By Meera Modi, Pursuer of Wisdom
Originally published February 2009.
As the semester draws to a close for many of us our rational self slowly starts to give way to our inner emotional beings. Through classes, grant writing and endless lab work we struggle to remain clear-headed, rational and frankly, sane. As the pressure piles on we are pushed closer to the edge until we reach the point where that one additional bandless gel sends us off into a fit of rage or a wave of tears. Situations like these invite reflection on which processes are actually in control of our thoughts, decisions and actions; is it our emotions or our rationality?
Philosophers have long attempted to address this question often recognizing that under different circumstances different processes may dominate. Plato believed that the man’s soul was comprised of three parts: reason, passion (akin to emotion) and the will. Of these three, he believed that ideally reason should dominate over passion and will, such that reason determined the path one should take. David Hume presented the contradictory view that “Reason is, and ought to be, the slave of the passions and to try to do nothing other than to be at their services” Hume believed that emotions defined purpose and motivation in life and that rationality was merely a tool to use to meet the needs of the emotions.
Modern neuroscientists like Antonio Damasio and Antoine Bechara have shown through their work with lesioned human patients that in actuality emotion and reason work in conjunction with one another in decision making processes, though through independent but intersecting systems. The ventromedial prefrontal cortex (VMPC) is a brain region that has been shown to be necessary for the generation of emotions, particularly social emotions. The VMPC projects to the basal forebrain and the brainstem regions, which control the somatic emotional response. Patients with lesions of this region exhibit diminished emotional responsivity and show reduced social emotions, like compoassion shame and guilt. Yet people with these lesions are typically normal in intelligence, logical reasoning and declarative knowledge.
Classical deductive reasoning on the other hand has typically been associated with a network including the left inferior frontal and parietal as well as the bilateral caudate nucleus. These brains interestingly, differ from those used in inductive reasoning, but both methods of reason utilize systems distinct from emotional processing.
It is thought that these systems can run in parallel, processing information with each of these systems making necessary contributions to decision making. For example a patient with a VMPC lesion possesses the neural structure necessary to compute rational decisions, without the contribution of emotional information may be unable to rule out options without analytical properties. Imagine flipping through the channels on your TV. These days we have hundreds of options for what to watch, most of fairly equal (albeit mediocre) quality. Most of us will scan the channels and in the absence of our favorite program will simply and fairly randomly pick the least offensive channel to rest on. Now imagine trying to make that decision without emotion. You analyze each channel one by one, weighing the pros and cons of its educational vs. entertainment potential over and over, until you have gone through a hundred channels and can no longer remember the score you assigned the first channel, leaving you frustrated an unable to make a quick emotional decision to watch BRAVO. In the absence of the emotional contribution, decisions based on non-discrete analytical qualities become nearly impossible. Thus we are dependent on both emotion and reasoning systems to navigate our world.
Scientists have done a good job at describing how the processes underlying rational and emotional decision-making function, but it seems their empiricity has prevented them from addressing the questions philosophers pose. I know we use both of these systems, but which of these is the “right” process to use.?