Not long ago, many scientists had the belief that after the age of about three, the brain was pretty much fixed in function. You could imprint new memories and learn new skills, but that was about it.  There was an opposing belief too, that said the brain was a 'blank slate' upon which the various human parameters were written almost ad lib as life went on - an idea, of course, that Steven Pinker refuted in his famous book of the same name (Pinker, 2002).

It is generally accepted that the truth is somewhere in-between.  The brain appears to develop into a specific set of sub-systems, with the same 'modules' performing the same functions in different individuals (eg., Restak, 1994).  But, these subsystems are flexible, and can be altered to some extent; brain areas can grow, connections can be made and broken, and new neurons can grow.  This is a constant process; the brain is always changing; in fact, just by reading this sentence, your brain is changing.  Same with this sentence.  And this one.  I'll stop now.

As you know, this is called 'neuroplasticity', and the $4,000,000 question is: how is this buzzword relevant to positive psychology? (1)

Well, as fascinating as I find neuroscience to be, it's no surprise (anymore) to find different brain areas involved in different functions, including so-called 'positive' functions.   Accepting the above ideas (modular brain/no blank slate, neuroplasticity), it's not a profound thing to find a brain area associated with, say, positive affect: or even large differences in that area between, say, novice meditators and Tibetan monks with 20,000 hours' meditation practice.  If there's a massive difference on the outside, there should be one on the inside.  It's what you'd expect.

To give another example, there are brain areas associated with motor tasks, allowing me to type this blog post (Cannonieri et al, 2007).  These areas are probably very different in me than in the Tibetan monks, who have quite possibly never used a keyboard (or maybe they each take a MacBook Pro into the mountains with them; I really don't know).  

But you wouldn't need a brain scan to find this out.  A simple typing test would do.  I would be faster than the monks, and this functional difference has to have a biological correlate of some sort.  It has to 'be' somewhere.

Don't get the impression that I'm 'against' neuroscience - no way, far from it.  I like an fMRI study as much as the next person; I just think it's important to remain skeptical, not get too carried away too soon, and understand that a neural correlate might not be the holy grail.

There is even some preliminary evidence that diagrams of brains (McCabe and Caster, 2006) and neurological explanations (Weisberg et al, 2008) can increase the persuasiveness of even poor arguments!  So let's not mistake inherent fascination with our own brains as having any special relevance, and judge it as a starting point, like any other correlational evidence - until there is more data to go on.

That said, I actually think neuroscience has a lot to offer.  Here is where I think combining these two fields may be useful:

• 1) Validation of scale measures

Discovering neural correlates of variables can allow the questionnaires used to measure these variables to be tested for validity - as long as the neural correlates are themselves validated against things other than the questionnaire.  For example, if there are studies testing things like altruism, humour, and so on, the neural correlates of these could be compared with VIA strengths inventory, which measures character.  That could be interesting.  Likewise, well-being measures have been compared to left-right prefrontal asymmetry, because the left prefrontal cortex is thought to be involved in 'positive' emotion.

• 2) Building theoretical models

Neuropsychology can provide evidence to help to build theoretical models, from which further predictions can be made.  For example, the debate around whether positive and negative affect are along the same or distinct dimensions.  Some people believe they lie on one continuum, e.g., -10 (negative) to +10 (positive).  Others believe they lie on two dimensions, and can be largely unrelated.  One way of digging into this is to measure the biological correlates of each, which Ryff et al (2006) did and found support for the 'distinct' hypothesis.

• 3) A two-way street?

Maybe positive psych is good for neuroscience too.  If we accept Seligman's founding premise that psychology had been skewed onto what you might call 'less positive' lines of inquiry - that is, focused (understandably, following WWII) on reducing illness and disorder as opposed to cultivating character and positive traits, then the same is possibly true of neuropsychology.  Combining the two fields could bring a broader understanding of the brain and behaviour, encouraging lines of research that might not have been considered otherwise.

I'm generally always in favour of combining different avenues of research - I think it's good to look at things through a different lens - in science and in life in general!

NOTE:

(1) I mean that literally.  The Templeton Foundation has pumped $4,000,000 into answering that question.

References:

Cannonieri, G., Bonilha, L., Fernandes, P., Cendes, F.,&Li, L. (2007). Practice and perfect: Length of training and structural brain changes in experienced typists. NeuroReport: For Rapid Communication of Neuroscience Research, 18(10), 1063-1066

McCabe, D.,&Castel, A. (2008). Seeing is believing: The effect of brain images on judgments of scientific reasoning. Cognition, 107(1), 343-352.

Pinker, S. (2002). The Blank Slate: The Modern Denial of Human Nature, Penguin Putnam

Restak, R. (1994). The modular  brain: How new discoveries in  neuroscience are answering age-old questions about memory, free will, consciousness, and personal identity. New York: Scribner’s. 

Ryff, C., Love, G., Urry, H., Muller, D., Rosenkranz, M., Friedman, E., et al. (2006). Psychological Well-Being and Ill-Being: Do They Have Distinct or Mirrored Biological Correlates?. Psychotherapy and Psychosomatics, 75(2), 85-95. 

Weisberg, D.S., Keil, F.C., Goodstein, J., Rawson, E., Gray, J. R. (2008). The Seductive Allure of Neuroscience Explanations. Journal of Cognitive Neuroscience, 20 (3), 470-477