This evening's NewsHour with Jim Lehrer on PBS incuded a segment entitled Using Your Brain: "A report on what is really going on inside our heads when we make economic decisions. Researchers are beginning to understand how the pre-frontal cortex and our "lizard brain" is driving our decisions in the stock market."
The segment included an interview with neuropsychologist Jordan Grafman.
By the way, "lizard brain" refers to the evoluntarily older parts of the brain, such as the limbic system. The contrast, as it relates to economics and decision-making, is the classic dichotomy of rational vs. impulsive, deliberate vs. emotional, with the "lizard brain" representing the impulsive and emotional and the prefrontal cortex representing the rational and deliberate aspects of decision making.
A transcript of the segment (along with a link to an audio stream) can be found on the show's website.