Second to Arrive - the Limbic System

Emotions are born and processed in an area deep in the middle of the brain called the limbic system. This area is much older evolutionarily than the cortex that surrounds it. Some poetically call it the "mammalian brain" to signify its primitive and basic functionality.

The limbic system consists of a network of small functional units, including the hippocampus that controls long-term memory and learning, the amygdala (two of them, one in the right hemisphere and one in the left) that are critical to both negative and positive emotional processing, and the anterior cingulate cortex (ACC) that plays a role in cognitive functions such as reward anticipation, empathy, and choice.

In our grocery store example, the limbic system gets activated as soon as memory activation begins. As your brain starts to assemble a perceptual picture of the salad dressing shelf, it starts assembling an emotional, or affective, picture as well. The purpose of this picture is prepare you to make a fundamental survival decision - "do I approach or do I avoid?"

If the assembled emotional picture indicates a dangerous situation, the limbic system automatically begins to launch a number of physiological responses to prepare your body for fight or flight. If on the other hand the emotional picture indicates a possible reward, different physiological responses are triggered, also automatically, to prepare your body for approaching the stimulus. These processes are all fully activated within 200 to 400 milliseconds following sensory input.

This may all seem like wonderful machinery for dealing with snakes in the grass or love at first sight, but what does it have to do with salad dressing? The amazing fact is that the same processes of emotional priming occur for every stimulus we encounter, just at different levels of intensity. In less than half a second, your brain has taken in the whole salad dressing shelf, has activated your memories of delicious and disappointing salad dressings past, and is guiding your gaze toward the salad dressing of your dreams.

All of these processes are automatic and occur outside your conscious awareness. You only know they have occurred when they have yielded their result - a conscious shift in your focus of attention to some object, in our example, a particular bottle of salad dressing. Only at this point in the process can you begin to report on what you're thinking and feeling.

Unfortunately for pollsters and market researchers, what you report may be quite different from what actually went on in your brain. That's because "answering questions about buying salad dressing" is in fact a very different cognitive task that "buying salad dressing," and the former may be a very unreliable account of the latter.

At this point, you become consciously aware of "thinking about" your current situation.  Your goals, implicit emotional reactions, and associated memories have been activated, and you are now ready to begin the conscious processes of evaluating, deciding, and acting.