Tag: neural networks

Mechanical Consciousness

Mankind has attempted for a long time to explain consciousness, one’s awareness  of one’s own existence, of the world we live in, and of the passage of time.  And mankind has further believed for a very long time that consciousness extends beyond death and the destruction of the body.

Most explanations of consciousness have tended to rely on religion, and on philosophical strains associated with religion.  Possibly as a result, there has been a tendency to explain consciousness as being caused by a “soul” which lives on after death and in most traditions gets judged for its actions and beliefs during its time of residence in the body.

In this article, it is proposed that consciousness can have a purely mechanical origin.

The proposal is merely conjecture, but observations that support the conjecture (though they do not prove it) and I hope, render the conjecture plausible, are provided.  The explanatory power of the model is also somewhat explored.

It is also proposed that the working of the human mind is similar to that of many machine learning models in that they share certain limitations.

 

Preliminaries

First, let me define consciousness.  Consciousness of something is the knowledge of the presence or existence of something (of time or of our selves or of the world around us).

I argue that consciousness requires at the very least what we call “awareness” (that is, being able to sense directly or indirectly what one is conscious of).

Claim:  If I were not aware of something, I wouldn’t be conscious of it.

Argument: If all humanity lived underground for all time and never saw the sky, we would not be aware of the existence of the sky either by direct experience or by hearsay.  So, we couldn’t be conscious of it.  So, it is only when we are aware of the existence of something that we are conscious of it.

So, we have established a minimum requirement for consciousness – and that is “awareness” (being able to sense it).

But does consciousness require anything more than awareness?

The ability to reason and to predict behavior are things the human mind is capable of.

But are they required for consciousness?

Claim:  Reasoning is not required for consciousness.

Argument:  I argue that reasoning is not required because one cannot reason about something that one is not aware of the existence or presence of.  So, anything that one reasons about is something that one has registered the presence of in some manner, in other words, that one is conscious of.

Claim:  Prediction of the behavior of something is not required for consciousness.

Argument:  Prediction of the future behaviour of a thing is not possible without observation over time of how that thing behaves.  So observation (and consciousness) precedes prediction.

Yann LeCun argues that “common sense” is the ability to predict how something might behave in the future (if its future state is not completely random).  If we accept that definition, we might say that common sense builds on consciousness, not the other way around.

So, it appears that consciousness (knowledge of the existence of something) requires the bare minimum of awareness through the senses, and does not require reasoning or the ability to predict.

 

Development

The next question to consider is whether awareness constitutes consciousness or if there is more to it.

Claim:  There is more to consciousness than the signals that our senses send to the brain (awareness).

Argument:  The signals sent to the brain are analogous to signals that are present in completely inanimate things.  A camera has a sensor that records images of the outside world.  Even a pin-hole camera senses the outside world upon the wall on which the image of the sensed world is cast.  Even a shadow can be considered to be a “sensing” of the object that casts the shadow.  That does not imply consciousness.  There must be something else in animate “living” things that produces consciousness.

What is that something extra that is over and above what our senses record?

I believe that the extra thing that constitutes consciousness is the ability to create a model of what we sense and remember it (keep it in memory).

By “create a model”, I mean store a representation of what is sensed in some kind of memory so that what is sensed can be reproduced in some medium possibly at a later stage.

The model cannot be reproduced if it is not stored and remembered, so memory is also key to consciousness.

So, consciousness is the creation of a model in memory of what is sensed.

In other words, anything that can sense something in the world and actively create a model of what it senses (be able to reproduce it exactly or inexactly) is conscious.

I will attempt to justify this claim later.

 

Elaboration

So, the claim is that anything – even if it is a machine – that can actively create a model of something that it senses (is aware of) and store it in memory in such a way as to permit retrieval of the model, is conscious of it.

I am not saying that conscious beings are conscious of every aspect of what they sense as soon as they sense it. It can be possible that they sense and temporarily store a lot of things (for humans, for example, that could be every pixel of what we see outside the blind spot) but only model in a more abstract form and store in memory as an abstraction (and in a retrievable form) those parts that they pay attention to.

So it is possible that a conscious being may be conscious of the pixels of a bird outside the window but not conscious of it as a bird (model it in a more abstract form) or of its colour (model its properties) unless the conscious being pays attention to it.

For example, let us say we’re talking of a human.  Let’s say further that the human sees a mountain.

The human senses (sees) the mountain when rays of light scattered by the surface of the mountain or from things upon the mountain enter her or his eye and impinge upon the retina, triggering a chain of chemical reactions that lead to electrical potentials building up that act upon the nerves in the retinal cortex.

