What is Consciousness?

October 20, 2013 at 8:54 pm | Posted in Brain and mind | 2 Comments
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The caption on http://en.wikipedia.org/wiki/Brain : The main anatomical regions of the vertebrate brain, shown for shark and human. The same parts are present, but they differ greatly in size and shape.  Image by Looie496, 2011-09-30 .

The caption on http://en.wikipedia.org/wiki/Brain : The main anatomical regions of the vertebrate brain, shown for shark and human. The same parts are present, but they differ greatly in size and shape. Image by Looie496, 2011-09-30 .

Imagine placing your hands near the sensor of an automatic faucet, or getting up from a self-flushing toilet, or approaching at night a building whose front light is turned on and off by a motion sensor.

The faucet turns on, the toilet flushes, the building’s front light turns on.

In each case, a signal was sent from a sensor to an operating device.  But the recipient of the signal operated automatically, without being conscious of the signal, nor of its own response.  It detected the signal, but did not feel it.  It did not tingle, or wince, or become happy or sad.  It sensed the signal, but had no sensation – a seemingly paradoxical statement that is actually meaningful and accurate, because of the vagueness of human language.  (The vagueness is often useful and efficient, but that is another story.)  It was aware of the signal in a limited sense, but was not aware of the signal in the vivid way that a person would be aware of a pin prick, for example.

Now imagine that you are pricked by a pin.  The signal from nerves in your skin travels to your brain.  One result is an automatic reflex: you draw back, unless you consciously over-rule that reflex.  But another result is your vivid awareness of the pin prick.  You feel it.  It produces a sensation, at nearly the same time as your reflex.  You are conscious of it.

Conscious awareness seems to activate many of your brain systems at the same time: emotions, your model of how the world works, memories, your expectations of what happens next.  Apparently, a message was broadcast to a large part of your brain.  That seems to be what is distinctive about conscious sensation, or a conscious thought (viewed as a signal from within your own brain).  It is likely that conscious awareness of something is synonymous with “all or most of brain knows about it, and is paying attention to it”.

That is a testable hypothesis.  Brain imaging, such as functional MRI (fMRI) could test it.

Caption on http://en.wikipedia.org/wiki/Pain : Regions of the cerebral cortex associated with pain.  Authors: Borsook D, Moulton EA, Schmidt KF, Becerra LR., © 2007 Borsook et al; licensee BioMed Central Ltd.

Caption on http://en.wikipedia.org/wiki/Pain : Regions of the cerebral cortex associated with pain. Authors: Borsook D, Moulton EA, Schmidt KF, Becerra LR., © 2007 Borsook et al; licensee BioMed Central Ltd.

If conscious awareness of something is indeed synonymous with “all or most of brain knows about it, and is paying attention to it”, that would explain why we can be aware of – conscious of – only a limited number of items at the same time.  Any one conscious item requires the attention of much of the brain.  Each item occupies many resources, and there are only a limited number of them available.

That the limiting number of items is roughly seven for most individuals is an accident of our evolved wet-ware.  We can handle more simultaneous factors by building artificial intelligent systems.

If this view of the nature of consciousness is correct, then consciousness has a cultural analog.  In a family, a business, a village, a nation, a scientific or other cultural community, the analog of an object of conscious awareness is anything that becomes part of the general culture of that group of people.

It is clarifying to consider the sensations of pain and of pleasure.  What does it mean to feel pain or pleasure?

Among the sensations, pain and pleasure were probably the first to evolve.  These two sensations are the most helpful ones for helping an individual to survive long enough to produce descendents.  Darwin noted the evolutionary utility of experiencing pleasure from satisfying hunger, and the evolutionary utility of the unpleasantness of feeling hunger.  (See p.64 of The Autobiography of Charles Darwin and Selected Letters, edited by Frances Darwin, reprinted 1958 by Dover Publications.)

To be useful, pain or pleasure must activate most or all of the systems in the brain to avoid something or some situation, or to seek more of it.  We must react and act in manifold ways to avoid the threat or to seek the reward.  An ever-varying mix of the systems in our brain must work in a coordinated fashion.  So the signals that elicit the sensations of pain and of pleasure must be broadcast to much of the brain.

