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Consciousness and Mary the Neuroscientist

Forget the human genome.
Forget string theory.
Forget “spooky action at a distance”.
Forget the reason we sleep.
Forget the nature of time and forget artificial intelligence.
You can even forget the origin of life.

While its undisputed that these are our Brave New Worlds and our Undiscovered Countries, they all fall short of being called the Holy Grail. That’s because there’s one question in science that stands above all the rest, though few think to ask it. While it’s the one thing we all know most directly, it’s the one thing we know the least about.

Welcome to the enigma of consciousness.

consciousness

Photo Credit: Dirk Dallas

Though the term consciousness is a fairly common noun in the English language, settling on a consensus definition of it is quite a task. In fact, if you were to peruse the relatively limited spectrum of material on the subject, you’d be hard pressed to come up with a functional definition yourself.

This is a problem. And while the case can be made that the answers to these questions are some of the most fundamental to the understanding of ourselves and the world around us, it’s not even really clear what the questions are.

Being confronted with such a monumental problem, one has to start the discussion somewhere. Thus, we will begin with two illustrations that lead us down the long journey towards an understanding of consciousness:

Brain Illustration #1: MARY THE NEUROSCIENTIST

This is an illustration originally put forth by the Australian philosopher Frank Jackson. In it, a neuroscientist named Mary is locked all of her life in a black and white room with a black and white television monitor, through which she studies and observes the external world as it relates to the neurological process of seeing and experiencing color.

While Mary does not herself visualize color, she is able to observe every last aspect of the process in others- from the light reflected off an apple hitting the retina to the neurological pathways up to the visual cortex to finally the muscle contractions that produce the word “red”. She understands all there is to know about the wavelengths of light and the processes by which people identify an object and its color. But then a strange thing happens…

One day someone opens the door to Mary’s room and she is let out into the normal world, free to visualize color for the first time. What’s odd about this change is not that she is able to be a part of that which she has studied. The odd thing is that in all of her understanding and studying, she had never once come across the raw experience of the color red. She knew all there was to know about how the experience happened and could conceivably predict exactly what a person would experience and how they would behave if presented with a red object- but she knew absolutely nothing about the actual experience itself.

Naturally following this illustration are two questions: 1) What is this extra element that cannot be known but can only be experienced? 2) Why does it exist in the first place?

Brain Illustration #2: NEURONS AND SILICON CHIPS:

This illustration is a thought experiment put forth by numerous philosophers in recent decades. In it, one is asked to imagine a situation in which a neurosurgeon attempts to replace, one by one, each of the 100 billion individual neurons in someone’s brain with an equivalently functioning silicon chip. Though the technology to attempt such an experiment does not exist today, it’s not inconceivable that at some point in the future it will.

The point of the thought experiment is to ask at what point (if any) would the individual cease to be conscious- would consciousness gradually fade away as neuron after neuron is replaced? Would it remain the same until all of the sudden (perhaps once the majority of the neurons are replaced) it just vanishes? Or would it be completely unaffected by the process? Secondary to the last possibility- if it is not affected by the process at all, then why could robots (who would be made of identically connected silicon chips) not one day be conscious?

 

*Photo Credit: Dirk Dallas (Creative Commons)