Subsequently, the neurons in the optical pathway of the human’s brain fire in such a manner that eventually, various parameters of the mountain come to be represented in the pattern of neural activations in the human’s brain.

We know that the human has modeled the mountain because the human can be asked to draw the mountain on a sheet of paper and will be able to do so.

Now, the human can be conscious of various parameters of the mountain as well.  For example, if the predominant colour of the mountain is represented in those neural activations, then the human is conscious of the predominant colour of the mountain.  For instance, if the human can answer, accurately or inaccurately, a question about the colour of the mountain, the human can be said to have modeled the same.

If the height of the mountain is represented in the neural patterns, then the human is conscious of the height of the mountain.  This can be tested by asking the human to state the height of the mountain.

If the shape of the mountain is vaguely capture in the neural activations so that the human identifies the same with that of a typical mountain, then the human is conscious of the mountain’s shape and that it is a mountain.

This ability to model is not present in what we typically consider an inanimate object.  A pin-hole camera would not actively create a model of what it senses (projects onto the wall) and is therefore not conscious.  Its projection is purely a result of physical phenomena external to it and it has no agency in the creation of the image within it.  So it has no consciousness.

Let’s say we use a digital camera which records the pixels of let’s say a mountain before it.  It can reproduce the mountain pixel by pixel, and so can be said to have a model in its memory of the mountain.  In other words, such a camera is conscious of the pixels of the mountain and everything else in the field of view.  It wouldn’t be conscious of the shapes or sizes or colours or even of the presence of  a mountain in the sense that a human would.

Claim:  Consciousness requires the active acquisition and storage of information from what is sensed.

Argument:  If the “model” is just the result of physical phenomena, say a projected image in a pin-hole camera, then there is no information acquired and stored by the system from what is sensed, and hence no consciousness.

Now, supposing that we were to build a machine of sand that created a representation of the mountain in sand and of the height and colour of the mountain and of the shape of the mountain and of the association of this shape with typical mountain shapes and of every other parameter that the human brain models.

Now, I would argue that this sand machine could be said to be conscious of the mountain in the same way as we are, even though it uses a completely different mechanism to create a model of the mountain.

Claim:  The hypothetical sand machine and a human brain are equivalent

Argument:  Consciousness of something is only dependent on what is modeled, and no on the method of modeling.  So, as long as the parameters of the mountain are modeled in exactly the same way in two systems, they can be said to be conscious of it in the same way.

 

Corollary

We are machines.

 

All right, so that’s a claim as well.

Here are two arguments in support of the claim.

a) Our behaviour in some sensory tasks is similar to that we would expect from machine learning tools called classifiers.

  1. The Himba colour experiment discovered that the Himba tribe of Africa were distinguishing colours differently from the rest of the world. They could not distinguish between blue and green but could distinguish between many shades of green which other humans typically had a hard time telling apart.
  2. People who speak languages that do not have vowel tones have trouble hearing differences in tone. Similarly, people who speak languages where the consonants ‘l’ and ‘r’ are conflated cannot easily tell them apart.

This is typically how a machine learning tool called a classifier behaves.  A classifier needs to be trained on labelled sounds or colours and will learn to recognize only those, and will have a hard time telling other sounds or colours apart.

b) The limitations that our brains reveal when challenged to perform some generative tasks (tasks of imagination) are identical to the limitations that the machine learning tools called classifiers exhibit.

Let me try the experiment on you.   Here’s a test of your imagination.  Imagine a colour that you have never seen before.

Not a mixture of colours, mind you, but a colour that you have never ever seen before.

If you are like most people, you’ll draw a blank.

And that is what a classifier would do too.

So, I would say that the human brain models things like colours or phonemes using some kind of classification algorithm, because it displays the limitations that such algorithms do.

So it is possible that we shall be able to discover by similar experiments on different types of human cognitive functions, that humans are merely machines capable of consciousness (of modeling a certain set of parameters related to what we perceive) and other cognitive functions that define us as human.

 

Further Discussion

People with whom I’ve discussed this sometime ask me if considering consciousness as the process of building a model of something adequately explains feelings, emotions, likes and dislikes and love and longing.

My answer is that it does, at least as far as likes and dislikes go.

A liking of something is a parameter associated with that thing and it is a single-value parameter that can be easily modeled by one or more numbers.

Neural networks can easily represent such numbers (regression models) and so can model likes and dislikes.

