Robert Sapolsky, Professor of Biology, Neurology and Neurosurgery at Stanford University, writes on 'This Is Your Brain on Metaphors': 
Consider an animal (including a human) that has started eating some rotten, fetid, disgusting food. As a result, neurons in an area of the brain called the insula will activate. Gustatory disgust. Smell the same awful food, and the insula activates as well. Think about what might count as a disgusting food (say, taking a bite out of a struggling cockroach). Same thing.My conclusions?
Think about something shameful and rotten that you once did … same thing. Not only does the insula “do” sensory disgust; it does moral disgust as well. Because the two are so viscerally similar. When we evolved the capacity to be disgusted by moral failures, we didn’t evolve a new brain region to handle it. Instead, the insula expanded its portfolio.
Or consider pain. Somebody pokes your big left toe with a pin. [As well as the reflex and other physiological responses, there’s a] region in the frontal cortex called the anterior cingulate and that’s involved in the subjective, evaluative response to the pain.
Now instead, watch your beloved being poked with the pin. And your anterior cingulate will activate, as if it were you in pain. When humans evolved the ability to be wrenched with feeling the pain of others, where was it going to process it? It got crammed into the anterior cingulate. And thus it “does” both physical and psychic pain.
Our early physical experiences become the basis,
by 'metaphorical extension', for more complex and less tangible aspects
of life. And ‘early’ applies both to the development of the individual
and the species. This is a key principle of a new but growing field of Embodied Cognition (more on this tomorrow).
That's why the same area of the brain is often involved in both ‘physical’ and ‘psychological’ aspects, in both ‘real’ and ‘imagined’ situations, in both ‘literal’ and ‘metaphorical’ interpretations, and when both the ‘self’ or ‘another’ is involved.
I have put quotation marks around ‘physical,’ ‘psychological,’ ‘real,’ ‘imagined,’ ‘literal,’ ‘metaphorical,’ and even ‘self’ and ‘other’ because the more we understand about how humans be humans the more we realise that these categories are fuzzy – very fuzzy. Except in a few circumstances there is little to separate these experiences (a) because they recruit the same parts of our neurology; (b) because they are all happening all the time; (c) because they can be considered different ways of describing the same thing; (d) you cannot begin to understand what it is to be human without taking them all into account.
Within our society, people who don't or who can't make these distinctions are considered 'mad' or 'mystics'. Either way they are viewed with fear and suspicion.
Sapolsky asks some interesting questions:
What are we to make of the brain processing literal and metaphorical versions of a concept in the same brain region? Or that our neural circuitry doesn’t cleanly differentiate between the real and the symbolic? What are the consequences of the fact that evolution is a tinkerer and not an inventor, and has duct-taped metaphors and symbols to whichever pre-existing brain areas provided the closest fit?
Here are some of my partial answers:
- As I mentioned in yesterday’s blog, we can assume that if evolution is a tinkerer across all levels of biological organisation, then, chances are, the same applies to the evolution of the individual human mind. It therefore follows that todays ‘problems’ are the result of previous duct-taped tinkering, and that tomorrow’s ‘solutions’ will “borrow, repurpose, recombine” what is available.
- It is not just that “people already have (or potentially have) all of the resources they need to act effectively” 
. It is that people only have what they have to develop with. Probably all of us have at some time expended a vast amount effort attempting to reject some aspect of ourself, only to find that no matter how far or how fast we move away – there we are. Penny Tompkins and I have found that the structure of self-deception, delusion and deceipt
is predicated on a person's highly creative ability to (temporarily) fool themselves that what is true about them, is not true, and what is false is actually true.
- Whether the content of a person’s description is ‘literal/sensory’, ‘conceptual’ or ‘metaphoric/symbolic’
the processes by which the mind evolves are likely to be much the same. Since those processes are not generally in the foreground of awareness they operate mostly unconsciously. This means that in terms of personal development, whether we are working with a ‘a memory of an actual event’, a ‘present-time description', or ‘an imagined future’ the client is recruiting much of the same neurology and changes to the organisation
of that experience will have a similar effect. How
anyone “does” them self – whatever they are doing, saying, feeling, thinking is what is important.
1 New York Times 'The Opinion Pages', 14 November 2010:
2 Dilts & Delozier, NLP Encyclopedia p. 1003
3 We first made the distinction between sensory, conceptual and symbolic in our 1996 article, 'Meta, Milton and Metaphor:
Models of Subjective Experience'