Last night, I went to a talk by Professor Liz Phelps, hosted by NYU Abu Dhabi. The title of her talk was Heart or Head? How Brain Science Alters Our Understanding of Emotions and Decisions.
She commenced her talk on the dualist debate about decision-making. Heart decisions are supposed to be fast, risk-taking, impulsive, hot, and now-focused. Head decisions are considered to be slow, cognitive, reflective, logical, and focus on later rewards. She focused her talk on intertemporal choice – looking at how much people would delay taking an instant reward for a greater reward later. This has implications for societal issues such as obesity, poor savings, problem gambling, etc.
The main thesis of her talk was that this dual system (heart vs head) does not stand up to science on brain imaging and autonomic responses. What research has found is that emotional arousal comes from future reward; emotion drives rational choices. It is becoming more known that emotion has a modulatory role in cognition, memory and perception. She focused on the amygdala and the striatum; the striatum in particular codes subjective value and responds to money, food, cocaine, co-operation and beauty.
There are two components to risky decisions; loss aversion and risk sensitivity. People tend to weigh losses more than the potential gains. The amygdala and autonomic responses are correlated with loss aversion but no relationship was found with risk sensitivity. More interestingly, when the trials turned to auctions (which have a tendency for overbidding), responses are linked with potential losses rather than gains. It is actually the fear of losing that drives overbidding rather than the joy of winning.
Ways to limit a loss aversion response include beta blocker drugs and cognitive therapy. Once again no effect was found on risk sensitivity. Side effects include finding that the drugs actually limit memory. Also of note was that the drugs were less effective in high BMI people. Cognitive therapy was helpful if people thought of a portfolio of decisions rather than just one decision.
In summary, Phelps finds no evidence of dual systems in the brain. Emotion and cognition work together in decision-making. There are multiple neural pathways dependent on the context and no link to the limbic system was found.