As for love and longing, these could result from biological processes and genetic inclinations, but as long as they are experienced, they would have had to be modeled in the human mind, possibly represented by a single number (a single point representation of intensity) or a distributed representation of intensity.  What is felt in these cases would also be modeled as an intensity (represented at a point or in a distributed manner).  One would be conscious of a feeling only when one could sense it and model it.  And the proof that one has modeled it lies in the fact that one can describe it.

So, when  the person becomes conscious of the longing, it is because it has been modeled in their brain.

 

Still Further Discussion

Again, someone asked if machines could ever possibly be capable of truth and kindness.

I suppose the assumption is that only humans are capable of noble qualities such as truth and kindness or that there is something innate in humans which gives rise to such qualities (perhaps gifted to humanity or instilled in them by the divine or the supernatural or earned by souls that attain humanity through the refinement of past lives).

However, there is no need to resort to such theories to explain altruistic qualities such as truthfulness, goodness and kindness.  It is possible to show game theoretically that noble qualities such as trustworthiness would emerge in groups competing in a typical modern economic environment involving a specialization of skills, interdependence and trading.

Essentially the groups that demonstrate less honesty and trustworthiness fail to be competitive against groups that demonstrate higher honesty and trustworthiness and therefore are either displaced by the latter or adopt the qualities that made the latter successful.  So, it is possible to show that the morals taught by religions and noble cultural norms can all be evolved by any group of competing agents.

So, truth and kindness are not necessarily qualities that machines would be incapable of (towards each other).  In fact, these would be qualities they would evolve if they were interdependent and had to trade with each other and organize and collaborate much as we do.

 

Related Work

This is a different definition than the definition used by Max Tegmark in his book “Life 3.0” but his definition of “consciousness” as “subjective experience” confuses it with “sentience” (the ability to feel).

Tegmark also talks about the work of the philosophers David Chalmers and Scott Aaronson, who seem to be approaching the question from the direction of physics – as in we are just particles from food and the atmosphere rearranged, so what arrangement of particles causes consciousness?

I think that is irrelevant.

All we need to ask is “What is the physical system, whatever it is made of, capable of modeling?”

Interestingly, in the book, Tegmark talks about a number of experiences that any theory of consciousness should explain.

Let’s look at some of those.

 

Explanatory Power of this Model

Explaining Abstraction

He talks about how tasks move from the conscious to the unconscious level as we practise them and get good at them.

He points out that when a human reads this, you do not read character by character but word by word.  Why is it that as you improve your reading skills, you are no longer conscious of the letters?

Actually, this can be explained by the theory we just put forth.

When we are learning to read (modeling the text is reading), we learn to model characters when we see a passage of text like this one and read character by character.

But with practice, we learn to model words or phrases at a higher level from passages of text, and direct our attention to the words or phrases because that facilitates reading.

We can chose to direct our attention to the letters and read letter by letter as well, if we so choose.

So, this model can explain attention too.

Attention

The brain is limited in its capacity to process and store information, so the human brain focuses its attention on the parts of the model it has built that are required for the performance of any task.

It can chose to not keep in memory more granular parts of the model once it has built a larger model.  For instance it can choose to not keep in memory the characters if it already has modeled the word.

This also explains phenomena such as “hemineglect” (patients with certain lesions in their brain miss half their field of vision but are not aware of it – so they may not eat food in the left half of their plate since they do not notice it).

We can explain it by saying that the brain has modeled a whole plate from the faulty sensory information provided to it and therefore the user is conscious of a whole plate, but minus the missing information.

Blindsight

Tegmark also talks of the work of Christof Koch and Francis Krick on the “neural correlates of consciousness”.

Koch and Krick performed an experiment where they distracted one eye with flashing images and caused the other eye to miss registering a static image presented to it.

They inferred from this that the retina is not capable of consciousness.

I would counter that by saying that the retina is conscious of the pixels of the images it sees if it constructs models of them (as it does) and stores them.

But if the brain models more abstract properties more useful to the tasks we perform, we focus our attention on those and therefore do not store in the memory the images that are not relevant to the more critical task (the distracting task).

So, I would argue that our consciousness can include models that comes from the retina (if some neural pathway from the retina creates models in memory at the pixel level).

But if our attention decides to focus on and consign to memory better things than what the retina models, it will, and then it will not necessarily model and be conscious of pixels from the retina.

 

Still Other work

Tegmark also talks extensively about the work of Giulio Tononi and his collaborators on something called “integrated information” and the objections to it by Murray Shanahan, but I’ll leave those interested in those theories to refer the work of their authors.

I also examine Graziano’s Attention Schema Theory of consciousness in another post https://aiaioo.wordpress.com/2017/12/18/mechanical-consciousness-and-attention/

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