Thursday, 21 June 2007

Why oh why? (full text)

I'm wrestling with the neurobiology stuff within the Climate Change book. I've never quite been satisfied with the model that was in the skeletal draft, and pursuing a more detailed and robust understanding has led me to a bit of a philosophical biggie.

So, if you'll indulge me for just a moment, I'll romp about in some neurobiology, a bit of morality, a dash of sociology and some logic and philosophy, and hopefully we'll get to something that makes some sense, or something that clearly makes no sense and can be abandoned.

Our 'memory' is not a single thing. It can be categorised into two primary types: implicit memory and explicit memory.

Explicit memory contains narrated memory, it is episodic and declarative. It is created through the hippocampus and it can be related back in terms of symbols - either words or sketches. Explicit memories are stories. They contain answers to the questions: when? where? what? who? ('who?' is really an extension of 'what?', applied specifically to human beings).

Implicit memories are not translated into symbols. We have two types of implicit memories. 'How?' memories, which are procedural, store skills which we have practiced until they are automatic. I am using my implicit memory about 'how' to type right now. We use the word 'how?' sometimes in place of 'what?' - for example 'how do I get to the cinema?' is really the question 'what do I do to get to the cinema?'. Pure 'how?' can't really be explained in words: teaching a child to use chop-sticks is a tricky business.

The other type of implicit memories, emotional memories, are stored responses to external and internal stimuli.

We know there are two types of memory because people who have had brain injuries to their hippocampus develop a type of amnesia where they can't create new explicit memories. They will have no memory of ever having met their doctor, but if their doctor begins to hold a buzzer in their hand when they greet the patient then within a few meetings the patient will become afraid of shaking hands with the doctor - even though they believe they have never met them before. They can't learn a list of new information, but they can learn to paint or draw or ride a bike, even if they didn't have the skill before their injury.

So - we've covered what?, where?, when? and how?, but the source of all of our problems is 'why?'.

Human beings are the only species concerned with 'why?', and here's my big wobbly thought for today:

There are no 'truths' that can be used to answer a 'why?' question.

You might, as I was earlier today, be testing this against questions like "Why does a stone drop to the floor?", and thinking that I am talking rubbish because the answer is obvious: gravity. I am concluding that this is not really a 'why?' question - the question we are asking is really "What happens when a stone drops to the floor?". The partial-answer is to do with the action of gravity, but 'why?' gravity does this is something we can't answer.


So. The human brain is loosely composed of three discrete-ish parts: the brain stem (lizard brain), the limbic system (mammal brain) and the cortex (problem-solving brain). The brain stem does the stuff that keeps you alive, even in your sleep. Master Melancholy is particularly fond of responding to unhelpful suggestions that he "might want to do something with his afternoon other than just watch television" by reminding us that he is also respiring, his heart is beating, he is digesting his breakfast...

He is correct. His lizard brain is doing stuff. Important stuff. Without his lizard brain he would die.

The limbic system is the source of emotion. Lizards famously eat their babies; mammals generally put some effort into nurturing them into adulthood. The limbic system only pays attention to things that are important to our survival. To the limbic system every stimulus is either dangerous or pleasurable or irrelevant. Very-dangerous things invoke a rapid response in a bit of our limbic system called the amygdala, flooding our body with the chemicals required to fight, flee or freeze. The limbic system even has its own direct connections to our senses. A person who has had a head injury resulting in them being unable to process images will be blind as far as their conscious thought is concerned, but will still have a fear response if a picture of a spider is put in front of them.

The limbic system is quicker than the cortex. You feel before you think, and the feelings you have start neural-networks firing, for this is what a memory seems to be - a set of neurons which will fire together in response to a stimulus.

Our current understanding is that neural networks form pairings. When I make use of Pavlov's research, training Ruby to cooperate with my instruction to go to her bed, I am making use of the paired neural networks in Ruby's brain which I have built up by giving her a biscuit when she goes there. Bed = biscuit = pleasure.

So, the cortex comes into action not against a blank canvas, but midst a whole host of chemical changes and neural activity triggered by the speedy limbic system. If the limbic system believes the stimulus to be important enough then it may not allow the cortex to get involved at all until the danger has passed. This makes great survival sense because wondering whether something in the bushes might be a tiger is not a useful activity. Better to run like hell and wonder about the tiger later.


The paradox of being a human is that we are constantly asking 'why?' questions, for which there are no answers. If we believe that there is an answer to a 'why?' question then we are heading into an area which I'm going to call 'felt-truth'. Felt-truths are always responses to 'why?' questions, and are an attempt to make explicit some of what is stored in our limbic memory. We take un-symbolisable feelings and we mix them in with some explicit knowledge about the world and we come up with a story which is presented as a truth.

We know that our limbic memory doesn't bother with things that aren't important for our survival. This is what makes teaching maths to teenagers so challenging. A 15-year-old's limbic system is doing a very important survival job of ignoring all this survival-irrelevant rubbish about triangles so that it can direct attention to the survival-important task of getting the cute girl in the corner to give him or her their phone number.


When we come across a 'why?' question, we have two possible responses: curiosity and felt-truth.

Yesterday, Ms M and I found ourselves tangled up in this when we were stuck in traffic behind an Aston Martin DB9. As an engineer, I can appreciate the design work and elegance, but, in my head, Mr Aston-Martin was a tosser. He wasn't even aware I was behind him (in the dog-bus) but he pissed me off, because I have a felt-truth about people who drive expensive cars. They are clearly idiots.

The curious response to the question "Why would someone choose to spend £100,000 on a sports car?" is to be open and interested in the numerous possible explanations (or bored by the question and not bother answering it). The felt-truth responses range from my own "Because they are an idiot." to "Because they are a stud." to "Because women like it." to "Because it's beautifully engineered." ... etc.

To a person expressing a felt-truth response to a 'why?' question, their answer feels true. It doesn't just feel true intellectually, it feels true biologically. My limbic system has only stored stuff which is important for my survival. If you start to question the validity of my responses which are based on my limbic memories then I feel like my survival is under threat. My heart starts beating faster, my senses are heightened and I may respond with a level of vigour which would be appropriate if I was about to run away from a tiger, but isn't useful if we're having a discussion about whether expensive sports-cars are a good way to spend money.


There are no objective answers to 'why?' questions. There are only subjective answers which are a messy combination of explicit understanding and implicit memory. Any time we believe we have an answer to a 'why?' question we can infer that:

a) we don't.

b) our limbic system believes this question to be important to our survival.

c) our response will be shaped by the particular survival challenges of our experience of the world so far.

d) resolving any conflict around this felt-truth will require us to shift from felt-truth to curiosity.

e) our biology is set up to prevent us from being curious in dangerous situations, so shifting from felt-truth into curiosity is really bloody difficult.


The challenge in resolving Global Climate Change is to address the 'what?', 'when?' and 'where?', without allowing ourselves to be sent into conflict by differences in our 'answers' to the question 'why?'.