Left Brain Vs Right Brain

The brain is far from understood, if it were simple enough for us to understand then we would be too dumb to understand it.  However, we do know a lot about it.  Only quite recently the plasticity of the brain has become accepted - it used to be thought that the brain structures were fixed and that they filled up with knowledge and experience, much like a computer.  I remember as a boy being taught that the number of neurons in the brain grew until adulthood and then they just started dying off with no new ones replacing them.  The truth is more complicated - our brains form new connections all the time and can become rewired dramatically through necessity if one area becomes damaged, but generally there are structures in the brain that perform [more-or-less] specific functions.

People sometimes talk about being left or right brained, i.e. more dominant in the left / right hemisphere.

The left hemisphere contains the structures strongly associated with: grammar and vocabulary; logically structured thinking; analysing and controlling feelings; reality.

The right hemisphere contains the structures strongly associated with: intonation of speech; an unstructured approach to tasks (they call it 'multitasking' which has been shown to be less efficient in tests); emotional responses; fantasy.

To summarise, the left brain is rational, and the right brain is a hippy.

No prizes which side I'd be associated with, although actually I'd say I am much better than average at seeing the big picture - the less immediate consequences of actions - which is a right-brain trait.

The 2 hemispheres communicate by little roads called commissures, and one superhighway called the corpus callosum.

For severe epilepsy this superhighway of communication is sometimes severed, leading to some fascinating discoveries.  The two halves of the brain can be thought of as having separate consciousnesses!  Imagine being trapped inside someone else's head, much like in the film 'Being John Malkovic', able to see everything but only able to have a slight influence on his behaviour.  That may be happening inside you right now!  With some subjects who have had their corpus callosum severed, a written command can be flashed up visible only to the eye without the subject being consciously aware of it.  For example, if the word "LEAVE" is flashed up, the subject may get up and start to leave the room - when asked why they are leaving they reply something like "I'm thirsty, I want to go get a soda".  The right brain has invented a story for the the conscious mind that is coherent with the action demanded by the subconscious.

Some of these patients also experience 'alien hand syndrome' in which one arm is under the control of the 2nd hidden consciousness.  Freaky.

I wonder if the religious doctors see these patients as having 2 souls?

Most people invent stories for their lives that fit with their actions.  Most people believe they have rational reasons for their actions, but actually it is just lies told to them by the ultimate manipulating puppet master - their own subconscious.

The Iterated Prisoner's Dilemma

Critical to fully understanding the evolution of behavioural traits is understanding some basic game theory, such as the iterated prisoner's dilemma.

The basic prisoner's dilemma is as follows: two criminals are taken to the police station and interviewed separately. They went on a crime spree together and there is enough evidence to convict them of some of the minor offences. Imagine you are one of the prisoners and you are given a choice, which you assume your partner in crime has also been given: confess to everything and thereby grass up your partner for the major charges [defect]; or keep your mouth shut [cooperate]. If you talk and your partner doesn't, then you get a reduced sentence of 2 years in prison because of helping to convict your partner; and he gets 10 years. If he talks and you don't then obviously the reverse happens. If you both give a full confession then you both get 8 years, and if neither of you talk you both get 4 years. What do you do?

Now imagine that you and your partner can both live forever, and any time either of you are not in prison you go on another crime spree together and each time you get caught and face the same decision. You know your partner's previous responses, so this will obviously affect whether you cooperate or defect in the latest interview with the police. This situation is the iterated prisoner's dilemma, and occurs (in other forms!) every day in societal life (the social contract).

The various consequences to the options can be formalised into a pay-off matrix, and different weightings given to the possible outcomes. So long as all the options are sensible, for example the benefit to you for defecting when your partner cooperates should always be more than the benefit to you for cooperating when your partner cooperates, then it is possible to make some firm conclusions about the worth of different strategies.

Axelrod created a tournament in which different programs played against each other (200 iterations for one game) and then each program's total score was added up. Some of these programs had very sophisticated algorithms to predict whether the opponent would cooperate or defect, however the overall winner was a program called tit-for-tat which simply started out cooperating and then did whatever the opponent had done the previous move. In the second tournament the winner was called tit-for-2-tats, I don't think I need to explain that one's tactics!

It is important to note that in a population it isn't as simple as there being an optimum strategy that everyone should abide by. One of the founders of modern game theory, John Nash (of “A Beautiful Mind”), showed that strategies of cooperation and defection settle to a balance (the Nash equilibrium) – so long as the frequency of defection is low, then on average the cooperators gain by continuing to cooperate and the small number of defectors can take advantage.

Continuity of Self

What constitutes you.  Every day some of your cells die and others are created to replace them, some memories are lost (perhaps only temporarily) and new memories are formed, and over time our neuroplasticity shapes the very physiology of our brains.  Where is the you that you identify as a constant through all this change?

When I wake up I often have a few seconds of coherent intelligent thought before I remember what my life is like, where, and who I am.  During these few seconds I sometimes wonder about whether I am young or old, rich or poor, and I can revel in the simple state of being where I am unaware of pretty much everything.  A state where all my thoughts are occurring for the first time, devoid of context.  

A similar situation is invoked as  a plot device in Dark City, which is a shit film (much worse than its IMDB rating suggests)  but it does leave a lasting impression.  Each night, the memories and lives of all the inhabitants are swapped around and they all live the next day with a new husband/wife, a new job, new hobbies etc. and they are unaware of their previous/original lives.

The classic example of a thought experiment about continuity of self involves a star-trek transporter.  This device maps out all the atoms in your body and then simultaneously destroys the original and creates a duplicate elsewhere.  Is the transported you you?  What if the original weren't destroyed - which one would be you, or would both be?

The most common real life application of this concept is in drugs, especially ones that change personality.  If I took a pill that gave me empathy and turned me into a sensitive metrosexual man then I would not be me.  Whoever that person was may fit in better with society, and they may be happier than I am, but they would not be me.

I think we are more accepting of gradual changes in our self - if we go to therapy or just decide to work on an aspect of ourselves then we are changing our thought patterns; that can lead, slowly, to physical changes in the brain.  If it happens overnight then we are much more wary of it, but where is the logical difference?

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