Sunday, October 23, 2011

Mind, body and emotion

By Steve Rensberry

 The essence and source of human emotions, like that of consciousness itself, is a complex phenomenon that has caused a great deal of bewilderment throughout history. Author and professor Paul Thagard makes an interesting observation in an April 15, 2010 blog for Psychology Today, entitled very simply, "What are emotions?"
   Thagard first appraises the dualist view as being weak on evidence and heavy on wishful thinking or motivated inference, then points to two main scientific explanations for how emotions arise. One is the cognitive appraisal theory, which suggests that emotions represent a reaction to how well we are achieving any particular goal, the result being happiness when we're getting closer and anger when we encounter obstacles. The second explanation argues that emotions are tied to physiological changes.
   "On this view, happiness is a kind of physiological perception, not a judgment, and other emotions such as sadness and anger are mental reactions to different kinds of physiological stages," he writes.
   Most intriguing is Thagard's comment that our current understanding of how the brain functions suggests that the two theories can be unified.
   "Visual and other kinds of perception are the result of both inputs from the senses and top-down interpretations based on past knowledge. Similarly, the brain can perform emotions by interactively combining both high-level judgments about goal satisfactions and low-level perceptions of bodily changes," he says.
   As for the physiological connection, research also points to a number of compounds and molecules in the body that appear to drive various emotional states. These include adrenaline, acetylcholine, dopamine, epinephrine, norepinephrine, serotonin, testosterone, estrogen, melatonin and oxytocin.
   When so many of these substances perform multiple functions in the context of a biologically complex, dynamic living organism, it's no wonder emotions are so difficult to quantify. In artificial intelligence, it remains to be seen if duplication of human emotional reactions will be worthy of broad-based emulation or perhaps something that is a little more on the level of sanity.