research has reached the stage where one can start
mapping this experience to the triggering of specific sets of neurons in our
brains[1].
Thus, seeing an object is nothing more than triggering of specific
neurons inside our brains, initiated by the interactions between the EM waves
and our eyes.
Our brain has been designed through the evolutionary process to
focus only on how our bodies interact with external objects (for vision,
it is interaction with EM waves). It is not designed to understand the reality
of those external objects. It makes more survival sense to know how big and far
away an object is from us than to know the number of molecules it is made up
off. It is this relentless focus on the quality of our interactions with
external objects that has helped us navigate in this world and survive as a
species.
Our brain is thus programmed to identify different types of
interactions that our bodies have with external objects. It stores these
interactions in the form of experiences, which are nothing but codes that the
brain creates to identify these interactions. All sensory experiences are
essentially codes that the brain creates and stores in memory for future
reference.
Continuing with our example of the experience of vision, during
vision our brain creates and stores code for broadly two types of information
associated with the EM wave 1) frequency of the EM wave 2) relative distance
between the point of reflection and our eyes
Notes
Frequency of the EM wave reaching our eyes is associated with the
sensation of colour. Our brain has distinct colour codes (e.g. RED colour) for
the visible spectrum of the EM Waves. Thus, colour is a code that our brain
associates with the frequency of the EM wave reaching our eyes and since the EM
wave originates from a point on the surface of an object, our brain associates
that point on the object with this EM wave and its colour code. This is how we
experience the colour of an object[2].
Since the EM waves have very small wavelengths, compared to the
external objects, our brain can resolve small differences in distance between
different points on the surface of the objects being viewed from our eyes. It
allows the brain to create a view of the shape of the object and its relative
distance from other objects in the field of vision. Our brain stores this
spatial view of the external objects as the code for sight (it is a complex
combination of codes for object shapes, colour, and spatial distances between
objects).
Like colour and shape, external objects don’t have the property of
smell. Odour is also a sensation created inside our brains. The sensation of
odour corresponds to specific olfactory codes that our brain creates to
identify the chemicals that reaches our nose.
Similar process is adopted for the sensations of taste, touch, and
sound.
The brain also creates the sensation of pain when an external object
hits us causing damage to our skins. In the case of pain however, the brain is
interested in the location of the body where the damage has occurred.
Our brains can create and store in memory a group of sensations
(read codes) for a given event to form an experience. For example, we get the
sensations of vision, sound, and pain when a stone hits us. This complex array of sensations (codes)
grouped together and stored in memory can tell us in future to avoid a moving
stone coming our way. The multi-dimensional nature of our experience of an
event is what has helped us navigate and survive on earth.
Since the sensation of pain is associated with damage in some form
of our material body, it is not limited to damage due to external objects only,
it can also be created if there is damage inside our bodies. Sensation of pain
inside body is normally not associated with any other form of sensation (code)
like vision, sound, or smell. Spatial location and intensity of the pain is all
that the brain is interested in for internal damages and it has separate codes
for each of these features of the experience.
To conclude, sensations or experiences are nothing but codes that
our brain creates to identify distinct interactions that our bodies have with
external objects.
Notes
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