This is unlike the distribution of most of the signals from the nerves to the brain.  Most signals affect only a few systems in the brain.  It is not a coincidence that they also do not register in our consciousness: they are not felt by us, they do not produce sensations.

There is an evolutionary benefit to widely broadcasting to the brain only certain types of signals.  Signals about things to avoid and things to seek are among them.  So are any signals that require a versatile, coordinated response by many systems in the brain.

There is an evolutionary benefit to not widely broadcasting any signals that do not require a versatile, coordinated response by many systems in the brain.

Our brains seem to interpret any widely broadcast signal as a sensation, as a feeling, and as consciously perceived.

There was a clear evolutionary advantage to developing neurochemical mechanisms that activate, respectively, a general avoidance of a thing or situation, or a general seeking for more of it, that is, for developing mechanisms for feeling pain and pleasure, that is, for experiencing them consciously.

[By the way, the mechanisms that produce an urge for avoidance seem to be distinct from those that urge us to seek a situation, because some stimuli can elicit both urges at the same time.  Examples are hot peppers, strong drink, a horror movie, thrill seeking.  (‘Strong drink’ is oddly named, since it for the weak.)]

The other sensations probably evolved as outgrowths of those two fundamental sensations.  So the neurochemical mechanisms that produce the sensations of pain and of pleasure are the root of basic consciousness.

If a sensation is tagged by a location on the body, we feel pain or pleasure that we associate with a finger, or with our tongue, a tooth, our genitals, our gut.

Once the mechanisms for basic consciousness are available, higher consciousness can evolve or be built in, by adding mechanisms for the mental mirroring of other individual animals (and of artificial intelligences, if needed), then of groups of them, and, eventually, also of inanimate objects, as explained in an earlier post.  Before a biologically evolved or built species develops mechanisms for mirroring, its abilities increase by relatively small steps.  But once it has developed mechanisms for mirroring, the increases in its capabilities can compound, and, like compound interest, grow exponentially.

Great versatility is conferred by activating many systems in the brain, that then act together in coordinated ways that adapt to the changing incoming signals. .  Obtaining that evolutionary advantage required developing felt sensations (feelings), and, more generally, consciousness.  Feelings motivate action by assigning values to outcomes: avoid => bad, seek => good.  After much extension (caused by the development of mental mirroring) of the scope of application of sensations and consciousness, the development of values as felt motivators led to our sense of right and wrong, of good and evil, of morality, of fairness, and hence of justice, and enlarged our emotional lives.

Two comments about consciousness:

1 – The concepts of cruelty and of kindness pertain to our actions toward the members of any species whose individuals feel, experiencing pain and pleasure.  The species can be biological, or it can be artificial.  Plants do not feel.  It seems certain that paramecia and amoeba do not feel.  But the frantic wriggling of a worm suggests that it feels pain, and is not merely manifesting a reflex.  If so, it has basic consciousness, despite not having much of a brain.  As for the scurrying cockroach, the spider, the spider’s prey, we do not know yet.  More certainly, pain seems to be felt by the wriggling fish impaled by a hook in its mouth, or with its body grasped by the bill of a heron.  We need to invent a way to tell, because feeling pain and/or pleasure confers moral status, as vegetarians know.

2 – There is an common confusion about consciousness.  We are often said to be unconscious while we sleep.  That may be true during non-REM sleep, but it is not true during a dream.  A dream amounts to being conscious – aware – of certain internal signals, and to attempting to make sense of those signals,  while not being conscious of most, or all, of the signals from our environment.

See also these posts: here, and here.

New Navy and Marine Corps officers during the graduation of the class of 2011 at the U.S. Naval Academy. U.S. Navy photo by Mass Communication Specialist 1st Class Chad Runge/Released.

New Navy and Marine Corps officers during the graduation of the class of 2011 at the U.S. Naval Academy. U.S. Navy photo by Mass Communication Specialist 1st Class Chad Runge/Released.

 

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  1. […] previous post suggested a framework for thinking about the phenomenon of consciousness.  The same framework can […]

  2. […] posts are here, here, here, here, here, here, and here.  One post also constitutes an example of a human who is mentally mirroring a […]


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