Friday, July 25, 2008
Ventromedial Prefrontal Cortex
From "Blink" by Malcolm Gladwell, p. 59-60:
Damasio studied patients with damage to a small but critical part of the brain called the ventromedial prefrontal cortex, which lies behind the nose.
The ventromedial area plays a critical role in decision making. It works out contingencies and relationships and sorts through the mountain of information we get from the outside world, prioritizing it and putting flags on things that demand our immediate attention.
People with damage to their ventromedial area are perfectly rational. They can be highly intelligent and functional, but they lack judgment. More precisely, they don't have that mental valet in their unconscious that frees them up to concentrate on what really matters.
In his book 'Descartes' Error' Damasio describes trying to set up an appointment with a patient with this kind of brain damage:
I suggested two alternative dates, both in the coming month and just a few days apart from each other. The patient pulled out his appointment book and began consulting the calendar.
The behavior that ensued, which was witnessed by several investigators, was remarkable. For the better part of a half hour, the patient enumerated reasons for and against each of the two dates: previous engagements, proximity to other engagements, possible meteorological conditions, virtually anything that one could think about concerning a simple date.
[He was] walking us through a tiresome cost-benefit analysis, an endless outlining and fruitless comparison of options and possible consequences. It took enormous discipline to listen to all of this without pounding on the table and telling him to stop.